MEAL SIZE AND SUSTENANCE TIME IN THE DEEP-SEA AMPHIPOD EURYTHENES GRYLLUS COLLECTED FROM THE ARCTIC-OCEAN

Lysianassid amphipods (Eurythenes gryllus) were attracted to bottom-mo ored baited traps exposed for 6-8 h at 2075 m depth in the Canada Basi n of the Arctic Ocean. Instars were separated by body length using a c lustering algorithm, and meal sizes for instars were calculated from t wo allometric regressions of body length on wet weight for amphipods c ollected with and without protection for bait. No sex-related differen ces were observed in the length-weight relationships. Calculated value s of meal size were not significantly different (P < 0.05) from the we ight of dissected gut contents removed from amphipods trapped in bait containers. Meal sizes in the Ist to 5th instars amounted to <50% of e mpty-gut body weight, but values increased to >60% for mature males >8 th instar and to >75% for mature females >14/15th instar. Proximate or ganic analyses of gut contents were used to estimate the calorific con tent of ingested material. Energy ingested plus that stored in body li pid would support respiration for 1-6 months in juveniles, for 9-14 mo nths in mature males and for 14-22 months in mature females.