Integrated model of moulting and feeding of Antarctic krill Euphausia superba off South Georgia

Publisher Website
Google Scholar
Abstract
The vertical and temporal distribution of krill undergoing molt and the physiolgical relations between feeding activity and molting behavior of Antarctic krill E. superba Dana are used in a model of ecological aspects of molting. Two periods per day of peak molting activity occur in krill off South Georgia: in the afternoon and early night. This suggests that existence of 2 strategies for fuelling the post-molt hardening of the exoskeleton. The temporal and vertical distribution of krill undergoing molt also indicates the importance of both light and predation as potential factors affecting molting behavior. This may account for published observations, both in the field and in the laboratory, of synchronous molting in krill. The consistency of the pattern of molting activity is examined for each of the 6 days of the study period, and derived intermolt periods and rhythmicities in molting are discussed in terms of the homogeneity of the population studied. These observations and previously published detailed models for the feeding activity, in relation to water depth and time of day, of E. superba off South Georgia are synthesized into a single model that links feeding, swarming, vertical migration, environmental variables and molting. Published energy requirements and the levels of plants pigment found in the components of the alimentary tract of krill are also integrated with published egestion rates, to derive estimates of a turnover time for the alimentary tract and an assimilation efficiency.

This publication has 2 references indexed in Scilit: