Egg production, population structure and biochemical composition of the subantarctic copepod Paraeuchaeta antarctica in the Kerguelen Archipelago

The population structure and reproductive biology of the predatory calanoid copepod Paraeuchaeta antarctica (Giesbrecht, 1902) were investigated in th e Kerguelen Archipelago over 1 yr. The seasonal frequencies of the various developmental and adult stages showed that the population produces 1 genera tion per year, with recruitment taking place during the austral spring. Occ urrence of females with spermatophores indicated that mating occurred in wi nter. Counts of egg-bearing females and of number of eggs per sac confirmed that the peak of reproduction was from winter to late spring. Seasonal var iations in body dry weight, lipid and protein contents of the various devel opmental and adult stages reflected changes in food availability and the re production cycle. P. antarctica increased lipid and protein content during spring and summer when prey organisms were abundant. The subsequent loss in winter was associated with the production of eggs. A study of lipid classe s showed that lipid accumulations were essentially composed of wax esters, which permitted production of eggs when food conditions were unfavorable. T he population dynamics and reproductive biology of P. antarctica from Kergu elen are discussed in comparison with the antarctic populations described a t South Georgia and off the Antarctic Peninsula, as well as with the northe rn euchaetiid Euchaeta norvegica.