Comparative mortality of three esocids due to stocking stressors

Evaluted mortality of young-of-year northern pike Esox lucius, muskellunge E. masquinongy and their F₁ hybrid, tiger muskellunge, in response to simulated handling, transport and thermal stressors. In 15°C acclimated esocids, a 10° rapid temperature increase caused little mortality. A 12° increase killed some fish in all taxa, but mean mortality did not differ significantly among northern pike (30%), tiger muskellunge (23%), and muskellunge (10%). Nearly all 15°C acclimated fish (98%) died in response to a 15° increase. Tempering (0.15°.min^-1) did not reduce this near complete mortality. Handling (30 s dipnet) and transport confinement (60 g.L^-1 for 120 min) also did not alter mortality when compared with a 12° temperature increase alone. -from Authors