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-moored baited traps exposed for 6-8 h at 2075 m depth in the Canada Basin of the Arctic Ocean. Instars were separated by body length using a clustering algorithm, and meal sizes for instars were calculated from two allometric regressions of body length on wet weight for amphipods collected with and without protection for bait. No sex-related differences were observed in the length-weight relationships. Calculated values of meal size were not significantly different (P < 0.05) from the weight of dissected gut contents removed from amphipods trapped in bait containers. Meal sizes in the Ist to 5th instars amounted to <50% of empty-gut body weight, but values increased to >60% for mature males >8th instar and to >75% for mature females >14/15th instar. Proximate organic analyses of gut contents were used to estimate the calorific content of ingested material. Energy ingested plus that stored in body lipid would support respiration for 1-6 months in juveniles, for 9-14 months in mature males and for 14-22 months in mature females.