Effectiveness of Using a Vinyl Sheet to Reduce Mortality Caused by Collision During Rearing of Pacific Saury Cololabis saira

To reduce mass mortality of Pacific saury caused by collision with the tank wall, we examined rearing of saury in a tank with a vinyl sheet attached to the tank wall, and no vinyl sheet tank. We compared survival rate and ratio of the lower jaw length to the knob length of those fish. Survival rate of the former was higher than the latter. No significant difference was recognized for the ratio. These results suggest that the vinyl sheet could not reduce the damage to the lower jaw, but it could reduce the mortality caused by collision

Relationships Between Survival Period and Temperature of Newly Hatched Pacific saury Cololabis saira under Starvation Conditions

To clarify the relationships between the survival period of newly hatched Pacific saury Cololabis saira which use only endogenous nutrition and water temperature, we observed the survival periods under starvation conditions at four temperatures (10, 15, 20 and 25°C). The starvation tolerance period was shortened with increasing temperature. This study suggests that newly hatched Pacific saury can survive for approximately 5-10 days (50% mortality period) without feeding in 10-25°C under non-predator conditions, but such an extended period of starvation is considered to affect subsequent growth and survival