Use of fatty acids as dietary indicators in northern krill, , Meganyctiphanes norvegica , from northeastern Atlantic, Kattegat, and Mediterranean waters

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Virtue, P, Mayzaud, P, Albessard, E, Nichols, PD
• Format: Article in Journal/Newspaper
• Language: English
• Published: Natl Research Council Canada 2000
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Kattegat; Meganyctiphanes norvegica; Northern krill; Copepods
• Online Access: https://doi.org/10.1139/f00-182; http://ecite.utas.edu.au/90445

Fatty acids of the triacylglycerol (TG) and polar lipid (PL) fractions were compared from northern krill,Meganyctiphanes norvegica, sampled in the Clyde Sea in the Atlantic, the Kattegat at the Alkor Deep, and the LigurianSea in the Mediterranean. Possible biotransformations of fatty acids in the food chain were examined in mixed zooplanktonand krill faecal material from the Ligurian Sea and Kattegat. The Ligurian Sea population was distinguishedfrom the Kattegat and Clyde Sea populations in terms of both TG and PL fatty acid profiles. The Kattegat and ClydeSea populations were separated from each other in terms of their PL fatty acid profiles only. Krill sampled in winterfrom all sites had significantly higher levels of 20:1 and 22:1 fatty acids in the TG fraction (917%) than krill sampledin summer (110%). These fatty acids in particular indicate carnivorous dietary input, as they are found in high levelsin copepods, which are the major prey species of M. norvegica. Levels of 22:6(n3) were significantly higher than20:5(n3) in Ligurian krill, which, together with other specific marker fatty acids, suggested a predominance ofdinoflagellates and other nondiatom species in their diet. TG fatty acids in Kattegat and Clyde Sea krill indicate a predominanceof diatoms in the diet.