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Aspects of krill growth and condition during late winter-early spring off East Antarctica (110-130°E)

Citation

O'Brien, CJ and Virtue, P and Kawaguchi, S and Nichols, PD, Aspects of krill growth and condition during late winter-early spring off East Antarctica (110-130°E), Deep-Sea Research. Part 2: Topical Studies in Oceanography, 58, (9-10) pp. 1211-1221. ISSN 0967-0645 (2011) [Refereed Article]


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DOI: doi:10.1016/j.dsr2.2010.11.001

Abstract

Antarctickrill, Euphausiasuperba, isakeystonespeciesintheSouthernOcean.However,informationon growth,dietandconditionduringwinterandearlyspringislimited,hamperingourunderstandingof these fundamentalbiologicalparametersatthisimportantperiodintheirlifecycle.Ourstudyassessed diet andconditionoflarvalandpostlarvalkrillcollectedfromopenwaterandbelowtheiceoffEast Antarctica(110–130% o E) inSeptember/October2007.Conditionwasassessedusinglipidcontent,growth ratesanddigestiveglandsize;feedinghistorywasassessedusingfattyacidprofilesandstomachcontent analysis;anda207-daystarvationstudyinvestigatedtheresponseofkrilltolong-termfooddeprivation. Potentialfooditems(Calanuspropinquus and sea-icebiota)wereanalysedforlipidandfattyacid compositiontocomparewithkrillsamples.Krillwerefoundtobeingoodcondition,withmeangrowth rate of0.95%permoultforpostlarvaeand14.79%forlarvae,andmeanlipidcontentof24.1%forpostlarvae and 6.6%forlarvae.Fattyacidprofilesandstomachcontentanalysisrevealedtwomainfeedingstrategies - krillbelowtheicewerefeedingmostlyonsea-icediatoms,whilethoseinopenwaterwereingesting copepodsanddetritus.Krillbelowtheicehadlargerdigestiveglandsthanthoseinopenwater.Furciliae fatty acidprofilesindicatedadietofheterotrophicflagellatesand/ordetritus.Postlarvalkrillsurvived207 days offooddeprivationbyusingbodyproteinandlipidreservesforenergy.Incontrast,krillfurciliae were severelydepletedafterjust5daysoffooddeprivation,indicatingthattheymustfeedcontinuallyat this timeofyear.Krill,copepodsandsea-icebiotawerealllowinpolyunsaturatedfattyacids,indicating that krillmustrelyonlaterspringphytoplanktonbloomstoobtaintheseessentialnutrientsrequiredfor reproduction.

Item Details

Item Type:Refereed Article
Keywords:Euphausia superba, Lipids, Fatty acids, growth, overwintering, East Antarctica
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and Estuarine Ecology (incl. Marine Ichthyology)
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Antarctic and Sub-Antarctic Flora, Fauna and Biodiversity
Author:O'Brien, CJ (Miss Colleen O'Brien)
Author:Virtue, P (Associate Professor Patti Virtue)
Author:Nichols, PD (Dr Peter Nichols)
ID Code:76369
Year Published:2011
Web of Science® Times Cited:17
Deposited By:IMAS Research and Education Centre
Deposited On:2012-03-05
Last Modified:2012-07-06
Downloads:0

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