Rey, C. C. University P.M. Curie (Paris VI) CNRS-INSU ESA 7076, rey@ccrv.obs-vlfr.fr
Carlotti, F. C. University P.M. Curie (Paris VI) CNRS-INSU ESA 7076, carlotti@ccrv.obs-vlfr.fr
Tande, K. K. University of Tromso, The Norwegian College of Fishery science, kurtt@nfh.uit.no
Hygum, B. B.H.. Roskilde University, Dep. of Life Sciences & Chemistry, hygum@VIRGIL.ruc.dk

 
EGG AND FAECAL PELLET PRODUCTION OF CALANUS FINMARCHICUS FEMALES FROM CONTROLLED MESOCOSMS AND IN SITU POPULATIONS: INFLUENCE OF AGE AND FEEDING HISTORY
 
Egg and faecal pellet production of Calanus finmarchicus females was investigated under superabundant food conditions at 5 C and 10 C. The experimental females were from (1) in situ populations in the Raunefjord (southern Norway) in March and May 1997 and (2) cohorts reared in two mesocosms, one with high (H) and one with low (L) food concentrations. The egg production rates of newly moulted females from mesocosms increased from low (or zero) to maximal rates over 10 to 15 days at 10 C and 5 C, respectively. The delay in reaching maximal fecundity rates was related to the time required for gonad maturation during which storage lipid was used as well as food supply for ending the maturation. The faecal pellet production rates of young females from mesocosms also increased suggesting that fecundity was governed by ingestion. The fecundity, egestion and lipid metabolism of wild females (caught in March and May) were compared to that of young females from mesocosms and the influence of seasonal origin of females on these processes was assessed. The different feeding histories of females from both mesocoms do not influence the fecundity. In contrast, the egestion rate of females from mesocosm L was significantly higher than that of females from mesocosm H, suggesting either different ingestion rates or assimilation processes.
 
Day: Thursday, Feb. 4
Time: 10:45 - 11:00am
Location: Eldorado Hotel
 
Code: SS51TH1045E