Growth:Ration relationships in the antarctic fish Notothenia coriiceps Richardson maintained under different conditions of temperature and photoperiod

Four feeding trials were conducted on captive juvenile N. coriiceps maintained under conditions simulating natural seasonal changes in temperature and photoperiod. Fish were deprived of food for 10 days (to measure fasting body weight), then fed for 12 days on freshly killed amphipods (to measure individual daily intake). Thereafter, one group was left unfed whilst daily intake of other individuals, offered 2 g and 4 g daily, was monitored. Growth was measured as change in body weight. Growth:Ration relationships were compared between trials and were found to be independent of the different environmental conditions. Appetite was higher under summer conditions and it is argued that seasonality in growth of Antarctic fish is mediated through seasonal variation in resource utilisation rather than seasonal resource availability or temperature-dependent effects on growth.