Effects of Emersion Temperature on the Oxygen Consumption Rates of Male Tanner Crabs, Chionoecetes Bairdi

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Delivery of live crustaceans to markets has the potential to increase profits for Alaskan fishermen, but the practice has been limited in part by mortality occurring during shipment to distant markets. Protocols that select crabs more likely to survive shipment would likely further develop this niche market and evaluating the physiological stress response in crustaceans provides a logical entry point to explore this area. This study measures oxygen consumption rates |$\left( {{\text{M}}{{\text{O}}_{\text{2}}}{\text{; mg}}{{\text{O}}_{\text{2}}}\,{{\text{g}}^{ - {\text{1}}}}\,{\text{h}}{{\text{r}}^{ - {\text{1}}}}} \right)$| of male Tanner crabs, Chionoecetes bairdi, following 15, 30 or |$45\min $| of emersion at |${\text{8}}^\circ {\text{C}}$| or |$ - 15^\circ {\text{C}}$| followed |$12\,\,\text{h}$| later by a uniform handling stressor (emersion at |$ - 15^\circ {\text{C}}$| for |$10\min $|⁠). |${\text{M}}{{\text{O}}_{\text{2}}}$| increased immediately following 15, 30 and |$45\min $| emersion at |${\text{8}}^\circ {\text{C}}$| (on average 1.5 times pre-treatment levels). All crabs survived emersion at |${\text{8}}^\circ {\text{C}}$| and |${\text{M}}{{\text{O}}_{\text{2}}}$| returned to pre-treatment levels within |$12\,\,\text{hours}$|⁠. These animals also responded similarly to a uniform second stress test by increasing |${\text{M}}{{\text{O}}_{\text{2}}}$|⁠. Crabs previously exposed to air at |$ - 15^\circ {\text{C}}$| for |$15\min $| had an increased |${\text{M}}{{\text{O}}_{\text{2}}}$| following a standardized handling stress in a pattern similar to the |${\text{8}}^\circ {\text{C}}$| groups. However, |${\text{M}}{{\text{O}}_{\text{2}}}$| in crabs exposed to air at |$ - 15^\circ {\text{C}}$| for |$30\min $| did not respond to a uniform secondary stress treatment with an increase in |${\text{M}}{{\text{O}}_{\text{2}}}$|⁠. Thus, a robust increase in |${\text{M}}{{\text{O}}_{\text{2}}}$| to a uniform stress treatment indicates animals with a less severe stress history and likely an indicator of overall vigor.