Dissertations / Theses: 'Pinnipedia'

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Stewardson, Carolyn Louise. "Biology and conservation of the Cape (South African) fur seal arctocephalus pusillus pusillus (Pinnipedia: Otariidae)from the Eastern Cape Coast of South Africa /." View thesis entry in Australian Digital Theses Program, 2001. http://thesis.anu.edu.au/public/adt-ANU20030124.162757/index.html.

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au, aappelb@meddent uwa edu, and Amber Appelbee. "Giardia and Cryptosporidium in Pinnipeds from the Gulf of St. Lawrence, Canada." Murdoch University, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070327.152130.

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Giardia and Cryptosporidium are protozoan parasites known to cause enteric disease in terrestrial mammals, reptiles and birds. Compared to the abundance of surveys that have examined Giardia and Cryptosporidium in terrestrial wildlife species, very few studies on either parasite have been undertaken on marine mammal species. Studies of shellfish, marine waters and water treatment plants clearly indicate that marine ecosystems are contaminated with Giardia and Cryptosporidium. In spite of these data the extent to which these parasites extend into the marine environment and how they may impact on marine mammal health remains largely unknown. The aim of this thesis was to expand our current knowledge of Giardia and Cryptosporidium in the marine environment and in particular, the harp and hooded seal populations of the Gulf of St. Lawrence, Canada. A large-scale serological survey of a large cohort of serum samples clearly show that, as is the case with terrestrial mammals, Giardia is ubiquitous in the marine environment. Sera positive for G. duodenalis-specific IgG were detected in almost all cetacean and pinniped species examined, and from all regions of the St. Lawrence estuary, Gulf of St. Lawrence and from the Canadian arctic. In the case of harp and hooded seals, they are actively infected with Assemblage A, a zoonotic strain of G. duodenalis and represent a previously unrecognised contributor to the overall environmental parasite burden. The discovery of this variant of Giardia in a phocid host, along with their susceptibility to infection with terrestrial strains of both Giardia and Cryptosporidium, highlight the potential zoonotic transmission from seals to humans through the consumption of uncooked intestines and general animal handling during research or hunting practices. The identification of this zoonotic strain of Giardia in seals also demonstrates the potential for anthropogenic activities such as human sewage treatment and agriculture runoff to be a significant source of contamination for marine mammals.

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Ruoppolo, Valeria. "Patologia comparada de cetáceos e pinípedes." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/10/10133/tde-26072007-102327/.

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O conhecimento das causas de morbidade e mortalidade dos mamíferos aquáticos pertencentes à ordem Cetacea e subordem Pinnipedia no Brasil é escasso. Este trabalho teve por objetivo caracterizar as principais causas que contribuem para a morte destes animais, incluindo dentre outras as enfermidades infecciosas, parasitárias, traumáticas, metabólicas e nutricionais. Foram analisadas amostras provenientes de necropsias de 110 indivíduos oriundos de encalhes naturais e capturas acidentais em redes de pesca ocorridos na costa sul e sudeste do Brasil. Ocasionalmente, amostras de cetáceos e pinípedes provenientes de centros de reabilitação, zoológicos, aquários e oceanários também foram analisadas. As amostras consistiram de fragmentos de 1 a 2 cm3 dos órgãos principais acondicionados em formalina a 10%. As afecções foram diagnosticadas através de exames anatomopatológicos, associados, quando possível a resultados microbiológicos e parasitológicos. Dos diagnósticos finais elucidados para os cetáceos 88,6% (70/79) tiveram a morte relacionada com o sistema respiratório, 3,8% (3/79) de origem metabólica, 2,5% (2/79) de etiologia infecciosa, 1,3% (1/79) com origem traumática antropogênica e em 3,8% (3/79) foi indeterminada. Nos pinípedes as causas de morte também estiveram relacionadas principalmente com o trato respiratório (48,5% - 15/31). A morte decorrente de outras causas incluiu: 29,1% (9/31) de causas metabólicas; 3,2% (1/31) nutricional; 3,2% (1/31) digestivo; 3,2% (1/31) urinário; 3,2% (1/31) físico; 3,2% (1/31) síndrome, colapso; 3,2% (1/31) vandalismo; 3,2% (1/31) indeterminado. A análise parasitológica foi realizada em 15,4% (17/110) dos casos e a bacteriologia em 10,9% (12/110) dos casos. As interpretações anatomopatológicas foram associadas aos demais resultados, quando presentes, e então analisados conforme informações recentes de literatura relativas ao assunto. As amostras utilizadas na realização deste projeto complementam o banco de tecidos de animais selvagens mantido pelo Laboratório de Patologia Comparada de Animais Selvagens da FMVZ, formando dessa forma o primeiro acervo de tecidos de mamíferos marinhos disponível no Brasil. Os resultados alcançados neste estudo reforçam a necessidade da abordagem multidisciplinar dos animais encalhados e também dos capturados acidentalmente em redes de pesca, buscando informações que possam colaborar para uma maior compreensão dos processos patológicos que os acometem e os predispõe à morte.
The known causes of morbidity and mortality of aquatic mammals belonging to the Order Cetacea and Suborder Pinnipedia in Brazil is limited. The aim of this work was to characterize the main processes that contribute to or cause the death of these animals, and included investigating infectious, parasitic, traumatic, metabolic and nutritional diseases. Samples coming from 110 fresh animals were analyzed, including individuals from strandings and incidentally caught in fishing nets along the south and southeastern coasts of Brazil. Circumstantially, carcasses coming from zoological collections, aquariums and rehabilitation centers were also included. The samples consisted of fragments of 1-2 cm3 taken of the main organs and fixed in 10% formalin. All the tissues have been processed according to routine histological procedures and analyzed under light microscopy. Diseases were diagnosed through anatomopathologic examinations, associated, whenever possible, with microbiologic and parasitologic results and then compared to related bibliography. Final results, mentioning the cause of the death, included: cetaceans: 88,6% (70/79) had lesions associated with the respiratory tract; 3,8% (3/79) of metabolic origin, 2,5% (2/79) of infectious etiology, 1,3% (1/79) were human related injuries, and 3,8% (3/79) of the cases were undetermined. For the pinnipeds the main cause of death was also related to the respiratory tract (48,5% - 15/31). The causes of death implicated in the other cases included: 29,1% (9/31) metabolical causes; 3,2% (1/31) nutritional origin; 3,2% (1/31) digestive causes; 3,2% (1/31) urinary tract; 3,2% (1/31) physical causes; 3,2% (1/31) syndrome; 3,2% (1/31) human related injuries; 3,2% (1/31) were undetermined. Parasitological analyses were performed in 15,4% (17/110) of the cases and bacteriology in 10,9% (12/110). The samples utilized in this project were stored to create a tissue bank for further studies. The results achieved in this work reinforce the need for a multidisciplinary view of stranded and by-caught animals, searching for information that can collaborate to better understand the pathologic processes affecting marine mammals and predisposing their death.

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Sanfelice, Daniela. "Ontogenia craniana comparada de Arctocephalus australis, Callorhinus ursinus e Otaria byronia (Otariidae: Pinnipedia)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/15623.

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The search for mechanisms that can generate major morphological changes has led to the study of ontogeny, in part because some kinds of modifications of ontogenies seem an excelent way to generate major phenotypic change. We focus here on Arctocephlaus australis, Callorhinus ursinus and Otaria byronia with the aim of contributing to the understanding of the origin, structure and temporal patterns of otarid morphological diversity. The pattern of change in shape during postnatal development in otarid skull was studied and described by geometric and traditional morphometrics. Our aims are: to compare the skull ontogeny of the species invocated in identifying and in describing shape alterations in the skull; to evaluate and to describe comparatively the sexual dimorphism and disparity during the ontogeny; to study the covariance between size and shape in relationship with age-groups; to investigate the changes in the ontogeny and their relationships with the evolution of the Otariidae Family; to analyze the conservation of ontogenetic trajectories over time, between sexes and among species; to characterize growth trajectories and to compare them among taxa with respect to isometry; to describe the parameters of growth and development of the focused species and to compare the two different approaches employed. Using traditional morphometrics, the allometry vectors for all species were significantly different from isometry. Dimorphism in the allometric vector is observed only in O. byonia and the difference between males and females of the fur seals are related with adult body size. The comparisons species/sex groups revealed similar vectors (any significant shape disassociation are verified in the inter-specific analyzes), suggesting lower plasticity of the ontogenies. Using geometrical methods, the dimorphism is more conspicuous in adult shapes but this is not true for the level of disparity between sexes of O. byronia. Although that dimorphism is linked with size this is not only a question of scaling or allometry (which is present in the morphogenesis of all species, especially in O. byronia). Additionally, the slopes of changes in shape related with size increase are different in A. australis and O. byronia, but are equal in C. ursinus, which is the smaller species. We suggest post-displacement as one of the factors that could have acted in the origin of the sexual dimorphism in the skull of C. ursinus. Heterochrony, perhaps is present in the roots of the modifications suffered by the ontogeny of A. australis and O. byronia too, considering the differences in the rates of development between the sexes of both species (and overall in O. byronia), but surely repatterning allometric is involved too in these cases. We verified that ontogenies can not be summarized by a single linear vector in any analyzed group, where C. ursinus ontogeny is the more linear and O. byronia the more multi-dimensional species among the 3 that we had examined. Shape changes in the otarids studied here are more related with size than with age and any of the species share a common growth allometry or a common ontogenetic trajectory/pattern. In the same way, shapes at onset or offset are not the same in any case. When the three species are pooled together, initial shapes are always very different among the species and the distances between shapes increase with time almost independently from size. On the other hand, when the complete samples are considered, all the ontogenetic trajectories are significantly different in the directions of the allometric vectors during ontogeny. Ontogenetic trajectories differ significantly among almost all the pairs compared, except for the trajectories of A. australis and C. ursinus males. They are no more different than expected by chance considering the range of angles within each sample. A similar pattern is found when the subadults are compared between pairs of species and when we compare adult males of A. australis with adult males of O. byronia. The juveniles are no more different than expected by chance (correlation between ontogenies in that phase is equal to one), excepti between C. ursinus and O. byronia. The ontogenetic trajectory of C. ursinus is the shorter and of O. byronia is the longer being almost three times longer than the former. A. australis has an intermediary length of ontogenetic trajectory. For the sample comprising all three species disparity increase significantly over ontogeny since the disparity of the adults is near the two times of the disparity between juveniles. For any ontogenetic stage, O. byronia is the species that contributes for the disparity of the all group, followed by C. ursinus. When we consider the three species together, the pattern of disparity do not change a lot during ontogeny. Ontogenies examined herein are clearly not constrained and perhaps the differences in patterns have additive effects in the differentiation of the ontogenies. Whether ontogenetic trajectories are linear or curve could be a function of developmental timing or more specifically it could depend on the age at which allometries stabilize in post-natal ontogenies. Otherwise, the amount of differences between species in the ontogenies is in agreement with the phylogenetic relationships. Finally, we addressed basically the following questions: Is onset time the same in the species? Is offset time the same in these species? Does growth rate differ between the species. The answer to those questions could be summarized by the conclusion. but we conclude that the changes in otarids skull ontogenies had occurred in spatial and temporal terms.

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Appelbee, Amber Justine. "Giardia and Cryptosporidium in pinnipeds from the Gulf of St. Lawrence, Canada /." Access via Murdoch University Digital Theses Project, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070327.152130.

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Drehmer, César Jaeger. "Variação geográfica em Otaria byronia (de Blainville, 1820) (Pinnipedia, Otariidae) com base na morfometria sincraniana." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2005. http://hdl.handle.net/10183/8135.

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Otaria byronia (de Blainville, 1820), o leão-marinho sul-americano é uma espécie de otarídeo amplamente distribuída pela costa da América do Sul. No oceano Atlântico estende-se desde o sul do Brasil, passando pelo Uruguai até o sul da Argentina e no oceano Pacífico, ao longo das costas do Chile e do Peru. Estudos prévios indicam a possibilidade de existência de diferenças geográficas entre as unidades populacionais dessa espécie. No presente trabalho objetiva-se identificar a existência de variação geográfica e avaliar a intensidade da mesma. Para tal, utilizou-se a morfometria sincraniana com base em morfometria tradicional – 41 medidas abrangendo o crânio e o dentário e também a técnica da morfometria geométrica com base na configuração de marcos anatômicos para quatro vistas distintas – dorsal, palatal, lateral e mandibular medial. Utilizaram-se apenas espécimes adultos identificados através do comprimento côndilo-basal. Machos e fêmeas foram tratados separadamente devido ao intenso dimorfismo sexual na morfologia sincraniana. Utilizaram-se inicialmente testes t para identificar diferenças entre os grupos, dividindo-os de acordo com a distribuição geográfica das unidades populacionais, gerando um total de 4: Atlântico Segmento I (Sul do Brasil Uruguai e província de Buenos Aires), Atlântico Segmento II (Patagônia da Argentina), Pacífico Segmento I (Peru) e Pacífico Segmento II (Chile). Através de uma ANOVA sobre as medidas tradicionais e sobre o tamanho do centróide, bem como de uma MANOVA sobre a configuração de marcos anatômicos, foi possível identificar diferenças nas médias desses quatro grupos. Caracterizou-se uma forte variação geográfica, onde a variação entre os grupos sempre foi maior do que a variação dentro dos grupos. As diferenças entre os grupos de fêmeas do Pacífico são maiores do que as diferenças entre os grupos do Atlântico; já em machos as diferenças entre os grupos do Pacífico foram menores do que entre os grupos do Atlântico. Quando analisados em conjunto os dados das unidades populacionais do Pacífico em comparação com o Atlântico, estas diferenças permanecem. Utilizando técnicas exploratórias como Análise de Componentes Principais e Análise Discriminante, tanto para morfometria tradicional quanto para morfometria geométrica, foi possível caracterizar as unidades populacionais de forma mais consistente, bem como mensurar as diferenças entre estas. Os resultados obtidos confirmam as diferenças encontradas nas análises anteriores. A morfometria craniana indica a existência de quatro unidades populacionais para Otaria byronia, duas no Pacífico e duas no Atlântico, sem que haja isolamento geográfico entre estes grupos, uma vez que tanto a corrente das Malvinas no Atlântico como a corrente de Humboldt no Pacífico são grandes vias de deslocamento entre estas unidades populacionais, bem como o extremo-sul da América do Sul no qual os canais do Estreito de Magalhães não devem ser barreira para o intercâmbio, ainda que limitado, de indivíduos entre os oceanos. Este intercâmbio está diretamente relacionado com a capacidade de dispersão de machos e fêmeas e com aspectos da dinâmica populacional desta espécie. Algumas limitações, entretanto, impedem que se avance em direção a alguma conclusão taxonômica em nível de subespécies, embora a craniometria esteja a indicar uma clara tendência à separação das unidades populacionais, especialmente quando comparadas as do Atlântico com as do Pacífico.

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Gundlach, Neele Hendrika [Verfasser]. "Untersuchung zur Stressbelastung von Robben (Pinnipedia) und Rindern: Entwicklung und Validierung eines Belastungsindex / Neele Hendrika Gundlach." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2015. http://d-nb.info/1080797726/34.

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Stewardson, Carolyn Louise, and carolyn stewardson@anu edu au. "Biology and conservation of the Cape (South African) fur seal Arctocephalus pusillus pusillus (Pinnipedia: Otariidae) from the Eastern Cape Coast of South Africa." The Australian National University. Faculty of Science, 2002. http://thesis.anu.edu.au./public/adt-ANU20030124.162757.

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[For the Abstract, please see the PDF files below, namely "front.pdf"] CONTENTS. Chapter 1 Introduction. Chapter 2 Gross and microscopic visceral anatomy of the male Cape fur seal with reference to organ size and growth. Chapter 3 Age determination and growth in the male Cape fur seal: part one, external body. Chapter 4 Age determination and growth in the male Cape fur seal: part two, skull. Chapter 5 Age determination and growth in the male Cape fur seal: part three, baculum. Chapter 6 Suture age as an indicator of physiological age in the male Cape fur seal. Chapter 7 Sexual dimorphism in the adult Cape fur seal: standard body length and skull morphology. Chapter 8 Reproduction in the male Cape fur seal: age at puberty and annual cycle of the testis. Chapter 9 Diet and foraging behaviour of the Cape fur seal. Chapter 10(a) The Impact of the fur seal industry on the distribution and abundance of Cape fur seals. Chapter 10(b) South African Airforce wildlife rescue: Cape fur seal pups washed from Black Rocks, Algoa Bay, during heavy seas, December 1976. Chapter 11(a) Operational interactions between Cape fur seals and fisheries: part one, trawl fishing. Chapter 11(b) Operational interactions between Cape fur seals and fisheries: part two, squid jigging and line fishing. Chapter 11(c) Operational interactions between Cape fur seals and fisheries: part three, entanglement in man-made debris. Chapter 12 Concentrations of heavy metals (Cd, Cu, Pb, Ni & Zn) and organochlorine contaminants (PCBs, DDT, DDE & DDD) in the blubber of Cape fur seals. Chapter 13 Endoparasites of the Cape fur seal. Chapter 14(a) Preliminary investigations of shark predation on Cape fur seals. Chapter 14(b) Aggressive behaviour of an adult male Cape fur seal towards a great white shark Carcharodon carcharias. Chapter 15 Conclusions and future directions.

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Saporiti, Fabiana. "Cambios en la ecología trófica de los depredadores apicales del Mar Argentino durante el Holoceno." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/284582.

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El Mar Argentino ha sufrido un impacto humano creciente desde el Holoceno medio hasta hoy en día, fruto del cual se han producido importantes cambios en los niveles más altos de la red trófica. Las actividades extractivas (caza y pesca), tanto la aborigen como la actual, tienen la tendencia a explotar las especies de mayor tamaño, produciendo el efecto conocido en gestión de pesquerías como “fishing down the food web”. En otras palabras el impacto humano llevaría a cadenas tróficas más cortas como consecuencia de la extinción de los depredadores apicales. Sin embargo, las especies que sobreviven a la explotación, si bien reducidas drásticamente en número de individuos, permanecen en el ecosistema y desempeñan un papel trófico. En esta tesis se han analizado los cambios que ocurrieron en la red trófica del Mar Argentino durante el Holoceno medio y tardío como consecuencia de la actividad humana, centrándose principalmente en dos de sus depredadores más abundantes: el lobo marino común (Otaria flavescens) y el lobo marino fino (Arctocephalus australis). Por un lado se observó que los cazadores-recolectores no tuvieron un impacto relevante sobre los patrones de uso del hábitat y alimentación de estas dos especies, ya que durante todo el Holoceno no se produjeron apenas cambios en sus dietas. Sin embargo, sí variaron los patrones de explotación de pinnípedos por parte de los aborígenes, seguramente como consecuencia de cambios en la producción primaria marina que debido a una posible sobreexplotación de los pinnípedos. No hay duda, por el contrario, de que los cambios radicales en la dieta de ambas especies de lobos marinos observados hace unos 150 años fueron la consecuencia de su extinción virtual en el Mar Argentino entre los siglos XVIII y XX. A la vez que las dietas cambiaron, la red trófica se alargó y se hizo menos redundante. Estos sorprendentes resultados se pueden interpretar como la respuesta de los depredadores apicales a la disminución de la presión intraespecífica generada por la explotación humana. Los estudios históricos como la presente tesis pueden ayudar a comprender los mecanismos que actúan en ecosistemas perturbados por la actividad humana y ofrecer una perspectiva más amplia para su restauración.
The Argentine Sea has suffered increasing human impact from the middle Holocene until today, and significant changes in high levels of the marine food web are the result of such an impact. Both aboriginal and industrial exploitation of marine resources (hunting and fishing) are characterised by the preferential removal of the largest species, a process that is supposed to shorten size-structured marine food webs. This process is known in fisheries management as "fishing down the food web" because the human impact would shorten the food chains as a result of the extinction of the top predators. However, the species that are not extinguished remain in the ecosystem and play a trophic role, although they are drastically reduced in number. This thesis analyzed the changes that occurred in the food web of the Argentine Sea during the middle and late Holocene as a result of human activity, mainly focusing on two of its most abundant predators: the South American sea lion (Otaria flavescens) and the South American fur seal (Arctocephalus australis). It was observed that hunter-gatherers did not have a significant impact on habitat use patterns and trophic ecology of these two species, since there were no changes in their diets throughout the Holocene. However, the patterns of exploitation of pinnipeds by aborigines varied through time, probably as a result of changes in marine primary productivity more than overexploitation of pinnipeds by hunter-gatherers. There is no doubt, however, that the radical changes observed about 150 years ago in the diet of both sea lion and fur seal were the result of their virtual extinction in the Argentine Sea between the 18th and 20th century, during the fur trade. While diets changed the food web became longer and less redundant. These surprising results can be interpreted as the response of top predators to the decrease of the intraspecific pressure generated by the human impact. Historical studies such as this thesis may help to understand the mechanisms playing in ecosystems disturbed by human activity and provide a broader perspective for their restoration.

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Bryant, Edmund Bernard. "Radio tracking of pinnipeds." Thesis, University of Sheffield, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364311.

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Holt, Maria M. "Spatial auditory processing in pinnipeds /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2006. http://uclibs.org/PID/11984.

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Murphy, Christin Taylor. "Structure and Function of Pinniped Vibrissae." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4733.

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The vibrissal system of pinnipeds relies on sturdy, specialized vibrissae and supporting neural architecture apparently designed for the reception of waterborne disturbances. Although it is known that pinnipeds can use their vibrissae for fine-scale tactile discrimination and hydrodynamic detection, many aspects of vibrissal function remain poorly understood. The present work examined the adaptive significance of vibrissal structure, the sensitivity of the vibrissal system, and the signals received by this system. All of these points were considered with respect to their function in hydrodynamic reception. Four methods of study: laser vibrometry, computed tomography (CT) scanning, psychophysical testing and animal-borne tagging were used to investigate the functioning of this sensory system. Laser vibrometer recordings were used to investigate the effect of vibrissal surface structure and orientation on flow-induced vibrations in excised vibrissae. Vibrations were recorded from the shaft of excised vibrissae exposed to laminar water flow in a flume tank. Samples from three pinniped species were tested: the harbor seal (Phoca vitulina), northern elephant seal (Mirounga angustirostris) and California sea lion (Zalophus californianus). The vibrissae of the seals had an undulated surface structure, while the vibrissae of the sea lion had a smooth surface. No significant difference between species, and therefore surface structure, was observed. However, when vibrissae were tested at three angles of orientation to the water flow, a strong effect of orientation on vibration frequency and velocity was observed across species. CT scanning data revealed that the vibrissae of all the species tested had flattened cross-sectional profiles. This cross-sectional flattening could account for the observed orientation effects. Furthermore, this morphological characteristic may represent an adaptation for improved functioning in the aquatic environment by reducing self-induced-noise from swimming and potentially enhancing detection of signals from other planes. Psychophysical testing was conducted with a trained harbor seal in order to investigate the sensitivity of the vibrissal system of this species. A behavioral procedure was used to measure absolute detection thresholds for sinusoidal stimuli delivered to the vibrissae by a vibrating plate. Thresholds were measured at 9 discrete frequencies from 10 to 1000 Hz. The seal's performance in this stimulus detection task showed that the vibrissal array was sensitive to directly coupled vibrations across the range of frequencies tested, with best sensitivity of 0.09 mm/s at 80 Hz. The velocity thresholds as a function of frequency showed a characteristic U-shaped curve with a gradual low-frequency roll-off below 80 Hz and a steeper high-frequency roll-off above 250 Hz. The thresholds measured for the harbor seal in this study were about 100 times more sensitive than previous in-air measures of vibrissal sensitivity for this species. The results were similar to those reported by others for the detection of waterborne vibrations, but show an extended range of frequency sensitivity. Animal-borne tagging methods were used to investigate the signals received by the vibrissae and better understand the relevant signal components involved in hydrodynamic detection. A novel tagging system, wLogger, was developed to record vibrations directly from a vibrissa by means of an accelerometer coupled to the vibrissal shaft. Laboratory testing using excised whiskers in a water flume confirmed that the tag is capable of recording vibrational signals without hampering the natural movement of the vibrissa. In addition, the tag successfully measured vibrations from the vibrissae of a harbor seal during active swimming and hydrodynamic detection. Live animal testing, along with the supplemental recordings from excised vibrissae, revealed that interaction with hydrodynamic disturbances disrupted the vibrational signal received by the whisker. When exposed to a hydrodynamic signal, whisker vibrations increased in bandwidth, spreading energy across a wider range of frequencies. This finding suggests that modulation of the vibrational signal may play a key role in the detection of hydrodynamic stimuli by the seal. The results of this dissertation research provide insight into the functioning of the vibrissal system in pinnipeds and establishes the groundwork for future pathways of investigation. By investigating the vibrissal system from the focal points of structure, sensitivity and received signals, a more comprehensive understanding of this refined sensory modality is emerging.

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Edwards, Mickie Rae. "Peruvian Pinnipeds as Archivists of ENSO Effects." Thesis, NSUWorks, 2018. https://nsuworks.nova.edu/occ_stuetd/495.

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Environmental fluctuations in the eastern Pacific Ocean are reflected in the tissues of some of its most vulnerable apex predators, the Peruvian fur seal (PFS) Arctocephalus australis ssp.and the South American sea lion (SASL) Otaria byronia.These large pinnipeds live in sympatry along the Pacific coastline of South America and forage within the neritic waters over the continental shelf. The coastal waters off Peru are a region of great environmental fluctuations due to periodic, oscillating El Niño- La Niña- Southern Oscillation (ENSO) events, which result in ecosystem-wide food web changes. Pinniped vibrissae (whiskers) are continuously growing keratinous tissues and reflect the incorporation of prey from the region. Fine resolution sampling along their length provided trophic information on a weekly to monthly time scale over several years. Vibrissae were obtained from 2010-2016 from female (n=47), male (n=17) and newborn pup (n=6) fur seals and male (n=6) sea lions collected during pinniped rookery health assessments. Stable isotope ratios (δ13C and δ15N) in vibrissae infer temporal primary production and dietary variations in individuals. ENSO conditions were dictated by the sea surface temperature anomaly (SSTA) recordings from the Niño 1+2 Index region over 12 years. Fluctuations in vibrissae δ15N were correlated to varying SSTA readings (p15N (p15N signatures (p13C revealed minor fluctuations ranging from -18.13 to -13.17‰over the 12-year period, δ13C did reveal a significant depletion and enrichment oscillation during specific points in time, such as the 2014-2016 El Niño event, which ranged from -15.09 to -13.83‰(p=0.040). Stable isotope signatures varied between genders, but not by species. Female fur seal stable isotope signatures were significantly more depleted in both δ13C and δ15N than males (p13C and δ15N were inversely correlated to each other from 2014 to 2016; this was during the strongest El Nino-Southern Oscillation event on record (p=0.002). As δ13Csignatures became more enriched, δ15N signatures depleted from 2014 until 2016. This suggests that when ENSO warm phase conditions occur, the environments resources change in historic foraging grounds, possibly forcing pinnipeds to travel farther distances offshoreto forage or altering what they feed on throughout these stressful conditions.This study serves to help understand of the impact of oceanographic influences on these pinnipeds.ENSO conditions influence the trophic dynamics and resultant survival adaptations in both of these vulnerable Peruvian marine mammals.

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Jurczynski, Kerstin. "Tuberculosis in South American sea lions (Otaria flavescens) - diagnostic options and its epidemiologic importance for other mammals within the zoological garden." Doctoral thesis, Universitätsbibliothek Leipzig, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-99710.

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Tuberculosis is a widely spread zoonotic disease caused by acid-fast bacteria of the Mycobacterium tuberculosis complex in a variety of mammalian species. In pinnipeds, tuberculosis has been reported in different captive and wild sea lions and fur seals. The causative agent, Mycobacterium pinnipedii, is part of the M. tuberculosis complex and has shown pathogenicity in other mammalian species including human beings. Since 2000 the Heidelberg zoo has been dealing with tuberculosis in its collection of South American sea lions (Otaria flavescens). After a Malayan tapir (Tapirus indicus) was transferred to a zoological institution in France it transmitted the disease to the other tapirs that succumbed to tuberculosis. Culturing and spoligotyping confirmed the origin, the sea lions at the Heidelberg zoo. An investigation of the sea lion group housed at Heidelberg in addition to different species of mammals living in adjacent exhibits as well as a sea lion, born in Heidelberg but then living in Hamburg, revealed multiple cases of pinniped tuberculosis.

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Kinnear, Mark William B. "Evolution of the SRY gene in the Pinnipeds." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620052.

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Muslow, Jason. "Electrophysiological and psychophysical assessment of aerial hearing in pinnipeds /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2009. http://uclibs.org/PID/11984.

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Browne, Patience. "Some aspects of the reproductive physiology of otariid pinnipeds /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.

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Thesis (Ph. D.)--University of California, Davis, 2004.
Degree granted in Molecular, Cellular, and Integrative Physiology. Includes bibliographical references. Also available via the World Wide Web. (Restricted to UC campuses)

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18

Costa, Helena Sofia Gomes. "Molecular and phylogenetic analysis of parapoxvirus in north American pinnipeds." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2019. http://hdl.handle.net/10400.5/18138.

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Dissertação de Mestrado Integrado em Medicina Veterinária
Parapoxvirus causes nodular lesions in the skin and mucosal membranes of diverse species of pinnipeds, worldwide. Seal parapoxvirus is currently categorized as a tentative species of the Parapoxvirus genus. Between 2009 and 2018, 22 samples were collected from 12 pinnipeds representing 5 different species (grey seal, harp seal, harbor seal, California sea lion and northern elephant seal) with clinical suspicion of parapoxvirus infection, from rehabilitation facilities on the east and west coast of the United States of America. The aims of this study were to confirm the presence of parapoxvirus in the clinical samples by PCR, to resolve evolutionary relationships to other members of the genus and to determine whether pinnipeds from different species and locations are infected with the same parapoxvirus strains. Parapoxvirus DNA was detected in 11 of the 12 animals. The sequence analysis showed that the parapoxvirus sequences from the seal samples differed significantly from parapoxviruses found in terrestrial hosts and that the pinniped parapoxviruses formed a separated cluster within the genus. Five distinct parapoxvirus variants were detected. Parapoxviruses from harbor seals from the Atlantic and Pacific coast clustered separately, indicating different virus variants in the two subspecies. One variant of parapoxvirus was found in both a California sea lion (Otariidae family) and a northern elephant seal (Phocidae family) housed in the same facility. Therefore, the results of this study support the classification of Seal parapoxvirus as a separate species within the genus Parapoxvirus and give further insight into the phylogenetic relationships between the different circulating Seal parapoxvirus strains.
RESUMO - Análise molecular e filogenética de parapoxvirus em pinípedes norte-Americanos - Os parapoxvírus causam lesões nodulares na pele e mucosa de diferentes espécies de pinípedes, por todo o mundo. O Seal parapoxvirus ainda não se encontra incluído como uma espécie do género Parapoxvirus. Entre 2009 e 2018, foram colhidas 22 amostras de 12 pinípedes de 5 espécies diferentes (foca cinzenta, foca da Groenlândia, foca-comum, leão-marinho Californiano e elefante marinho do norte) com suspeita clínica de infecção por parapoxvírus, internados em diferentes em centros de recuperação nas costas Este e Oeste dos Estados Unidos da América. Os objectivos deste trabalho consistiram em confirmar a presença de parapoxvírus nas amostras por PCR, estudar a relação evolutiva deste vírus com outros membros do género e determinar se pinípedes de diferentes espécies e locais estão ou não infectados com a mesma variante de parapoxvírus. Foi detectado ADN de parapoxvírus em 11 dos 12 animais. A análise das sequências revelou que as sequências virais obtidas a partir das amostras de focas diferiram significativamente dos parapoxvírus encontrados em hospedeiros terrestres e que os parapoxvírus dos pinípedes formaram um agregado separado dentro do género. Foram detectadas cinco variantes distintas de parapoxvirus. Parapoxvírus da espécie foca-comum da costa do Atlântico e do Pacífico agruparam-se separadamente, indicando diferentes variantes de vírus nas duas subespécies. Uma variante de parapoxvirus foi detectada tanto num leão-marinho Californiano (família Otariidae) como num elefante marinho do norte (família Phocidae) alojados na mesma instalação. Desta forma, os resultados deste estudo suportam a classificação do Seal parapoxvirus como uma nova espécie pertencente ao género Parapoxvirus e fornecem uma visão adicional sobre as relações filogenéticas entre as diferentes variantes circulantes de parapoxvírus de pinípedes.
N/A

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19

Kuhn, Carolin Verfasser], and Eberhard [Akademischer Betreuer] [Frey. "Evolution pinnipeder Carnivora - eine konstruktionsmorphologische Fallstudie / Carolin Kuhn. Betreuer: E. Frey." Karlsruhe : KIT-Bibliothek, 2015. http://d-nb.info/1081213108/34.

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Kuhn, Carolin [Verfasser], and Eberhard [Akademischer Betreuer] Frey. "Evolution pinnipeder Carnivora - eine konstruktionsmorphologische Fallstudie / Carolin Kuhn. Betreuer: E. Frey." Karlsruhe : KIT-Bibliothek, 2015. http://d-nb.info/1081213108/34.

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21

Kuhn, Carey Elizabeth. "Measuring at sea feeding to understand the foraging behavior of pinnipeds /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2006. http://uclibs.org/PID/11984.

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22

Appelbee, Amber. "Giardia and Cryptosporidium in pinnipeds from the Gulf of St. Lawrence, Canada." Thesis, Appelbee, Amber (2006) Giardia and Cryptosporidium in pinnipeds from the Gulf of St. Lawrence, Canada. PhD thesis, Murdoch University, 2006. https://researchrepository.murdoch.edu.au/id/eprint/74/.

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Giardia and Cryptosporidium are protozoan parasites known to cause enteric disease in terrestrial mammals, reptiles and birds. Compared to the abundance of surveys that have examined Giardia and Cryptosporidium in terrestrial wildlife species, very few studies on either parasite have been undertaken on marine mammal species. Studies of shellfish, marine waters and water treatment plants clearly indicate that marine ecosystems are contaminated with Giardia and Cryptosporidium. In spite of these data the extent to which these parasites extend into the marine environment and how they may impact on marine mammal health remains largely unknown. The aim of this thesis was to expand our current knowledge of Giardia and Cryptosporidium in the marine environment and in particular, the harp and hooded seal populations of the Gulf of St. Lawrence, Canada. A large-scale serological survey of a large cohort of serum samples clearly show that, as is the case with terrestrial mammals, Giardia is ubiquitous in the marine environment. Sera positive for G. duodenalis-specific IgG were detected in almost all cetacean and pinniped species examined, and from all regions of the St. Lawrence estuary, Gulf of St. Lawrence and from the Canadian arctic. In the case of harp and hooded seals, they are actively infected with Assemblage A, a zoonotic strain of G. duodenalis and represent a previously unrecognised contributor to the overall environmental parasite burden. The discovery of this variant of Giardia in a phocid host, along with their susceptibility to infection with terrestrial strains of both Giardia and Cryptosporidium, highlight the potential zoonotic transmission from seals to humans through the consumption of uncooked intestines and general animal handling during research or hunting practices. The identification of this zoonotic strain of Giardia in seals also demonstrates the potential for anthropogenic activities such as human sewage treatment and agriculture runoff to be a significant source of contamination for marine mammals.

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Appelbee, Amber. "Giardia and Cryptosporidium in pinnipeds from the Gulf of St. Lawrence, Canada." Appelbee, Amber (2006) Giardia and Cryptosporidium in pinnipeds from the Gulf of St. Lawrence, Canada. PhD thesis, Murdoch University, 2006. http://researchrepository.murdoch.edu.au/74/.

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Giardia and Cryptosporidium are protozoan parasites known to cause enteric disease in terrestrial mammals, reptiles and birds. Compared to the abundance of surveys that have examined Giardia and Cryptosporidium in terrestrial wildlife species, very few studies on either parasite have been undertaken on marine mammal species. Studies of shellfish, marine waters and water treatment plants clearly indicate that marine ecosystems are contaminated with Giardia and Cryptosporidium. In spite of these data the extent to which these parasites extend into the marine environment and how they may impact on marine mammal health remains largely unknown. The aim of this thesis was to expand our current knowledge of Giardia and Cryptosporidium in the marine environment and in particular, the harp and hooded seal populations of the Gulf of St. Lawrence, Canada. A large-scale serological survey of a large cohort of serum samples clearly show that, as is the case with terrestrial mammals, Giardia is ubiquitous in the marine environment. Sera positive for G. duodenalis-specific IgG were detected in almost all cetacean and pinniped species examined, and from all regions of the St. Lawrence estuary, Gulf of St. Lawrence and from the Canadian arctic. In the case of harp and hooded seals, they are actively infected with Assemblage A, a zoonotic strain of G. duodenalis and represent a previously unrecognised contributor to the overall environmental parasite burden. The discovery of this variant of Giardia in a phocid host, along with their susceptibility to infection with terrestrial strains of both Giardia and Cryptosporidium, highlight the potential zoonotic transmission from seals to humans through the consumption of uncooked intestines and general animal handling during research or hunting practices. The identification of this zoonotic strain of Giardia in seals also demonstrates the potential for anthropogenic activities such as human sewage treatment and agriculture runoff to be a significant source of contamination for marine mammals.

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Liori, Ourania. "Development and application of non-destructive biomarkers for biomonitoring endocrine disruption in pinnipeds." Thesis, Kingston University, 2006. http://eprints.kingston.ac.uk/20378/.

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Over the past years there has been an increased concern regarding widespread pollution of the environment with persistent organic pollutants (POPs) that biomagnify and bioaccumulate along the food chain. Marine mammals, especially seals being top predators of the marine food chain, are significantly exposed to biomagnified levels of POPs that bioaccumulate in the blubber which acts as a reservoir for these lipophilic compounds. POPs have been associated with a number of pathological changes in the seals, thus early detection of the adverse health effects resulting from pollutant exposure is vital, since exposure may cause irreversible damage to entire populations or ecosystems in the long term. Biomonitoring studies to investigate changes in fecundity of marine mammal populations due to exposure to POPs are needed. Biological indicators (biomarkers) that reflect the exposure levels or toxic effects of the contaminant load in wildlife populations can be used as early warning system for the reproduction and survival of the animals with non-destructive or minimal invasion. The aim of this study was to research and develop new and existing exposure and effect biomarkers for biomonitoring endocrine disruption in Ringed (Phoca hispida), Grey (Halichoerus grypus) and Harbour (Phoca vitulina) seals from different geographical areas using non-destructive/non-invasive sampling. Sex steroids, lactoferrin and blood chemistry parameters were investigated ill seal faecal and serum samples as potential biomarkers. Exposure level (PCBs, DDT, PBDEs) was determined using chromatographic and immunoassay techniques. Estrogens in the exposed populations showed a negative correlation with contaminant exposure and higher LTF, glucose and lipoprotein levels showed a positive correlation with contaminant exposure and negative correlation with sex steroids, thus they are proposed as biomarkers of endocrine disruption. This is the first study to quantify and measure LTF as well as sex steroids in seal faecal samples and to investigate their correlation with environmental exposure and the promising results justify further research in this area. Since the biomarkers in this study are influenced by endogenous hormones it is recommended that they should be used in conjunction with sex steroids.

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Bishop, Amanda Marie. "Behavioural mechanisms of conflict and conflict reduction in a wild breeding polygynous pinniped." Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11146/.

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Aggressive interactions arise as a means of resolving access to resources such as food, habitat or mates, but these interactions are often costly in time, energy, or physical damage. Therefore, natural selection favours social systems, spatial organisations and behavioural mechanisms which can balance the trade-offs between conflict and increasing fitness. The diversity of behaviours associated with animal conflict has been investigated in a variety of species; however, rarely are these investigations done in wild systems or with consideration of geographic and intra-seasonal variation in environmental factors, resource availability or social dynamics. Therefore, the aim of this thesis was to examine the behavioural mechanisms underpinning population and individual conflict and conflict reduction at a variety of temporal and spatial scales. I focused my investigation on a particular form of animal contest, male-male breeding aggression, and used the colonial, wild grey seal (Halichoerus grypus) as my model. Specifically, I studied males at Donna Nook, an atypical breeding colony, in order to: (1) update our current knowledge of grey seal breeding systems by comparing the behavioural patterns at recently expanding mainland colony to previously examined, offshore colonies, (2) investigate the information present in a geographically isolated behaviour used in male grey seal conflict, (3) identify the variation in assessment strategies used by individuals in grey seal conflict and conflict reduction, (4) examine how environmental, anthropogenic, and social environments shape individual variation in aggression, and (5) assess the individual variation in decision-making processes such as mating strategies within- and across seasons. Draws were identified as a common conflict outcome for male grey seals, and the acceptance of draws represented a behavioural mechanism which can promote conflict reduction. Assessment strategies relied on individual energetics when costs of conflict were high, but mutual assessment was used in low-cost contexts. Activity budgets were relatively conserved across colonies, and social stability played a key role in mediating conflict. These findings all demonstrate the trade-offs between conserving energy for reproductive activities and expending energy to ensure exploitation of resources. Methodological approaches which accounted for variation in individual partitioning of aggression and reproductive effort within- and between-seasons revealed that the relative importance of dominance as a driver of conflict, the use of specific aggressive behaviours, and broad assessment and mating strategies were all context-dependent at a variety of temporal and spatial scales. Overall, these findings have provided new insights into the evolution of conflict and conflict reduction within polygynous mating systems. This work highlights the importance of incorporating the natural environmental variation and social dynamics into models of individual behaviours. Such approaches not only reveal the plasticity or consistency in how individuals deal with tradeoffs, but they also allow for observing the importance of behavioural mechanisms such as draws, which might have been ‘artificially selected out’ in controlled, laboratory settings. Finally, by using the grey seal breeding system as a model, this work has contributed to our knowledge of this species’ behavioural repertoire, and the role of topography in the evolution of polygyny and aggression in pinnipeds.

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Fulham, Mariel. "Exploring the diversity of human-associated microbes and antimicrobial resistance in three species of Australian pinniped pups." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29850.

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Contamination of coastal marine environments with human-associated microbes and antibiotic resistance genes is continually increasing, impacting marine ecosystems and the wildlife species therein. Australian fur seals (Arctocephalus pusillus doriferus), long-nosed fur seals (Arctocephalus forsteri) and Australian sea lions (Neophoca cinerea) inhabit numerous coastal and offshore sites along the Australian coastline. The overarching aim of this thesis was to investigate the presence of human-associated Escherichia coli, an indicator of faecal contamination, and class 1 integrons, genetic determinants of antimicrobial resistance, in neonatal pinniped pups. Faecal samples were collected from A. p. doriferus, A. forsteri and N. cinerea pups from eight breeding colonies between 2016-2021. Escherichia coli was cultured from faecal swabs and DNA was subsequently extracted from E. coli isolates and a subset of faecal swabs. Phylotype diversity was not significantly different across species or breeding colonies and the human-associated E. coli B2 phylotype was the most prevalent phylotype across all species. Class 1 integrons were isolated from E. coli (n=36, 4.52%) and faecal DNA (n=15, 4.85%) in A. p. doriferus (n=40) and N. cinerea (n=11) pups but were absent in A. forsteri pups. Finally, the faecal microbiota of endangered N. cinerea pups was characterised to investigate the impact of anthelmintic treatment to eliminate hookworm infection on the composition of the gut microbiota. Topical treatment did not significantly change the microbial composition, suggesting that it is a safe and minimally invasive management strategy to aid in the conservation of endangered N. cinerea pups. The high prevalence of human-associated E. coli in addition to the detection of antimicrobial resistance genes highlights the imperative for ongoing monitoring and surveillance of microbes in marine sentinel species.

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Dixon, Katherine P. "The Influence of Disease and Climate on Pinniped Species at Local and Regional Scales." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1491654430053451.

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Jarman, Angela Kathleen. "The seal of approval: investigating the diets of otariids utilising the nutritional geometry framework." Thesis, The University of Sydney, 2019. https://hdl.handle.net/2123/21243.

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The mostly submerged lifestyle of otariids has provided a challenge in determining their dietary habits. Research on the prey species of Australian otariid species has increased and improved in recent years. Conventional prey selection theory is based on the view that carnivores select the highest energy food at the lowest energy cost. Recent research puts emphasis on the important role of optimising macronutrient intake in prey selection. The geometric framework allows for interpretation of how animals respond to their environment, and thus make consumption decisions. Nutritional guidelines for pinniped diets in captivity are loosely based on terrestrial carnivore models. Utilising the knowledge of prey consumed in the wild in conjunction with macronutrient preference in captivity will pave the way for otariid diets to be tailored to species and sex. Four otariid species (long-nosed fur seal Arctocephalus forsteri, Australian sea lion Neophoca cinerea, subantarctic fur seal Arctocephalus tropicalis and California sea lion Zalophus californianus) were provided with ad lib amounts of eight different prey items as a representation of selection decisions made by otariids in the wild. Macronutrient energy intake was tested for each otariid between seasons and sexes. Lipid energy intake was the discriminating factor between each otariid species, and by extension, between the sexes of the Australian sea lion. It is evident that there is disparity between the wild and captive macronutrient space for both the subantarctic fur seal and California sea lion. The geometric framework shows how an animal compensates when a diet of suboptimal macronutrient concentration is fed. For otariids to meet the optimal macronutrient target, they must be given the freedom to choose. In practice, these freedoms are often lost, and this means that zoos must make these decisions for the animal to ensure targets are met.

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Sweny, Jason Michael. "A comparison of diversity in the zfy gene in two species of pinnipeds with different breeding strategies." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3217.

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Sequence variation was examined for the Zinc-finger Y (zfy) gene and the mitochondrial control region for two species of pinnipeds, the Steller sea lion (Eumetopias jubatus) and harbor seal (Phoca vitulina). The two species differ in aspects of their breeding strategies, dispersal, and life histories. Comparable stock sample sizes of males from each species were taken from localities that span at least one wellrecognized phylogeographic stock as defined by mtDNA markers. Variation in zfy, a strictly paternally inherited marker located on the Y chromosome, was low in both species. An interesting pattern of subdivision was found for zfy in harbor seals that was concordant with population subdivision for mtDNA. In Steller sea lions, no such concordant pattern was evident with only a single rare zfy variant being observed. One explanation for the different patterns observed is that dispersal is less in male harbor seals than in male Steller sea lions.

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Levenson, David H. "The visual pigments of diving tetrapods : genetic and electroretinographic investigations of pinnipeds, cetaceans, sea turtles, and penguins /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3120446.

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Keech, Aaron L. "Fecal triiodothyronine assay validation using captive Steller sea lions (Eumetopias jubatus) and subsequent application to free-ranging populations to examine nutritional stress." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2817.

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Reduced availability of high energy-content prey (nutritional stress) is a predominant hypothesis to explain the decline of Steller sea lion (Eumetopias jubatus) populations in western Alaska from the late 1970's to the late 1990's. Animals may physiologically respond to consuming insufficient prey by increasing stress levels and decreasing metabolic rates. It may thus be possible to identify nutritional stress by measuring concentrations of glucocorticoids (stress) and thyroid hormones (metabolism) shed in feces. However, techniques to measure thyroid hormone concentrations from Steller sea lion feces have not been developed. We quantified variation of triiodothyronine (T3) and thyroxine (T4) concentrations in Steller sea lion feces following injections of thyrotropin (TSH) into four captive animals. Glucocorticoids (GC) were also assayed to examine any relationship to stimulated thyroid hormone secretion. We found that fecal T3 peaked 48 h post-injection and increased 25-57% in three sea lions (all animals, p=0.03). Pre-injection GC increases indicated stress from isolation for baseline fecal collections, but post-injection increases could not be confirmed as a response to TSH injections or as a product of the study design. The results demonstrated that pre- and post-injection changes in fecal GC and T3 concentrations were consistent with predictions of an increased stress response and metabolic rate within the animals. We then measured T3 and GC concentrations in 834 Steller sea lion fecal samples collected in 2005 and 2006 from 15 sites (haulouts and rookeries) between British Columbia and the Central Aleutian Islands. Overall, GC concentrations did not differ between haulout populations (western 2006 pre-pupping and eastern 2005 post-pupping). Fecal hard-part analyses revealed a lower energy-content diet in the western population, suggesting that diet quality is a relevant hypothesis to explain slightly higher GC concentrations found in the western population, specifically the Aleutian Islands region. However, nutritional stress could not be substantiated through T3 concentrations. The rookeries possessed the highest energy-content diets, but also exhibited a nutritional stress response with a significantly higher GC and lower T3 concentration than either haulout population (possibly related to lactation or decreased foraging opportunities), but T3 comparisons performed at scales of site and region were inconclusive.

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Sousa, Cláudia Sofia de Oliveira. "Abordagem cirúrgica e análise histopatológica de cataratas em focas: dois casos clínicos e sete amostras analisadas." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/25686.

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A catarata é uma doença ocular que resulta da opacificação da lente. É uma afeção comum em focas, sendo o seu diagnóstico difícil devido às caraterísticas anatómicas destes animais. O devido tratamento é importante para evitar complicações secundárias, que podem terminar em cegueira. A abordagem cirúrgica é a mais indicada, no entanto deve-se estar consciente do risco anestésico nestas espécies. A cirurgia foi realizada com sucesso em dois casos clínicos, sendo a extração intracapsular a técnica utilizada devido à elevada dureza das lentes das focas. Para obter resultados positivos, uma devida monitorização e tratamento pós-cirúrgico são essenciais. Posteriormente as lentes obtidas juntamente com outro material ocular armazenado, num total de três globos oculares e sete lentes foram sujeitas a análise histopatológica, o que permitiu o seu estudo e comparação. As alterações proliferativas foram as mais encontradas nas amostras do estudo, no entanto também lesões degenerativas foram assinaladas; ABSTRACT: Surgical approach and histopathological analysis of cataracts in seals - two clinical cases and seven analyzed samples Cataract is an eye disease that results from lens opacification. It is common in seals, and its diagnosis is difficult due to the anatomical characteristics of these animals. Proper treatment is important to avoid secondary complications, which can lead to blindness. The surgical approach is the most indicated, however, it is important to be aware of the anesthetic risk in these species. The surgery was successfully performed in two clinical cases, being the intracapsular extraction the used technique due to the high hardness of the lenses in these animals. For the success of the procedure, proper monitoring and post-surgical treatment are essential. Posteriorly, the lenses obtained along with other stored ocular material, in a total of three eyeballs and seven lenses were subjected to histopathological analysis, which allowed their study and comparison. The proliferative changes were the most found in the study samples, however degenerative lesions were also noted.

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António, Ana Catarina Fogaça Esteves. "Deteção de vírus de excreção fecal em pinípedes de coleções zoológicas." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2017. http://hdl.handle.net/10400.5/13067.

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Dissertação de Mestrado Integrado em Medicina Veterinária
As recentes técnicas de sequenciação genómica têm permitido aumentar o conhecimento acerca do viroma fecal dos pinípedes, sem contudo estar ainda esclarecida a sua associação ou não a eventos de doença, prevalência em diferentes populações, e distribuição no ambiente aquático. O presente trabalho laboratorial teve como principal objetivo a realização de um rastreio de vírus de excreção fecal, designadamente astrovírus, sapovírus e bocavírus através da amplificação de sequências nucleotídicas específicas por PCR convencional, em duas coleções zoológicas de pinípedes: do Zoomarine, no Algarve, e do Aquário Vasco da Gama, em Lisboa. De uma população de 19 pinípedes de 4 espécies [8 otárias sul-africanas (Arctocephalus pusillus pusillus), 6 leões-marinhos californianos (Zalophus californianus), 4 focas comuns (Phoca vitulina) e 1 foca cinzenta (Halichoerus grypus)] obtiveram-se 3 sequências positivas a astrovírus (15.7%) cuja especificidade foi confirmada através de uma análise BLAST (http://blast.ncbi.nlm.nih.gov/Blast.cgi). Estas sequências foram obtidas através da utilização de primers que flanqueiam regiões conservadas da RdRp, a polimerase viral, codificada pelo domínio da ORF1b dos astrovírus, pela técnica de RTsn-PCR. A análise filogenética de 41 sequências aminoacídicas representativas dos dois géneros taxonómicos virais revelou que as sequências obtidas formaram um agrupamento independente com um valor de bootstrap estatisticamente robusto (96%). Este trabalho representa o primeiro relato da deteção de astrovírus em amostras fecais das espécies otária sul-africana (Arctocephalus pusillus pusillus) e foca comum (Phoca vitulina) a nível mundial e em ambiente zoológico, tendo ainda promovido a realização de estudos epidemiológicos sobre agentes virais em populações de mamíferos marinhos mantidos sob cuidados humanos.
ABSTRACT - Virus detection in faecal samples of pinnipeds in a zoological context - Recent techniques of genomic sequencing have increased the knowledge regarding the faecal viroma of pinnipeds. However, its association with disease events, prevalence in different populations and distribution in the aquatic environment are not fully characterized. In order to collect information regarding faecal viruses in pinnipeds, faecal samples from two zoological collections: Zoomarine, in Algarve, and Vasco da Gama Aquarium, in Lisbon, were collected and a molecular survey for astrovirus, sapovírus and bocavírus was conducted by conventional PCR. From a total of 19 pinnipeds of 4 different species [8 Cape fur seals (Arctocephalus pusillus pusillus), 6 California sea lions (Zalophus californianus), 4 Harbour seals (Phoca vitulina) and 1 Grey seal (Halichoerus grypus)], 3 positive samples for astrovirus were identified (15.7%) and the specificity of the amino-acidic sequences was compared by BLAST analysis (http://blast.ncbi.nlm.nih.gov/Blast.cgi). Primers targeting the conserved regions of astrovirus RdRp, the viral polymerase, encoded by the ORF1b domain were used in a RT-snPCR assay. The phylogenetic analysis of 41 amino-acidic sequences representative of the two taxonomic genera, revealed an independent cluster of the Portuguese sequences with a significant bootstrap value (96%). This work presents the first report of astrovirus detection on faecal samples from Cape fur seal (Arctocephalus pusillus pusillus) and Harbour seal (Phoca vitulina) species, in a global level and in a zoological context. It also prompted to future epidemiological studies regarding viral pathogens in marine mammal populations under human care.
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Weitzner, Emma. "The Development of Diving Capabilities in Weddell seal (Leptonychotes weddellii) Pups Throughout Early Ontogeny." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2046.

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Weddell seals (Leptonychotes weddellii) are among the deepest diving pinnipeds (i.e., seals, sea lions, and walrus) and one of the best studied marine mammals in the world; as such, these seals are considered a model species for the study of diving physiology and behavior. Adult Weddell seal dive physiology is rather comprehensively understood, yet previous research has excluded an examination of pups’ initial independent diving attempts, beginning instead with the diving capabilities of near-weaning individuals at four to five weeks of age. This is beyond the point many pups have attempted their first independent dives; pups begin to enter the water at 8-10 days after birth, with some observed in the water earlier. The aim of this study was to investigate the development of diving capabilities and fine-scale behaviors of Weddell seal pups beginning at one week of age throughout their dependence period. Pups were sampled longitudinally at 1, 3, 5, and 7 weeks of age. Total body oxygen stores (TBO2, mL O2) were calculated as the sum of blood, muscle, and lung oxygen stores for each seal at all time points. Blood samples were collected under sedation, muscle oxygen parameters were interpolated, and lung oxygen content was extrapolated from adult values. Flipper-mounted time-depth recorders were used to collect concurrent dive behavior data. In chapter 1, I hypothesized that diving capability (TBO2) would be more strongly correlated with dive experience than calendar age; to examine this, age, mass, and diving parameters were correlated with oxygen stores. I instead found mass and age were most significantly correlated with individual tissue oxygen stores and TBO2. I predicted diving experience would be an important driver of oxygen storage development due to hypoxia exposure, but pups spent the majority of their time in the water at the surface and had little to no exposure to hypoxia during dependence. Increases in mass may enable early advances in diving ability, and with increased diving capabilities, pups will be able to become successful independent foragers. Later exposure to hypoxia may be the key to the subsequent increases in TBO2 observed in yearlings and juveniles. In chapter 2, I used TDR data to predict when pups would be in the water based on developmental, temporal, and environmental factors including age, weaning status, time of day, and weather parameters. Pups spent the most time in the water and made their deepest, longest, and most frequent dives during the late night and early morning hours. These data indicate pups are following the diving patterns of their mothers, which follow the diurnal vertical migration of their prey. The data also suggest Weddell seal pups most likely prioritize learning to swim and navigate as opposed to practicing foraging while still dependent. It is critical for pups to develop their swimming, navigational, and diving abilities while they are still with their moms to ensure their survival. This study is the first to describe the complete trajectory of the development of diving physiology and behavior in Weddell seal pups throughout dependence. It is important to understand how the internal diving physiology of Weddell seal pups develops because this directly determines their diving capabilities and their ability to forage successfully, which in turn directly correlates with their survival. Pup survival is an indicator of population growth rates, so the development of diving physiology in pups can lend insights into larger population-level trends.

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Kim, Sunghee. "Olfactory discrimination ability of South African fur seals (Arctocephalus pusillus) for enantiomers." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-78364.

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The sense of smell in marine mammals is traditionally thought to be poor. However, increasing evidence suggests that pinnipeds may use their sense of smell in a variety of behavioral contexts including communication, foraging, food selection, and reproduction. Using a food-rewarded two-choice instrumental conditioning paradigm, I assessed the ability of South African fur seals, Arctocephalus pusillus, to discriminate between 12 enantiomeric odor pairs, that is, between odorants that are identical in structure except for chirality. The fur seals significantly discriminated between eight out of the twelve odor pairs (according to p < 0.05, with carvone, dihydrocarvone, dihydrocarveol, limonene oxide, menthol, beta-citronellol, fenchone, and alpha-pinene), and failed with only four odor pairs (isopulegol, rose oxide, limonene, and camphor). No significant differences in performance were found between the animals (p > 0.05). Cross-species comparisons between the olfactory performance of the fur seals and that of other species previously tested on the same set of odor pairs lend further support to the notion that the relative size of the olfactory bulbs is not a reliable predictor of olfactory discrimination abilities. The results of the present study suggest that sense of smell may play an important and hitherto underestimated role in regulating the behavior of fur seals.

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Heerah, Karine. "Ecologie en mer des phoques de Weddell de l'Antarctique de l'Est en relation avec les paramètres physiques de l'environnement." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066533/document.

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L'étude des mouvements et du comportement de plongée des prédateurs marins en relation avec les caractéristiques biotiques et abiotiques de l'environnement permet d'apporter des indications précieuses sur les stratégies comportementales innées et/ou qu'ils ont développé afin de maximiser l'acquisition des proies dans un environnement donné. Le phoque de Weddell est le seul mammifère marin vivant toute l'année dans la banquise permanente. Bien que son comportement ait été bien étudié en été lorsque les individus se reproduisent et muent sur la glace de mer, nous ne savons presque rien de leur l'écologie hivernale. Cependant, l'hiver est une période cruciale dans le cycle de vie des phoques de Weddell durant laquelle ils passent 80% de leur temps à chasser sous la glace afin de stocker l'énergie nécessaire pour la saison de reproduction suivante. Grâce à l'utilisation de données télémétriques, l'objectif principal de cette thèse était d'améliorer notre compréhension des stratégies de recherche alimentaire adoptées par les phoques de Weddell pendant l'hiver dans deux régions de l'Antarctique de l'Est (Dumont D'Urville et Davis). Tout d'abord, nous avons développé deux méthodes permettant d'identifier et de quantifier l'effort de recherche alimentaire au sein de la plongée, pour des données de plongée haute et basse résolutions. Ces indices de l'effort de recherche alimentaire ont été ensuite utilisés afin d'étudier l'influence de plusieurs paramètres clés de l'environnement (topographie, intensité lumineuse, glace de mer, masses d'eau) sur le comportement de recherche alimentaire des phoques de Weddell
Studying the movement patterns and diving behaviour of top predators in relation with biotic and abiotic environmental features can provide valuable insights in the behavioural tactics they have evolved and/or learned to maximize prey acquisition in a given environment. The Weddell seal is the only marine mammal inhabiting the coastal fast-ice area year-round. While its behaviour has been well studied in summer when individuals are breeding or moulting on the sea-ice, virtually nothing is known about their winter ecology. However, winter is a crucial period in Weddell seals life cycle during which they spend 80% of their time diving under the ice to store the energy needed for the following breeding season. Using telemetric data, the main aim of this thesis was to improve our understanding of the foraging strategies adopted by Weddell seals during winter in two locations of East Antarctica (Dumont D’Urville and Davis). First, we developed two methods to identify and quantify within dive foraging effort from both high and low-resolution dive datasets. Then, these foraging metrics were used to investigate the influence of several key abiotic parameters of the Antarctic environment (topography, light intensity, sea-ice, water masses) on Weddell seals’ foraging behaviour

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Negro, Sandra Silvia. "Reproductive ecology and life history trade-offs in a dimorphic polygynous mammal, the New Zealand fur seal." Thesis, University of Canterbury. School of Biological Sciences, 2008. http://hdl.handle.net/10092/2505.

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Polygyny is the most common mating system in mammalian species (95%), yet our understanding of polygynous systems and microevolutionary processes is still limited. Pinniped mating systems range from extreme polygyny (e.g. elephant seals) to sequential female defence by males and hence have often been used as models for mating system studies. Parentage analysis has enabled the examination of mating success, the identification of pedigrees, and the elucidation of social organisation, greatly enhancing our understanding of mating systems (Chapter 1). However, such analyses are not without pitfalls, with erroneous assignments common in open systems (i.e. when parental and offspring samplings are incomplete). We investigated the effects of the user-defined parameters on the accuracy of parental assignment using two commonly used parental allocation programme, CERVUS and PASOS (Chapter 2). We showed that inaccurate user-defined parameters in CERVUS and PASOS can lead to highly biased output e.g. the assignment rate at 95% CL of offspring with a sampled known mother to sampled males decreased from 58% to 32% when the proportion of candidate males sampled in the parameter options decreasing 4-fold. We found that the use of both CERVUS and PASOS for parentage assignment can increase the likelihood of correctly allocating offspring to sampled parents to 97% in our study system. Incorrect parental assignment can bias estimates of various biological parameters, such as lifetime reproductive success and mate choice preference, and hence bias ecological and evolutionary interpretations. Here, we propose solutions to increase the power of parentage assignment and hence decrease the bias in biological parameter estimates. In addition, we analysed the effects of the intrinsic bias in likelihood assignment approaches towards assigning higher probability of parentage on individuals with rare alleles and those with heightened offspring-parent matches, which increase with the number of homozygous loci (Chapter 3). We showed that, as a consequence of the algorithms employed in the programmes CERVUS and PASOS, heterozygote males with rare genotypes are assigned higher rates of parentage than males with common alleles. Consequently, where two males could both be biological fathers of a given offspring, parentage assignment will more often go to the male with the rarer alleles (most often in heterozygous loci). Thus, the commonly used parentage assignment methods may systematically bias the results of parentage analyses towards supporting the notion that females prefer more genetically unusual, most often heterozygous, males. Such a bias may sway investigators towards incorrectly supporting the concept that females choose genetically more unusual males for heterozygosity fitness benefits that underpin the good genes hypothesis, when in fact no such relationship may exist. In polygynous mammals, successful males mate with multiple females by competing with and limiting the access of other males to females. When the status of many males (age, size, health, genetic etc.) prevents them from achieving the primary mating tactic, theory predicts selection for a diversification of male mating tactics. Recent studies in pinnipeds have shown that observed male mating success was correlated to male paternity success in some species (elephant-seals), but not in others (grey seals). The existence of alternative mating strategies can explain those discrepancies. Chapter 4 implemented the guidelines provided in Chapter 2 and 3 and focused on the polygynous New Zealand fur seal Arctocephalus forsteri, predicting that 1) competition for females is likely to cause a diversification of male mating tactics; and 2) that alternative tactics can yield reproductive success. Our results indicated three male behavioural profiles; one corresponded to large territorial males and two illustrated a continuum of alternative tactics employed by non-territorial subordinate males. Our study highlights that holding a territory is not a necessary condition for reproductive success in a population of otariids. The degree of sexual size dimorphism in polygynous species is expected to increase with the degree of intra-sexual competition and in turn with the degree of polygyny. The life history of an individual is the pattern of resource allocations to growth, maintenance, and reproduction throughout its lifetime. Both females and males incur viability costs of mating and reproduction. However, male viability costs due to increase growth and male-male competition can be greater than female viability costs of mate choice and reproduction. Although an abundant literature on sexual dimorphism in morphology, physiology, and parasite infections is available, little is known on the intra-sexual differences in physiology and parasite infections associated to the reproductive success of different mating strategies in mammalian species. Chapter 5 examined the reproductive costs between territorial and subordinate males New Zealand fur seal related to their relative reproductive success using a multidisciplinary approach (behaviour, genetics, endocrinology, parasitology). We found that dominant New Zealand fur seal males endure higher reproductive costs due to the direct and indirect effects of high testosterone levels and parasite burdens. Our study highlights that holding a territory confers a higher reproductive success, but induces higher costs of reproduction that may impair survival. Understanding microevolutionary processes associated to polygynous systems is fundamental in light of the ongoing anthropogenic alteration of the environment through climatic variations and habitat reduction which ultimately affect opportunity for sexual selection and shape the life history trade-offs.

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Heerah, Karine. "Ecologie en mer des phoques de Weddell de l'Antarctique de l'Est en relation avec les paramètres physiques de l'environnement." Electronic Thesis or Diss., Paris 6, 2014. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2014PA066533.pdf.

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L'étude des mouvements et du comportement de plongée des prédateurs marins en relation avec les caractéristiques biotiques et abiotiques de l'environnement permet d'apporter des indications précieuses sur les stratégies comportementales innées et/ou qu'ils ont développé afin de maximiser l'acquisition des proies dans un environnement donné. Le phoque de Weddell est le seul mammifère marin vivant toute l'année dans la banquise permanente. Bien que son comportement ait été bien étudié en été lorsque les individus se reproduisent et muent sur la glace de mer, nous ne savons presque rien de leur l'écologie hivernale. Cependant, l'hiver est une période cruciale dans le cycle de vie des phoques de Weddell durant laquelle ils passent 80% de leur temps à chasser sous la glace afin de stocker l'énergie nécessaire pour la saison de reproduction suivante. Grâce à l'utilisation de données télémétriques, l'objectif principal de cette thèse était d'améliorer notre compréhension des stratégies de recherche alimentaire adoptées par les phoques de Weddell pendant l'hiver dans deux régions de l'Antarctique de l'Est (Dumont D'Urville et Davis). Tout d'abord, nous avons développé deux méthodes permettant d'identifier et de quantifier l'effort de recherche alimentaire au sein de la plongée, pour des données de plongée haute et basse résolutions. Ces indices de l'effort de recherche alimentaire ont été ensuite utilisés afin d'étudier l'influence de plusieurs paramètres clés de l'environnement (topographie, intensité lumineuse, glace de mer, masses d'eau) sur le comportement de recherche alimentaire des phoques de Weddell
Studying the movement patterns and diving behaviour of top predators in relation with biotic and abiotic environmental features can provide valuable insights in the behavioural tactics they have evolved and/or learned to maximize prey acquisition in a given environment. The Weddell seal is the only marine mammal inhabiting the coastal fast-ice area year-round. While its behaviour has been well studied in summer when individuals are breeding or moulting on the sea-ice, virtually nothing is known about their winter ecology. However, winter is a crucial period in Weddell seals life cycle during which they spend 80% of their time diving under the ice to store the energy needed for the following breeding season. Using telemetric data, the main aim of this thesis was to improve our understanding of the foraging strategies adopted by Weddell seals during winter in two locations of East Antarctica (Dumont D’Urville and Davis). First, we developed two methods to identify and quantify within dive foraging effort from both high and low-resolution dive datasets. Then, these foraging metrics were used to investigate the influence of several key abiotic parameters of the Antarctic environment (topography, light intensity, sea-ice, water masses) on Weddell seals’ foraging behaviour

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Carter, Matt. "From pup to predator : ontogeny of foraging behaviour in grey seal (Halichoerus grypus) pups." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/13068.

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For young animals, surviving the first year of nutritional independence requires rapid development of effective foraging behaviour before the onset of terminal starvation. Grey seal (Halichoerus grypus) pups are abandoned on the natal colony after a brief (15-21 days) suckling period and must learn to dive and forage without parental instruction. Regional and sex-specific differences in diet and foraging behaviour have been described for adults and juveniles, but the early-life behaviour of pups during the critical first months at sea remains poorly understood. This thesis investigates sources of intrinsic and extrinsic variation in the development of foraging behaviour and resource selection in grey seal pups. The studies presented here feature tracking and dive data collected from 52 recently-weaned pups, tagged at six different breeding colonies in two geographically-distinct regions of the United Kingdom (UK). Original aspects of this thesis include: (Chapter I) a comprehensive review of analytical methods for inferring foraging behaviour from tracking and dive data in pinnipeds; (Chapter II) description and comparison of regional and sex differences in movements and diving characteristics of recently-weaned pups during their first trips at sea; (Chapter III) implementation of a novel generalized hidden Markov modelling (HMM) technique to investigate the development of foraging movement patterns whilst accounting for sources of intrinsic (age, sex) and extrinsic (regional) variation; and (Chapter IV) the first analysis of grey seal pup foraging habitat preference, incorporating behavioural inferences from HMMs and investigating changes in preference through time.

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MACIEL, Israel de S? "Vocaliza??es subaqu?ticas e fen?menos n?o lineares em focas ant?rticas." Universidade Federal Rural do Rio de Janeiro, 2016. https://tede.ufrrj.br/jspui/handle/jspui/2162.

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CAPES
Pinnipeds produce a variety of underwater sounds that are often related to reproductive activities and social interactions. In addition, several species of seals provide evidence of vocalizations with geographical and individual variations. Most of bioacoustics researches with seals studied the terrestrial environment repertoire using linear analysis. However, some characteristics of vocalizations can not be explained with linear analysis only or taking into account only one part of the animal's life. The nonlinear phenomena (NLP) present in vocalizations (sideband, harmonic, sub-harmonic, biphonation, jump of frequency and deterministic chaos) are still poorly studied. Given the importance of this phenomena in vocalizations to individual recognition, especially in social mammals, was studied the underwater vocalizations of Antarctic seals in order to know their vocal repertoire and their NLP as well as discuss their possible function. In 2013, Brazilian Navy conducted acoustic recordings on Half Moon Island. In this collection were recorded 128GB of sound files between 12th and 30th of November. A total of 18 days of uninterrupted collections, producing 7,448 files of 3 minutes each. These recordings were taken at the presence of seals to Lobodontini Tribe. A total of 15 types of vocalizations were found in the period between days 12-16/November. A pattern in the vocalizations types L, K and E, arranged in sequence K, L and E, respectively, was observed in all seal recordings. All files presented biphonations, jumps of frequency, harmonics, sidebands and chaos in nine types of vocalizations (A, C, E, F, K, L, M, N and O). The nonlinearities were abundant on all files, being present in 75.56% (N = 1829) of vocalizations. Deterministic chaos was most common, present in 53.86% of non-linear features and 43.08% of vocalizations in general. Taking into account only the tonal vocalizations, 88.85% of vocalizations were nonlinear. The repetition of the KLE pattern also displays a recognition function. The NLP, mainly deterministic chaos, had high incidence in the studied vocalizations indicating that this type has an important role in communication. Furthermore, it seems to belong to the acoustic pattern of Antarctic?s Lobodontines.
Pin?pedes produzem uma variedade de sons subaqu?ticos que frequentemente s?o relacionados com atividades reprodutivas e intera??es sociais. Diversas esp?cies de focas apresentam evid?ncias de vocaliza??es com varia??es geogr?ficas e individuais. A maioria dos trabalhos com focas estudou o repert?rio em ambiente terrestre e com olhares para as an?lises lineares. Entretanto, algumas caracter?sticas das vocaliza??es n?o podem ser explicadas apenas com an?lises lineares ou levando em conta apenas uma parte da vida do animal. Os fen?menos n?o lineares (FNLs) presentes em vocaliza??es (banda lateral, harm?nico, sub-harm?nico, bifona??o, pulos de frequ?ncia e caos determin?stico) ainda s?o pouco estudados. Dada a import?ncia deste fen?meno nas vocaliza??es para o reconhecimento individual, principalmente em mam?feros sociais, este trabalho buscou estudar as vocaliza??es subaqu?ticas de focas ant?rticas, visando conhecer seu repert?rio vocal e seus FNLs, bem como discutir a poss?vel fun??o dos mesmos. Em 2013, a Marinha do Brasil realizou grava??es ac?sticas na Ilha Meia Lua na Ant?rtica. Nesta coleta foram registrados 128GB de arquivos de som nos dias entre 12 e 30 de novembro, totalizando 7.448 arquivos de 3 minutos cada. Nestas grava??es foi constatada a presen?a de focas pertencentes ? Tribo Lobodontini. Contatou-se tamb?m a presen?a de 15 tipos de vocaliza??es no per?odo entre os dias 12 a 16/novembro. Em todos os dias que houve grava??es de focas foi observado um padr?o nos tipos L, K e E, organizados na sequ?ncia K, L e E, respectivamente. Ap?s a inspe??o visual de todos os arquivos, foram encontrados pulos de frequ?ncia, bifona??es, harm?nicos, bandas laterais e caos determin?stico em nove tipos de vocaliza??es (A, C, E, F, K, L, M, N e O). As n?o linearidades foram abundantes em todos os arquivos, estando presentes em 75,56% (N=1829) das vocaliza??es. O caos determin?stico foi o mais comumente observado, estando presente em 53,86% das fei??es n?o lineares e 43,08% das vocaliza??es em geral. Levando em conta apenas as vocaliza??es tonais, 88,85% das vocaliza??es foram n?o lineares. A repeti??o do padr?o KLE parece apresentar uma fun??o de reconhecimento. Os FNLs, principalmente os do tipo caos determin?stico, estiveram muito presentes nas vocaliza??es estudadas, indicando que este tipo de emiss?o possui uma fun??o importante na comunica??o. Al?m disso, estes parecem pertencer ao repert?rio ac?stico padr?o de Lobodontines ant?rticos.

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Silva, Ana Paula da. "Organização e arquitetura microscópica do sistema tegumentar do Lobo-marinho-sul-americano (Arctocephalus australis, Zimmermann, 1783)." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-08012009-091944/.

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O lobo-marinho-sul-americano (Arctocephalus australis) membro da Ordem Carnivora, é comumente visto nos períodos de outono e inverno na costa brasileira do Rio Grande do Sul até o Rio de Janeiro, porém, sem colônias reprodutivas estabelecidas. A espécie pertence ao grupo dos pinípedes, carnívoros com membros em forma de nadadeiras que vivem em ambiente aquático e terrestre. Estudos sobre a morfologia da pele em pinípedes são raros e antigos, destes procederam muitos relatos divergentes, em virtude da colheita da pele sem referências anatômicas. O objetivo desta pesquisa foi descrever o sistema tegumentar da espécie Arctocephalus australis, utilizando animais que vieram a óbito por causas naturais de uma colônia reprodutiva do Uruguai. As áreas corporais colhidas dorso-ventralmente foram identificadas anatomicamente. Essas regiões foram examinadas por microscopia óptica, segundo critérios histológicos, histomorfométricos, histoquímicos e imuno-histoquímicos nas diferentes estruturas que constituem o sistema tegumentar. A pele do Arctocephalus australis apresentou diferenças entre as regiões de epiderme delgada e espessa. A epiderme delgada apresentou maior quantidade de pêlos do que a epiderme espessa, a qual em algumas regiões era destituída destes. Como os demais mamíferos, a pele do lobo-marinho-sul-americano apresentou glândulas sebáceas, glândulas sudoríparas apócrinas e merócrinas. As nadadeiras apresentaram o maior número de especializações entre as regiões do corpo estudadas, especialmente vinculadas à termorregulação, como o maior volume de glândulas sudoríparas e secções vasculares. Esta pesquisa apontou os aspectos morfofuncionais relacionados à biologia da espécie em ambientes distintos, e esclareceu alguns dados controversos na literatura sobre o sistema tegumentar em pinípedes.
The South American fur seal (Arctocephalus australis) members of the Order Carnivora is usually seen during the autumn and winter season in the Brazilian coast from Rio Grande do Sul to Rio de Janeiro, however, there are no reports of reproductive colonies established. The species belongs to the group of pinnipeds, carnivorous with limbs fin-shaped that inhabits both terrestrial and aquatic environments. Studies of the skin morphology are rare and ancient; these studies have arisen many divergent reports, due to sampling of the skin without anatomical references. The purpose of this research was to describe the integumentary system of the species Arctocephalus australis, using animals that came to death by natural cases from reproductive colonies from Uruguay. The body dorsal and ventral regions were identified anatomically. These regions were examined by light microscopy, according to the histological, histomophometric, histochemical and immunohistochemical criteria in the different structures constituting the integumentary system. The skin of the Arctocephalus australis showed differences between the thin and thick epidermis. The thin epidermis showed larger amount of hair follicles than the thicker epidermis, which in some regions was devoid of hair. As well as the other mammals, the South-american-fur-seal skin showed sebaceous glands, apocrine and eccrine sweat glands. The limbs showed the largest number of the specialization among the regions of the body examined, particularly related to thermoregulation, as well as the largest volume fraction of sweat glands and vascular sections. This research pointed the morphofunctional aspects related to biology of the species in different environments, and elucidated some controversial data in the investigation about the integumentary system in pinnipeds.

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Wierucka, Kaja. "Multimodal mother-offspring recognition in the Australian sea lion, Neophoca cinerea." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS432.

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La reconnaissance joue un rôle important dans les systèmes de communication animale et plusieurs modalités sensorielles sont impliquées à cette fin. Bien que la reconnaissance mère-jeune ait été largement étudiée, il y a un manque d'information sur la reconnaissance multimodale et l'importance relative des différentes modalités dans ce processus. Dans cette thèse, j'ai exploré la communication multimodale chez un mammifère colonial - le lion de mer Australien (Neophoca cinerea). La reconnaissance mère-jeune est connue pour être multimodale chez cette espèce, mais les processus sous-jacents de la reconnaissance olfactive et visuelle, ainsi que les interactions entre les indices acoustiques, visuels et olfactifs, et leurs contributions relatives restent inconnues. Des analyses chimiques ont permis de déterminer si les profils chimiques diffèrent selon le sexe et l'âge, les colonies et les régions corporelles des animaux. La présence de similarités chimiques entre la mère et son petit suggèrent que l'appariement des phénotypes pourrait être utilisé pour la reconnaissance olfactive. J'ai examiné le rôle des indices visuels lors de la reconnaissance mère-jeune et j'ai constaté que les indices visuels spécifiques à l'âge sont utilisés par les femelles pour affiner la recherche de leur petit dans la colonie. Les jeunes ont également la capacité de distinguer divers indices visuels, qui peuvent être utilisés pour identifier les différentes classes de congénères. Enfin, j’ai pu aussi déterminer comment les indices acoustiques, olfactifs et visuels sont utilisés de manière synergique dans le processus d’identification individuel, et les résultats sont interprété dans une perspective coûts-avantages pour démêler les pressions évolutives sur chaque composante de ce système de communication. Si les différents indices sensoriels ont la capacité de transmettre des informations en isolation, leur rôle peut être différent lorsque d'autres indices sensoriels sont présents. Les résultats de cette recherche fournissent des résultats sans précédent, contribuant à une meilleure compréhension de la reconnaissance mère-jeune chez les mammifères, ainsi que des règles générales de communication chez les vertébrés
Recognition plays an important role in animal communication systems and individuals often employ different sensory modalities to enact this activity. Although recognition has been widely investigated, especially for mother-offspring interactions, there is a dearth of information about multimodal recognition and the relative importance and interactions of various sensory cues. In this thesis, I explored multimodal communication in a colonial mammal – the Australian sea lion (Neophoca cinerea). Communication during mother-pup reunions is known to be multimodal in this species, yet the underlying processes of olfactory and visual recognition, as well as the interactions between acoustic, visual and olfactory cues remain unclear. Through chemical analyses, I determined whether chemical profiles differ among sex and age classes, colonies, and body regions of animals. Chemical similarities between mothers and pups indicate that phenotype matching may be used by Australian sea lions for olfactory recognition. I examined the role of visual cues in mother-pup recognition and found that age-specific visual cues assist mothers to refine their search for their offspring in the colony. Pups are capable of distinguishing various visual cues that can be used in the assessment of conspecifics. Having provided baseline information about the role of sensory cues in isolation, I determined how acoustic, olfactory, and visual cues are used in a synergistic way to ensure accurate mutual recognition and then interpreted the results using a cost-benefit perspective to disentangle the evolutionary pressures on each component of this communication system. I showed that although cues have the ability to convey given information in isolation, their role may be different when other sensory cues are present. Furthermore, there is a mutual dependency in the communication system, where the limitations imposed on one participant of the dyad affect cue use by the other. These findings contribute to a better understanding of mammal mother-offspring recognition and communication mechanisms in vertebrates

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Dailey, Rachael. "Impact of Nutritional Status on the Somatotropic Axis and Ghrelin in Phocid Seals." UNF Digital Commons, 2013. http://digitalcommons.unf.edu/etd/481.

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Metabolic hormones and their axes, including the target tissues and receptors, regulate the tissue specific utilization of nutrients with in the body. The purpose of this research was to understand the hormonal control of complex nutrient partitioning mechanisms involved in young, growing animals. Specifically, this involved the investigation of metabolic hormones and the regulation of growth in two common species of phocids (true seals): harbor seal (Phoca vitulina) and Northern elephant seal (Mirounga angustirostris) pups. This longitudinal study examines young phocids from nutritional nadir through realimentation (realimentation) to investigate how metabolic hormones involved in both food intake and nutrient partitioning change with respect to nutritional state. To investigate the role of metabolic hormones during realimentation in a small phocid seal, chapter 2 focuses on the changes in the somatotropic axis and ghrelin during a 10-week period of realimentation following nutritional nadir. Chapter 3 focuses on the application of the results of previous research and the second chapter of this thesis to a specific experimental feeding project. Chapter 4 focuses on the response to changes in nutritional status in the fasting adapted NES. Given the changes in metabolism and priority of nutrient utilization associated with transitioning from a nursing neonate to a fasting adapted juvenile, NES provide a unique opportunity to assess the effect of age on the response to realimentation. Overall, this research will further expand the understanding of tissue specific demands and the effect on endocrine response to realimentation. By incorporating assessments of metabolic changes based on nutrition as well as age, this study will expound on how metabolic hormones are involved in regulating the trade-off between adipose and lean tissue development in this unique taxon.

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McKenzie, Jane, and janemckenzie@malpage com. "Population demographics of New Zealand fur seals (Arctocephalus forsteri)." La Trobe University. Zoology Department, School of Life Sciences, 2006. http://www.lib.latrobe.edu.au./thesis/public/adt-LTU20080509.121141.

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Assessment of trophic interactions between increasing populations of New Zealand fur seals (Arctocephalus forsteri) and fisheries in southern Australia is limited due to a lack of species specific demographic data and an understanding of the factors influencing population growth. To establish species specific demographic parameters a cross-sectional sample of New Zealand fur seal females (330) and males (100) were caught and individually-marked on Kangaroo Island, South Australia between 2000 and 2003. The seals were aged through examination of a postcanine tooth, which was removed from each animal to investigate age-specific life-history parameters. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known-age. Indirect methods of assessing reproductive maturity based on mammary teat characteristics indicated that females first gave birth between 4-8 years of age, with an average age at reproductive maturity of 5 years. Among reproductively mature females, age-specific reproductive rates increased rapidly between 4-7 years of age, reaching maximum rates of 70-81% between 8-13 years, and gradually decreased in older females. No females older than 22 years were recorded to pup. Age of first territory tenure in males ranged from 8-10 years. The oldest female and male were 25 and 19 years old, respectively. Post-weaning growth in females was monophasic, characterised by high growth rates in length and mass during the juvenile growth stage, followed by a gradual decline in growth rates after reproductive maturity. In contrast, growth in males was biphasic and displayed a secondary growth spurt in both length and mass, which coincided with sexual and social maturation, followed by a rapid decline in growth rates. Age-specific survival rates were high (0.823-0.953) among prime-age females (8-13 yrs of age) and declined in older females. Relative change in annual pup production was strongly correlated with reproductive rates of prime-age females and adult female survival between breeding seasons.

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Planque, Yann. "Écologie trophique de deux espèces sympatriques de phoques en périphérie de leur aire de répartition." Thesis, La Rochelle, 2021. http://www.theses.fr/2021LAROS032.

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Le phoque veau-marin (Phoca vitulina) et le phoque gris (Halichoerus grypus), deux espèces sympatriques de mammifères marins, sont de plus en plus considérés comme des compétiteurs potentiels, et ce plus particulièrement au cœur de leur distribution européenne. L’objectif de cette thèse est d’étudier les stratégies de chasse et l’écologie trophique de ces espèces en limite de leur aire de distribution (baie de Somme, Manche Est, France), et d’explorer l’hypothèse de compétition interspécifique. Des outils de bio-télémétrie ont été déployés sur 49 individus afin d’obtenir des données sur leurs déplacements et plongées en mer. L’analyse des localisations en surface et du comportement en plongée, complétée plus récemment par la détection de tentatives de captures de proies (accélérométrie), a permis de mieux comprendre les stratégies de chasse de ces espèces, et d’améliorer la détection des zones de chasse. Les niches trophiques des deux espèces de phoques ont ensuite été caractérisées par analyse du régime alimentaire, des isotopes stables (vibrisses des mêmes individus capturés), et des zones de chasse. Un important chevauchement interspécifique a été identifié entre ces niches, résultant de la consommation de poissons plats benthiques en zone côtière, ce qui apporte ici le contexte informatif d’une potentielle compétition. Cette étude montre aussi le rôle clé des stratégies individuelles de chasse sur les conclusions écologiques à l’échelle de l’espèce/sous-population,dont la potentielle compétition qui serait induite par certains phoques gris. La poursuite des suivis est nécessaire pour détecter tout potentiel changement écologique dont l’origine serait trophique
Harbour seal (Phoca vitulina) and grey seal (Halichoerus grypus) are two sympatric marine mammal species that are increasingly considered as potential competitors, especially at their European core distributions. The objective of this PhD was to study the foraging strategies and trophic ecology of these species at the limit of their range (Baie de Somme, Eastern English Channel, France), and to investigate the hypothesis of potential interspecific competition. Biotelemetry devices were fitted on 49 individuals to document their movements and dives at sea.The analysis of surface locations and diving behaviour, completed recently by the detection of Prey Capture Attempts (accelerometry), allowed for a better understanding of the two seal species’ foraging strategies and improved the detection of their foraging areas. Trophic niches of the two seal species were then characterised with the analysis of diet, stable isotopes (in the whiskers of the same captured individuals), and foraging areas. A high interspecific trophic overlap was identified between these niches, resulting from the consumption of benthic flatfish in coastal areas, and we suggest that it provides here the basis for potential competition between both species. This study also showed the key role of individual foraging strategies on the ecological conclusions at the scale of the species/sub-population, including that the potential competition may be due to some individual grey seal strategies. Continuing these studies is essential to detect any potential ecological changes that could be trophically-induced

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LAI, Yun-Ru, and 賴韻如. "Life History Strategies in Marine Mammal's Pinnipedia and Sirenia." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/84264933693754302802.

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碩士
國立臺灣海洋大學
環境生物與漁業科學學系
95
Comparative studies among different life history patterns of marine mammal’s Pinnipedia and Sirenia would be very valuable to understand their strategies of adaptation and selection in view of evolution. Therefore, this study is designed to find life history patterns in various species of Pinnipedia and Sirenia of based on 11 life history traits (LHT) that are asymptotic body length (Lx), length at birth (Lb), weight at birth (Wb), weight at weaned (Ww), asymptotic body weight (Wx), age at sexual maturity (Am), longevity (Ax), calving interval (CI), gestation period (GP), lactation period (LP) and weight gain per day during lactation period (WG). Data were collected from published papers and books. These LHT were analyzed individually, correlatively, and collectively. I determine the relationship between LHT with general linear model and use factor analysis by principle component method to transform the LHT into differentiated major independent factors. Finally, discriminant analysis is applied on the new classified groups, and to find the general patterns. Three independent factors: reproduction factor (Ax, Am and GP), size factor (Wb and Lx) and time factor (LP and CI) can explain 85.3% variance for 37 species in Pinnipedia and Sirenia. Almost all the five families can be differentiated significantly with 88% correct classification. This life history patterns can provide theoretical support for Pinnipedia and Sirenia management in making conservation policy.

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Stewardson, Carolyn Louise. "Biology and conservation of the Cape (South African) fur seal Arctocephalus pusillus pusillus (Pinnipedia: Otariidae) from the Eastern Cape Coast of South Africa." Phd thesis, 2001. http://hdl.handle.net/1885/48199.

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Chapter 1 Introduction. Chapter 2 Gross and microscopic visceral anatomy of the male Cape fur seal with reference to organ size and growth. Chapter 3 Age determination and growth in the male Cape fur seal: part one, external body. Chapter 4 Age determination and growth in the male Cape fur seal: part two, skull. Chapter 5 Age determination and growth in the male Cape fur seal: part three, baculum. Chapter 6 Suture age as an indicator of physiological age in the male Cape fur seal. Chapter 7 Sexual dimorphism in the adult Cape fur seal: standard body length and skull morphology. Chapter 8 Reproduction in the male Cape fur seal: age at puberty and annual cycle of the testis. Chapter 9 Diet and foraging behaviour of the Cape fur seal. Chapter 10(a) The Impact of the fur seal industry on the distribution and abundance of Cape fur seals. Chapter 10(b) South African Airforce wildlife rescue: Cape fur seal pups washed from Black Rocks, Algoa Bay, during heavy seas, December 1976. Chapter 11(a) Operational interactions between Cape fur seals and fisheries: part one, trawl fishing. Chapter 11(b) Operational interactions between Cape fur seals and fisheries: part two, squid jigging and line fishing. Chapter 11(c) Operational interactions between Cape fur seals and fisheries: part three, entanglement in man-made debris. Chapter 12 Concentrations of heavy metals (Cd, Cu, Pb, Ni & Zn) and organochlorine contaminants (PCBs, DDT, DDE & DDD) in the blubber of Cape fur seals. Chapter 13 Endoparasites of the Cape fur seal. Chapter 14(a) Preliminary investigations of shark predation on Cape fur seals. Chapter 14(b) Aggressive behaviour of an adult male Cape fur seal towards a great white shark Carcharodon carcharias. Chapter 15 Conclusions and future directions.

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Higdon, Jeffrey Wayde. "Biogeography and conservation of the pinnipeds (Carnivora: Mammalia)." 2011. http://hdl.handle.net/1993/4346.

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This thesis examines the biogeography of world pinnipeds, a unique group of marine mammals that have adapted to marine foraging while maintaining terrestrial (land or ice) habitat links. Comparative analyses of species range sizes controlled for phylogenetic relationships using a multi-gene supertree with divergence dates estimated using fossil calibrations. Adaptations to aquatic mating and especially sea ice parturition have influenced range size distribution, and ranges are larger than those of terrestrially mating and/or pupping species. Small range size is endangering for many taxa, and most at risk pinnipeds are terrestrial species with small ranges. Ancestral state reconstructions suggest that pinnipeds had a long association with sea ice, an adaptation that would have allowed early seals to expand into novel habitats and increase their distribution. Range sizes exhibit a strong Rapoport effect (positive relationship between range size and latitude) at the global scale, even after controlling for phylogeny and body size allometry. A latitudinal gradient in species diversity cannot explain the Rapoport effect for global pinniped ranges, as diversity is highest at mid-latitudes in both hemispheres. These regions are characterized by marginal ice zones and variable climates, supporting a mix of pagophilic and temperate species. The climatic variability hypothesis also did not explain the Rapoport effect. Variability is bimodal, and annual sea surface temperature (SST) variability does explain diversity patterns. Range size has a significant negative relationship with annual mean SST, and the largest ranges are found in areas with low mean SST. Temperature responses are possibly related to thermoregulation, sea ice availability, and ecological relationships with other large marine predators. These results agree with other studies and suggest that ocean temperature, and not productivity, drives marine species richness patterns. Future research needs include studies of physiological tolerances, interactions with sharks as predators and competitors, and the role of climate and sea ice in speciation and evolution. A better understanding of distribution and diversity patterns, and the role of the environment in shaping these patterns, will improve conservation efforts, and studies on the role of SST and sea ice are particularly important given current warming trends and declines in ice extent.

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Mottishaw, Petra Deigh. "The diving physiology of pinnipeds : an evolutionary enquiry." Thesis, 1997. http://hdl.handle.net/2429/5965.

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During the last century, studies of diving physiology and biochemistry made great progress in mechanistically explaining the basic diving response of aquatic mammals and birds. Key components of the diving response (apnea, bradycardia, peripheral vasoconstriction, redistribution of cardiac output) were generally taken to be biological adaptations, but the evolution of the diving response has not been seriously examined. This study compares several key characters of the diving response in the pinnipeds using phylogenetically independent contrasts. As the traits examined are known to be functionally important for diving, I expected them to correlate positively with diving ability. Instead, some physiological/biochemical characters considered adaptive for diving do not correlate with diving ability. These traits are similar in phocids (true seals) and otariids (sea lions and fur seals) and include diving apnea and bradycardia (and probably also include tissue hypoperfusion, and hypometabolism of hypoperfused tissues). This finding contradicts the generally accepted theory that these traits are adaptations for extending dive time in pinnipeds. The key components of the diving response are more appropriately seen to be ancestral (plesiomorphic) characters. Another group of physiological/biochemical characters was more variable among the taxa examined. These included body weight, spleen weight, whole body hemoglobin content, and blood volume. Increases in these characters correlate with increased diving capacity (defined as maximum recorded diving duration). This correlation of characters, along with functional knowledge of current utility, leads to the conclusion that changes in two traits - spleen size and whole body oxygen carrying capacities - may have been driven by selection for increased diving duration in pinnipeds.

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Ginter, Carly C. "Comparative Analysis of the Morphology and Materials Properties of Pinniped Vibrissae." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10491.

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Vibrissae (whiskers) are important components of the mammalian tactile sensory system, and primarily function as detectors of environmental vibrotactile cues. Pinnipeds possess the largest and most highly innervated vibrissae among mammals and their vibrissae demonstrate a diversity of shapes and likely mechanical properties. These two characteristics are important for vibrotactile sensory perception. Vibrissae of most phocid seals exhibit a beaded morphology with repeated sequences of crests and troughs along their length. I comparatively characterized differences in vibrissae morphologies among phocid species with a beaded profile, phocid species with a smooth profile, and otariids with a smooth profile using traditional and geometric morphometric methods to test the hypothesis that vibrissal morphologies are species-specific manipulations of a common pattern. The traditional and geometric morphometric datasets were subsequently combined by mathematically scaling each to true rank, followed by a single eigendecomposition. Quadratic discriminant function analysis demonstrated that 79.3, 97.8 and 100% of individuals could be correctly classified to taxon based on vibrissal shape variables in the traditional, geometric and combined morphometric analyses, respectively. At least three separate morphologies were identified since phocids with beaded vibrissae, phocids with smooth vibrissae, and otariids each occupied distinct morphospace in the geometric morphometric and combined data analyses. Another important characteristic that influences the transduction of vibrotactile information to the mechanoreceptors in the follicle-sinus complex is the materials properties of the vibrissae. Vibrissae were modeled as cantilever beams and flexural stiffness (EI) was measured to test the hypotheses that the shape of beaded vibrissae reduces flexural stiffness and that vibrissae are anisotropic (orientations differ in EI). Species were significantly different and smooth vibrissae were generally stiffer than beaded vibrissae. Beaded vibrissae decrease vibrations in flow, which, combined with lower flexural stiffness values, may enhance detection of small changes in flow from swimming prey. The anterior plane of the vibrissae is likely the most biologically significant in tracking hydrodynamic trails but had lower flexural stiffness values than the dorsoventral orientation. There is likely a complex interaction between shape and mechanical properties in pinniped vibrissae but the ecological and functional implications are currently unknown.

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Dissertations / Theses on the topic 'Pinnipedia'

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