eCite Digital Repository

The scheduling of spawning with the moult cycle in Northern krill (Crustacea: Euphausiacea): a strategy for allocating lipids to reproduction

Citation

Cuzin-Roudy, J and Albessard, E and Virtue, P and Mayzaud, P, The scheduling of spawning with the moult cycle in Northern krill (Crustacea: Euphausiacea): a strategy for allocating lipids to reproduction, Invertebrate Reproduction & Development, 36, (1-3) pp. 163-170. ISSN 0168-8170 (1999) [Refereed Article]

Copyright Statement

Copyright 1999 Balaban

DOI: doi:10.1080/07924259.1999.9652694

Abstract

Euphausiids moult and grow throughout their life, which implies sharing of resources between growth and reproduction for adult krill. In the Northern krill, Meganyctiphanes norvegica (M. Sars), female krill produce eggs cyclically. Spawning moult cycles alternate with vitellogenic moult cycles for lipid yolk accumulation. Histology shows that lipids are associated with the R cells of the digestive gland in both sexes, with the yolk platelets of mature oocytes and with the fat body cell membranes and blood lacunae in reproducing females. Mature female krill can have a total lipid content twice as high as males, mostly due to accumulation in the ovary, the fat body and the haemolymph. In contrast, in males, as well as in non-reproducing females, the highest percentage of lipids is found in the digestive gland and the haemolymph. In Meganyctiphanes norvegica, the most abundant lipid fractions are polar lipids and triglycerides, the latter being relatively low in reproducing female gonad and fat body. Triglycerides are believed to be a pure energy source and polar lipids are essential for membrane development in embryos. The fatty acid content and composition of the triglyceride and polar lipid fractions in females are different from males, related to both reproductive and dietary processes. Higher levels of polyunsaturated fatty acids (PUFA) in the polar lipid fraction were found in reproductive females. During the non-reproductive season, the converse was found, indicating the specific role PUFA and other fatty acids play in growth and egg production. Adaptive processes linked to reproduction were studied comparatively in three populations of the Northern krill - Clyde Sea (W, Scotland), Kattegat (E, Denmark), Ligurian Sea (Mediterranean) - all differing considerably in climatic and trophic conditions. such adjustments in lipid synthesis and storage are viewed as reproductive strategies developed by the Northern krill in response to different environmental conditions

Item Details

Item Type:Refereed Article
Keywords:Meganyctiphanes norvegica, Northern krill, lipids, reproductive strategies
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:Virtue, P (Associate Professor Patti Virtue)
ID Code:90438
Year Published:1999
Web of Science® Times Cited:16
Deposited By:IMAS Research and Education Centre
Deposited On:2014-04-03
Last Modified:2014-07-02
Downloads:0

Repository Staff Only: item control page