Metabolic responses of the sympagic amphipods Grammarus wilkitzkii and Onisimus glacialis to acute temperature variations

Acutely elevated seawater temperatures had pronounced metabolic effect on the Arctic under-ice amphipods Gammarus wilkitzkii and Onisimus glacialis , collected in May 1986 and 1988 in the Barents Sea. An increased rate of oxygen consumption vs temperature was observed for both species. In the range from 0 degree to 10 multiplied by 'C G. wilkitzkii and O. glacialis exhibit Q sub(10) values of 3.4 and 3.6, respectively. The results also indicate increased ammonia excretion rates for G. wilkitzkii and O. glacialis by an elevation of temperature from 0 degree to 10 degree C, with an overall Q sub(10) of 1.9 and 2.3, respectively. The present study demonstrates an increased O:N ratio with ambient temperature elevation from 0 degree to 10 degree C for G. wilkitzkii and O. glacialis , with overall Q sub(10) values of 2.0 and 1.6, respectively. This indicates a temperature-induced change in the metabolic substrate towards lipids.