The influence of turbidity on larval walleye, Stizostedion vitreum, behavior and development in tank culture

Abstract

The behavior and development of larval walleye, Stizostedion vitreum, cultured in clear and turbid water in laboratory aquaria are compared from hatch to 17 days post-hatch. Significant differences ( P ≤ 0.05) in larval distribution and swimming speed were observed. In clear water, larvae showed a strong association with the sides of the aquaria, but in tanks with turbid water, larvae avoided the sides of the aquaria. Larvae in turbid water had greater average swimming speeds, faster growth rates, and improved gas bladder inflation (GBI) than larvae cultured in tanks with clear water. There were no significant differences between the two treatments in larval survival or cannibalism. Larval viability (survival x GBI) was three times greater in turbid water (19.0%) than in clear water (5.7%). The improved performance and viability in turbid water are attributed to the changes in larval distribution as a consequence of larval reaction to diffused light in turbid water.