Dissertations / Theses on the topic 'Cuttlefis'

Cephalopods first appeared around 500 million years ago. Since then they have developed from the external shelled ammonites, belemnites and nautiloid's to the soft bodied organisms we find today. By becoming soft bodied, protection which would have been provided by the shell was lost and a different approach to predator avoidance was adopted. Modern day cephalopods such as octopus, squid and cuttlefish frequently use camouflage techniques to avoid detection. In addition to countershading, which is an often used camouflage technique by aquatic species, the presence of chromatophores allow a versatile and rapid response in relation to stimuli. Cuttlefish expression of these chromatic responses can be categorised into chromatic components. It is the intensity and combination of the expression which makes them an interesting organism to study, when looking at how the environment influences camouflage decisions. In this thesis, I present six experiments looking at how external environmental factors influence camouflage in Sepia officinalis. The first experimental chapter looks at how 3D objects and proximity play a role in not only camouflage, but behavioural responses. The first set of experiments discuss how factors such as contrast and size of an object may elicit different responses both behaviourally and chromatically. The proximity of the cuttlefish to the object was then investigated to determine if visual input was a possible cause for the differences. Size of the object, proximity and contrast produced a differing response to that of a cuttlefish on a uniform background. The two subsequent chapters look at differing light information and whether cuttlefish treat these differences similar to that of low contrast. Reaction to turbid and low light levels show similar responses in camouflage, suggesting that similar mechanisms are employed when there is reduced light and high scatter information. In respect to luminance versus reflectance, cuttlefish seem to be able to differentiate between a projected and reflected image where they appear to treat projected images like a lower contrast value. The last experimental chapter investigates motion camouflage in respect to predation. Prey and distance had a large effect on behaviour and how camouflage was expressed. Over greater distances behavioural variance reduced. Darkening of the head region and arm waving was also present over a greater distance. Camouflage varied in relation to background with a more uniform background producing reduced expression when moving. Stationary predation therefore elicits a different response than that of motion camouflage in cuttlefish.

Pendant longtemps, le voyage mental dans le temps a été considéré comme unique à l’humain. Selon des auteurs, les animaux ne pourraient pas se projeter dans le passé ou le futur parce qu’ils sont ancrés dans le présent. Néanmoins, pendant les 30 dernières années les chercheurs ont apporté des connaissances considérables sur les capacités des animaux à se souvenir de leur passé et à anticiper leur futur. Même si les opinions ont évolué, le débat sur l’unicité du voyage mental dans le temps est toujours d’actualité. Le but de ma thèse est d’apporter de nouvelles données sur les capacités des animaux à se souvenir du passé et à anticiper le futur. Plus particulièrement, je me suis intéressée à la mémoire de la source, qui est la capacité de retrouver l’origine d’un souvenir, chez deux espèces animales très éloignées, la seiche commune Sepia officinalis, et le geai des chênes, Garrulus glandarius. Les résultats ont montré que les seiches étaient capables de résoudre une tâche de discrimination perceptive, montrant qu’elles pouvaient discriminer et retenir leurs propres perceptions après un délai de 3 heures. Les geais, eux, ont révélé des différences mâles/femelles inattendues concernant leur capacité d’encoder et de retrouver une information contextuelle non-intentionnelle (source contextuelle). Une étude sur le comportement orienté vers le futur a montré que les seiches étaient capables de prendre une décision dans le présent en fonction de ce qu’elles avaient appris dans le passé, et en fonction des conditions expérimentales futures. Une étude préliminaire sur la planification a également apporté des résultats prometteurs sur la capacité des seiches à anticiper leurs besoins futurs. Enfin, nous avons pu explorer et mettre en lumière pour la première fois les substrats neuroanatomiques de la mémoire de type épisodique chez la seiche. Ces résultats permettent d’enrichir nos connaissances sur le voyage mental dans le temps chez la seiche et chez le geai, suggérant que cette capacité cognitive complexe peut avoir évolué sous différentes contraintes environnementales
Some authors support that mental time travel is unique to humans. To their point of view, animals are not able to project themselves into the past of the future because they are bound into the present. Nevertheless, during the last 30 years, researchers have brought considerable knowledge on animals’ capacities to travel mentally through time. Even though opinions have evolved, the debate concerning the unicity of mental time travel is still on. My PhD thesis aimed at bringing further knowledge on this matter by focusing on an innovative aspect of episodic cognition in common cuttlefish, Sepia officinalis and Eurasian jay, Garrulus glandarius, namely, source-memory. Source-memory is the capacity to retrieve the origin of an episodic memory. Results showed that cuttlefish were able to perform a source-discrimination study, revealing that they were able to discriminate and retrieve their own perceptions after 3-hours delay. A study on jays’ capacity to encode incidentally a contextual information (contextual source) revealed unexpected differences between males and females. Investigation of future-oriented behaviour in cuttlefish showed that they were able to take a decision in the present according to previous encoded knowledge and according to future experimental conditions. A preliminary study also revealed promising results on cuttlefish capacity to anticipate their future needs. To finish, we explored and revealed for the first time the neuronal substrates of episodic-like memory in cuttlefish. Alltogether, these results provide new knowledge on mental time travel in cuttlefish and in jays, suggesting that this capacity would have evolved under different environmental contraints

En 2013, les céphalopodes sont intégrés dans la directive européenne 2010/63/UE qui impose aux scientifiques de leur fournir des conditions de bien-être en laboratoire. Or, ils ne disposent d’aucun outil d’évaluation. Les réponses émotionnelles des animaux s’avèrent être de bons indicateurs pour évaluer leur bien-être en captivité. Cette thèse vise donc à identifier des indicateurs comportementaux chez la seiche commune. La seiche réalise des changements d’apparence (chromatiques et texturaux), qui s’apparentent dans leur fonctionnement aux expressions faciales des vertébrés. Ces changements s’observent notamment dans un contexte alimentaire, un contexte propice à l’expression d’émotions. Dans un premier temps, les travaux menés décrivent les changements d’apparence des seiches lors de l’attaque d’une proie pour identifier les composants exprimés. Dans un second temps, ces derniers sont évalués dans des contextes de prédation induisant probablement des émotions de valence et d’intensité différentes, ainsi que dans un contexte social compétitif. Les résultats obtenus mettent en évidence 8 composants (1 textural et 7 chromatiques, dont 3 observés pour la première fois) qui sont exprimés différemment d’une seiche à l’autre et d’un contexte à l’autre. Lors de l’attaque d’une proie, les seiches semblent donc réaliser deux stratégies différentes de camouflage (l’une « chromatique » et l’autre « textural ») dirigées vers un prédateur. Ces stratégies semblent révéler un trait de personnalité. Pour les seiches qui utilisent la première stratégie, l’expression de 6 composants chromatiques semblent corrélés à leurs préférences et à leur motivation. Cette thèse conclut que les changements chromatiques intègrent probablement une composante émotionnelle et propose pour la première fois que les seiches ont des états affectifs, mais sans pouvoir l’affirmer avec certitude. A l’avenir, les composants chromatiques pourraient être proposés comme un outil pour l’évaluation du bien-être des seiches, du moins au niveau alimentaire
In 2013, cephalopods were included in European Directive 2010/63/EU, which requires scientists to provide them with welfare conditions in the laboratory. However, they do not have any evaluation tools. The emotional responses of animals are proving to be good indicators for assessing their welfare in captivity. The aim of this thesis is therefore to identify behavioural indicators in common cuttlefish. Cuttlefish change their appearance (chromatically and texturally) which are similar in function to the facial expressions of vertebrates. These changes are particularly observed in a feeding context, a context that is conducive to the expression of emotions. Firstly, the work described the changes in the appearance of cuttlefish when attacking prey to identify the components expressed. Secondly, these components were evaluated in predation contexts, probably inducing emotions of different valence and intensity, as well as in a competitive social context. The results highlight 8 components (1 textural and 7 chromatic, including 3 observed for the first time) that are expressed differently from one cuttlefish to another and from one context to another. When attacking prey, cuttlefish therefore appear to use two different camouflage strategies (one “chromatic” and the other “textural”) directed towards a predator. These strategies seem to reveal a personality trait. For cuttlefish using the first strategy, the expression of 6 chromatic components seems to correlate with their preferences and motivation. This thesis concludes that chromatic changes probably integrate an emotional component and proposes for the first time that cuttlefish have affective states, but without being able to state it with certainty. In the future, chromatic components could be proposed as a tool for evaluating the welfare of cuttlefish, at least at the feeding level

Cuttlefish are renowned for their ability to quickly alter the colour and texture of their skin, for camouflage and communication. This is due to the presence of thousands of pigment-filled sacs, known as chromatophores, which are distributed across the skin. The chromatophores are innervated by motoneurons, which dilate the chromatophores to create the spots, stripes, and other markings, known as chromatic components. There are 34 recognized chromatic components, and it is an interesting question how cuttlefish coordinate the expression of these components to camouflage and communicate. The digital age has introduced new, powerful algorithms and methods to tease out subtle features in the coloration patterns, by means of image registration, segmentation, and identification, as well as methods for modeling the underlying control systems. These tools offer major new insights into the mechanisms of visual perception. In addition, powerful techniques have recently been developed that have yet to be applied to this complex visual motor control system. These methods have large potential in helping discover what features between the pattern and the environment are necessary to prevent detection. Here I present four laboratory experiments, that for the first time use machine learning models, to investigate cuttlefish pattern formation, implementation, and information. The first two experimental chapters investigate how cuttlefish orchestrate their chromatic components for camouflage patterns, and what strategies they employ on diverse backgrounds. I demonstrate that components are expressed more independently than previously believed, finding that the range of patterns expressed lie on a continuum, allowing us to suggest a revised classification scheme for cuttlefish body patterns. The diversity of patterns seem to imply that a cuttlefish could use its repertoire flexibly to display the maximally cryptic pattern for a given background, however I show that cuttlefish to not in fact select a single (possibly optimal) camouflage pattern, continually alter their appearance on a given background, and that the frequency of change increases in relation to the size of the objects in the environment. My third chapter investigated the language-like properties of cuttlefish communication using human speech recognition models. From our subset of cuttlefish patterns, I discovered cuttlefish utilize a lexicon of 10 patterns, with language-like properties such as: they obeyed Zipf's law, contained around 1.6 bits per display, and interestingly, while 2 patterns were visually similar, they were displayed in separate contexts. By implementing a regression onto the patterns, I introduce a basic dictionary of cuttlefish terms and their meaning. From my investigations into cuttlefish intraspecific signaling, I discovered two previously undocumented patterns, used in agonistic encounters between cuttlefish. My final chapter describes these patterns and the contexts they are displayed.

Cephalopods, including cuttlefish, have a reputation for ‘living fast and dying young’. The aim of the work described in this thesis was to perform a metabolic assessment of the European cuttlefish (Sepia officinalis), so as to determine if cuttlefish live up to the cephalopod reputation as a high energy consumer. To begin the assessment in Chapter 2, the standard metabolic rate (SMR) of Sepia officinalis was investigated over a water temperature range of 11-21°C. The SMR of cuttlefish was compared to 17 other marine ectotherms at a similar body mass and in corresponding water temperatures. Cuttlefish had an SMR 1.7 times higher than the teleost fish species examined. In Chapter 3, cuttlefish cellular energy budgets were calculated to identify cellular drivers of whole-animal SMR. The purpose of Chapter 4 was to discover the primary catabolic fuel used by adult Sepia officinalis. Respiratory quotients (RQ) and O:N ratios were calculated at 16 and 21°C. Carbohydrates were the primary metabolic substrate in both fasting and fed states. Temperature significantly affected ammonium and phosphate excretion, and the excretion of each substance was tightly correlated with the other. In Chapter 5, experiments were taken outside the laboratory and into a tidal pond. Large (1800 g) cuttlefish were tagged with acoustic jet pressure transmitters and released into a marais in L’Houmeau, France. Cuttlefish were found to be nocturnal, with night time activity significantly influenced by moonlight levels. The respiratory component ‘R’ of the cuttlefish energy budget is calculated in the thesis conclusions of Chapter 6. After deriving estimates of the daily energy expended in activity for Sepia officinalis in the marais, the European cuttlefish may indeed be ‘living faster’ than fish.

This thesis investigated the behaviour and physiology of the visual system of Sepia officinalis by studying systematically its visual sensitivity and its spatial resolution. The cephalopod retina is composed of only photoreceptors and supporting cells, thereby providing a unique opportunity to study the interactions between photoreceptors, without the influence of other neurons, such as those typically found in the vertebrate retina. The minimum separable angle (MSA), a measure of spatial resolution, of S. officinalis was determined from behavioural experiments to be 42' for animals of 8 cm mantle length at 15 µW/cm² light intensity. As the animals grew in size and as the ambient light intensity was increased, S. officinalis showed improved visual acuity. Through these experiments, it was revealed that each tested size of animal adapted to light with similar efficiencies, and that factors other than retinal growth were involved in the improvement of behavioural MSA with increasing size. The minimum light intensity to which the retina of S. officinalis responded was 0.1 µW /cm2 , which was slightly higher than that to which individual photoreceptor cells responded. Retinal sensitivity decreased with increasing animal size. This was unexpected, as previous theoretical and behavioural studies in other species have shown sensitivity to increase with increasing animal size. Possible reasons for the decrease in sensitivity were a reciprocal decrease in cell resistance or an increase in dark noise. The visual sensitivity of S. officinalis was also affected by the stimulus flash wavelength and duration. Its retina adapted to background light in a way similar to vertebrate photoreceptors and the extracellular calcium concentration of the solution perfusing the retina affected this process. Finally, two series of experiments provided some evidence that functioning gap junctions exist in the retina of S. officinalis. By completing a study of the visual sensitivity of S. officinalis at the three levels of single cell, retina and whole animal, the visual processing that occurs between these physiological levels was investigated. From the work presented in this thesis, it is concluded that, although S. officinalis did not prove comparable in every aspect to other species on an intracellular level, it would be a useful model of behavioural and extracellular visual processes for both invertebrate and vertebrate species.

Thesis (Ph. D.)--University of Oregon, 2004.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 83-91). Also available for download via the World Wide Web; free to University of Oregon users.

La seiche commune, Sepia officinalis, est un céphalopode côtier connu pour ses performances écophysiologiques soutenues par un large répertoire de comportements lui permettant, malgré son cycle de vie court, de tenir un rôle central dans les réseaux trophiques. Cependant, elle est également connue pour accumuler efficacement les éléments métalliques tel que le mercure (Hg), un contaminant neurotoxique sous sa forme organique (methylmercure ; MeHg). De plus, dans le contexte des changements environnementaux globaux, l’acidification des océans (AO) induite par l’augmentation des émissions de CO2, peut impacter le métabolisme, le développement et le système nerveux central, notamment chez les jeunes stades de vie. Le présent travail a donc pour but d’étudier les effets de l’AO sur la bioaccumulation du Hg et les effets de ces deux neurotoxiques (Hg et CO2) sur le comportement et les performances cognitives chez les juvéniles de seiches. Préalablement, des mesures in-situ ont montré que le Hg s’accumulait dans le cerveau des céphalopodes sous forme méthylé (MeHg). Par ailleurs, les approches expérimentales utilisant des traceurs isotopiques (stables et radioactif) du Hg ont démontré que l’accumulation du Hg total provenait majoritairement de l’assimilation du MeHg présent dans les proies, en comparaison à l’accumulation du mercure inorganique (iHg) par voie dissoute. Ce MeHg est ensuite très fortement retenu malgré la mise en évidence de processus de déméthylation du Hg dans la glande digestive. Étonnamment, l’AO n’a aucun effet sur les efficacités de la bioaccumulation et le métabolisme du Hg. En termes d’effets, des essais comportementaux ont montré que le Hg et CO2, seuls ou combinés, n’impactaient pas l’acuité visuelle et les performances de prédation chez les juvéniles. Par contre, ces deux derniers induisent une augmentation de l’activité locomotrice, compromettant le comportement défensif à travers notamment une altération de la coloration disruptive et un non-alignement de la latéralisation. Parmi les processus neuronaux susceptibles d’être impactés par le Hg et le CO2, le système GABAergique a été analysé dans les lobes optiques mais n’a montré aucun lien évident avec les réponses comportementales suggérant des processus d’effets plus complexes. L’ensemble de ce travail questionne donc les effets des conditions futures de l’océan sur les juvéniles de seiches, et plus largement les impacts sur les populations de céphalopodes
The common cuttlefish, Sepia officinalis, is a coastal cephalopod known for its eco physiological performance supported by a wide repertoire of behaviors that allows it, despite its short life cycle, to play a central role in food webs. However, it is also known to efficiently accumulate metallic elements such as mercury (Hg), a neurotoxic contaminant in its organic form (methylmercury; MeHg). Moreover, in the context of global changes, ocean acidification (OA) induced by the increase of CO2 emissions, can impact metabolism, development and the central nervous system, especially in young life stages. The present work therefore aims to study the effects of OA on Hg bioaccumulation and the effects of these two neurotoxicants (Hg and CO2) on behavior and cognitive performance in juvenile cuttlefish. In the first place, in-situ measurements showed that Hg accumulated in the brain of cephalopods in methylated form (MeHg). Moreover, experimental approaches using isotopic tracers (stable and radioactive) of Hg have shown that the accumulation of total Hg comes mainly from the assimilation of MeHg present in preys, compared to the accumulation of inorganic mercury (iHg) dissolved in seawater. This MeHg is then very strongly retained despite evidence of Hg demethylation processes in the digestive gland. Surprisingly, OA has no effect on the bioaccumulation efficiencies and metabolism of Hg. In terms of effect, behavioral assays showed that Hg and CO2, alone or in combination, did not impact visual acuity and predation performance in juveniles. However, both induced an increase in locomotor activity, compromised defensive behavior through, in particular, an alteration of disruptive coloration and a non-alignment of lateralization. Among the neural processes likely to be impacted by Hg and CO2, the GABAergic system was analyzed in the optic lobes but showed no obvious link with behavioral responses suggesting more complex effect processes. All of this work therefore questions the effects of future ocean conditions on juvenile’s cuttlefish, and more broadly the impacts on cephalopod populations

The locomotive systems of animals play a key role in behaviours such as foraging, predator avoidance and migrations. The range of behaviours and morphologies exhibited by animals have led to a variety of locomotor strategies. This thesis investigates the jet propulsion of cuttlefish (Sepia officinalis), where water is taken into a compressible cavity, this is compressed by surrounding musculature, forcing water out and forming a jet. This process involves the transfer of chemical energy into mechanical energy, before mechanical energy is transferred into the wake, propelling the animal through the water. Here the energy transduction chain is investigated from the biochemical level through the mechanical and ultimately into the wake of the animal, providing the most complete investigation into the energy transduction chain during locomotion to date. Investigations into the structure and function of cuttlefish jet propulsion swimming found cuttlefish produced two distinct jet modes. Jet mode use differed between hatchlings and juveniles. Differential use of jet modes may relate to flow environments inhabited by animals. Different flow environments may impact propulsive efficiency, where hatchlings are more efficient than juveniles. Juvenile propulsive efficiency was ~73 %, the highest reported value among cephalopods to date. Further investigations into the mechanical properties of mantle musculature found shortening velocities scale weakly with animal age, while cyclic measures revealed frequencies which produce the greatest net mechanical power decreased with age. Mechanical and hydrodynamic data reveal a transfer efficiency of ~26 %. Biochemical analyses of mantle muscle worked at three cycle frequencies revealed musculature heavily utilised ATP and phosphagen stores, however, no significant differences were seen between cycle frequencies, with the contractile efficiency being ~26 %. Taken together, these data revealed ~19 % of the available biochemical energy was successfully transferred into useful movement, this seems to question the idea of jet propulsion swimming being an inefficient mode of locomotion; this value does not account for recovery processes, suggesting efficiency may be lower.

This thesis aims to improve the in vitro cultivation of hematopoietic stem cells (HSCs) by exploring the effects of various biophysical and biochemical factors. The study uses KG-1a cells as a model for HSCs and evaluates the impact of different O2/CO2 conditions on apoptosis, proliferation, and primitivity. Additionally, the effect of differently-treated cuttlefish bone (CB) on mouse bone marrow hematopoietic cells is examined. The results show that combining hypoxia and hypercapnia is more effective in maintaining CD34+ cell count, survival, and primitivity compared to other gas combinations and control conditions. The study also found that crushed cuttlefish bone supports cell proliferation, viability, and primitivity, most likely through the presence of CaCO3 microparticles and the production of VEGF and TGF-1. These findings have the potential to improve engraftment success rates in medical treatments and enhance the reconstitution of a healthy hematopoietic system in patients.

Cephalopods have extremely well developed visual systems which are of particular interest due to the well known morphological similarity of the cephalopod eye to the vertebrate eye. This similarity ends at the level of the photoreceptors where vertebrates and invertebrates have been found to use different intracellular second messengers. Although the effect of extracellular ion manipulation on the light response has been examined and some very useful biochemical studies carried out, the pathway has not been investigated by the use of pharmacological intervention; a method which has proved to be useful in other preparations. This study examines various properties of the photoreceptors of the cuttlefish, Sepia officinalis, with particular interest in the second messenger signalling pathway. Both extracellular and whole cell patch clamp recording has been utilised. The second messenger signalling pathway, which mediates phototransduction in the retina of S. officinalis, was investigated by recording the electroretinogram and examining how this changed with the application of various extracellularly applied, membrane permeable pharmacological agents. Invertebrate phototransduction utilises the phosphoinositide (PI) signalling pathway therefore specific activators and inhibitors targeted at precise sites of this pathway were applied to the extracellular bathing solution. These studies indicated that cleavage of phosphatidylinositol-4,5-bisphosphate is essential for the production of a light response and that the inositol trisphophate (IP3) branch of this pathway is of greatest importance in this preparation, as opposed to the diacylglycerol branch. How this second messenger cascade transfers the incoming information into a temporally coded signal was studied by measuring maximum critical flicker fusion frequency. The effect of cell size on this property was investigated and also how cell sensitivity was affected and whether these properties appeared to fit the animal's environmental conditions or whether they were restricted by cellular properties. The animals were found to have relatively "slow" eyes. However the younger age group studied, with shorter photoreceptors, was found to be both faster and more sensitive. This was an unexpected finding considering temporal resolving power is often sacrificed for sensitivity. It is suggested that the observed differences between age groups was attributable to the effects of increased cell size on the cell membrane time constant and that deterioration of signalling molecules with aging may also be a contributing factor. An investigation of the cell signalling pathway at the level of individual cells was also carried out using the whole cell patch clamp technique. Using this technique, two voltage activated currents were found; an inward sodium current characterised by its voltage and tetrodotoxin sensitivity, and an outward potassium current characterised by its tetraethylammonium sensitivity. As well as finding further evidence for the involvement of the IP3 branch of the PI pathway there is also evidence of a role for cyclic guanosine monophosphate. A suitable mode of measuring light-induced fluctuations in the intracellular calcium levels was also investigated with a view to observing the impact of the pharmacological agents on intracellular calcium concentration. This investigation has enhanced the understanding of the S. officinalis visual system by greatly adding to the present knowledge of the second messenger signalling cascade and by giving an insight into how this transfers into the animal's temporal resolving power. Some preliminary information regarding the membrane currents activated by light has also been presented. This has all been possible by the development of a versatile retinal slice preparation that has been proven to be accessible to extracellular recording and whole cell patch clamp recording combined with pharmacological manipulation.

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente
The Sado estuary (SW Portugal) is an example of the type of pressures coastal areas are subjected to, encompassing fisheries, agriculture, industries and other human activities, most of which may act as sources of aquatic pollution. In order to assess the impact of aquatic contaminants onto the biota, biomonitoring is compelling and the search for suitable bioindicator organisms is mandatory. The common cuttlefish, Sepia officinalis, is a very important species to fisheries, especially in the Sado estuary, albeit yet unsurveyed in ecotoxicological studies. For the purposes of biomonitoring, cuttlefish were collected from two different sites in the Sado estuary and from an external reference area. Additionally, environmental contamination was determined from sediment samples. Sediments were characterized for granulometric fractions, total organic matter, redox potential and for the levels of metals (Cr, Ni, Cu, Zn, Cd and Pb), metalloids (As and Se), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and the pesticides dichloro diphenyl trichloethane plus its main metabolites (DDTs) and hexoclorobenzene (HCB). A multi–biomarker approach was applied in two organs, digestive gland and gills, through the analysis of lipid peroxidation, total glutathione, the reduced/oxidised glutathione ratio, glutathione S–transferase activity and induction of metallothionein–like proteins. The results showed that the Sado estuary is especially contaminated by metals when compared to the reference area. In addition, even within the Sado estuary, considerable heterogeneity exists regarding sediment contamination. The biomarker responses, especially in the digestive gland, were overall consistent with sediment contamination. This relationship was less obvious in the gills, reflecting, nevertheless, high sensibility to environmental pressures. Thus, S. officinalis revealed to be a good species to address environmental contamination and likely an adequate bioindicator in environmental risk assessment programs. The integration of all biomarker responses disclosed that the levels of contamination of the Sado estuary, although considered to be moderate, cause responses and adverse effects in organisms, from which it may be inferred that current management policies have not yet been able to eradicate pollution from this ecosystem.

Over the last 50 years there has been a rapid increase in global landings of cephalopods (octopus, squid and cuttlefish). In European waters, cuttlefish are among the most important commercial cephalopod resources and within the North-East Atlantic, the English Channel supports the largest cuttlefish fishery, with the common cuttlefish, Sepia o cinalis (Linnaeus, 1758), dominating landings. S. o cinalis has a short (2 year) life cycle in the English Channel that is punctuated by seasonal migrations inshore and o shore. Using a combination of di erent métiers including beam trawling, otter trawling and coastal trapping, this shared fisheries resource is targeted at nearly every phase of the life cycle. Despite this continuing increase there remain only minimal management measures in place, with no quotas, no total allowable catches, no closed areas, no minimal landing size and no routine assessment of stocks. In order to provide sustainable fisheries management advice for S. o cinalis populations it is essential that a thorough understanding of the ecology and life history of this species, in particular the factors a ecting spawning and recruitment variability, is attained.In this thesis, I examine critical gaps in our understanding of the distribution, movements, habitat use and behaviours of spawning and sub-adult S. o cinalis. This research provides baseline data for this species within the inshore waters of the English Channel and uses a combination of novel field-based electronic tracking techniques, in situ subtidal observations of spawning patterns within natural environments and presence-only species distribution modelling. A maximum entropy (MaxEnt) modelling approach was used to predict the distribution of benthic egg clusters using presence-only data. The model showed very good performance in terms of predictive power and accuracy (test area under the receiver operating characteristics curve [AUC] = 0.909) and among the explanatory variables used to build the model, depth (gain = 1.17), chlorophyll-a concentration (used here as a proxy for turbidity; gain = 1.06) and distance from coastline (gain = 1.02) were shown to be the greatest determining factors for the distribution of S. o cinalis spawning. As part of the model output, maps (logistic and binary) of the predicted spawning distribution of S. o cinalis within the English Channel were produced.Subtidal observation were undertaken at spawning grounds on both the North and South coast of the English Channel to investigate spawning habitat and structure use. A total of 15 types of natural spawning structures were identified. The range of spawning structures used varied among sites with Zostera marina identified as the dominant spawning structure at two of the UK sites (Torbay and Poole Bay), potentially indicating a ‘preference’ for this structure within localities. Fractal dimension analysis of the seagrass beds at Torbay revealed that the spatial dynamics of seagrass beds within this site varied significantly between 2011 and 2012 (Mann- Whitney U: Z = 4.92, P < 0.0001) as a result of both anthropogenic and natural disturbance. Interannual changes in the spatial dynamics of these beds could a ect the annual pattern and intensity of spawning at a site. The use of structures with small diameters was found to occur, with cuttlefish adapting the device to their requirements by utilising multiple leaves or thalli in order to achieve a suitable diameter for egg attachment, this was evident in their use of both Chorda filum and Z. marina.This research also provided the first data on the fine-scale movements and behaviours of adult and sub-adult individuals, tracked within their natural environments, using electronic tagging methodologies. That expected patterns of short-term spawning site fidelity at a local level were observed in only two individuals, whilst larger scale movements (up to 35 km) along the coastline were observed in three individuals, indicated that a range of behaviours and movement patterns could occur among spawning adults. Similarly varied patterns of site fidelity were also observed in tagged sub-adults, tracked over an extended period (up to 73 days), using a static acoustic array. These results highlight the complex range of patterns and plasticity in behaviour that exist within natural populations.In summary, a series of di erent approaches was used within this thesis in an e ort to improve our understanding of the fine-scale movement, behaviours and habitat use of S. o cinalis (in both spawning adults and non spawning sub-adults), as well as their potential spawning distribution within the inshore waters of the English Channel. Observing the movements and behaviours of small marine animals like S. o cinalis in their natural environments has traditionally been di cult. Recent developments in technologies and techniques however, including those used within this thesis (e.g. electronic tagging), have highlighted the potential capacity of novel tools to monitor the in situ movements and behaviour of cuttlefish. By providing important insights into the ecology of this species these new tools can aid conservation and management advice for this important commercial fishery species, both within the English Channel and further afield.

La seiche commune Sepia officinalis est un Mollusque Céphalopode présent sur les côtes Normandes. En Baie de Seine, elle représente la troisième espèce visée par les flottilles hauturière et côtière, ce qui en fait une ressource économique importante pour la région. Dans un contexte de protection de la ressource, l’étude et la compréhension des mécanismes liés à la reproduction représentent un objectif majeur. Cette étude est donc focalisée sur les mécanismes régulateurs de la ponte, et en particulier sur les facteurs impliqués dans l’émission des ovocytes. Des recherches antérieures effectuées au laboratoire ont mis en évidence un contrôle multifactoriel du processus de ponte, avec trois niveaux de régulation. (i) Les neuropeptides sont impliqués dans la perception des paramètres environnementaux, (ii) les facteurs ovariens assurent la régulation paracrine du tractus génital, et (iii) les phéromones sexuelles, tout en interférant avec la ponte, sont suspectées de jouer un rôle important dans le comportement des géniteurs associé à la reproduction. Cette thèse met en lumière le rôle de 2 familles de neuropeptides identifiées récemment : les CCAPs et les FLGamides (ou So-orcokinines B). Ces deux familles participent au transport de l’ovocyte et à la sécrétion capsulaire en agissant sur l’activité contractile du complexe oviducte/glande de l’oviducte et des glandes nidamentaires principales. Ces neuropeptides sont par ailleurs suspectés de jouer un rôle dans la biosynthèse des protéines vitellines et des protéines capsulaires. Parallèlement, des phéromones sexuelles sont exprimées par la glande de l’oviducte et sécrétées avec les protéines capsulaires. Des travaux antérieurs ont permis de caractériser des produits d’expression issus de clivages de type prohormone convertase. Dans cette nouvelle étude, un second mode de clivage a été mis en évidence avec l’identification de produits de clivage de masse moléculaire supérieure à 20 kDa. L’un de ces produits, la phéromone beta, a été produit en système recombinant mais son activité biologique sur l’appareil génital mâle et sur l’oviducte n’a pas été démontrée. Quant aux tests comportementaux, ils n’ont pu être exploités du fait d’un nombre d’animaux testés trop restreint. Enfin, une approche transcriptomique comparative et différentielle réalisée à partir de l’organe olfactif mâle et du pavillon de l’oviducte a permis d’identifier un récepteur candidat à la liaison avec les phéromones sexuelles
The common cuttlefish (Sepia officinalis) is a Cephalopod mollusk found on the Normandy coasts. In the Bay of Seine, it is the third species targeted by offshore and coastal fleets, so it is an important economic resource for the whole region. In a context of resource protection, the study and understanding of its reproductive mechanisms is a major objective. This study is therefore focused on the regulatory mechanisms of egg-laying, and in particular on the factors involved in the release of oocytes. Previous research in the laboratory demonstrated multifactorial control of the egg-laying process, with three levels of regulation: (i) neuropeptides involved in the perception of environmental cues, (ii) ovarian factors providing paracrine regulation of the genital tract, and (iii) sexual pheromones, which are implied in egg-laying and are suspected to play a determining role in the reproductive behavior. This thesis highlights the role of two families of recently identified neuropeptides called CCAPs and FLGamides (or So-orcokinins B). These two families participate in oocyte transport and in egg capsule secretion by acting on the contractile activity of the oviduct/oviduct gland complex and of the main nidamental glands. These neuropeptides are also suspected to play a role in the biosynthesis of yolk and capsular proteins. At the same time, sex pheromones are expressed by the oviduct gland and secreted along with capsular proteins. Previous work made it possible to characterize expression products resulting from cleavages of the prohormone convertase type. In this new study, a second mode of cleavage is highlighted, evidenced by the identification of cleavage products with MWs greater than 20 kDa. One of these products, beta pheromone, was produced in a recombinant system but its biological activity on the male reproductive system and on the oviduct was not demonstrated. As for behavioral tests, they were not exploited because the number of animals tested was too small. Finally, a comparative and differential transcriptomic approach of the male olfactory organ and the oviduct pavilion evidenced a candidate receptor expected to bind to sex pheromones

Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Mechanical Engineering; and the Woods Hole Oceanographic Institution), June 2014.
Cataloged from PDF version of thesis. "June 2014."
Includes bibliographical references (pages 103-112).
Evolutionary pressures have led to some astonishing camouflage strategies in the animal kingdom. Cephalopods like cuttlefish and octopus mastered a rather unique skill: they can rapidly adapt the way their skin looks in color, texture and pattern, blending in with their backgrounds. Showing a general resemblance to a visual background is one of the many camouflage strategies used in nature. For animals like cuttlefish that can dynamically change the way they look, we would like to be able to determine which camouflage strategy a given pattern serves. For example, does an inexact match to a particular background mean the animal has physiological limitations to the patterns it can show, or is it employing a different camouflage strategy (e.g., disrupting its outline)? This thesis uses a computational and data-driven approach to quantify camouflage patterns of cuttlefish in terms of color and pattern. First, we assess the color match of cuttlefish to the features in its natural background in the eyes of its predators. Then, we study overall body patterns to discover relationships and limitations between chromatic components. To facilitate repeatability of our work by others, we also explore ways for unbiased data acquisition using consumer cameras and conventional spectrometers, which are optical imaging instruments most commonly used in studies of animal coloration and camouflage. This thesis makes the following contributions: (1) Proposes a methodology for scene-specific color calibration for the use of RGB cameras for accurate and consistent data acquisition. (2) Introduces an equation relating the numerical aperture and diameter of the optical fiber of a spectrometer to measurement distance and angle, quantifying the degree of spectral contamination. (3) Presents the first study assessing the color match of cuttlefish (S. officinalis) to its background using in situ spectrometry. (4) Develops a computational approach to pattern quantification using techniques from computer vision, image processing, statistics and pattern recognition; and introduces Cuttlefish 72x5, the first database of calibrated raw (linear) images of cuttlefish.
by Derya Akkaynak.
Ph. D.

Les juvéniles de la seiche commune, Sepia officinalis, et du crabe vert, Carcinus maenas, se développent au niveau de la zone intertidale et des eaux côtières affectées par la pollution continentale telle que les résidus pharmaceutiques. Cette recherche se concentre sur les effets de deux antidépresseurs, la fluoxétine et la venlafaxine, sur le camouflage et le comportement de la seiche et du crabe vert. Ces deux molécules sont particulièrement inquiétantes car elles sont conçues pour agir sur le système sérotoninergique et sont communément détectées dans les environnements aquatiques. Ainsi, pour se rapprocher de scénarii d’exposition réalistes, la fluoxétine a été associée ou non à la venlafaxine. Les résultats montrent des effets significatifs à des concentrations environnementalement réalistes, d’autant plus avec le mélange des deux antidépresseurs, sur des paramètres sensibles tels que le comportement d’ensablement, le changement de couleur et la coloration cryptique chez nos deux espèces, ainsi que l’activité locomotrice chez le crabe et le comportement prédateur chez la seiche. En outre, l’exposition de stades de développement précoces aux antidépresseurs semble modifier la maturation et les processus d’apprentissage chez la seiche. Enfin, ces résultats ont démontré la nécessité de mener davantage d’études avec de faibles concentrations sur les comportements clefs d’espèces non-cibles
Juveniles of the common cuttlefish, Sepia officinalis, and the green shore crab, Carcinus maenas, develop themselves in the intertidal zone and coastal waters impacted by continental pollution such as pharmaceutical residues. This research focused on the effects two antidepressants, the fluoxetine and the venlafaxine, on the camouflage and behaviour of cuttlefish and shore crabs. Both molecules are worrying because they are designed to act on serotonergic system and are commonly detected in aquatic environments. Thus, to approach realistic scenario of exposure fluoxetine was either combined or not with venlafaxine. The results show significant effects of antidepressants at environmentally realistic concentrations, especially the combination of fluoxetine and venlafaxine, on sensitive endpoints such as burying behaviour, colour change and background matching, locomotor activity in crabs and predatory behaviour in cuttlefish. Furthermore, the exposure to antidepressants at early development stage seems to alter maturation and/or learning processes in cuttlefish. Overall, these studies demonstrated the need to investigate further with low range concentrations on key behaviours of non-target species

Doutoramento em Biologia
The common cuttlefish, Sepia officinalis, is a necto-benthic cephalopod that can live in coastal ecosystems, with high influence of anthropogenic pressures and thus be vulnerable to exposure to various types of contaminants. The cuttlefish is a species of great importance to the local economy of Aveiro, considering the global data of catches of this species in the Ria de Aveiro. However, studies on this species in Ria de Aveiro are scarce, so the present study aims to fill this information gap about the cuttlefish in the Ria de Aveiro. The cuttlefish enters Ria de Aveiro in the spring and summer to reproduce, returning to deeper waters in the winter. In terms of abundance, the eastern and center regions of the lagoon, closer to the sea, showed the highest values of abundance, while the northern and southern regions of the main channel had the lowest abundance. This fact may be related to abiotic factors, as well as depth, salinity and temperature. In the most southern point of the Ria de Aveiro (Areão) no cuttlefish was caught. This site had the lowest values of salinity and depth. The cuttlefish has an allometric the females being heavier than males to mantle lengths greater than 82.4 mm. Males reach sexual maturity first than females. In Ria de Aveiro in a generation of parents was found. The cuttlefish, presents itself as opportunistic predators, consuming a wide variety of prey from different taxa. The diet was similar in different sampling locations observing significant differences for the seasons. S. officinalis was captured at 10 sites in the Ria de Aveiro with different anthropogenic sources of contamination. Thus, levels of metals analyzed were similar at all sampling sites, with the exception of a restricted area, Laranjo, which showed higher values. The cuttlefish has the ability to accumulate metals in your body. The levels of Fe, Zn, Cu, Cd, Pb and Hg found in the digestive gland and mantle reflect a differential accumulation of metals in the tissues. This accumulation is related to the type and function of tissue analyzed and the type of metal analysis (essential and non-essential). The metal concentrations in the digestive gland are higher than in the mantle, with the exception of mercury. This may be due to the high affinity of the mantle for the incorporation of methylmercury (MeHg), the most abundant form of mercury. The accumulation of metals can vary over a lifetime, depending on the metal. The concentrations of Zn, Cd and Hg increases throughout life, while Pb decreases and essential metals such as Fe and Cu remain constant. The data collected suggest that the cuttlefish (Sepia officinalis) can be used as a bioindicator of environmental contamination for some metals.
O choco comum, Sepia officinalis, é um cefalópode necto-bentónico que pode viver em ecossistemas de águas costeiras, com elevada influência de pressões antropogénicas e assim, estar vulnerável à exposição por vários contaminantes. O choco é uma espécie de grande importância para a economia local de Aveiro, considerando os dados globais de capturas desta espécie para a Ria de Aveiro. No entanto, os estudos acerca desta espécie na Ria de Aveiro são escassos, desta forma o presente estudo pretende preencher esta lacuna de informação sobre o choco na Ria de Aveiro. O choco entra para a Ria na primavera e no verão para reprodução, e volta para águas mais profundas no inverno. Em termos de abundância, as zonas, este e central da ria, a mais próxima da embocadura com o mar, apresentaram os valores de abundância mais elevados, sendo as regiões mais a norte e a sul dos principais canais, as de abundância mais baixa. Este fato pode estar relacionado com fatores abióticos, como a profundidade, a salinidade e a temperatura. No ponto mais a sul da Ria de Aveiro (Areão) nunca foram capturados chocos, tendo este local apresentado os valores mais baixos de salinidade e profundidade. O choco apresenta um crescimento alométrico, sendo as fêmeas mais pesadas que os machos, para comprimentos do manto superiores a 82.4 mm. Os machos atingem a maturação sexual primeiro que as fêmeas. Na Ria de Aveiro apenas uma geração de progenitores foi encontrada. O choco apresenta-se como predador oportunista, consumindo uma grande diversidade de presas de diferentes grupos taxonómicos. A dieta mostrou-se semelhante nos diferentes locais de amostragem observando-se diferenças significativas para as estações do ano. S. officinalis foi capturada em 10 locais da Ria de Aveiro com contaminação de diferentes origens antropogénicas. Assim, os níveis de metais analisados apresentaram-se semelhantes em todos os locais de amostragem, com a exceção de uma área restricta, o largo do Laranjo, que apresentou valores mais elevados. O choco possui a capacidade de acumular metais no seu organismo. Os níveis de Fe, Zn, Cu, Cd, Pb and Hg encontrados no manto e na glândula digestiva refletem uma acumulação diferencial de metais nos tecidos. Esta acumulação está relacionada com o tipo e função do tecido analisado e com o tipo de metal analisado (essencial e não essencial). As concentrações dos metais na glândula digestiva são mais elevadas que no manto, com exceção do mercúrio. Este fato pode dever-se à grande afinidade do manto para a incorporação de Metilmercúrio (MeHg), a mais abundante forma de mercúrio. A acumulação de metais pode variar ao longo da vida, dependendo do metal. As concentrações de Zn, Cd and Hg aumentam ao longo da vida, o Pb diminui e os metais essenciais como o Fe e Cu permanecem constantes. Os dados recolhidos sugerem que o choco (Sepia officinalis) possa ser usado como bioindicador de contaminação ambiental para alguns metais.

This doctoral work was developed in the frame of bone tissue engineering, dealing with the fabrication of scaffolds for the regeneration of bones. At this purpose, calcium phosphates derived from natural sources are very interesting because they are more similar to the bone mineral and possess better bioactivity. Indeed, the bone mineral is different from synthetic hydroxyapatite as it is non-stoichiometric, nanosized, it presents a high degree of disorder and contains many additional ions and impurities such as CO32-, Mg2+, Sr2+, Na+, etc. These characteristics can be easily obtained by synthesizing hydroxyapatite from natural sources, such as corals, starfishes, seashells, animal bones, bird eggshells etc. The natural sources used in the present work are three types of biogenic calcium carbonate, i.e. calcium carbonate that is produced by living organisms in the form of aragonite or calcite. Among the different sources, three biogenic calcium carbonates were chosen: cuttlefish (Sepia Officinalis) bones, mussel (Mytilus Galloprovincialis) shells and chicken eggshells. Besides their abundance and availability, they were selected because of their different composition: aragonite in cuttlebones, calcite in eggshells and a mixture of aragonite and calcite in mussel shells. After the first chapter, which is a theoretical introduction, this thesis is divided into other five chapters. Chapter 2 contains a careful characterization of the three biogenic raw materials while Chapter 3 deals with the synthesis of hydroxyapatite starting from these natural sources. The process developed here takes place entirely at nearly room temperature, which allows the organic part of the biological materials to be preserved. This synthesis process is basically a wet mechanosynthesis followed by a mild heat treatment (up to 150°C). The study focuses on the influence of several process parameters on the synthesis efficiency: temperature, milling time, pH and raw material. The temperature used to dry the slurry after the wet ball-milling was found to be the most important parameter, the higher the temperature the faster the conversion of CaCO3 into hydroxyapatite. Moreover, aragonite was found to transform more easily into hydroxyapatite with respect to calcite, and also to follow a different reaction path. The synthesis process described in Chapter 3 allowed to produce different bio-derived powders that were found to be non-stoichiometric, nanosized, carbonated hydroxyapatites, containing also additional ions, especially Mg2+ in the eggshell-derived material and Sr2+ in the cuttlebone-derived one. These powders were then used as a starting point for the studies presented in the next three chapters. Chapter 4 shows a very preliminary evaluation of the interaction with human cells in vitro. First, the as-synthesized powders were consolidated by uniaxial pressing and sintering at temperatures between 900°C and 1100°C and their crystallographic composition was analyzed. Then, after having established the non-cytotoxicity of the sintered pellets, osteoblasts from human osteosarcoma cell line were seeded on the pellets and their behavior after 1, 3 and 5 days of culture was observed by confocal microscopy. In general, all materials promoted good cell adhesion and proliferation, especially the eggshell-derived one. At this point, the bio-derived materials were found to induce a good cellular response but, in order to foster the regeneration of bones, a scaffold must also contain a large amount of interconnected porosity. Among the numerous methods to fabricate porous structures, additive manufacturing is surely very attractive due many advantages, such as the possibility of customizing the shape based on tomography images from the patients, the fact that no mold is needed and the freedom of fully designing the porosity. Indeed, not only the size and the amount of porosity are important, but also the shape of the pores and their position and orientation have a deep effect on the interaction with the cells. Therefore, Chapter 5 and Chapter 6 deal with the fabrication of scaffolds by 3D printing, following two different approaches. In the study presented in Chapter 5, the powders synthesized from cuttlebones, mussel shells and eggshells were used in combination with a thermoplastic polymer (PCL, polycaprolactone) to obtain bioactive composites. Composite materials made of 85 wt% PCL and 15 wt% bio-derived hydroxyapatite were used to fabricate porous scaffolds by extrusion 3D printing. The biological in vitro tests showed that the composite scaffolds possess better bioactivity than the pure PCL ones, especially those containing mussel shell- and cuttlebone-derived powders, which promoted the best cell adhesion, proliferation and metabolic activity of human osteosarcoma cells after 7 days of culture. In addition, the elastic compressive modulus, which was found to be between 177-316 MPa, thus in the range of that of trabecular bone, was found to increase of about ∼50% with the addition of the bio-derived nanopowders. Finally, in Chapter 6, the cuttlebone-derived powder was used to fabricate porous bioceramic scaffolds by binder jetting 3D printing. Due to serious technical issues related to the printing of a nanosized powder, 10 wt% of bio-derived powder was mixed with a glass-ceramic powder with bigger particle size. Moreover, the organic part of the cuttlebone had to be previously eliminated by a heat treatment at 800°C. Thanks to the great freedom of design that is allowed by the binder jetting process, scaffolds with two different pore geometries were fabricated: with pores of uniform size and with a size-gradient. Indeed, natural bone possesses a gradient in porosity from the core to the surface, from porous trabecular bone to dense cortical bone. The sintered scaffolds showed a total porosity of ∼60% for the pure glass-ceramic and ∼70% for the glass-ceramic with 10 wt% of cuttlebone-derived nanoparticles, which most probably slowed down the densification by limiting the contact between the glassy particles. All the bioceramic scaffolds promoted good adhesion and proliferation of human bone marrow-derived mesenchymal stem cells in vitro, without any significant difference between the different samples. However, the scaffolds with the cuttlebone-derived powder and with gradient porosity showed the greatest decrease of metabolic activity after 10 days of culture, which could be accounted as a sign of differentiation of stem cells.

Cephalopods constitute an important faunistic group in marine ecosystems, representing keystone elements in marine food webs. Additionally, they are an important fishing resource, and their contribution to worldwide fishery landings has been rising significantly over the last decades. In the Mediterranean Sea, several local short-term studies on cephalopod abundance and distribution exist, but few integrate longer time scales and larger areas. The present thesis work combines large-scale, long-term studies on cephalopods community composition, diversity and abundance (Part I) with small-scale, local case studies around the Balearic Islands (Part II). First, a community analysis was conducted at the whole Mediterranean scale in order to describe the present status and reveal possible differences between the western and the eastern Mediterranean sub-basins (Chapter 2). The aim was to compare assemblage structures between sub-basins together with the influence of large-scale environmental gradients on species composition. While basins did not differ significantly in cephalopod species composition, relative species contributions varied. Cephalopods are very sensitive to environmental changes, and adapt quickly due to their short life cycle and typically seasonal semelparity impeding generation buffering. Therefore sea surface temperature (SST) and chlorophyll a (Chl a) were hypothesised and documented as important drivers of cephalopod assemblages. While their importance differed between sub-basins, depth was confirmed as the most important factor structuring cephalopod communities. At the same spatial scale, cephalopod diversity was analysed during two decades (Chapter 3). Results revealed the absence of clear longitudinal or latitudinal gradients in cephalopod diversity, combined with no distinct temporal trends over the last twenty years. Besides, temporal changes in diversity varied between various Mediterranean sub-regions. Location, depth, SST and productivity regime resulted to influence diversity. To assess whether environmental variability impacts cephalopod populations at species level, the influence of SST and surface primary production on the spatial structuring and the population dynamics of two commercially important cephalopod species was investigated (Chapter 4). Although Octopus vulgaris and Illex coindetii exhibit contrasting life history traits and inhabit different habitats, long-term abundance trends and synchronic behaviour of their populations was similar, and population sub-structuring across the Mediterranean Sea were revealed. In consistency with former chapters, SST and Chl a regimes were shown to be significant drivers of distribution patterns and inter-annual abundance fluctuations. The motivation for the second part of the thesis was fuelled by the present situation in the Mediterranean Sea, where cephalopod stocks are presumably overexploited, but where their ad-hoc assessment and management is far from being implemented. To contribute to existing knowledge of the current situation in the Balearic Sea, a case study on cuttlefish fishery, life-history and population dynamics was conducted using short-term and intra-annual data (Chapter 5). Possible drivers of cuttlefish abundance fluctuations were analysed, revealing significant influences of SST and local climatic variability. While the study provided an overview of possible intrinsic and extrinsic drivers of cuttlefish population fluctuations in the Balearic Sea, the next step was applying stock assessment techniques to cuttlefish and squid fisheries of this area (Chapter 6). Being the first application of depletion methods to Mediterranean cephalopod stocks, the study combined information of those two fisheries with the evaluation of this stock assessment method for short life cycle species. Results uncovered existing problems and suggested that the current sampling scheme under the EU-Data Collection Framework is inadequate for cephalopods in view of the assessment´s data requirements. Consequently, a modification of the existing scheme was proposed.
Los cefalópodos constituyen un grupo faunístico importante en los ecosistemas marinos, representando elementos clave en la estructura y dinámica de las redes tróficas. Además, son un importante recurso pesquero y su contribución a los desembarcos pesqueros mundiales se ha incrementado significativamente en las últimas décadas. En el Mar Mediterráneo existen varios estudios locales sobre la abundancia y distribución de cefalópodos, pero pocos integran escalas temporales largas y áreas extensas. Esta tesis combina estudios sobre la estructura de la comunidad, la diversidad y la abundancia de cefalópodos a gran escala espacio-temporal (Parte I) con estudios a escala local alrededor de las Islas Baleares (Parte II). En primer lugar, se realizó un análisis de la comunidad de cefalópodos a escala de todo el Mediterráneo para describir el estado actual y determinar posibles diferencias entre las sub-cuencas occidental y oriental (Capítulo 2). El objetivo fue comparar la estructura de las comunidades faunísticas entre estas dos sub-cuencas y analizar la influencia de gradientes ambientales a gran escala sobre la composición específica. Aunque no se observaron diferencias significativas en la composición específica, las contribuciones relativas de las diferentes especies variaron entre ambas cuencas. Debido a su corto ciclo vital y estrategia reproductiva semélpara, los cefalópodos son muy sensibles a los cambios ambientales, adaptándose a ellos con relativa rapidez. Se esperaba, por tanto, que factores ambientales como la temperatura superficial del mar (SST) y el contenido de clorofila a (Chl a) fueran factores importantes en la estructuración de las comunidades de cefalópodos. Si bien su importancia difirió entre las dos sub-cuencas, se confirmó que la profundidad era el factor estructural más importante en dichas comunidades. Se analizaron también cambios en la diversidad específica de las comunidades de cefalópodos a escala de todo el Mediterráneo durante los últimos 20 años (Capítulo 3). Los resultados no mostraron ninguna tendencia temporal ni espacial (latitud, longitud) clara y homogénea en la diversidad. Las únicas tendencias temporales observadas variaron entre diferentes sub-regiones, siendo la posición geográfica, profundidad, SST y productividad los principales factores determinantes de estas tendencias. Para confirmar la importancia de la variabilidad ambiental a nivel específico, se analizó la influencia de la SST y la producción primaria en la estructura espacial y la dinámica poblacional de dos especies de cefalópodos de importancia comercial (Capítulo 4). Aunque Octopus vulgaris e Illex coindetii exhiben diferentes estrategias vitales y viven en diferentes hábitats, las tendencias temporales a largo plazo en su abundancia y el comportamiento sincrónico de sus poblaciones fueron similares, observándose sub-poblaciones temporalmente persistentes a lo largo de todo el Mediterráneo. En consonancia con los capítulos anteriores, la SST y Chla resultaron ser factores significativos en la definición de patrones de distribución y fluctuaciones interanuales de la abundancia. La segunda parte de la tesis estaba motivada por la situación actual de los cefalópodos en el Mar Mediterráneo, donde no existen medidas de evaluación y gestión específica para este grupo y algunas de sus poblaciones se encuentran sobreexplotadas. Para contribuir al conocimiento de la situación actual en el Mar Balear, se analizó la pesquería, ciclo vital y dinámica poblacional de la sepia utilizando series temporales intra-anuales (Capítulo 5). El análisis de diferentes factores ambientales reveló que la SST y la variabilidad climática local influían significativamente en las fluctuaciones de abundancia de la especie. En un trabajo posterior (Capítulo 6) se aplicaron técnicas de evaluación de stocks a las pesquerías de sepia y calamar de las Islas Baleares utilizando datos procedentes de la EU Data Collection Framework (DCF). Hasta donde sabemos, este trabajo constituye la primera aplicación de los Lesly-Delury Depletion Methods a stocks de cefalópodos del Mediterráneo. Los resultados demostraron que el esquema actual de muestreo de la DCF es inadecuado para la evaluación de cefalópodos y se proponen posibles modificaciones.
Els cefalòpodes constitueixen un grup faunístic important als ecosistemes marins, essent elements clau a les xarxes tròfiques. A més, són importants recursos pesquers i la seva contribució als desembarcs pesquers mundials s’ha incrementat en les últimes dècades. representant al voltant del 30% de la captura desembarcada a nivell mundial. Al Mar Mediterrani existeixen varis estudis locals sobre l’abundància i distribució de cefalòpodes, però pocs integren escales temporals llargues i àrees extenses. Aquesta tesi combina estudis sobre la composició de la comunitat, la diversitat i l’abundància de cefalòpodes a gran escala espaciotemporal (Part I) amb estudis a escala local al voltant de les Illes Balears (Part II). En primer lloc, es va realitzar un anàlisi de les comunitats de cefalòpodes a escala de tot el Mediterrani per descriure l’estat actual i determinar possibles diferències entre les sub-conques occidental i oriental (Capítol 2). L’objectiu fou comparar l’estructura de les comunitats faunístiques entre sub-conques i analitzar la influència de gradients ambientals a gran escala sobre la composició específica. Tot i que no s’observaren diferències significatives en la composició específica, les contribucions relatives de les diferents espècies variaren entre sub-conques. Degut al seu cicle vital curt i estratègia reproductiva semèlpara els cefalòpodes són molt sensibles als canvis ambientals, adaptant-se a ells amb relativa rapidesa. S’esperava, per tant, que factors ambientals com la temperatura superficial del mar (SST) i el contingut de clorofil·la a (Chla) fossin factors importants en l’estructuració de les comunitats de cefalòpodes. Si bé la seva importància va diferir entres les dues sub-conques, es va confirmar que la profunditat era el factor estructural més important en aquestes comunitats. S’analitzaren també canvies en la diversitat específica de les comunitats de cefalòpodes a escala de tot el Mediterrani durant els últims 20 anys (Capítol 3). Els resultats no mostraren cap tendència temporal ni espacial (latitud, longitud) clara i homogènia en la diversitat. Les úniques tendències temporals observades variaren entre diferents sub-regions, essent la posició geogràfica, profunditat, SST i productivitat els principals factors determinants d’aquestes tendències. Per tal de confirmar la importància de la variabilitat ambiental a nivell específic, es va investigar la influència de la SST i la producció primària en l’estructuració espacial i la dinàmica poblacional de dues espècies de cefalòpodes d’importància comercial (Capítol 4). Tot i que Octopus vulgaris i Illex coindetii tenen característiques vitals diferents i viuen en hàbitats diferents, les tendències temporals a llarg plaç en la seva l’abundància i el comportament sincrònic de les seves poblacions va ser similar, observant-se sub-poblacions temporalment persistents al llarg del Mediterrani. En consonància amb els capítols anteriors, la SST i Chla resultaren ser factors significatius en la definició de patrons de distribució i fluctuacions interanuals de l’abundància. La segona part de la tesi estava motivada per la situació actual dels cefalòpodes al Mar Mediterrani, on no existeixen mesures d’avaluació i gestió específica per aquest grup i algunes de les seves poblacions es troben sobre-explotades. Per contribuir al coneixement de la situació actual al Mar Balear, es va analitzar la pesqueria, cicle vital i dinàmica poblacional de la sípia utilitzant sèries temporals intra-anuals (Capítol 5). L’anàlisi de diferents factors ambientals va revelar que la SST i la variabilitat climàtica local influïen significativament en les fluctuacions d’abundància de l’espècie. En un treball posterior (Capítol 6) s’aplicaren tècniques d’avaluació d’stocks a les pesqueries de sípia i calamar de les Illes Balears utilitzant dades procedents de la EU Data Collection Framework (DCF). Fins on sabem, aquest treball constitueix la primera aplicació dels Lesly-Delury Depletion Methods a stocks de cefalòpodes del Mediterrani. Els resultats demostraren que l’esquema actual de mostratge de la DCF és inadequat per a l’avaluació de cefalòpodes i es proposen possibles modificacions.

Les Céphalopodes comme la seiche Sepia officinalis, malgré une durée de vie courte, sont retrouvés dans les océans depuis des millions d’années. Chez ces animaux atypiques, peu de pathologies ont été observées révélant la présence d’un système immunitaire efficace mais peu étudié qui repose sur des processus innés. L’étude du système immunitaire de la seiche a été menée au niveau du corps blanc, organe hématopoïétique ; des cellules circulantes, les hémocytes et au niveau de la peau, première barrière avec le milieu extérieur. Au niveau du corps blanc, l’étude transcriptomique et protéomique a mis en évidence la présence de facteurs en lien avec l’hématopoïèse dont des membres de la voie de signalisation JAK-STAT. Des facteurs immunitaires ont également été identifiés révélant une possible multifonctionnalité du corps blanc. La réponse immunitaire face à Vibrio splendidus a pu être appréhendées à partir d’une analyse transcriptomique comparative sur les hémocytes. Toutefois cette dernière n’ayant pas permis d’identifier clairement des peptides antimicrobiens, une analyse in silico originale a été développée permettant de sélectionner cinq peptides candidats dont trois ont révélé une activité antibactérienne ciblée contre des bactéries du genre Vibrio. Enfin, une étude au niveau de la peau et de son mucus a été initiée. Cette étude par des approches -omiques a permis l’identification de facteurs en lien avec la reconnaissance des pathogènes et la réponse immunitaire. Par ailleurs, douze souches ont pu être isolées et identifiées au niveau du microbiome cutané. L’ensemble de ces résultats représente un apport majeur concernant le système immunitaire chez la seiche permettant d’initier des études fonctionnelles lors d’une infection ou en fin de vie. Ces études permettraient de comprendre le mode d’action des facteurs immunitaires identifiés, l’implication de chaque entité dans la réponse immunitaire ou dans la mise en place et la maintenance du microbiome
Cephalopods such as the cuttlefish Sepia officinalis, despite their short lifespan, have been found in the oceans for millions of years. In these atypical animals, few pathologies have been observed, revealing the presence of an effective but little studied immune system based on innate processes. The study of the cuttlefish's immune system has been carried out on the white body, a haematopoietic organ; on the circulating cells, the haemocytes; and on the skin, the first barrier with the external environment. At the white body level, the transcriptomic and proteomic study highlighted the presence of factors linked to haematopoiesis, including members of the JAK-STAT signalling pathway. Immune factors have also been identified, revealing a possible multifunctionality of the white body. The immune response to Vibrio splendidus could be apprehended from a comparative transcriptomic analysis of haemocytes. However, as the latter did not allow the clear identification of antimicrobial peptides, an original in silico analysis was developed to select five candidate peptides, three of which revealed a targeted antibacterial activity against bacteria of the Vibrio genus. Finally, a study of the skin and its mucus was initiated. This study using -omic approaches enabled the identification of factors related to pathogen recognition and immune response. In addition, twelve strains were isolated and identified at the level of the skin microbiome. All these results represent a major contribution concerning the immune system in cuttlefish, making it possible to initiate functional studies during an infection or at the end of life. These studies would make it possible to understand the mode of action of the identified immune factors, the involvement of each entity in the immune response or in the establishment and maintenance of the microbiome

L’évaluation et la gestion des stocks de poissons ont pour objectif d’atteindre une exploitation durable des ressources fournies par les océans. Si les progrès dans ce domaine sont bien réels pour certains stocks de grande importance commerciale, la situation est différente pour les stocks dits à données limitées. Souvent historiquement moins exploités, ces stocks ne bénéficient pas des mêmes ressources, tant économiques qu’humaines, pour réaliser une évaluation de stock permettant par la suite la mise en place de mesures de gestion. Ce travail s’appuie sur deux cas d’étude, le lieu jaune (Pollachius pollachius) et la seiche (Sepia officinalis), afin d’explorer des méthodologies d’évaluation de stocks adaptées aux situations de données limitées. Après une première partie introductive reprenant le contexte de l’évaluation des stocks et présentant les deux cas d’étude, une revue des méthodes d’évaluation de stocks à données limitées est proposée. Une troisième partie compare les résultats d’un modèle de biomasse à deux stades et d’un modèle multi-annuel de déplétion généralisé appliqués au stock de seiche de Manche. Une version améliorée du modèle de biomasse à deux stades codé en Bayésien est également présentée. Le travail se poursuit avec l’application d’un modèle d’analyse intégrée Stock Synthesis au stock de lieu jaune de mer Celtique. Les résultats sont comparés aux résultats de modèles plus simples nécessitant moins de données. Les résultats du modèle Stock Synthesis s’avèrent sensibles aux hypothèses sur la valeur de mortalité naturelle, dont le calcul dépend des paramètres de croissance du stock. La cinquième partie présente l’acquisition et le traitement de nouvelles données qui pourront permettre une meilleure estimation de l’état du stock de lieu jaune. Un modèle hiérarchique Bayésien est construit, permettant un transfert d’information entre trois stocks et la mise à jour des paramètres biologiques du lieu jaune. Le dernier chapitre conclut ce travail en reprenant les principaux résultats obtenus et en élargissant la discussion sur des perspectives de recherche
The assessment and the management of fish stocks aim at achieving a sustainable exploitation of the resources provided by the oceans. While progress have been made in this field for some stocks of great commercial importance, the situation is different for the so-called “data limited” stocks. Often historically less exploited, these stocks do not benefit from the same economical resources nor workforce to conduct the stock assessments required to set management measures. This work is based on two case studies, pollack (Pollachius pollachius) and cuttlefish (Sepia officinalis). The aim is to investigate the stock assessment methods adapted to data-limited situations. A first introductive part presents the background of fish stock assessment as well as the two case studies. This first chapter is followed by a review of data-limited stock assessment methods. The third part compare the results of a two-stage biomass model with the results of a multi-annual generalized depletion model applied to the English Channel stock of cuttlefish. An improved version of the Bayesian two-stage biomass model is also presented. In the fourth part, a Stock Synthesis model based on integrated analysis methods is applied to the stock of pollack in the Celtic Seas Ecoregion. The results are compared to the results of simpler models which require less data. The Stock Synthesis model results are sensitive to the assumptions on the natural mortality value, which relies on the growth parameters of the stock. The fifth part presents the collection and analysis of new data which will allow a better estimate of pollack stock status. A Bayesian hierarchical model is constructed, allowing information transfer between three stocks and the update of pollack biological parameters. The last chapter concludes this work by summarizing the main results. The discussion is extended to the research perspectives

Bibliography: leaves 126-144.
144 leaves : ill., maps ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Biology, 2000

碩士
國立清華大學
系統神經科學研究所
98
Abstract Observational learning is the ability to learn through observing others’ behavior. The benefit of observational learning is clear in that individuals can save time and energy without try-and-error learning, and enhance the chance of survival and reproduction. Cephalopods (squid, octopus, and cuttlefish) have the most sophisticated central nervous system among invertebrates, thus it is conceivable that cephalopods can develop some forms of cognition. Although it has been suggested that octopus equips the capacity of observational learning, a previous study has indicated that cuttlefish do not improve their predation tactics by observing conspecifics. Given that the danger avoidance is important for survival, we sought to reevaluate whether cuttlefish show some form of observational learning under threatening circumstances. Cuttlefish (Sepia pharaonis) were divided into two groups, the Self-Experience Group and the Observe-Other Group. Two background patterns were used to probe the threat-place association learning in these experiments. In the training phase, a toy submarine was remotely controlled to expel the cuttlefish at its innately preferred place to establish the threat-place association in the Self-Experience Group. In the Observe-Other Group, the threat-place association was established by expelling the conspecific demonstrator at the observer’s innately preferred place while the observer watched the whole process behind a transparent divider. In the testing phase, the choice of safe place in the absence of threat was used to probe the learning of cuttlefish in both groups. In the Self-Experience Group, we found that most animals chose the safe side more often than their innately preferred side, an indication of the association learning. However, in the Observe-Other Group, only a subset of animals showed this threat-place association by observation. Thus, our results suggest that some cuttlefish can learn by observing others, but individual difference exists.

碩士
國立清華大學
系統神經科學研究所
104
Identifying the amount of prey available is an important part of an animal’s foraging behavior. The risk-sensitive foraging theory predicts that an organism’s foraging decisions with regard to food rewards depend upon its satiation level. However, the precise interaction between optimal risk-tolerance and satiation level remains unclear. In the present study, we examined, firstly, whether cuttlefish, with one of the most highly evolved nervous system among the invertebrates, have number sense, and secondly, whether their valuation of food reward is satiation state-dependent. When food such as live shrimps is present, without training, cuttlefish turn toward the prey and initiate seizure behavior. Using this visual attack behavior as a measure, cuttlefish showed a preference for a larger quantity when faced with two-alternative forced choice tasks (1 vs. 2, 2 vs. 3, 3 vs. 4, and 4 vs. 5). However, cuttlefish preferred the small quantity when the choice was between one live and two dead shrimps. More importantly, when the choice was between one large live shrimp and two small live shrimps (a prey size and quantity trade-off), the cuttlefish chose the large single shrimp when they felt hunger, but chose the two smaller prey when they were satiated. These results demonstrate that cuttlefish are capable of number discrimination and that their choice of prey number depends on the quality of the prey and on their appetite state. The findings also suggest that cuttlefish integrate both internal and external information when making a foraging decision and that the cost of obtaining food is inversely correlated with their satiation level, a phenomenon similar to the observation that metabolic state alters economic decision-making under risk among humans.

碩士
國立清華大學
系統神經科學研究所
102
Concept formation has long been considered as a complex cognitive behavior that only exists in vertebrates, e.g., mammals and birds. But a previous study has shown that honeybees, an invertebrate with a simpler brain, also possess the ability of knowing the sameness and difference in visual and olfactory modalities. In the present study, we hypothesized that cuttlefish (Sepia pharaonis), a marine invertebrate with keen vision, complex central nervous system, and exhibiting sophisticated behaviors, share a great convergence of cognitive functions that are similar to those found in vertebrates and insects. To examine if cuttlefish could learn the concept of sameness, a 3-D maze was developed to apply the delayed matching-to-sample (DMTS) paradigm. At the bottom part of the maze, cuttlefish were trained to match the same background pattern (secondary pattern) after seeing the pattern (primary pattern) at the upper part of the maze. The learning criterion, with statistical significance, was set to assess if cuttlefish were able to extract the rule of sameness through the training. Once cuttlefish reached the learning criterion, the transfer test was proceeded to exam if cuttlefish could apply the rule of sameness when they encountered a new pattern pair. Cuttlefish failed to reach the criterion in the training phase. Their choices to the background pattern were biased to their innate preferences. We conducted a control experiment to confirm the failure of training was not because cuttlefish were unable to succeed in the DMTS task. One out of five animals passed the criterion in the control experiment with only 23 trials, and this criterion-reached animal chose the background pattern according to its innate preference in absence of the primary pattern. Individual cuttlefish solving the DMTS task suggests that cuttlefish might be able to associate the background pattern with what they have seen previously, and this implies that cuttlefish possess the short-lasting memory, or the working memory. In summary, we conclude that cuttlefish are unable to learn the abstract concept under current experimental condition, but cuttlefish are able to solve the DMTS task and possess the visual working memory.

碩士
國立臺灣科技大學
機械工程系
102
In recent years, due to the changes of population, family and social structure, more single people appear, seeking spiritual comfort and companionship, which makes the human needs of pets increase every year. Pet robots combine the advantages of both pets and intelligent robots, and it extends the different ages of interactive electronic toys. It will make the pet-type robots have great market potential and development space. Nowadays, pet robots, mostly are land-based and less for underwater types. This study uses the concept of smart devices APP and develope the interactive pet cuttlefish bionic robots. The study improve previous cuttlefish robot and devided into three parts: interactive mode, emotional performance, bionic performance. In interactive mode,user use smart device with speech recognition App to interact with the cuttlefish robot. In emotional performance, according to different emotional word, cuttlefish can perform corresponding behavior. There are four emotion such as happy, mad, sad, crazy. In bionic performance, we manufactured bionic cuttlefish skin to improve the appearance. We also improve the propulsion of the previous cuttlefish robot with different method. The components of the cuttlefish robot were designed by 3D CAD software, and manufactured by additive manufacturing technologies such as FDM and other technologies such as RT, hand-made model.The overall size of the cuttlefish robot is 195mm×115mm×78mm. All the parts are assembled and test underwater. The test results show that the cuttlefish robot can discriminate the statements given by user and make appropriate emotional behavior.

碩士
國立清華大學
系統神經科學研究所
106
Cuttlefish lack parental care, and hatchlings face high predatory risk immediately after hatching. Thus, cuttlefish hatchlings need to equip the anti-predatory ability as soon as they hatch. Pharaoh cuttlefish Sepia pharaonis and European common cuttlefish Sepia officinalis have similar morphological appearances, but their egg characteristics are distinctly different. Pharaoh cuttlefish produce eggs with transparent capsules, and European common cuttlefish produce eggs with a black envelop which is stained by ink. Previous studies have shown that sensory systems of European common cuttlefish are fully developed in late embryonic stages, and they can use these sensory systems to receive information from the environment. Moreover, European common cuttlefish can alter their food preference by their embryonic visual experience. However, there is little known about the effect of embryonic experience to predatory cues on postnatal behaviors in cuttlefish. Compared with European common cuttlefish, eggs of pharaoh cuttlefish are more vulnerable to predators, but the transparency of eggs may provide embryos an opportunity of collecting visual cues from the environment and thus increase their survival rate. The present study was aimed to understand whether cuttlefish’s embryonic experience of predators affects their postnatal defensive behaviors, and to compare the difference between pharaoh cuttlefish and European common cuttlefish. During the embryonic exposure period, all eggs of cuttlefish were separated into seven groups: one control group and six cue exposure groups. Embryos in three groups were exposed to the predatory cues (visual cue only, chemical cue only, and combination of visual and chemical cues). Similarly, Embryos in the other three groups were exposed to the cues of non-predator. Cuttlefish were tested their primary and secondary defensive behaviors after they hatched. The result showed that early exposure to predatory cues altered the cuttlefish hatching period and postnatal defensive behavior. However, effects of embryonic sensory information were different in pharaoh cuttlefish and European common cuttlefish. Specifically, visual information is more important than chemical information for pharaoh cuttlefish embryos, and chemical information may even reduce these effects. In contrast, visual information and chemical information are equally important for European common cuttlefish embryos. These results may explain the functional difference between egg appearance of two species.

Dissertação de mestrado, Aquacultura e Pescas (Aquacultura), Faculdade de Economia, Universidade do Algarve, 2014
The increasing cephalopod human seeking as a source of food have been defined it as an aquaculture candidate in the past 20 years. Such have been propelling the cephalopods culturing, such of the European cuttlefish Sepia officinalis. However there are bottlenecks for this species, for instance, at nutritional level. It has been difficult to define a diet with high nutritional value for the cuttlefish and with reasonable costs for the producer. A variety of alternative types of foods have been tried, but these have been showed to be costly and not as good as natural diets. Artificial diets had been unsuccessful within the culturing of cuttlefish This study aimed to characterize the development of digestive tract during embryogenesis of European cuttlefish Sepia officinalis. The external and internal yolk sacs were mainly focused, as well as their nutritional content (using specific stains) and function. Analysis at macroscopical scale (weight and measurements) and microscopical scale (photographs, histology and image analysis) was performed. Eggs were weighed and measured in width and length. Then, these were cut open and embryos were removed from capsule and photographed. The embryos were then kept in formaldehyde. Images were treated and the area of the external yolk sac and the embryo was measured using image J. Histological techniques were performed to characterize the different embryonic stages and external and internal yolk sacs. Changes in the eggs sizes were observed. An initial reduction of the weigh, width and length during the first 10 dpp (days post posture) was observed. Followed by a rapid increase until hatching (p < 0.001). A strong correlation between the weight and width of eggs (R2 = 0.92) was observed. Being suggested as the most viable form of measurements for different studies. The evolution of egg weight was compared with the study of Sykes, et al. (2009). Similar variation was observed (P <0.05), however, in the present study the weight of the eggs was higher. Females at the present study were bigger and laid larger eggs. Both, external yolk sac and the embryo areas, measured with the image J were correlated. As the external yolk sac decreased, and thus consumed, the embryo increased its size. During embryonic development (from 12 day post posture, dpp) there was an inverse relationship between these two factors (p < 0.001, R2 = 0.91). The total area of the embryo (TEA, sum of the yolk sac area and embryo area) was estimated and compared with the weight of the eggs during the same time period. TEA had an almost linear evolution while the weight of the eggs was exponential during embryonic development. Despite the high correlation between these two factors (R2 = 0.68), it was suggested that the water content may be also relevant in this period. Different stages were identified according to the description of Naef (1928). Throughout embryogenesis it was observed the development of various rudimentary organs, such as eyes, arms and tentacles, mantle and its pigmentation. From stages X-XI onwards, the enclosure of the external yolk sac was observed. From the 13 dpp onwards histological images were collected and allowed a more detailed evolution of both yolk sacs. The contents of the sacs were PAS positive, suggesting the presence of polysaccharides. The extra-ectoderm layer (exe) was observed surrounding the external yolk sac, which was positive for Toluidine-O. The outer side of this layer presented cilia that are responsible for molecules diffusion present in the perivitelline fluid (pf). The inner side of the exe was in contact with the perivitelline sinus (ps), which cells appeared to be absorbed or pinocytosis to the yolk sinus (ys). The sacs content was composed of yolk platelets and empty spaces that may be related to the presence of lipids. Similar spaces were also observed in the internal yolk sac but in this structure, agglomeration of yolk droplets were mostly observed. Such droplets could be the early stages of the digestive gland cells of the embryo. A darker layer around the internal yolk sac was observed, which might be its epithelium, where it was noticed some triangular cells. It was suggested that, similarly to other cephalopods, these cells could either be hemocytes reacting to bacteria or either cellular replacement or detoxification. Near hatching, the animals showed some resemblance with the adults and the external yolk sac was greatly reduced.
A procura por cefalópodes como fonte de alimento tem vindo a definir, nos últimos 20 anos, o seu potencial como candidatos para a aquacultura, propulsionando o cultivo de espécies como o choco (Sepia officinalis). Esta espécie apresenta um ciclo de vida curto e rápido crescimento, o que permite rápidos ciclos de produção a reduzido custo de manutenção. Têm altas taxas de sobrevivência e resistência a elevadas densidades e patologias. Contudo existem ainda alguns obstáculos à sua produção em grande escala, nomeadamente a nível nutricional. Apesar de diferentes tipos de alimentos terem sido testados em chocos, ainda não se definiu uma dieta com elevado valor nutricional e simultaneamente com custos reduzidos para o produtor. Este trabalho teve como objetivo caracterizar o desenvolvimento do trato digestivo durante a embriogénese de S. officinalis. Os sacos vitelinos externo e interno foram o foco principal desta dissertação, onde foi estudado não só o seu conteúdo nutricional (com recurso a colorações específicas), como também as suas funções. Foram realizadas análises a nível macroscópico (peso e medidas) e microscópico (fotografia, histologia e análise de imagem). Ao longo de 31 dias de amostragem, no Centro de Ciências do Mar (Estação Experimental do Ramalhete), foram recolhidos um total de 364 ovos de choco. Estes foram colocados em cestos de incubação, num tanque de 1500 L, com temperatura (19.4 ± 0.95 ºC), salinidade (34.5 ± 0.63 ‰) e oxigénio (93.7 ± 3.58 %) constantes. Foram recolhidos, aleatoriamente, 5 ovos por dia para pesagem e medição de largura e comprimento. Estes ovos foram abertos e cada embrião foi retirado da cápsula e córion, fotografado e de seguida preservado em formaldeído. Foi realizado o protocolo padrão de histologia para caracterizar os sacos vitelinos externo, interno e os diferentes estágios embrionários. Os chocos foram inicialmente desidratados através de lavagens em etanol de percentagens crescentes por períodos de tempo estabelecidos. Realizaram-se pré-infiltrações, infiltrações e polimerizações de acordo com as instruções em Heraeus Technovit 7100 (Heraeus Kulzer GmbH, Germany). Depois da solução de resina ter sido preparada, cerca de 3 ml foram colocado em moldes e os embriões cuidadosamente posicionados. Após 48 h de secagem, cortes longitudinais de 3 μm foram obtidos, colocados em lâminas de microscópio (3 a 5 cortes por lâmina) e corados com azul de tolueno e ácido periódico de Schiff (PAS – periodic acid-Schiff). Após a secagem, as lâminas foram observadas sob uma lupa Zeiss STEMI 2000-C e para maiores amplificações foi utilizado um microscópio Leica DM200 com câmara Leica SFC480 incorporada. As medições efetuadas permitiram detetar alterações no crescimento dos ovos. Foi observada uma redução inicial do peso, largura e comprimento durante os primeiros 10 dias após a postura (dpp - days post posture). Houve desidratação dos ovos endurecendo a cápsula gelatinosa exterior, o que permitiu a retenção dos nutrientes necessários ao desenvolvimento embrionário e ainda proteção contra agentes patológicos. De seguida, observou-se o aumento rápido das três variáveis (peso, largura e comprimento) até à eclosão (p < 0.001). A reabsorção de água facilitou a eclosão. Há uma maior correlação entre o peso e a largura dos ovos (R2 = 0.92) do que entre as restantes variáveis. O peso e a largura do ovo foram então sugeridas como as mais viáveis para diferentes estudos. O crescimento em peso dos ovos teve uma variação semelhante à obtida por Sykes, et al. (2009a) (p < 0.05), no entanto, o peso dos ovos apresentou valores superiores no presente estudo. Uma possível explicação é o facto de as fêmeas utilizadas neste estudo serem maiores, produzindo ovos de maiores dimensões. Fezse uma correlação entre a dimensão do saco vitelino externo e do embrião. O saco vitelino externo diminui à medida que foi consumido, o que se traduziu no aumento de tamanho do embrião. Assim, estas variáveis estão inversamente relacionadas (p < 0.001, R2 = 0.91). A área total do embrião (TEA – total embryo area, área do saco vitelino mais a área do embrião) foi estimada e comparada com o peso dos ovos durante o desenvolvimento embrionário. A TEA apresentou uma evolução quase linear, enquanto o peso dos ovos aumentou exponencialmente. Apesar de a correlação entre as duas variáveis ter sido elevada (R2 = 0.68), o teor de água poderá ser o aspeto mais relevante neste período. Os diferentes estágios de desenvolvimento embrionário foram identificados de acordo com a descrição de Naef (1928). Foi observado o desenvolvimento de órgãos rudimentares como olhos, braços e tentáculos, manto e sua pigmentação. A partir do estágio X-XI foi observada a inclusão do saco vitelino externo. De 13 dpp (estágio XIII-XIV) em diante, foi possível reunir imagens histológicas que permitiram uma observação detalhada de ambos os sacos vitelinos. Os conteúdos dos sacos tiveram resultados positivos para PAS, o que sugere a presença de polissacarídeos, enquanto que órgãos rudimentares e membranas dos sacos vitelinos tiveram resultados positivos para azul de tolueno. Foi observada a camada extra-ectodérmica (exe), positiva para tolueno. O lado exterior de exe é composto por cilia que é responsável pela difusão de moléculas presentes no fluido perivitelino. O lado interno de exe está em contato com o sinus perivitelino onde foram absorvidas e pinocitadas células para o sinus do vitelo. Os sacos eram constituídos por várias plaquetas de vitelo e por espaços, relacionados com a presença de lípidos. No saco vitelino interno foram também observados pontualmente os mesmos espaços, mas na maior parte dos casos foi observado um aglomerado de gotículas, que poderão ser fases iniciais de células da glândula digestiva do embrião. Foi observada uma camada mais escura em torno do saco vitelino interno, correspondendo possivelmente ao epitélio no qual existiam algumas células de formas triangulares. Estas células poderão advir do processo de substituição ou desintoxicação celular, ou poderão ser ainda hemócitos, que reagem à presença de bactérias, como observado anteriormente noutros cefalópodes. O volume do saco vitelino externo foi idêntico ao volume do embrião no fim do estágio XVI, podendo ser comparado com os resultados da correlação anteriormente efetuada entre a área do saco vitelino externo e a área do embrião. Nos estágios XVII-XVIII, o volume do saco vitelino externo e interno apresentaram semelhantes proporções. Próximo da eclosão os animais eram morfologicamente semelhantes aos adultos e o saco vitelino externo era bastante reduzido.

Every austral winter, thousands of giant Australian cuttlefish, Sepia apama Gray, 1849, aggregate to spawn over a small area of subtidal rocky reef in northern Spencer Gulf, South Australia, constituting the only known spawning aggregation of cuttlefish in the world. Rapid expansion of commercial fishing operations on the aggregation between 1994 and 1997 caused considerable concern for the sustainability of the population. However, determining an appropriate management strategy for the fishery was hampered by a paucity of biological information. Despite its large size and common occurrence, S. apama had previously attracted little scientific interest. Therefore, the general aim of this study was to provide some understanding of the life history of S. apama in the wider northern Spencer Gulf region and to relate this to the popUlation dynamics at the aggregation area. The dynamics of the spawning population were investigated using underwater visual transect methods from 1998 to 2001. Different time and area closures were implemented over this four-year period, allowing for comparisons between fished and unfished sites. Temporal trends in density indicated a distinct annual spawning season between May and August, with a consistent peak in early June. During the season densities as high as 85 cuttlefish.1OOm'2 were recorded, whereas at other times they were less than I cuttlefish.lOOm'2. Tagging work verified that individual cuttlefish remained at the aggregation area for a large part of the spawning season, such that it was valid to estimate total abundance and biomass at the time of peak numbers. In non-fished years total abundances reached over 170,000 individuals. Although biomass estimates indicated a decline in the total population size from 222 t in 1999 to 184 t in 2001, no long-term effects due to previous fishing could be concluded. Cuttlefish were not evenly distributed amongst habitats or sites within the aggregation area, although the pattern of distribution was consistent between years. To this effect, the original closed area in 1998 represented 43% of the estimated hard substrate but only accounted for 19 to 28% of the total estimated biomass in each year. Therefore, the spatial distribution and movement patterns of cuttlefish within the aggregation area have important implications for the implementation of future area closures. At non-spawning times, cuttlefish were widely distributed throughout the northern Spencer Gulf at much lower densities than those recorded at the aggregation area. One cuttlefish tagged 65 km south of the aggregation area was later recaptured at the spawning site, suggesting that the aggregated population is drawn from that of the broader region. There were multiple size classes within both the spawning and non-spawning populations of the Gulf, which suggested the presence of multiple year classes. The cuttlebones and other hard structures were examined as potential indicators of age. The width of growth increments in the cuttlebones varied seasonally over the length of the bone. The analysis of many bones indicated the existence of two year classes for each sex. They also suggested there were two alternative life cycle types in northern Spencer Gulf. The first was characterised by rapidly growing juveniles that attained maturity within 7 to 8 months, and which then returned to spawn as small adults in the first spawning season following hatching. The second life cycle type was characterised by slower growing juveniles that ultimately did not return to the aggregation area until the second year after hatching, and thus lived for nearly two years. Individuals conforming to the first life cycle type vastly outnumbered those of the second. Aquarium experiments using juveniles hatched and reared in captivity under different temperature and feeding regimes supported the above interpretation of the adult cuttlebone microstructures. Juveniles fed double rations achieved higher growth rates and had wider and more numerous growth increments in their bones than those fed half rations. The effect of temperature was confounded by the use of equal rations across temperature treatments rather than ad libitum feeding. Reproductive indices confirmed that all individuals at the aggregation area, irrespective of size or age, were mature and spawning, whilst those in the wider Gulf population were immature and feeding. Gonad weight and gamete size were positively correlated with body size in both sexes; suggesting a difference in the reproductive potential of the two different year classes. There was a decline in condition during spawning, supporting the hypothesis of a semel parous spawning strategy. The sex composition of the spawning population was highly biased toward males, with 3 to 6 males per female, whilst the sex ratio of the northern Spencer Gulf population tended toward unity. No single explanation for this disparity could be determined. The mating system was described through analysis of the reproductive behaviours of spawning individuals from video recordings. Many behaviours related to sexual selection were displayed by individuals of both sexes, which were consistent with expectations that relate to the biased operational sex ratio. Large and small males, representing the different year classes, used different behavioural tactics to compete for females, but there was no assortative mating with respect to size. Therefore, the two year classes were not reproductively isolated. Various mechanisms for the determination of life cycle type were discussed with the most likely a cut-off conditional mechanism.
Thesis (Ph.D.) -- University of Adelaide, Dept. of Environmental Biology, 2003

碩士
國立臺灣海洋大學
生物科技研究所
96
Estrogen Receptor (ER) is a member of nuclear receptors, which is activated by steroid hormone estrogen. The liganded ER acts as a DNA binding transcription factor to mediate a variety of target gene transcriptions. The structure of ERs is composed of six modular domains, in which the A/B domain is a ligand-independent activation function (AF-1) domain as well as a dimerization domain, the C domain is DNA-binding domain (DBD) and the E/F domain is ligand-dependent activation function (LBD/AF-2) domain. In vertebrate, more than 162 ER sequences, including both ERα and ERβ subtypes, have been identified. By contrast, only 5 ER sequences have been characterized in invertebrate species. Here I have cloned a partial sequence of ER cDNA from cuttlefish (Sepioteuthis lessoniana) overy. The conservation of DBD and LBD of cuttlefish ER was compared with all ER family sequences. The phylogenetic analysis of ER was made by neighbor joining method. It appears that mollusk ER has similar degree of alliance to both vertebrate ERα and ERβ subtypes. The DBD and LBD of ERs are highly conserved in molluscan species, but have low sequence identities between mollusck and vertebrate ERs. The tissue distribution and regulation of ER transcription in cuttlefish needs to be identified.

Tese de mestrado, Biologia da Conservação, Universidade de Lisboa, Faculdade de Ciências, 2019
Atmospheric CO 2 levels are rising since the beginning of the Industrial Era, and concomitantly, the uptake of CO 2 by the oceans is increasing and changing the seawater chemistry, a phenomenon known as ocean acidification (OA). These changes can compromise key biological traits of many marine organisms, with potential cascading effects to population and ecosystem levels. Besides the significant neurological/physiological impairments, there is increasing evidence of detrimental OA effects on the behavioural ecology of certain marine taxa, including in cephalopods. Yet, the previous behavioural studies performed in these highly developed invertebrates were only focused on squids and the potential impacts in cuttlefish behaviour are still unknown. Within this context, the main objectives of this dissertation were to investigate OA effects in the development and behaviour of the common cuttlefish ( Sepia officinalis ) early-life stages – from early embryogenesis until 20 days after hatching, namely by exposing them to either present day ( ~ 400 μatm) and to the near-future levels of p CO 2 ( ~ 1000 μatm; ΔpH = 0.4). A comprehensive assessment of OA effects on cuttlefish development was performed by gauging embryogenesis duration, hatching success, early survival rate and body size measures (e.g. weight and length). Furthermore, different aspects of the cuttlefish behavioural ecology, including shelter-seeking, hunting behaviour and response to a visual alarm cue, were analysed to achieve a holistic overview of the OA impacts in cuttlefish early development. The present work did not find any evidence that OA future conditions compromise the cuttlefish embryonic development. The development time, hatching success, survival rate, and the length and weight of newly-hatched cuttlefish were similar between normocapnia and hypercapnia treatments. The Fulton’s Index was the only parameter that showed significant differences, with higher values to the hypercapnia treatment, which may be related with a denser cuttlebone. Concerning to the behaviours analysed, and in contrast with previous cephalopod studies, the results suggest a certain behavioural resilience of the cuttlefish hatchlings towards near-future acidification conditions. The behaviours of hunting, shelter-seeking and response to a visual alarm cue did not show significant differences between treatments. Their nekton-benthic (and active) lifestyle, their adaptability to the abiotic-fluctuating coastal environment and to the adverse conditions inside their eggs may favour the odds of the common cuttlefish recruits to endure the future acidified ocean. Nonetheless, this species is not only exposed to acidification in their natural environment, they may be also particularly susceptible to other anthropogenic pressure and other climate change-related variables. The cumulative effects of multiple stressors should be further addressed to accurately predict what the future reserves to this ecologically and economically important species.
As alterações climáticas abrangem um conjunto de diferentes fatores, resultantes predominantemente da combustão de combustíveis fósseis, sendo o aumento global da temperatura um dos indicadores mais conhecidos. Para além deste, fazem também parte a subida do nível do mar, a perda de massa de gelo na Antártida, no Ártico e nas montanhas glaciares de todo o planeta, a ocorrência de eventos climáticos extremos e a acidificação dos oceanos. Dada a dependência humana da energia obtida através dos combustíveis fósseis, a carga atmosférica dos gases de efeito estufa tem vindo a aumentar, desde o início da Era Industrial (1750), sendo o dióxido de carbono (CO 2) o GHG que regista o maior aumento. Os valores de CO 2 atmosférico observados hoje em dia são mais elevados do que aqueles que a Terra experienciou nos último 800.000 anos, no entanto, é esperado que continuem a aumentar. O oceano global é um dos grandes reservatórios de CO 2 atmosférico e, nos últimos séculos, tem vindo a absorver cerca de 30% do CO 2 gerado pelo Homem, o que desencadeou um aumento de 26% na concentração de iões de hidrogénio. Esta absorção de CO 2 atmosférico é considerada a causa principal da acidificação dos oceanos (nome dado ao processo de redução de pH gerado pelo aumento excessivo da pressão parcial de CO 2 ( p CO 2 ) na superfície dos mesmos), tendo já instigado uma redução de 0,1 unidades de pH e, no final do século, espera-se uma descida de 0,2 a 0,4 unidades de pH. Quando o CO 2 reage com a água do mar desencadeia um conjunto de reações que levam à formação de ácido carbónico (H 2 CO 3 ), ao aumento dos iões de bicarbonato (HCO 3 - ), à redução dos iões de carbonato (CO 3 2- ) e, consequentemente, à diminuição dos níveis de carbonato de cálcio (CaCO 3 ), o principal constituinte dos organismos com exosqueleto calcário ou concha. Este processo afeta a formação das estruturas calcárias, que necessitam dos iões de carbonato, e ainda outros processos biológicos e químicos fundamentais, devido à alteração no equilíbrio químico da água do mar. A diminuição de pH e o aumento de CO 2 no meio aquático apresentam sérias consequências para a saúde dos ecossistemas, interferindo com a biogénese de estruturas calcárias e induzindo alterações fisiológicas, neurológicas e comportamentais nos organismos marinhos. Apesar destas implicações, os organismos marinhos que possuam sistemas excretor e regulador de pH eficazes (e.g. peixes adultos, crustáceos e cefalópodes) podem apresentar alguma tolerância quando expostos a concentrações elevadas de CO 2 durante períodos prolongados. Contudo, diferentes espécies de cefalópodes apresentam sensibilidades distintas a concentrações elevadas de pCO 2 , sendo que estas diferenças poderão estar relacionadas com o tipo de estratégia de vida – as espécies pelágicas (i.e. mais ativas), tais como as lulas, demonstraram maior sensibilidade quando comparadas com animais bentónicos, tais como polvos e chocos. O choco-comum, Sepia officinalis , é uma espécie necto-bentónica que realiza migrações sazonais para zonas de baixa profundidade, como os estuários, durante a época de reprodução. Trata-se de uma espécie com maior atividade durante a noite, passando o dia camuflada na areia. Tem uns olhos bastante desenvolvidos e depende das suas características visuais para aumentar a capacidade de sobrevivência, quer pela evasão de predadores, quer pela procura de alimento. Durante o desenvolvimento embrionário, os embriões estão protegidos do ambiente externo por camadas gelatinosas e por camadas de tinta existentes no ovo. Contudo, em condições naturais, o ambiente interno do ovo está sujeito a condições de hipercapnia (elevados níveis de pCO 2 ), que podem funcionar como uma pré-adaptação a uma futura exposição a condições de acidificação. Os estudos existentes sobre o efeito da acidificação dos oceanos nestes organismos focam-se sobretudo no impacto relativamente à concha interna, desenvolvimento embrionário e desenvolvimento de indivíduos recém-eclodidos/juvenis, sendo o efeito sobre as questões comportamentais praticamente desconhecido. Como tal, o presente estudo teve como objetivo descobrir e esclarecer as consequências da acidificação dos oceanos, prevista para o final do século (ΔpH = 0,4), sobre as fases iniciais de vida do choco-comum, Sepia officinalis . Neste sentido, ovos e indivíduos recém-eclodidos de choco-comum foram sujeitos a um cenário de acidificação, com valores estimados para o final do século (pH = 7,7; p CO 2 ~ 1000 μatm) e a um cenário de controlo, com valores atuais (pH = 8,1; pCO 2 ~ 400 μatm). Durante o tempo de exposição, que englobou o desenvolvimento embrionário e 20 dias pós eclosão, foi avaliado um conjunto de respostas biológicas, nomeadamente: 1) tempo médio de desenvolvimento embrionário, 2) sucesso de eclosão e 3) taxa de sobrevivência aos 20 dias pós eclosão. Aos 15 dias pós eclosão foi realizada uma bateria de testes comportamentais essenciais à sobrevivência nos primeiros estágios de vida, nomeadamente: a) escolha de abrigo, b) predatório e c) reação a um estímulo visual conspecífico (tinta). No final dos testes comportamentais foram recolhidos dados relativos à condição física dos indivíduos: i) peso, ii) comprimento total e iii) comprimento do manto, úteis para o cálculo do índice de condição (índice de Fulton). O presente trabalho não encontrou evidências de que a acidificação dos oceanos, esperada num futuro próximo, possa provocar alterações no desenvolvimento embrionário, dada a inexistência de resultados estatisticamente significativos relativamente ao tempo de desenvolvimento, ao sucesso de eclosão e à taxa de sobrevivência, e ainda ao comprimento e peso dos animais recém-eclodidos entre os tratamentos aos quais foram expostos. Relativamente aos parâmetros comportamentais analisados, e em contraste com os resultados obtidos noutros estudos com cefalópodes, também não foram encontradas diferenças estatisticamente significativas nos comportamentos de procura de abrigo, de predação e reação a um estímulo visual conspecífico, demonstrando que a acidificação dos oceanos esperada para 2100 possivelmente não provocará alterações comportamentais (nos comportamentos aqui abordados) nos indivíduos recém-eclodidos. Contudo, foram observados resultados estatisticamente significativos relativamente ao fator de condição, apresentando um valor mais elevado nos indivíduos expostos às condições de hipercapnia. Tal facto, poderá estar relacionado com resultados obtidos por estudos anteriores que indicam que em condições de acidificação estes animais são capazes de hipercalcificar a sua concha interna, levando a que esta se torne mais densa. Todavia, permanecem desconhecidas as consequências desta hipercalcificação. Sendo a concha interna responsável pela flutuação neutra destes animais, alterações na sua estrutura poderão alterar comportamentos essenciais, como a natação e a predação. Permanece também por descobrir quais os efeitos desta exposição no desenvolvimento futuro dos indivíduos e o efeito quando expostos a concentrações mais elevadas de pCO2. Em suma, esta dissertação permitiu verificar que os estados iniciais de desenvolvimento de Sepia officinalis parecem ser resilientes a elevadas concentrações de pCO2 (~ 1000 μatm), dado que não foram observadas diferenças significativas no desenvolvimento nem no comportamento destes indivíduos. Estes resultados estão de acordo com estudos realizados anteriormente que apontam para uma baixa sensibilidade desta espécie quando exposta a elevadas concentrações de pCO2 que provocam respostas negativas na grande maioria dos invertebrados (e.g. corais e bivalves). Tal poderá estar relacionado com: i) o seu estilo de vida necto-bentónico, frequentemente exposto a um meio (costeiro e estuarino) já por si propenso a flutuações ambientais e ii) as condições naturais de hipercapnia experienciadas durante todo o desenvolvimento embrionário (i.e. no ambiente interno dos ovos). Contudo, o índice de Fulton foi a única variável resposta que demonstrou diferenças significativas entre os tratamentos, sublinhando a necessidade de compreender melhor quais as possíveis consequências de uma concha interna potencialmente hipercalcificada. Adicionalmente, estudos futuros deverão ter em conta os efeitos da acidificação dos oceanos ao nível neurológico, de modo a corroborar a ausência de efeitos comportamentais. Nesta dissertação apenas foi incluída a acidificação dos oceanos como fator das alterações climáticas. Porém, este não atua como um fator isolado, estando muitas vezes associado a outros, como por exemplo, aumento da temperatura, hipóxia ou poluição antropogénica. Como tal, é necessária uma pesquisa mais alargada (holística e multidisciplinar) e com base no efeito cumulativo de múltiplos fatores de stress para prever as consequências futuras das alterações climáticas nesta espécie ecologicamente e economicamente tão importante.

碩士
國立清華大學
系統神經科學研究所
105
Coleoid cephalopods are well known for their ability to rapidly change body patterns for communication and camouflage. This is primarily achieved by neural control of chromatophores in the skin. The neural connection of the chromatophore system in the central nervous system has been well studied. However, the specific mechanism of the peripheral neural control of chromatophores remains unknown. To determine the mechanism of the peripheral pathway, the several neurotransmitters such as L-Glutamate (L-Glu), serotonin, acetylcholine (ACh), AMPA, and NMDA were applied to the skin of oval squids (Sepioteuthis lessoniana) in vivo and the corresponding chromatophore expansion and retraction were recorded. The results showed that AMPA- and NMDA-like receptors expressed on radial muscles are involved in a postsynaptic mechanism to differentially control yellow and brown chromatophore expansions, and ACh is involved in a presynaptic mechanism of chromatophore control. In a separate study, cuttlefish embryos (Sepia pharaonis) were used to examine the peripheral development of the chromatophore system. The results showed that chromatophores are functional at embryonic stage 26 as evidence of its response to L-Glu and serotonin applications in vitro. In addition, three different checkboard backgrounds (small low-contrast, small high-contrast, and large high-contrast) were used to examine cuttlefish embryo’s ability of body patterning development. The results showed that cuttlefish could express some disruptive components at stage 27, though the full function of body pattern control was not developed completely before hatching. Taken together, this study suggests that the peripheral neural control of the chromatophore system develops early and is regulated by both pre- and post-synaptic mechanisms with various neurotransmitters.

碩士
國立清華大學
系統神經科學研究所
100
Modern cephalopods are the most intelligent invertebrates with keen vision which is important for them to move rapidly for successful predation, camouflage for danger avoidance and communicate in complex ways with their body patterns. Therefore, vision might impact the cognition of cephalopods to some degree, but knowledge about how visual information is processed in the perceptual level is still not completely understood. In this work, we investigated the intelligence developing in a different way from vertebrates by observing the cognitive behaviors of cuttlefish. Results from this research are expected to give insights into the visual processing mechanism of cuttlefish. Cuttlefish (Sepia pharaonis) were trained to discriminate figures of shrimp and fish. Training for discrimination was based on operant conditioning and was given in the home tanks of each animal. Experimental apparatus was composed of two separated regions, and cuttlefish had to enter the rewarded area where the rewarded figure was presented or even to strike the rewarded figure with their tentacles for food. After cuttlefish achieved the learning criteria, a discrimination task was conducted to confirm learning. The non-rewarded figure was replaced with a crab figure in the discrimination test. Several transfer tests utilizing novel stimuli which are modified versions of training figures followed up the discrimination test. The outcome of visual processing in cuttlefish was examined in these transfer tasks. The results show that cuttlefish are capable of discriminating figures of fish, shrimp and crab. Furthermore, they do generalize the small-scale, sketch, and silhouette of the training figures, and respond properly, though the response strength is lower than that in training and individual differences exist in performance. In addition, cuttlefish also recognize the fragmented image of the training figures. These findings suggest that cuttlefish have the ability of discrimination, generalization, and amodal completion.

Since neonates are often the age-class most susceptible to predation, there should be strong selective pressure on prey for the early development of successful antipredator behaviour. The ability to assess predation risk as early as the embryonic stages may increase an individual’s survival, as it would allow young individuals to be better adapted to current predation risk, since present conditions are often a good short-term indicator of future conditions. I exposed embryonic cuttlefish (Sepia officinalis) to the odour of a predator and tested both the responses of the embryos to this stimulus, and the latent effects of both long (approximately 3 weeks)- and short (a few days)- exposure on the behaviour of newly-hatched juveniles, in particular the efficiency of cryptic behaviour on uniform and sandy substrates. Exposure to novel odours, whether they were predators or non-predators, increased the ventilation rate of embryos. This may be adaptive, because it helps an individual survive first encounters with unknown potential dangers before they have opportunity to collect information about a novel stimulus. Long-term exposure to predator odour increased the camouflage efficiencies of juveniles on uniform substrates. On sandy substrate, the exposure did not affect camouflage, but increased the extent of sand digging behaviour. Juveniles were also larger in size at hatching when exposed to predators compared to those that were not. These results were not seen in individuals with only short-term exposure to predator. Short-term exposure also had no effect on camouflage efficiencies on uniform or sandy substrates, or on sand digging behaviour. The results of my thesis indicate that high predation risk during embryonic development induces behavioural and morphological changes in camouflage expression and body size in cuttlefish hatchlings. The behavioural plasticity may provide survival benefits for newly hatched individuals, but may come at a cost in terms of body size. Such behavioural and morphological plasticity may have an impact on predator-prey dynamics and organization of communities.

碩士
國立臺灣海洋大學
環境生物與漁業科學學系
96
In this study, we discuss the cuttlefish, Sepia pharaonis, fertilized egg hatching days and hatching rate in different temperature and observer the development of embryo. In the other hands, we try to understand the influence of substrate and the feeding rate to the growth and survival of juvenile culture. In the experiment of fertilized egg hatching, the best hatching temperature are 24℃ and 27℃ (hatching rate 100±0%), 90±21.69% at 21℃, the average hatching days are 21, 23 and 26 days respectively. The hatching at 18℃ and 30℃ are not good. In spite of , the days of hatching is only 19 days at 30℃, the hatching rate is the lowest (1515±13.23%). The hatching days is the longest ( 70 days ) at 18℃ and hatching rate 30%. In the experiment of culture at different substrate, we have four substrates – naked tank, fine sand, coral sand and basket for cuttlefish juvenile culture. We found that growth of four sets are no significant differences (P>0.05). But the survival rate of basket (20±5.00％) is significant with the other three sets (P<0.05). The result shows the basket is not good for the cuttlefish juvenile culture. The experiment of different feeding rate: the feeding rate 10%, 20% 30% 40% bw d-1 all presents exponential growth, the length of mantle and weight are no significant (P<0.05); During culture period, beside 10% bw d-1 set have 2 and 3 death at week 3 and 4 for food competition (survival rate 89.5%). The other sets survival rate are 100%.