Edmond J. Bacon, Jr.

Changes In The Ichthyofauna In The Beaver Reservoir Tailwaters

Collections of the fishes in the tailwaters of Beaver Reservoir were made during the spring and summer of 1968. The present study is a continuation of an investigation designed to follow the development of the ichthyofauna in the cold tailwaters below Beaver Dam, Arkansas. A total of 527 fishes representing 21 species, 12 genera, and 7 families has been identified. Eight species collected in 1968 were not reported by Brown, et al. (1967) and 7 species reported in the 1967 publication were not collected in this study. Campostoma anoma/um was still the most abundant cyprinid collected and...

Temperature Selection And Heat Resistance Of The Mosquito Fish, Gambusia Affinis

The average selected temperature of a sample of Gambusia affinis previously acclimated to 20°C decreased from 28-29°C to about 27"C after the fish had lived in a temperature-gradient tank for one month. The final thermal distribution of the fish varied with sex and developmental stage. Males selected lower temperatures than did adult females. The young fish, although more scattered than the adults, occurred mostly at temperatures higher than those selected by the adults. These results may indicate temperature separation of young and adult fish in nature which would reduce intraspecific...