Studies on the deep-water pelagic community of Korsfjqrden, Western Norway Changes in the size and biochemical composition ofMeganycitiphanes norvegica(Euphausiacea) in relation to its life cycle

Abstract

Seasonal changes in the length/weight relationship and biochemical composition have been studied in a geographically defined population of Meganyctiphanes norvegica. Individuals of the same carapace length were on average heavier in the summer and autumn than in the winter and spring. Growth was most intense during summer and autumn and individuals from the youngest generation showed the highest growth rate. During mid-winter growth stopped completely; the negative growth rate values calculated for December and January suggest poor feeding condition during this period. The lipid content showed distinct seasonal variation, yielding highest values in the winter and spring. From summer to early spring a positive correlation existed between individual dry weight and the proportion of lipid. This correlation disappeared at the same time as the overall lipid level decreased.