Proximate composition and energy density of nototheniid and

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TitleProximate composition and energy density of nototheniid and myctophid fish in McMurdo Sound and the Ross Sea, AntarcticaAbstractNototheniid and myctophid fish are primary prey for marine piscivores, yet little is known about their nutritional value. In this study, we characterized the proximate composition [PC: water, fat (neutral lipids), crude protein (CP) and ash] and energy density (ED; kJ g -1) of fifteen fish species from McMurdo Sound and the Ross Sea, Antarctica. We assayed the entire fish for all species except for the large Antarctic toothfish, Dissostichus mawsoni (muscle tissue only). On a wet mass basis (WM), fish were variable in composition: moisture content ranged from 64.9 to 87.3% WM, fat from 0.5 to 17.4% WM, CP from 7.7 to 16.7% WM, ash from 11. 2 to 21. 0% FFDM (fat-free dry mass), and ED from 2. 9 to 10. 3 kJ g -1. Myctophids and pelagic nototheniids such as Pleuragramma antarcticum and D. mawsoni were high in fat content (7-17% WM), while a bathylagid and benthic nototheniids including most Trematomus spp. and Lepidonotothen squamifrons were low in fat (0. 5-4% WM). The epibenthic Trematomus species (T. eulepidotus and T. lepidorhinus) were intermediate. Energy density tracked fat content, with highest values in myctophids and pelagic nototheniids. The variation in nutrient and energy density confirms that prey composition must be taken into account when modelling energy and nutrient fluxes within the Antarctic ecosystem. Further analyses of prey collected over a number of different locations and seasons are needed in order to determine how the nutritional value of certain species might affect annual or decadal variation in reproductive success or population size of top predators. Copyright 2011 Springer-Verlag.AcknowledgementsWe would like to thank Dr. Gretchen Hofmann (University of California Santa Barbara, Santa Barbara, CA), Dr. Art DeVries (University of Illinois, Urbana-Champaign, IL), and Dr. Matt Pinkerton (National Institute of Water and Atmospheric Research, Wellington, New Zealand) for providing samples. Specimens and data collected by and made available through the New Zealand International Polar Year-Census of Antarctic Marine Life Project are gratefully acknowledged. We would also like to thank Michael Jakubasz (Smithsonian National Zoological Park) for his help with all of the assays, Luis Apiolaza (University of Canterbury) for statistical advice and David Ainley and Graham Worthy for their comments on an earlier version of this manuscript. This manuscript was greatly improved by comments from three anonymous reviewers. This work was supported by the National Science Foundation, OYce of Polar Programs grant 0538592 to Oftedal, Eisert and DJ Boness.

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1st AuthorLenky, C.AuthorLenky, C.Eisert, R.Oftedal, O.Metcalf, V.Year2012JournalPolar BiologyVolume35Number5Pages717-724DOI10.1007/s00300-011-1116-9URLhttps://www.scopus.com/inward/recor.....1b73418100ab8e6e6d6e0384aKeywordsbenthosbiochemical compositionbioenergeticsdietfishmoisture contentnutrient cyclingnutritive valuepopulation sizereproductive success, AntarcticaEast AntarcticaMcMurdo SoundRoss SeaSouthern OceanWeddell Sea, BathylaginaeDissostichus mawsoniLepidonotothen squamifronsLeptonychotes weddelliiMyctophidaeNototheniidaePleuragramma antarcticumTrematomusTrematomus eulepidotusTrematomus lepidorhinus, rank3Author KeywordsDietDissostichus mawsoniNototheniidProximate compositionRoss SeaWeddell seal

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TypeArticleCitationLenky, C., Eisert, R., Oftedal, O. and Metcalf, V. (2012). Proximate composition and energy density of nototheniid and myctophid fish in McMurdo Sound and the Ross Sea, Antarctica. Polar Biology, 35(5): 717-724