Lower Lethal Temperature for Juvenile Cobia Rachycentron Canadum |
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| Authors: | Dusty L McDonald Britt W Bumguardner |
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| Institution: | 1. Texas Parks and Wildlife Department , Perry R. Bass Marine Fisheries Research Station , Palacios, Texas, USA dusty.mcdonald@tpwd.state.tx.us;3. Texas Parks and Wildlife Department , Perry R. Bass Marine Fisheries Research Station , Palacios, Texas, USA |
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| Abstract: | Cobia are a migratory marine species that have recently gained popularity as foodfish in the aquaculture market and for stocking. Unfortunately, when culturing these species, aquaculturalists may unknowingly expose these fish to temperature extremes not normally experienced in situ. We set out to test for the critical thermal minimum temperatures of juvenile cobia by exposing them to a simulated freeze, at a drop rate of 0.33°C per hour. We observed and documented behavioral effects due to low temperature exposure using criteria for loss of equilibrium and death. We determined that the median temperature for loss of equilibrium was 12.1 ± 0.40°C and the median lethal temperature was 9.7 ± 0.28°C for low temperature tolerance. We recommend that precautions be taken well before water temperatures reach 13°C in a freeze scenario. |
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| Keywords: | Cobia freeze mortality critical thermal minimum |
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