Changes in oxygen consumption and heart rate of the blue swimming crab, Portunus pelagicus (Linnaeus, 1766) following exposure to sublethal concentrations of copper

Weight specific oxygen consumption and heart rates were investigated in blue swimming crab, Portunus pelagicus to indicate the stress in response to increasing salinities (50, 75, 100 and 125%SW) and increasing copper concentration (0, 0.75, 1.5, 3 and 6 ppm copper) at temperature 25 degrees C. Oxygen consumption (micromol.g(-1).h(-1) was measured using closed system respirometer (Strathkelvin Instruments oxygen meter model 781). Heart rates (beat.min(-1)) were recorded using impedance techniques. It has been found that oxygen consumption and heart rate increased with decreasing salinities and increasing copper concentration. The statistic showed weight specific oxygen consumption of P. pelagicus after 96 hr exposure to 6 ppm copper in all salinities were significantly different (P < 0.05) from 0 ppm copper. Mean heart rate of P. pelagicus in 50%SW after 96 hr exposure to 6 ppm copper were significantly different (P < 0.05) from 0 ppm copper.