Comparative studies on the metabolism of Euterpina acutifrons (Dana) (Copepoda, Harpacticoida): temperature and salinity effects in copepods from Georgetown, South Carolina

The combined effects of temperature and salinity on the respiratory rate of female Euterpina acutifrons were determined for copepods from North Inlet estuary, Georgetown (USA). Results showed an increase in metabolic rates with increasing temperature over the range 15–25°C, decreasing at 30°C, in all salinities used. Highest Q₁₀ values were obtained over the range 20–25°C, except at 55‰ S. At all temperatures used, rates were generally lower in the extreme salinities (15 and 55‰), and highest in 35‰ S. Temperature and salinity effects were significant at a level of less than 1%. A comparison of results from this study with similar studies on a population of E. acutifrons from southern Brazil suggests that different annual thermal regimes affecting the two populations may also influence capability for metabolic regulation over a wide range of salinities.