Effect of a carnivorous diet on the lipids, fatty acids and condition of Antarctic krill, Euphausia superba

• Published in: Antarctic Science
• Main Authors: Hagen, W, Yoshida, T, Virtue, P, Kawaguchi, S, Swadling, KM, Nicol, S, Nichols, PD
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2007
• Subjects: Earth Sciences; Oceanography; Biological Oceanography; Antarctic; Antarc*; Antarctic Krill; Antarctic Science; Euphausia superba
• Online Access: https://doi.org/10.1017/S0954102007000259; http://ecite.utas.edu.au/49957

Krill are thought to be predominantly herbivorous, but a heterotrophic diet might be crucial for their growth and survival. To compare the influence of herbivory and carnivory on krill we conducted a nine month feeding trial. We examined lipid composition of the hepatopancreas, abdomen and remaining body portions of krill fed diatoms at bloom condition levels, and diatoms with the addition of pellets or minced clam meat to simulate a partly carnivorous diet. Mortality, dry mass and lipid content were similar among treatments. We examined lipid class and fatty acid profiles, with emphasis placed on the ratio of storage (triacylglycerol) to structural (polar lipid) lipid and key essential omega 3 polyunsaturated fatty acids: 20:53 and 22:63. The triacylglycerol : polar lipid ratio increased in krill fed on the mixed diet as did the 20:53 : 22:63 ratio. Overall these findings indicate that provision of clam in the diet improved krill condition, and further suggest that carnivory may aid krill growth in the wild under certain environmental conditions. Antarctic Science Ltd.