Temperature-dependent physiological response of Carcinus maenas exposed to copper

The effect of temperature on the heart rate (f(H)) of Carcinus maenas exposed to a sublethal nominal concentration (0.5 mgl(-1)) of copper is reported. Adult, intermoult males (4 cm carapace width) were collected from Stavanger Fjord (Norway) in August (seawater temperature = 17 degreesC) and maintained in the laboratory (fed ad libitum) at 5, 15 and 25 degreesC for 7 days. Following this holding period, crabs were exposed to waterborne copper at the same temperature. After 3 days of exposure, individual f(H) was measured using the non-invasive Computer Aided Physiological MONitoring system (CAPMON) method. Copper-exposed individuals demonstrated significantly increased f(H) compared with controls at 5 and 25 degreesC (P < 0.01). It is inferred that physiological function in C maenas may be more vulnerable to copper contamination at seasonal temperature extremes (5 and 25 degreesC) than at the 'standard' test temperature (15 degreesC). Additionally, cardiac arrest observed at 5degreesC is interpreted as a physiological response to limit coppei uptake while the erratic f(H) in the 25 degreesC group reflected enhanced copper toxicity. (C) 2004 Elsevier Ltd. All rights reserved.