Metabolic responses of the sympagic amphipodsGammarus wilkitzkii andOnisimus glacialis to acute temperature variations

Abstract

Abstract. Acutely elevated seawater temperatures had pronounced metabolic effect on the Arctic under-ice amphipods Gammarus wilkitzkii and Onisimus glacialis, collected in May 1986 and1988 in the Barents Sea. An increased rate of oxygen consumption vs temperature was observed for both species. In the range from 0 ° to 10 °C G. wilkitzkii and O. glacialis exhibit Qto 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 ° to 10°C, with an overall Qt0 of 1.9 and 2.3, respectively. The present study demonstrates an increased O : N ratio with ambient temperature elevation from 0 ° to 10 °C for G. wilkitzkii and O. glacialis, with overall Q~o values of 2.0 and 1.6, respectively. This indicates a temperature-induced change in the metabolic substrate towards lipids.

Oxygen consumption and ammonia excretion of the searobin Prionotus punctatus (Scorpaeniformes, Triglidae) at two different temperatures

“…Cockroft & DuPreez (1989, 1990 suggested mass exponent values of between 0.67 and 0.90 for oxygen consumption and of between 0.47 to 0.99 for ammonia excretion as a function of wet weight. Ammonia excretion is, in general, considered as more variable intraspecificaIly than oxygen consumption (Aarset & Aunaas, 1990). It is important to notice, however, that many authors believe that mass exponent found for fish varies widely and that exceptions are not uncommon (Hoss, 1967).…”

Annual routines and life history of the amphipod Onisimus litoralis: seasonal growth, body composition and energy budget

“…In Adventfjorden, the surface water varies from -1.8°C in winter to around 8°C in summer, while the salinity drops from 34.7 in winter to < 5 in summer (Zają czkowski et al 2010). For the sympagic amphipod O. glacialis, a Q 10 value of 3.6 has been measured in the range of 0 to 10°C (Aarset & Aunaas 1990b), while the benthic O. affinis shows a more temperature-insensitive metabolism (Percy 1975). An increase in the metabolism in O. litoralis due to temperature shifts is expected, but the exact relationship between temperature and metabolism is not known.…”