Metabolic physiology of the southeastern USA crayfish, Cambarus latimanus (LeConte), in response to different temperatures

Variable crayfish, Cambarus latimanus (LeConte), were collected and acclimated to four temperatures, 15, 20, 25, and 30°C. Following a two-week acclimation period, mean standard metabolic rates (SMR), as determined using oxygen consumption rates, were measured using an intermittent-flow, closed-loop respirometer. For ~10g mean weight C. latimanus, mean weight specific oxygen consumption rates (MO2) at 15, 20, 25, and 30°C were 73.4 ± 0.18, 81.6 ± 0.10, 103 ± 0.11, and 205 ± 0.12 mg O2·kg-1·h-1 (±SE), respectively. Calculated Q10 values of 1.25, 1.61, and 3.92 for the change in metabolic rate from 15 – 20°C, 20 – 25°C, and 25 – 30°C suggest the crayfish were responding normally to temperature increases and were metabolically stressed when temperatures increased above 25°C. Daily caloric energy budgets of 58 (15°C), 65 (20°C), 82 (25°C), and 164 (30°C) calories·day-1 were estimated for crayfishes using SMR data and suggested that crayfish standard (resting) energy requirements nearly tripled when acclimated to 15 versus 30°C. Overall, these data suggest that increased temperatures have substantial effects on C. latimanus energy demands which may reduce potential growth and reproduction.