Journal articles on the topic 'Benthic cephalopods'
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1
Fanelli, Emanuela, Joan E. Cartes, and Vanesa Papiol. "Assemblage structure and trophic ecology of deep-sea demersal cephalopods in the Balearic basin (NW Mediterranean)." Marine and Freshwater Research 63, no. 3 (2012): 264. http://dx.doi.org/10.1071/mf11157.
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Despite the important ecological role of cephalopods in energy and material flow in marine ecosystems, they are poorly understood, particularly those inhabiting deep-sea bottoms below 800 m. To define cephalopod species assemblages from the upper to the lower slope, we conducted 13 oceanographic and trawl surveys in the Balearic basin (NW Mediterranean) in 1985–92 and 2007–10 at depths between 450 and 2200 m. Multivariate analysis suggests the existence of three assemblages on the upper (450–600 m), middle (650–1500 m) and lower (1600–2200 m) slopes. Although seasonal changes in species abundance and composition were evident, no significant variations in the assemblage structure were observed between the two time periods. Two main trophic pathways involving deep-sea cephalopods were apparent: species mainly linked to benthic resources and species mostly connected to the pelagic food web through active swimming and frequent vertical migrations. Accordingly, two environmental variables best explained the observed patterns: net primary production and river discharge. Phytoplankton availability controls the increase of zooplankton that influences the distribution and abundance of pelagic cephalopods. River discharge affects, in some instances with delays, transfer of organic matter to the benthic trophic pathway and thus to bottom-dwelling cephalopods.
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Collins, Martin A., Cynthia Yau, Louise Allcock, and Michael H. Thurston. "Distribution of deep-water benthic and bentho–pelagic cephalopods from the north-east Atlantic." Journal of the Marine Biological Association of the United Kingdom 81, no. 1 (February 2001): 105–17. http://dx.doi.org/10.1017/s0025315401003459.
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The distribution of deep-water (150–4850 m) benthic and bentho–pelagic cephalopods in the north-east Atlantic is described, based on 592 specimens collected from commercial and research trawling. Thirty-six different species of cephalopod belonging to 14 families were identified, though problems remain with the taxonomy of some of the octopod genera. At the shallower depths (150–500 m) sepiolids were the most abundant group with five species identified. Sepiola atlantica, Sepietta oweniana and Rondeletiola minor were restricted to the shallow depths (<300 m), but Neorossia caroli (400–1535 m) and Rossia macrosoma (205–515 m) extended into deeper water. The squids Todaropsis eblanae and Loligo forbesi were also common in shallow areas (<250 m). Among the incirrate octopods, Eledone cirrhosa was found at depths of 208–490 m. Three putative species of Benthoctopus and two of Bathypolypus were identified occupying depths of 250–2700 m. Graneledoneverrucosa was caught at depths of 1785–2095 m. Cirrate octopods dominated the cephalopod catch from the deeper areas, with Opisthoteuthis massyae occurring from 877 to 1398 m, O. grimaldii from 2165 to 2287 m, Stauroteuthissyrtensis from 1425 to 3100 m, Cirroteuthismuelleri from 700 to 4854 m, Cirrothauma murrayi from 2430 to 4850 m and Grimpoteuthis (five putative species) from 1775 to 4877 m. Abundance estimates of the more frequently caught species were calculated from swept areas of trawls and sledges in the Porcupine Seabight and on the Porcupine Abyssal Plain.
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Martin, A. R., and M. R. Clarke. "The Diet of Sperm Whales (Physeter Macrocephalus) Captured Between Iceland and Greenland." Journal of the Marine Biological Association of the United Kingdom 66, no. 4 (November 1986): 779–90. http://dx.doi.org/10.1017/s0025315400048426.
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The stomach contents of 221 sperm whales were examined at the Icelandic whaling station between 1977 and 1981. Evidence of at least eight species of fish and 22 species of cephalopod was found, together with an assortment of foreign bodies including rock fragments and fishing nets. Fish remains were found in 87% and cephalopods in 68% of the sperm whale stomachs in this area, but quantification of dietary input is complicated by differential rates of digestion and variation in the retention of indigestible remains in the stomach. Prey species are benthic or pelagic in habit and are caught by the whale in waters from 400 m to at least 1200 m in depth. One fish, the lumpsucker Cyclopterus lumpus, forms a major part of the diet. Ninety-four per cent of cephalopods are oceanic and neutrally buoyant and 84 % of these are ammoniacal. Cranchiids contribute 57% by number and an estimated 25% of the weight, and histioteuthids 26% by number and 38 % of the weight of cephalopods eaten. Three species offish and two of cephalopod have not been previously recorded in sperm whale diets. Comparison with an earlier study shows that the diet is essentially stable over a 14-year period.
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Stevens, Darren W., Matthew R. Dunn, Matthew H. Pinkerton, and Jeff S. Forman. "Diet of Antarctic toothfish (Dissostichus mawsoni) from the continental slope and oceanic features of the Ross Sea region, Antarctica." Antarctic Science 26, no. 5 (March 4, 2014): 502–12. http://dx.doi.org/10.1017/s095410201300093x.
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AbstractThe diet of Dissostichus mawsoni captured by bottom longline in the Ross Sea region was examined during 2003, 2005 and 2010. The diet of sub-adult toothfish was similar to adult toothfish, comprising mainly benthic fishes and cephalopods. Sub-adult toothfish ate a greater variety of smaller prey than adults, including smaller fish and prawns. Grenadiers (Macrourus spp.) were the most important fish and overall prey species. On the continental slope, icefish (Channichthyidae) and eel cods (Muraenolepididae) were also important fish prey, while Psychroteuthis glacialis was the most important cephalopod prey. On oceanic features, toothfish fed mainly on Macrourus spp. but also fed on Antimora rostrata, cephalopods and the occasional mesopelagic to epipelagic fish. Diet varied significantly with toothfish size and location on northern parts of the Mawson and Iselin banks of the Ross Sea continental slope. There was no significant temporal change in diet composition.
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Montana, Jasper, Julian K. Finn, and Mark D. Norman. "Liquid sand burrowing and mucus utilisation as novel adaptations to a structurally-simple environment in Octopus kaurna Stranks, 1990." Behaviour 152, no. 14 (2015): 1871–81. http://dx.doi.org/10.1163/1568539x-00003313.
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Cephalopods are often celebrated as masters of camouflage, but their exploitation of the soft-sediment habitats that dominate the ocean floor has demanded other anti-predator strategies. Previous research has identified a small number of cephalopods capable of burying into sand and mud, but the need to directly access the water column for respiration has restricted them to superficial burying. Here, we report on the first known sub-surface burrowing in the cephalopods, byOctopus kaurna, a small benthic species that uses advanced sand-fluidisation and adhesive mucus for sediment manipulation. This burrowing strategy appears linked to easily fluidised sediments as shown in experimental trials in three size-grades of sediment. While the selective pressures that drove evolution of this behaviour are unknown, its identification enriches our understanding of the possible life-history traits and functional role of mucus in other benthic octopus species living in soft-sediment environments.
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Barbini, Santiago A., and Luis O. Lucifora. "Feeding habits of a large endangered skate from the south-west Atlantic: the spotback skate, Atlantoraja castelnaui." Marine and Freshwater Research 63, no. 2 (2012): 180. http://dx.doi.org/10.1071/mf11170.
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Elasmobranch predation has important effects on marine ecosystems. Identifying the main correlates of the feeding habits of skates is of paramount importance for determining their ecological role. We tested the hypotheses that the diet of the spotback skate, Atlantoraja castelnaui, off Uruguay and northern Argentina, changes with increasing body size, between seasons and regions and that prey size increased with predator’s size using a multiple-hypothesis modelling approach. A. castelnaui preyed mainly on teleosts, followed by cephalopods, elasmobranchs and decapods. Small individuals of A. castelnaui consumed decapods and large individuals ate elasmobranchs and cephalopods. The consumption of teleosts was constant along the ontogeny but differed between seasons; more demersal-benthic teleosts were consumed in the cold season, whereas more benthic teleosts were eaten in the warm season. Also, A. castelnaui consumed more cephalopods in the warm season than in the cold season. Benthic teleosts were consumed more in the south region, whereas decapods were eaten more in the north region. A. castelnaui is able to consume larger teleosts as it grows. We conclude that A. castelnaui is a versatile, mainly piscivorous, consumer that shifts its diet with increasing body size and in response to seasonal and regional changes in prey abundance or distribution.
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CIÉRCOLES, CRISTINA, CRISTINA GARCÍA-RUIZ, MARIA GONZÁLEZ AGUILAR, JOSÉ M. ORTIZ DE URBINA GUTIERREZ, NIEVES MARIA LÓPEZ-GONZÁLEZ, JAVIER URRA RECUERO, and JOSE LUIS RUEDA RUIZ. "Molluscs collected with otter trawl in the northern Alboran Sea: main assemblages, spatial distribution and environmental linkage." Mediterranean Marine Science 19, no. 1 (May 31, 2018): 209. http://dx.doi.org/10.12681/mms.2124.
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Molluscan assemblages of circalittoral and bathyal soft bottoms of the northern Alboran Sea were studied using an experimental otter trawl. Samples of fauna were collected from 190 hauls during four MEDITS surveys carried out in spring between 2012 and 2015 at depths ranging from 30 to 800 m. Measurements of water column variables (temperature and salinity) and sediment samples were taken in the same locations where faunistic sampling was carried out. A total of 101 species grouped in 55 families were recorded. Cephalopods were the most abundant group, with Abralia veranyi dominating in abundance, Octopus vulgaris in biomass and Illex coindetii and Todarodes sagittatus being the most frequently collected species. Multivariate analyses carried out separately with abundance data of demersal species, benthic species, bivalves, gastropods and cephalopods as well as of all molluscs, generally resulted in three main molluscan assemblages corresponding to a shelf assemblage (30-200 m depth), an upper slope assemblage (201-350 m depth), and a middle slope assemblage (351-800 m depth). PERMANOVA test revealed that significant differences of different groups of molluscs in relation to depth were more acute than to geographical sectors of the Alboran Sea (eastern, central, eastern and insular sectors). Abundance, biomass and species richness decreased with depth with a clear dominance of cephalopods in the slope. Significant geographical differences were mainly detected for demersal and benthic species as well as for gastropods and cephalopods between the insular sector (Alboran Island) and the western and eastern continental sectors. Both depth and temperature were the most influencing variables in the different CCA analyses using datasets of molluscs with different life styles and from different classes, but sedimentological variables displayed a more acute significant relationship with the benthic molluscs than with the demersal ones.
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Trueblood, Lloyd A., Sarah Zylinski, Bruce H. Robison, and Brad A. Seibel. "An ethogram of the Humboldt squid Dosidicus gigas Orbigny (1835) as observed from remotely operated vehicles." Behaviour 152, no. 14 (2015): 1911–32. http://dx.doi.org/10.1163/1568539x-00003324.
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Many cephalopods can rapidly change their external appearance to produce multiple body patterns. Body patterns are composed of various components, which can include colouration, bioluminescence, skin texture, posture, and locomotion. Shallow water benthic cephalopods are renowned for their diverse and complex body pattern repertoires, which have been attributed to the complexity of their habitat. Comparatively little is known about the body pattern repertoires of open ocean cephalopods. Here we create an ethogram of body patterns for the pelagic squid, Dosidicus gigas. We used video recordings of squid made in situ via remotely operated vehicles (ROV) to identify body pattern components and to determine the occurrence and duration of these components. We identified 29 chromatic, 15 postural and 6 locomotory components for D. gigas, a repertoire rivalling nearshore cephalopods for diversity. We discuss the possible functional roles of the recorded body patterns in the behavioural ecology of this open ocean species.
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Gales, R., D. Pemberton, CC Lu, and MR Clarke. "Cephalopod diet of the Australian fur seal: Variation due to location, season and sample type." Marine and Freshwater Research 44, no. 5 (1993): 657. http://dx.doi.org/10.1071/mf9930657.
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In Tasmanian waters, Arctocephalus pusillus doriferus preyed on 11 species of cephalopods, predominantly Nototodarus gouldi followed by Sepioteuthis australis and Sepia apama. Cephalopods were more important in the diet of the seals in Bass Strait than in southern Tasmanian waters. The species composition in the diet of the seals in these two areas also differed, with the seals in Bass Strait eating mainly N. gouldi, whereas the seals in southern waters fed on benthic octopods. The seals preyed on mainly adult cephalopods over the continental shelf. The size range and species composition of the diet varied according to the sample types, with faeces containing only small beaks relative to regurgitates and stomachs. Errors associated with sample types and application of regression equations are discussed.
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Kolis, Kayla M., and Bruce S. Lieberman. "Using GIS to examine biogeographic and macroevolutionary patterns in some late Paleozoic cephalopods from the North American Midcontinent Sea." PeerJ 7 (May 13, 2019): e6910. http://dx.doi.org/10.7717/peerj.6910.
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Geographic range is an important macroevolutionary parameter frequently considered in paleontological studies as species’ distributions and range sizes are determined by a variety of biotic and abiotic factors well known to affect the differential birth and death of species. Thus, considering how distributions and range sizes fluctuate over time can provide important insight into evolutionary dynamics. This study uses Geographic Information Systems (GIS) and analyses of evolutionary rates to examine how in some species within the Cephalopoda, an important pelagic clade, geographic range size and rates of speciation and extinction changed throughout the Pennsylvanian and early Permian in the North American Midcontinent Sea. This period is particularly interesting for biogeographic and evolutionary studies because it is characterized by repetitive interglacial-glacial cycles, a global transition from an icehouse to a greenhouse climate during the Late Paleozoic Ice Age, and decelerated macroevolutionary dynamics, i.e. low speciation and extinction rates. The analyses presented herein indicate that cephalopod species diversity was not completely static and actually fluctuated throughout the Pennsylvanian and early Permian, matching findings from other studies. However, contrary to some other studies, the mean geographic ranges of cephalopod species did not change significantly through time, despite numerous climate oscillations; further, geographic range size did not correlate with rates of speciation and extinction. These results suggest that pelagic organisms may have responded differently to late Paleozoic climate changes than benthic organisms, although additional consideration of this issue is needed. Finally, these results indicate that, at least in the case of cephalopods, macroevolution during the late Paleozoic was more dynamic than previously characterized, and patterns may have varied across different clades during this interval.
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Bello, Giambattista, Franco Andaloro, and Pietro Battaglia. "Non-indigenous cephalopods in the Mediterranean Sea." Acta Adriatica 61, no. 2 (December 28, 2020): 113–34. http://dx.doi.org/10.32582/aa.61.2.1.
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The present review critically assesses the records of cephalopods that have entered the Mediterranean Sea in the last few decades. It includes 13 species, namely Sepia dollfusi, Stoloteuthis leucoptera, Sepioteuthis lessoniana, Architeuthis dux, Cranchia scabra, Taonius pavo, Megalocranchia sp., Teuthowenia megalops, Cycloteuthis sirventi, Taningia danae, Octopus cyanea, Amphioctopus sp. and Tremoctopus gracilis. The presence of Sepia pharaonis needs to be confirmed, whereas that of Sepia gibba and Spirula spirula is excluded. The arrivals from the Atlantic Ocean through the Strait of Gibraltar are related to the entrance surface current, which either carried passively planktonic paralarvae or favoured in some other way the entrance of subadult and adult stray specimens. As a matter of fact, all Atlantic cephalopods are pelagic oegopsid squids, with the exception of the nekto-benthic sepiolid S. leucoptera; all of them have been found only in the western Mediterranean basin. None of them seemingly established a stable population there, apart from the latter species. On the contrary, the cephalopods entering the Mediterranean from the Red Sea through the Suez Canal (Lessepsian migrants) lead a benthic mode of life. At least two of them, namely S. lessoniana and Amphioctopus sp., set up stable populations in the eastern basin. Lastly the occurrences of the pelagic octopod T. gracilis are ascribed, in the literature, to human-mediated transfer.
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Park, Joo-Myun, Hae-Kun Jung, and Chung-Il Lee. "Factors Influencing Dietary Changes of Walleye Pollock, Gadus chalcogrammus, Inhabiting the East Sea off the Korean Coast." Journal of Marine Science and Engineering 9, no. 11 (October 20, 2021): 1154. http://dx.doi.org/10.3390/jmse9111154.
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This study examined the dietary patterns of walleye pollock, Gadus chalcogrammus, off the middle eastern coast of Korea between January 2016 and December 2017 to determine the influences of various predictors on dietary changes. Based on stomach content analyses, walleye pollock was found to be a demersal carnivore that mainly consumes carid shrimps, euphausiids, mysids, teleosts, and cephalopods. The main prey species identified in the diets of walleye pollock were Euphausia pacifica (euphausiids), Themisto japonicus (amphipods), Neomysis spp. (mysids), Neocrangon communis, Pandalus borealis (carid shrimps), Watasenia scintillans (cephalopods), and Bothrocara hollandi (teleosts), which are hyper-benthic and bentho-pelagic organisms. Dietary analyses based on the weight contributions of different prey taxa to the diets revealed significant variations in dietary composition in terms of fish size, water depth, and season, implying intraspecific dietary segregation. Euphausiids dominate the diets of smaller individuals (<30 cm TL), whereas the contributions of carid shrimps, teleosts, and cephalopods increase as body size increases. Similarly, the latter three prey items are dominant food resources in deeper habitats. The PERMANOVA results revealed that the size-related spatial and temporal changes in dietary composition are all significant for the species, as well as their two- or three-way interactions among those factors, except for the size-depth interaction. The coupling effect of size and depth is indicative of depth-dependent differences in fish sizes, with the tendency for larger individuals to be distributed in deeper habitats. In addition, seasonal and interannual variations in water column structures are also evident in the diets, which may, in part, account for the diet seasonality observed in the stomach content analysis. The dietary analyses of walleye pollock will improve our understandings to seek functional role of the species in benthic food webs, and to predict the effects of environmental and anthropogenic perturbations.
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Collins, Martin A., A. Louise Allcock, and Mark Belchier. "Cephalopods of the South Georgia slope." Journal of the Marine Biological Association of the United Kingdom 84, no. 2 (April 2004): 415–19. http://dx.doi.org/10.1017/s0025315404009373h.
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During January 2003 the bathymetric distribution of the cephalopod fauna of the South Georgia and Shag Rocks slope (100–900 m) was investigated using a commercial bottom trawl. Forty-four trawl stations caught 193 cephalopod specimens including six species of octopod and seven of squid. The benthic octopods Pareledone turqueti and Adelieledone polymorpha were abundant in shallow water at South Georgia, being replaced by Thaumeledone gunteri in greater depths. However, neither A. polymorpha nor T. gunteri were caught on the adjacent Shag Rocks area. Two specimens of the deep-sea genus Graneledone were caught on the South Georgia slope. The most abundant squid species caught were Moroteuthis knipovitchi, Psychroteuthis glacialis and Slosarczykovia circumantarctica, which are primarily pelagic and may have been taken when their vertical migrations impinged on the slope.
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Rasero, M., A. F. Gonzalez, B. G. Castro, and A. Guerra. "Predatory Relationships of Two Sympatric Squid, Todaropsis Eblanae And Illex Coindetii (Cephalopoda: Ommastrephidae) in Galician Waters." Journal of the Marine Biological Association of the United Kingdom 76, no. 1 (February 1996): 73–87. http://dx.doi.org/10.1017/s0025315400029027.
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The natural feeding of the two most abundant ommastrephid squid (Cephalopoda: Ommastrephidae) in Galician waters was studied and compared. A sample of 334 stomach contents of Todaropsis eblanae (34–222 mm ML) and 267 stomach contents of Illex coindetii (50–379 mm ML) caught by commercial trawlers was examined. A total of 21 (T. eblanae) and 23 (I. coindetii) different prey items, belonging to three zoological groups (Teleostei, Crustacea and Cephalopoda), were taken by these cephalopods. However, 43% of the T. eblanae diet comprised only one fish species, Micromesistius poutassou. The diet of these squid species was significantly influenced by the geographical area (both species), size (T. eblanae) and maturation (I. coindetii). Feeding rate of both species decreased with size, but the percentage of stomachs with food remains increased in maturing and mature females. Weight of prey captured was dependent on available prey sizes and, in small individuals, maximum prey weight was very close to the squid weight. Both squid species are mainly neritic nekto-benthic predators, but I. coindetii seems to have a broader and more pelagic diet.
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Simpfendorfer, Colin A., Adrian Goodreid, and Rory B. McAuley. "Diet of three commercially important shark species from Western Australian waters." Marine and Freshwater Research 52, no. 7 (2001): 975. http://dx.doi.org/10.1071/mf01017.
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The diets of dusky (Carcharhinus obscurus), whiskery (Furgaleus macki) and gummy (Mustelus antarcticus) sharks from south-western Western Australia were examined by analysis of stomach contents. The majority of samples were obtained from catches of commercial gill-net fishers. Carcharhinus obscurus had a diverse diet dominated by pelagic teleosts and cephalopods. A wide range of demersal and benthic prey were also consumed, but represented only a small portion of the diet. As body size increased, importance of elasmobranchs in the diet of C. obscurus increased, while most other groups remained at similar levels. Furgaleus macki had a specialized diet, feeding almost exclusively on octopus and other cephalopods. The diet of M. antarcticus was dominated by benthic and epibenthic prey, including crabs, lobsters, tetraodontid fishes and octopus. As M. antarcticus increased in size there was an increase in the occurrence of rock lobster and a decrease in the occurrence of crabs in the diet. Differences in the diet were also noted between male and female M. antarcticus, but were confounded with differences between size classes.
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Brett, Carlton E., and Sally E. Walker. "Predators and Predation in Paleozoic Marine Environments." Paleontological Society Papers 8 (October 2002): 93–118. http://dx.doi.org/10.1017/s1089332600001078.
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The Paleozoic body fossil record of potential benthic predators includes nautiloid and ammonoid cephalopods, phyllocarids, decapods, and several lineages of gnathostomes. The latter group, in particular, radiated rapidly during the Devonian. In the pelagic realm, predator-prey interactions involving cephalopods and some nektonic arthropods probably appeared in the Ordovician. Again, evidence indicates intensification of pelagic predation, much of it by arthrodires and sharks on other fishes, during the Devonian radiation of gnathostomes.Trace fossils provide direct evidence of predatory attack from the Ediacarian and Early Cambrian onward, but with a substantial increase in the Siluro-Devonian. Brachiopod and molluscan shells and trilobite exoskeletons show evidence of healed bite marks and peeling from the Cambrian onward, but with an increased frequency in the Devonian. Predatory drill holes with stereotypical position and prey-species preference are found in brachiopods (Cambrian onward) and mollusks (Ordovician onward); boreholes also show increased frequency in the middle Paleozoic. Certain of these boreholes are tentatively attributable to platyceratid gastropods.Hard-shelled benthic organisms with thicker, more spinose skeletons may have had a selective advantage as durophagous predators increased. Brachiopods, gastropods, trilobites, and crinoids show an abrupt increase in spinosity beginning in the Siluro-Devonian. But spinosity decreases after the early Carboniferous. Late Paleozoic benthos may have taken refuge in smaller size and resistant, thick-walled skeletons, as well as endobenthic and cementing modes of life. Conversely, in the pelagic realm, external armor was reduced, while more efficient, fast-swimming modes of life (e.g., in sharks) increased in the post-Devonian.
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Revelles, M., L. Cardona, A. Aguilar, and G. Fernández. "The diet of pelagic loggerhead sea turtles (Caretta caretta) off the Balearic archipelago (western Mediterranean): relevance of long-line baits." Journal of the Marine Biological Association of the United Kingdom 87, no. 3 (May 16, 2007): 805–13. http://dx.doi.org/10.1017/s0025315407054707.
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Gut content and stable isotope analyses were used to investigate the feeding habits of loggerhead sea turtles (Caretta caretta) inhabiting the Balearic archipelago. Turtles caught in the pelagic realm (δ13C: -16.0±0.6‰ and δ15N: 8.5±0.9‰) and turtles caught on the continental shelf (δ13C: -16.7±0.6‰ and δ15N: 8.4±1.3‰) did not differ in their isotopic signatures, suggesting that their diets include the same prey types. A mixing model revealed that for the turtles here analysed, squid and the jellyfish Cotylorhiza tuberculata were the most relevant prey, although stomach contents analysis revealed that carnivorous jellyplankton, neuston, fish and other cephalopods were also consumed. Gut content analysis also indicated that most of the prey identified, including all fish and most cephalopods, were of pelagic origin. Thus, loggerhead sea turtles inhabiting central regions of the western Mediterranean appear to seldom exploit benthic prey, even while on the continental shelf.
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Gales, NJ, and AJ Cheal. "Estimating diet composition of the Australian sea lion (Neophoa cinerea) from scat analysis: an unrliable technique." Wildlife Research 19, no. 4 (1992): 447. http://dx.doi.org/10.1071/wr9920447.
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Knowledge of the diet of the Australian sea-lion (Neophoca cinerea) has been restricted to anecdotal, qualitative accounts. In this study, we tested the validity of using identifiable prey remains in scats to quantify the diet of N. cinerea by analysis of scats from free-ranging sea-lions and feeding trials on captive sea-lions. Identifiable remains in the scats of free-ranging animals occurred infrequently: otoliths (n = 8) were present in only 9% of scats, cephalopod beaks (n = 23) in only 24% and lobster (Panulirus cygnus) remains in 7%. These limited data, combined with analysis of contents of five stomachs, indicated that N. cinerea has a broad diet and feeds on some benthic species. Feeding trials on two captive sea-lions demonstrated that scats were not representative of the diet. Fewer than 2% of ingested otoliths (by number) were recovered in scats. Otoliths less than 5 mm long were absent from scats; recovery of larger otoliths increased with their size. Defaecated otoliths were eroded by at least 28% (by length) during digestion. Transit of cephalopod mouth parts in two captive animals was variable (98% and 9% recovery), with only beaks of small cephalopods passing through the pyloric canal. The complete digestion of otoliths in transit through the gut tract and the variable recovery of cephalopod beaks indicated that scats cannot be used even for a qualitative description of the diet of N. cinerea.
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Ponganis, P. J., and T. K. Stockard. "Short Note: The Antarctic toothfish: how common a prey for Weddell seals?" Antarctic Science 19, no. 4 (October 1, 2007): 441–42. http://dx.doi.org/10.1017/s0954102007000715.
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The Antarctic toothfish (Dissostichus mawsoni Norman) has been considered an occasional large prey item of the Weddell seal (Leptonychotes weddellii Lesson) (Kooyman 1967, Calhaem & Christoffel 1969, Testa et al. 1985, Castellini et al. 1992, Davis et al. 1999, Fuiman et al. 2002). The seal's most common prey is the Antarctic silverfish (Pleuragramma antarcticum Boulenger) as well as benthic and sub-ice fish, cephalopods, and crustaceans (Dearborn 1965, Green & Burton 1987, Plotz 1987, Plotz et al. 1991, Castellini et al. 1992, Burns et al. 1998).
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Wollesen, Tim, Charuay Sukhsangchan, Pedro Seixas, Jaruwat Nabhitabhata, and Andreas Wanninger. "Analysis of neurotransmitter distribution in brain development of benthic and pelagic octopod cephalopods." Journal of Morphology 273, no. 7 (March 28, 2012): 776–90. http://dx.doi.org/10.1002/jmor.20023.
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Anderson, T. J., and R. C. Babcock Leigh. "Subcutaneous electromagnetic tagging of benthic octopus: a preliminary evaluation." Marine and Freshwater Research 50, no. 3 (1999): 225. http://dx.doi.org/10.1071/mf98152.
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Electromagnetic tags were subcutaneously implanted in the dorsal crown of 28 octopus (20 aquarium tagged; and 8 wild octopus tagged in situ) from two species: Octopus tetricus and O. maorum. Laboratory tagged octopus retained tags for the duration of the study (14 months), as did octopus tagged in the wild (13 weeks). No signs of lesions, physical deterioration, or abnormal behaviours were apparent in either laboratory or field tagged octopus. Tagging had no significant effect on growth trajectories. Both laboratory and field tagged octopus appeared healthy, physically vigorous, maintained voracious apetites, and regularly stalked and attacked vigorous prey (laboratory observations only). Subcutaneously implanted electromagnetic tags enabled individuals to be tagged, and tags to be read in situ with minimal disturbance to the animal. Electromagnetic tagging is a potentially invaluable tool in studying benthic octopus and may have similar value in the study of many cephalopods and other soft bodied organisms.
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Lemanis, Robert, Stefan Zachow, Florian Fusseis, and René Hoffmann. "A new approach using high-resolution computed tomography to test the buoyant properties of chambered cephalopod shells." Paleobiology 41, no. 2 (February 23, 2015): 313–29. http://dx.doi.org/10.1017/pab.2014.17.
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AbstractThe chambered shell of modern cephalopods functions as a buoyancy apparatus, allowing the animal to enter the water column without expending a large amount of energy to overcome its own weight. Indeed, the chambered shell is largely considered a key adaptation that allowed the earliest cephalopods to leave the ocean floor and enter the water column. It has been argued by some, however, that the iconic chambered shell of Paleozoic and Mesozoic ammonoids did not provide a sufficiently buoyant force to compensate for the weight of the entire animal, thus restricting ammonoids to a largely benthic lifestyle reminiscent of some octopods. Here we develop a technique using high-resolution computed tomography to quantify the buoyant properties of chambered shells without reducing the shell to ideal spirals or eliminating inherent biological variability by using mathematical models that characterize past work in this area. This technique has been tested onNautilus pompiliusand is now extended to the extant deep-sea squidSpirula spirulaand the Jurassic ammoniteCadocerassp. hatchling.Cadocerasis found to have possessed near-neutral to positive buoyancy if hatched when the shell possessed between three and five chambers. However, we show that the animal could also overcome degrees of negative buoyancy through swimming, similar to the paralarvae of modern squids. These calculations challenge past inferences of benthic life habits based solely on calculations of negative buoyancy. The calculated buoyancy ofCadocerassupports the possibility of planktonic dispersal of ammonite hatchlings. This information is essential to understanding ammonoid ecology as well as biotic interactions and has implications for the interpretation of geochemical data gained from the isotopic analysis of the shell.
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Pethybridge, H., R. Daley, P. Virtue, E. C. V. Butler, D. Cossa, and P. D. Nichols. "Lipid and mercury profiles of 61 mid-trophic species collected off south-eastern Australia." Marine and Freshwater Research 61, no. 10 (2010): 1092. http://dx.doi.org/10.1071/mf09237.
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Total mercury (Hg) concentrations and lipid composition data, including fatty acid profiles, for 61 mid‐trophic species (fish, cephalopods, crustaceans) collected from continental slope waters off south‐east Australia were examined. Overall, Hg concentrations were greatest in fish (0.01–0.30 μg g–1 ww) (with highest content found in barracouta (Thyrsites atun) and whiptails (Coelorinchus fasciatus)), compared with cephalopods (0.01 and 0.17 μg g–1 ww) and crustaceans (<0.04 μg g–1 ww). Lipid composition varied between species and within habitat (mesopelagic, bathypelagic and benthic). Mean total lipid content ranged from 0.5 to 13.2% ww, and in most species was dominated by triacylglycerols and phospholipids. In fish and squid, fatty acids were generally dominated by monounsaturated fatty acids, whereas crustaceans were higher in polyunsaturated fatty acids. Multidimensional scaling analyses separated species into groupings according to their fatty acid composition that could be interpreted with taxonomic, trophic and habitat information. Discriminant function analyses indicated the most influential (predictor) fatty acids for each group. Biochemical profile classifications can be used in wider trophodynamic studies to understand contaminant transfer, trophic relationships and community dynamics in marine environments.
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Moore, P. G. "Alexander Charles Stephen (1893–1966): contributions on Scottish benthic ecology, systematics and biological recording." Archives of Natural History 49, no. 1 (April 2022): 41–61. http://dx.doi.org/10.3366/anh.2022.0757.
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Alexander Charles Stephen (1893–1966) was a Scottish zoologist who, during a long career at the Royal Scottish Museum in Edinburgh, had interests in many fields: benthic marine ecology, systematics of Sipunculida and Echiura, natural history of cephalopods, cetaceans, fishes, turtles, birds and amphipods. He helped set up the Fair Isle Bird Observatory, eventually becoming one of its trustees, and served as President of the Royal Physical Society of Edinburgh. He had an amateur interest in astronomy. He co-edited the Scottish Naturalist and, in 1935, became Keeper of Natural History at the Royal Scottish Museum, yet little has been published about him and his contributions except for brief obituaries. His biography is here expanded, his scientific contributions assessed and a bibliography of his publications presented.
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Hart, Malcolm B., Kevin N. Page, Gregory D. Price, and Christopher W. Smart. "Reconstructing the Christian Malford ecosystem in the Oxford Clay Formation (Callovian, Jurassic) of Wiltshire: exceptional preservation, taphonomy, burial and compaction." Journal of Micropalaeontology 38, no. 2 (July 19, 2019): 133–42. http://dx.doi.org/10.5194/jm-38-133-2019.
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Abstract. The Christian Malford lagerstätte in the Oxford Clay Formation of Wiltshire contains exceptionally well-preserved squid-like cephalopods, including Belemnotheutis antiquus (Pearce). Some of these fossils preserve muscle tissue, contents of ink sacks and other soft parts of the squid, including arms with hooks in situ and the head area with statoliths (ear bones) present in life position. The preservation of soft-tissue material is usually taken as an indication of anoxic or dysaerobic conditions on the sea floor and within the enclosing sediments. Interestingly, in the prepared residues of all these sediments there are both statoliths and arm hooks as well as abundant, species-rich, assemblages of both foraminifera and ostracods. Such occurrences appear to be incompatible with an interpretation of potential sea floor anoxia. The mudstones of the Oxford Clay Formation may have been compacted by 70 %–80 % during de-watering and burial, and in such a fine-grained lithology samples collected for microfossil examination probably represent several thousand years and, therefore, a significant number of foraminiferal life cycles. Such samples (even if only 1–2 cm thick) could, potentially, include several oxic–anoxic cycles and, if coupled with compaction, generate the apparent coincidence of well-preserved, soft-bodied, cephalopods and diverse assemblages of benthic foraminifera.
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Sommerville, E., M. E. Platell, W. T. White, A. A. Jones, and I. C. Potter. "Partitioning of food resources by four abundant, co-occurring elasmobranch species: relationships between diet and both body size and season." Marine and Freshwater Research 62, no. 1 (2011): 54. http://dx.doi.org/10.1071/mf10164.
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The present study has tested statistically the hypothesis that the diets of four abundant and co-occurring elasmobranch species differ and change with body size and season and has determined the extent of any differences, to ascertain their potential for reducing competition for food resources. Non-metric multivariate analyses of volumetric contributions of dietary categories to stomach contents demonstrated that the dietary compositions of the rays Myliobatis australis and Aptychotrema vincentiana and the sharks Heterodontus portusjacksoni and Squatina australis in south-western Australian waters differed. M. australis fed predominantly on benthic invertebrates, whereas A. vincentiana consumed large volumes of teleosts. The durophagous H. portusjacksoni ingested a wide variety of prey, including gastropods, cephalopods, bivalves, echinoderms and teleosts, whereas S. australis ingested mainly teleosts and cephalopods. The extent and pattern of change in the diet with increasing body size varied among species. For example, the diet of H. portusjacksoni changed abruptly to larger, harder-bodied prey at ∼400-mm total length, whereas that of S. australis underwent small, gradual changes with increasing body size. The diets of each species changed seasonally. Inter- and intraspecific variations in dietary composition reduce the potential for competition between and within these abundant elasmobranch species in south-western Australian waters.
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Tobar, Claudio N., David Carmona, Jaime R. Rau, Jaime A. Cursach, and Jonnathan Vilugrón. "Dieta invernal del cormorán imperial Phalacrocorax atriceps (Aves: Suliformes) en Bahía Caulín, Chiloé, sur de Chile." Revista de Biología Marina y Oceanografía 54, no. 2 (September 13, 2019): 227. http://dx.doi.org/10.22370/rbmo.2019.54.2.1907.
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The imperial cormorant (Phalacrocorax atriceps) is one of the most abundant cormorant species in the Chilean channels and fjords. Although its reproductive and non-reproductive distributions have been studied, works on its diet are inexistent. This paper describes the diet and determines the dominance and diversity of the prey consumed during the winter periods of 2011 and 2014 in Caulín Bay, Chiloé, southern Chile. A total of 73 pellets were collected (30 in 2011 and 43 in 2014). Prey were identified and classified into three categories: fishes (53.57%), cephalopods (39.29%) and crustaceans (7.14%). When prey consumption was analyzed according to their distribution in the water column, we observed statistically significant differences in a preference of benthic demersal over pelagic prey.
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Mendonça, Luana Marina De Castro, Carmen Regina Parisotto Guimarães, and Silvio Felipe Barbosa Lima. "Mollusk bycatch in trawl fisheries targeting the Atlantic seabob shrimp Xiphopenaeus kroyeri on the coast of Sergipe, northeastern Brazil." Papéis Avulsos de Zoologia 59 (August 15, 2019): e20195933. http://dx.doi.org/10.11606/1807-0205/2019.59.33.
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The malacofauna bycatch of sea-bob shrimp Xiphopenaeus kroyeri (Heller, 1862) trawl fisheries on the coast of Sergipe was studied for 5 years. The malacofauna bycatch considered was obtained in nine oceanographic sampling campaigns carried out between May 1999 and June 2003 in 18 stations distributed in six transects along depths of 10, 20 and 30 m. A total of 2,669 individuals of mollusk belonging to 54 species were captured on the 18 sea-bob shrimp trawl stations carried out along the coast of Sergipe. The considerable richness of mollusks was composed by 19 families and 31 species of gastropods, 12 families and 19 species of bivalves and 2 families and 4 species of cephalopods. The highest abundance were observed at stations 13 (373 individuals) and 16 (685 individuals) that represents the lowest depth (10 m) and the richness was higher at stations 15 and 12 (17 and 11 species, respectively) both located at the highest depth (30 m). Cephalopods had high frequency of occurrence being collected in all the stations and by far the most abundant group with a total of 2,488 individuals captured. On the other hand, gastropods (with 142 individuals found in 83.3% of stations) and bivalves (about 1% of the individuals collected) contribute with a much smaller percentage of individuals captured. Lolliguncula brevis (Blainville, 1823) was most representative cephalopod in number and frequency of occurrence. Arcidae, Conidae, Muricidae and Strombidae were the families with the higher number of species in the trawl-fishery. Among bivalves, Pitar arestus (Dall & Simpson, 1901) and Spathochlamys benedicti (Verrill & Bush [in Verrill], 1897) were the species with higher frequency of occurrence. Although the considerable sample effort and a number of mollusks captured as bycath, the richness estimators indicated that the species richness could increase with additional sampling effort in the study area. The present study expands the taxonomic alpha knowledge on the mollusk bycatch of sea-bob shrimp trawl fisheries on the northeastern coast of Brazil. However, it is of crucial importance to assess urgently the negative impacts of the sea-bob shrimp trawl fisheries on the benthic community of the entire coast of Brazil.
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D’Iglio, Claudio, Serena Savoca, Paola Rinelli, Nunziacarla Spanò, and Gioele Capillo. "Diet of the Deep-Sea Shark Galeus melastomus Rafinesque, 1810, in the Mediterranean Sea: What We Know and What We Should Know." Sustainability 13, no. 7 (April 2, 2021): 3962. http://dx.doi.org/10.3390/su13073962.
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We reviewed literature on the diet of the Galeus melastomus Rafinesque, 1810, from the Mediterranean Sea. Specific keywords (“Galeus melastomus diet”, “feeding habits”, “trophic position”, “biology”, “deep environment adaptation”) in the principal data sources, such as Web of Science, PubMed, and Google Scholar were used. Seventeen studies conducted on the diet and trophic position of G. melastomus have been considered for Mediterranean Sea regions. The feeding habits have been analyzed in many areas of the western basin; instead, for the Tyrrhenian, Adriatic, and central Mediterranean Seas, information is outdated and fragmentary. In all investigated sub areas, the data showed that G. melastomus is an opportunistic demersal supra benthic predator, benthic feeder, and scavenger, that adapts its diet to the seasonal and geographical fluctuations of the prey availability. It occupies a generalist niche showing individual specialization. In all reviewed Mediterranean sub areas, the most important prey groups were crustaceans, cephalopods, and teleost fishes. Taxa percentage in its diet composition can vary depending on different habitats with ontogenetic development of individuals, depth (that is correlated with the ontogenetic development), seasonal availability, and distribution of different prey groups. Widening knowledge of G. melastomus feeding habits is a fundamental tool for better understand meso and bathy-pelagic ecosystems.
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Pervushov, E. M., V. B. Seltser, E. A. Kalyakin, E. I. Ilyinskij, and I. P. Ryabov. "The Turonian-Coniacian deposits of the south-west of the Ulyanovsk-Saratov trough." Proceedings of higher educational establishments. Geology and Exploration, no. 5 (November 28, 2019): 10–27. http://dx.doi.org/10.32454/0016-7762-2019-5-10-27.
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Integrated study of a series of the Turonian and Coniacian complete geological records has revealed the stratigraphic completeness and specified the faunal contents of the deposits. The south and the southwest of the Ulyanovsk-Saratov trough have been shown to comprise the thickest beds of the studied interval represented by carbonate and carbonate-terrigenous rocks. Northwards, in the zone of the Saratov dislocations, the Turonian – Coniacian bodies are peculiar for terrigenous and terrigenous-carbonate compositions. The beds are ubiquitously monotonous, which complicates identifications at the stage and the substage levels. Distributions of the benthic foraminifer assemblages and the data on the finds of cephalopods, inoceramus, echinoderms, brachiopods and siliceous sponges have allowed to distinguish detailed biostratigraphic units at the level of biozones traced within the examined structural units. An attempt has been made to reconstruct the conditions in the marine environment.
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Beyst, Bregje, Kris Hostens, and Jan Mees. "Factors influencing the spatial variation in fish and macrocrustacean communities in the surf zone of sandy beaches in Belgium." Journal of the Marine Biological Association of the United Kingdom 82, no. 2 (April 2002): 181–87. http://dx.doi.org/10.1017/s0025315402005337.
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An inventory of fish and epibenthic macrocrustaceans of the surf zones of sandy beaches along the Belgian coast was constructed. The surf zones were sampled intensively with a 2-m beam trawl in April–May 1996 (12 stations) and 26 species were recorded belonging to caridean shrimps (4), brachyuran crabs (5), cephalopods (1) and fish (16). The brown shrimp Crangon crangon dominated almost all samples (>80%). Total densities exceeded several times 250 ind 100 m−2 and 10 ind 100 m−2 if C. crangon was excluded. An east–west distinction as found in other (epi)benthic studies in deeper waters of the Belgian coast, was not found in the surf zone during this study. Spatial variation was mainly correlated with local characteristics such as turbidity of the water and the morphodynamic features of both the beach and the adjacent subtidal area.
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Lipej, L., B. Mavrič, D. Paliska, and C. Capapé. "Feeding habits of the pelagic stingray Pteroplatytrygon violacea (Chondrichthyes: Dasyatidae) in the Adriatic Sea." Journal of the Marine Biological Association of the United Kingdom 93, no. 2 (April 3, 2012): 285–90. http://dx.doi.org/10.1017/s0025315412000197.
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The feeding habits of the pelagic stingray (Pteroplatytrygon violacea) were studied using 84 stomachs of specimens caught in the northern Adriatic Sea in the period from April 2004 to October 2005. Percentage of empty stomachs found was overall very low, being a bit bigger in smaller specimens. The diet consisted of two main taxonomic groups such as teleost fish and cephalopods, but few specimens of crustaceans were recorded as well. The main food item was represented by anchovy, while cuttlefish and red band fish represented the alternative preys. Prey size was positively correlated with the size of predator. The proportion of anchovies in the diet grew with size of predator, while the one for red band fish decreased. The stingray was confirmed to be a top predator of pelagic fish species, although the presence of benthic prey shows that it feeds also at the bottom.
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Colominas-Ciuró, R., M. Bertellotti, VL D’Amico, E. Carabajal, J. Benzal, V. Vidal, M. Motas, M. Santos, N. Coria, and A. Barbosa. "Diet, antioxidants and oxidative status in pygoscelid penguins." Marine Ecology Progress Series 665 (April 29, 2021): 201–16. http://dx.doi.org/10.3354/meps13651.
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Ecologically similar marine species inhabiting the same areas compete for food resources. Such competition is reduced by resource-partitioning strategies that may affect physiology. For instance, diet and feeding strategies may affect the antioxidant defences or the production of reactive oxygen species. Oxidative stress is defined as the imbalance between pro-oxidants and antioxidant defences. If such an imbalance favours the former, this can lead to oxidative damage, and oxidative stress increases. However, to our knowledge, how free-ranging animals adjust their oxidative status in relation to their foraging habitats, diet and dietary antioxidants has not yet been studied. Penguins are an interesting biological model for such a comparison because their diet, based on krill, fish and/or cephalopods, presents strong variation in dietary antioxidant content. We therefore examined trophic level (δ15N), foraging habitat (δ13C), dietary antioxidants (retinol, α-tocopherol and astaxanthin) and oxidative status (plasma non-enzymatic antioxidant capacity and oxidative damage) in pygoscelid penguins (chinstrap Pygoscelis antarcticus, gentoo P. papua and Adélie P. adeliae) breeding in Antarctica. We found interspecific differences in all variables analysed except α-tocopherol. Gentoo penguins exploited more cephalopods and fish in coastal and benthic habitats, Adélies showed an intermediate position, whereas chinstraps foraged more on krill and fish in pelagic waters. Dietary antioxidant levels showed specific patterns resulting in relationships with prey items. However, we did not find any clear relationships between dietary antioxidants and species-specific antioxidant capacity, suggesting the importance of endogenously produced antioxidants. Oxidative status appeared to be differently related to foraging strategy and antioxidant capacity in each species.
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Rees, Jan. "Palaeoecological implications of neoselachian shark teeth from the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland." Acta Geologica Polonica 62, no. 3 (December 28, 2012): 397–402. http://dx.doi.org/10.2478/v10263-012-0022-y.
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ABSTRACT Rees, J. 2012. Palaeoecological implications of neoselachian shark teeth from the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland. Acta Geologica Polonica, 62 (3), 397-402. Warszawa. Systematic sampling through the Middle and Upper Bathonian strata at Gnaszyn has resulted in the discovery of 13 neoselachian teeth. Systematically, the teeth represent five taxa including Sphenodus sp., Protospinax sp. 1, Protospinax sp. 2, Palaeobrachaelurus sp. and another, indeterminate orectolobiform. The presence of two species of the flattened and bottom-dwelling Protospinax and two different orectolobiforms that are likely to have lived near the bottom, is a strong indication of oxygenated bottom conditions at the time of deposition. The dietary preferences of these taxa included a wide variety of benthic invertebrates. The synechodontiform Sphenodus may have been the first pelagic predatory neoselachian in the Jurassic, equipped with high and slender piercing teeth that formed a tearing-type dentition. The diet of Sphenodus probably included bony fish, smaller sharks and cephalopods.
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Valenzuela-Quiñonez, Fausto, Felipe Galván-Magaña, David A. Ebert, and E. Alberto Aragón-Noriega. "Feeding habits and trophic level of the shovelnose guitarfish (Pseudobatos productus) in the upper Gulf of California." Journal of the Marine Biological Association of the United Kingdom 98, no. 7 (July 10, 2017): 1783–92. http://dx.doi.org/10.1017/s0025315417000832.
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The shovelnose guitarfish (Pseudobatos productus) is the most abundant and economically important batoid in Gulf of California fisheries. Despite the importance of the guitarfish in the demersal ecosystem, its trophic relationships are poorly understood. Results from stomach content and stable isotope analysis indicate P. productus is a specialist predator that feeds on coastal benthic organisms, mainly crustaceans, followed by fishes and cephalopods in the Upper Gulf of California. Males and females did not differ in dietary composition and isotopic values. Pseudobatos productus displayed ontogenetic changes in the diet, with smaller, immature individuals having a more specialized diet and mature individuals becoming generalist predators. Size classes I (<570 mm) and II (>570 mm) fed almost exclusively on crustaceans (99.78% and 82.37 %IRI, respectively). Size class III (>832 mm) increased consumption of fishes (22.11 %IRI) and squid (6.54 %IRI). Ontogenetic diet shifts were strongly supported by the SIAR mixing model. Stomach content and stable isotope analyses classify P. productus as a second-order predator.
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Hallett, Chris S., and Ross K. Daley. "Feeding ecology of the southern lanternshark (Etmopterus baxteri) and the brown lanternshark (E. unicolor) off southeastern Australia." ICES Journal of Marine Science 68, no. 1 (September 8, 2010): 157–65. http://dx.doi.org/10.1093/icesjms/fsq143.
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Abstract Hallett, C. S., and Daley, R. K. 2011. Feeding ecology of the southern lanternshark (Etmopterus baxteri) and the brown lanternshark (E. unicolor) off southeastern Australia. – ICES Journal of Marine Science, 68: 157–165. Little is known about the ecological interactions between bycatch species and orange roughy (Hoplostethus atlanticus) within exploited slope and seamount communities off Tasmania. The diet of Etmopterus baxteri and E. unicolor, two important bycatch species of these fisheries, is described using four indices [percentage frequency of occurrence, percentage by number, percentage by weight, and percentage by the index of relative importance (%IRI)] calculated for broad prey categories, individual prey taxa, and functional prey groups. The identifiable diet of E. unicolor was dominated by benthic cephalopods (96%IRI), whereas benthic teleost prey, notably orange roughy (43%IRI), dominated the diet of E. baxteri. Similar trophic mechanisms appear to support aggregations of orange roughy and Etmopterus spp. off Tasmania; they feed on demersal species and mesopelagic or vertically migrating nekton advected laterally onto the mid-slope. The importance of teleost prey in the diet of E. baxteri apparently increases with shark length, whereas crustaceans become less important, which is a similar diet shift to that of orange roughy. Etmopterus baxteri is both a potential competitor and predator of orange roughy in these ecosystems. Fishery managers need to understand and consider the complex trophic interactions between orange roughy, sharks, and other exploited species in managing recently reopened deep-water fisheries off southeastern Australia.
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Lejeune, Benjamin, Dorothée Kopp, Sonia Mehault, and Maud Aline Mouchet. "Assessing the diet and trophic level of marine fauna in a fishing ground subject to discarding activity using stable isotopes." PLOS ONE 17, no. 6 (June 7, 2022): e0268758. http://dx.doi.org/10.1371/journal.pone.0268758.
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Discarding practices have become a source of concern for the perennation of marine resources, prompting efforts of discard reduction around the globe. However, little is known about the fate of discards in marine environments. Discarding may provide food for various marine consumers, potentially affecting food web structure and stability. Yet, quantifying reliance upon discards is difficult because identity and frequency of discards may change according to multiple factors, and most previously used diet assessment techniques do not allow to assume consistency of feeding strategies over time. One currently untested hypothesis is that significant contribution of discards over time should reflect in increased trophic level (TL) of marine fauna, particularly in low TL consumers. Here, we explored this hypothesis by modeling the TL and assimilated diet of consumers living in fishing grounds subject to important discarding activity using stable isotope analysis. We found indications that benthic invertebrates and Chondrichthyes may depict a higher than expected TL, while other fish tend to depict similar to lower TL compared to global averages from the literature. Based on prior knowledge of discard consumption in the same area, stable isotope mixing models congruently revealed that discards may represent substantial portions of the assimilated diet of most benthic invertebrate macrofauna, cephalopods and Chondrichthyes. We highlight limitations and challenges of currently used diet assessment techniques to study discard consumption and stress that understanding their reintegration in marine food webs is crucial in the context of an ecosystem approach to fisheries management and to better understand the functioning of marine ecosystems subject to fishing.
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CATALANO, SARAH R. "A review of the families, genera and species of Dicyemida Van Beneden, 1876." Zootaxa 3479, no. 1 (September 12, 2012): 1. http://dx.doi.org/10.11646/zootaxa.3479.1.1.
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The classification of the species in the phylum Dicyemida Van Beneden, 1876, a group of small organisms whichparasitise the renal appendages of benthic cephalopods, is reviewed. While dicyemid parasites have simple multicellularmorphology, their lifecycle is complex and it is uncertain whether their affinities are with the protozoans or metazoans.Hence they are commonly given an intermediate ‘mesozoan’ status. Although 112 species are described, confusion existsfor 20% of the taxa over the validity of certain families, genera and species, which has been attributed to incomplete andinformation-poor descriptions, loss of type specimens, errors in taxonomy and conceptual differences. The history ofdicyemids dating from the first known reference by Filippo Calvolini of Italy in 1787 is presented, along with thecharacteristics which are commonly used to classify genera and species. All species described to date are listed withreference to the original published records and the validity of ambiguous records is explored. A way forward usingalternative technologies such as molecular genetic methods based on next generation sequencing platforms is suggested,which may help to address unresolved systematic and life history questions surrounding this parasite group. This review aims to assist taxonomists to help unravel the confusion surrounding the poorly studied and little understood Dicyemida.
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Powter, David Mark, William Gladstone, and Margaret Platell. "The influence of sex and maturity on the diet, mouth morphology and dentition of the Port Jackson shark, Heterodontus portusjacksoni." Marine and Freshwater Research 61, no. 1 (2010): 74. http://dx.doi.org/10.1071/mf09021.
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Dietary studies are essential for an understanding of elasmobranch ecology and their role in marine ecosystems. The diet, head morphology and dentition of Heterodontus portusjacksoni, an abundant, epibenthic shark in the coastal waters of temperate eastern Australia, were examined in 2004–2005. The stomach contents of the juvenile, subadult and adult stages of 136 males and 100 females were examined. Diets were broad (32 prey taxa), but dominated by molluscs, teleosts and cephalopods. Analyses of stomach contents data demonstrated that diet differed significantly by ontogenetic stage, but not by sex. Juveniles and subadults consumed mainly benthic infauna and epifauna, with subadults ingesting greater amounts of diogenid crustaceans, and adult diets dominated by demersal/pelagic prey. Trophic level differed ontogenetically, from secondary consumers as juveniles and subadults to tertiary consumers as adults. The mainly tricuspidate juvenile dentition changed with maturity to a greater proportion of large molariform distal teeth, whereas the snout and jaw lengthened and broadened. Adult males retained a greater proportion of anterior S-family teeth than females, which was most likely related to copulation. The ontogenetic variation in dietary composition, facilitated by differences in dentition and mouth morphology, demonstrated that dietary resources were partitioned ontogenetically.
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CATALANO, SARAH R., IAN D. WHITTINGTON, STEPHEN C. DONNELLAN, TERRY BERTOZZI, and BRONWYN M. GILLANDERS. "First comparative insight into the architecture ofCOImitochondrial minicircle molecules of dicyemids reveals marked inter-species variation." Parasitology 142, no. 8 (April 16, 2015): 1066–79. http://dx.doi.org/10.1017/s0031182015000384.
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SUMMARYDicyemids, poorly known parasites of benthic cephalopods, are one of the few phyla in which mitochondrial (mt) genome architecture departs from the typical ~16 kb circular metazoan genome. In addition to a putative circular genome, a series of mt minicircles that each comprises the mt encoded units (I–III) of the cytochromecoxidase complex have been reported. Whether the structure of the mt minicircles is a consistent feature among dicyemid species is unknown. Here we analyse the complete cytochromecoxidase subunit I (COI) minicircle molecule, containing theCOIgene and an associated non-coding region (NCR), for ten dicyemid species, allowing for first time comparisons between species of minicircle architecture, NCR function and inferences of minicircle replication. Divergence inCOInucleotide sequences between dicyemid species was high (average net divergence = 31·6%) while within species diversity was lower (average net divergence = 0·2%). The NCR and putative 5′ section of theCOIgene were highly divergent between dicyemid species (average net nucleotide divergence of putative 5′COIsection = 61·1%). No tRNA genes were found in the NCR, although palindrome sequences with the potential to form stem-loop structures were identified in some species, which may play a role in transcription or other biological processes.
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FERNANDES, Jackellynne Fernanda Farias, Jailza FREITAS, Yago Bruno Silveira NUNES, Rafael Santos LOBATO, and Marina Bezerra FIGUEIREDO. "FEEDING HABITS OF Lutjanus synagris (TELEOSTEI: LUTJANIDAE) IN THE AMAZON COAST OF THE NORTHEAST REGION OF BRAZIL." Boletim do Instituto de Pesca 46, no. 4 (March 2021): 1–12. http://dx.doi.org/10.20950/1678-2305.2020.46.4.592.
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The feeding habit of lane snapper Lutjanus synagris was analyzed qualitatively and quantitatively, related to seasonality, its ontogenetic development, and the relationship between food and biotic and abiotic conditions on the Amazon Coast of Maranhão, between June 2018 and May 2019. Numerical, gravimetric, and ecological index methods were used to show the relative importance or preference of a category or food item in the diet. The food composition was studied related to the sex, size of the predator and seasonality. Of 359 stomachs sampled, 54 were empty due to regurgitation and presented a vacuity coefficient (Cv%) of 15.04%. In the analysis of diets between the sexes, it was possible to identify a greater participation of fish (30.43%) and Crabs (26.10%) for females, Shrimp (36.23%) and Organic Matter Not Identified (OMNI) (18.84%) in males. The diet showed spatial differences in length distributions. The analysis of stomach contents showed the presence synthetic materials (mesoplastics ranging from 5.0 mm to 2.5 cm) in 5.52% of the samples. The main food items found were from the Brachyura and Caridea species. The results clearly demonstrate that lane snapper prefers benthic prey, presenting a carnivorous and generalist-opportunistic habit. Its diet is also composed of demersal-pelagic species, such as Cephalopods and Teleost fish.
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Underwood, Charlie J. "Faunal transport within event horizons in the British Upper Silurian." Geological Magazine 131, no. 4 (July 1994): 485–98. http://dx.doi.org/10.1017/s0016756800012115.
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AbstractMany marine fossil concentrations are considered the result of episodic sedimentological events, and in particular those due to storms. Most storm or tempestite concentrations are identified as autochthonous or parautochthonous assemblages created by a variety of winnowing processes within shallow water environments. In contrast, samples described here from both a ‘shelf’ and a ‘basinal’ setting within the Ludlow (Upper Silurian) succession of the Welsh Basin reveal the presence of a biota transported by tempestite activity into a setting dominated by a more offshore biota. Tempestite horizons from within an ‘outer shelf’ mud dominated setting include shelly lenses with a transported fauna abounding in gastropods, tentaculitids and atrypid brachiopods, the background sediment being rich in graptolites, cephalopods and small strophomenid brachiopods. Within the ‘basinal’ area, distal tempestites range from minor siltstone layers to thicker bioclastic limestone lenses. The siltstones are largely graptolitic (dominated byBohemograptus), with some small brachiopods, whilstSaetograptus colonusis the only common graptolite in the limestones, which also contain a fauna of broken brachiopods and bryozoa. The transport of assemblages distally into a variety of settings represents a potential source of error in palaeoecological analysis. Transported assemblages may, however, provide evidence of the composition of both benthic and pelagic shallower water faunas no longer knownin situ.
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Rogers, Paul J., Charlie Huveneers, Brad Page, Derek J. Hamer, Simon D. Goldsworthy, James G. Mitchell, and Laurent Seuront. "A quantitative comparison of the diets of sympatric pelagic sharks in gulf and shelf ecosystems off southern Australia." ICES Journal of Marine Science 69, no. 8 (July 24, 2012): 1382–93. http://dx.doi.org/10.1093/icesjms/fss100.
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Abstract Rogers, P. J., Huveneers, C., Page, B., Hamer, D. J., Goldsworthy, S. D., Mitchell, J. G., and Seuront, L. 2012. A quantitative comparison of the diets of sympatric pelagic sharks in gulf and shelf ecosystems off southern Australia. – ICES Journal of Marine Science, 69: . Predator–prey dynamics represent an important determinant in the functioning of marine ecosystems. This study provides the first quantitative investigation of the diets of sympatric pelagic shark species in gulf and shelf waters off southern Australia. Stomachs of 417 sharks collected from fishery catches between 2007 and 2011 were examined, including 250 bronze whalers, 52 shortfin makos, 49 dusky sharks, 39 smooth hammerheads, and 27 common threshers. Dusky sharks had the highest dietary diversity of the five species examined. We found overlap in the consumption of cephalopods, small pelagic teleosts, crustaceans, and benthic teleosts in bronze whalers, dusky sharks, and smooth hammerheads, and preliminary evidence of specialization in the highly migratory species, the common thresher and the shortfin mako. Findings were discussed and compared with previous studies in other temperate marine ecosystems. This study will significantly improve the understanding of the ecological roles of these top predators in the gulf and shelf habitats off southern Australia, and enhance the ecosystem models being developed for this unique bioregion.
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Costa, Paulo A. S., Adriana C. Braga, Giovanna S. Malavolti, Marcos A. L. Franco, Pedro V. Gatts, Andressa Batista, and Carlos E. Rezende. "Feeding habits and trophic status of Merluccius hubbsi along the northernmost limit of its distribution in the South-western Atlantic." Journal of the Marine Biological Association of the United Kingdom 99, no. 06 (April 12, 2019): 1399–408. http://dx.doi.org/10.1017/s0025315419000237.
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AbstractStomach contents analysis and stable isotope results indicate M. hubbsi is a generalist predator that feeds mainly on demersal fishes, followed by crustaceans and cephalopods. Ontogenetic changes in diet were identified, with fish importance increasing in the diet with hake size. Smaller hake (<250 mm) fed mostly on the sepiolid Semirossia tenera (89.45%IRI) and engraulid fish (89.96%IRI). Mid-sized hake (250–300 mm) fed mainly on benthic fish such as Bellator brachychir (95.63%IRI) and euphausiids (56.46%IRI), while larger hake (>300 mm) fed heavily on Dactylopterus volitans (94.80%IRI) and occasionally on a variety of teleosts. Significant correlations between δ13C (P < 0.05), THg (P < 0.001) and hake size occurred, whereas no relationship was observed between δ15N and hake size or δ15N and total mercury. Signatures were lowest in smaller hake with a tendency of increasing with size. Smaller and larger hake were significantly different in δ13C. Differences regarding isotopic niche width were quantified for each size group; trophic diversity and trophic redundancy among them were negligible, but hake >300 mm possibly have a larger feeding plasticity due to the combination of prey from a wide trophic level range.
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Brown, Alastair, Chris Hauton, Tanja Stratmann, Andrew Sweetman, Dick van Oevelen, and Daniel O. B. Jones. "Metabolic rates are significantly lower in abyssal Holothuroidea than in shallow-water Holothuroidea." Royal Society Open Science 5, no. 5 (May 2018): 172162. http://dx.doi.org/10.1098/rsos.172162.
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Recent analyses of metabolic rates in fishes, echinoderms, crustaceans and cephalopods have concluded that bathymetric declines in temperature- and mass-normalized metabolic rate do not result from resource-limitation (e.g. oxygen or food/chemical energy), decreasing temperature or increasing hydrostatic pressure. Instead, based on contrasting bathymetric patterns reported in the metabolic rates of visual and non-visual taxa, declining metabolic rate with depth is proposed to result from relaxation of selection for high locomotory capacity in visual predators as light diminishes. Here, we present metabolic rates of Holothuroidea, a non-visual benthic and benthopelagic echinoderm class, determined in situ at abyssal depths (greater than 4000 m depth). Mean temperature- and mass-normalized metabolic rate did not differ significantly between shallow-water (less than 200 m depth) and bathyal (200–4000 m depth) holothurians, but was significantly lower in abyssal (greater than 4000 m depth) holothurians than in shallow-water holothurians. These results support the dominance of the visual interactions hypothesis at bathyal depths, but indicate that ecological or evolutionary pressures other than biotic visual interactions contribute to bathymetric variation in holothurian metabolic rates. Multiple nonlinear regression assuming power or exponential models indicates that in situ hydrostatic pressure and/or food/chemical energy availability are responsible for variation in holothurian metabolic rates. Consequently, these results have implications for modelling deep-sea energetics and processes.
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Turra, Alexander, Flávia Borges Santos, Eduardo Bessa, Wellington Silva Fernandez, Ligia Coletti Bernadochi, and Márcia Regina Denadai. "Population biology and diet of the southern kingcroaker Menticirrhus americanus (Linnaeus, 1758) (Perciformes: Sciaenidae) in Caraguatatuba Bay, southeastern Brazil." Brazilian Journal of Oceanography 60, no. 3 (September 2012): 343–52. http://dx.doi.org/10.1590/s1679-87592012000300007.
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This study evaluated the spatio-temporal distribution, population biology and diet of Menticirrhus americanus in Caraguatatuba Bay. Samples were taken monthly between August 2003 and October 2004, by trawling in two previously selected areas. The northern area is more exposed to wave activity and is influenced by a river, functioning as a small estuary. In contrast, the southern area is relatively sheltered from wave energy and influenced to a lesser degree by smaller rivers. The fishes' length was measured, and the sex and gonadal stage macroscopically identified. The abundance of this species was compared between areas and among months. The diet was identified and quantified. M. americanus occurred in equal proportions in the two study areas, being most abundant in April 2004, followed by December 2003 and January 2004. The population was dominated by small immature individuals. The few individuals in maturation or mature that were captured showed no seasonal pattern of distribution. This species had a varied diet, feeding on worms (nemerteans, sipunculans and echiurans), mollusks (bivalves and cephalopods), polychaetes, crustaceans and fish. The presence of intact nematodes in the intestine suggests that these are parasites. The results demonstrated that M. americanus has a homogeneous spatial and temporal distribution in Caraguatatuba Bay, being uniformly distributed between the south and north areas as well as across the months. This species can be considered a carnivorous predator, showing a preference for consuming benthic sandy-beach species such as glycerids and other polychaetes, crustaceans, and bivalve siphons.
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Adams, N. J., C. Moloney, and R. Navarro. "Estimated food consumption by penguins at the Prince Edward Islands." Antarctic Science 5, no. 3 (September 1993): 245–52. http://dx.doi.org/10.1017/s0954102093000331.
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The consumption of food by the four species of breeding penguins at the Prince Edward Islands is assessed on an annual and seasonal basis. Total annual food consumption was estimated at 880 000 t, of which king penguins accounted for 74%, macaroni penguins 21%, rockhopper penguins 5% and gentoo penguins <1%. Pelagic fish, almost entirely myctophids, were the most important prey (70% of total prey biomass), followed by pelagic crustaceans (18%) and cephalopods (11%). Demersal fish and benthic crustaceans accounted for <1% of total consumption, being consumed only by gentoo penguins. Peak demands of between 2 and 3.3 × 106 kg d−1 occurred from October–December when three of the four species were breeding, including the two demi-populations of king penguins. Food demand decreased to 1.2 × 106 kg d−1 during winter when only king and gentoo penguins were present. Much of the prey are presumably captured within 300 km of the islands. Assuming an even distribution of foraging effort within their respective foraging ranges, rates of food transferred to penguins in November ranged from 4.1 × 10−3 g m−2 d−1 for macaroni penguins to 1.24 × 10−2 g m−2 d−1 for king penguins. In mid-July, transfer rates to king and gentoo penguins were 3.9 × 10−3 g m−2 d−1 and 6.7 × 10−3 g m−2 d−1, respectively. The importance of pelagic myctophid fish to penguin populations at the Prince Edward Islands is clear.
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Frey, Robert C. "Paleoecology of a well-preserved nautiloid assemblage from a Late Ordovician shale unit, southwestern Ohio." Journal of Paleontology 63, no. 5 (September 1989): 604–20. http://dx.doi.org/10.1017/s0022336000041238.
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A diverse, well-preserved assemblage of nautiloid cephalopods was collected from the Treptoceras duseri shale, a 1.5-m-thick claystone within the Waynesville Formation (Late Ordovician, early Richmondian) exposed in southwest Ohio. The strata, the enclosed fauna, and its taphonomy indicate deposition in a low-energy, mud-bottom marine environment, in water depths of 20–25 m, below wave base but within the zone of storm-current reworking.Nautiloid specimens consist of complete conchs that have been replaced by calcite. Twelve species of nautiloids, belonging to eight genera, representative of four orders, have been collected from the shale in southwest Ohio. Longiconic orthocones are clearly the dominant nautiloid morphotype present, with the assemblage dominated by three species of the longiconic orthocerid Treptoceras and with fewer numbers of the endocerid Cameroceras and the slender orthocerid Isorthoceras?, the cyrtoconic oncocerids Oncoceras and Manitoulinoceras, and rare specimens of the orthocerid Gorbyoceras, the oncocerid Zittelloceras, and the ascocerid Schuchertoceras.Nautiloid taphonomy, the diversity of nautiloid taxa present, the lack of postmortem buoyancy in the shells of the more common taxa, the recurrent nature of this assemblage, and the restricted distribution of this Treptoceras–Cameroceras fauna to portions of eastern North America in the Late Ordovician suggest that this nautiloid assemblage represents an in-situ accumulation of nautiloids representative of a living assemblage. These nautiloids were important elements associated with benthic communities in these epeiric sea mud-bottom environments and not simply assemblages of drifted, necroplanktonic shells.
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Childerhouse, Simon, Bruce Dix, and Nick Gales. "Diet of New Zealand sea lions (Phocarctos hookeri) at the Auckland Islands." Wildlife Research 28, no. 3 (2001): 291. http://dx.doi.org/10.1071/wr00063.
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Scat and regurgitate samples (n = 206) from New Zealand sea lions (Phocarctos hookeri) were collected at the Auckland Islands between December 1994 and February 1997. Most (82%) samples were collected during three summer seasons while the remainder (18%) were collected during a single winter season. Thirty-three taxa were identified from 3523 prey items. The six most abundant prey species accounted for 90% of all prey items. The two most numerically abundant prey species, octopus (Enteroctopus zelandicus) and opalfish (Hemerocoetes species) made up almost 50% of total prey items. Other important prey species included lobster krill (Munida gregaria), hoki (Macruronus novaezelandiae), oblique-banded rattail (Coelorhynchus aspercephalus), and salps (Pyrosoma atlanticum). New Zealand fur seals (Arctocephalus forsteri) and seabirds were also identified in samples. New Zealand sea lions are generalist feeders utilising a wide variety of prey items, with fish comprising the most common taxa (59%) numerically and both cephalopods (21%) and crustacea (15%) forming lesser, but still important, parts of the diet. Prey taxa identified indicate that New Zealand sea lions are utilising a wide variety of benthic, demersal and pelagic species ranging from the inter-tidal zone to waters deeper than 300 m. New Zealand sea lions at the Auckland Islands target different prey species to New Zealand sea lions at other locations although they have broadly consistent prey types, with fish as the major taxa. There is only a small overlap of New Zealand sea lion prey species with commercially targeted species on the Auckland Islands Shelf in the months sampled.
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DAMALAS, DIMITRIOS, ALESSANDRO LIGAS, KONSTANTINOS TSAGARAKIS, VASSILIKI VASSILOPOULOU, KONSTANTINOS I. STERGIOU, ARGYRIOS KALLIANIOTIS, MARIO SBRANA, and FRANCESC MAYNOU. "The “discard problem” in Mediterranean fisheries, in the face of the European Union landing obligation: the case of bottom trawl fishery and implications for management." Mediterranean Marine Science 19, no. 3 (August 29, 2018): 459. http://dx.doi.org/10.12681/mms.14195.
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Since the first introduction of the landing obligation (a.k.a. Discard ban) in 2015, the EU Mediterranean fisheries are facing some unforeseen challenges. The demersal bottom trawl fisheries, being the most significant contributors to the so-called 'discard problem', are confronted with the greatest challenges. Data from the Italian and the Greek fleet, spanning over two decades (1995–2015), were analysed with the intention of revealing the diversity and heterogeneity of the discard problem, especially for regulated species. Species composition of discards, as well as discarding rates, were shown to be irregular, fluctuating among areas, depth strata, seasons and years. Although fish dominated the discarded gross catch in weight, benthic invertebrates (other than commercial cephalopods and crustaceans) were the taxa discarded almost exclusively. The established minimum conservation reference size was largely ignored by fishers. From a management point of view, the present investigation suggests that the recently established Discard Management Plans lack scientific evidence (given the high intrinsic variability of the parameters and confusion regarding the rules) and provide exemptions from the landing obligation that will in practice allow the average Mediterranean bottom trawl vessel to continue business as usual. Moreover, detecting if these rules are actually respected is an almost impossible task for the Mediterranean control and enforcement authorities. Incentivizing the adoption of fishing technologies and practices that reduce pre-harvest mortality and post-harvest discards, while avoiding damage to sensitive marine species and habitats, seems the only way to move forward, rather than dealing with the problem after it has occurred.