Effects of Temperature on Captive-Bred Devils River Minnows

Abstract Twelve pairs of captive-bred Devils River minnows, Dionda diaboli, were each held at 21, 24, and 27°C, as were a total of 236 of their offspring, for ≤252 days to test the effects of temperature on survival, growth, and reproduction. We found no significant difference in survival. Growth rate (millimeters per day) for adults was about two times higher at 21°C than at 24 or 27°C while, for offspring, it was significantly higher at 21 and 24°C than at 27°C. The weekly number of reproductions (per pair per week, 0 or 1) was significantly higher for fish held at 24°C than for fish held at 21 or 27°C. These results further support the importance of flow of springs as a necessary component for survival of this federally threatened species.