SREL Reprint #0387
Effects
of Thermal Effluent on Populations of Mosquito Fish
M.
Catherine Ferens and Thomas M. Murphy, Jr.
Abstract
Reproduction, sex ratios, and size structure were
examined in populations of the mosquito fish Gambusia affinis from
lentic and lotic environments with different thermal conditions.
Winter temperatures at the time of sampling ranged from 16.5°C
in a pond receiving no thermal effluent to 44°C in a heated pond.
Sex ratios varied greatly among locations with no apparent relation to
temperature or habitat. No females from nonheated areas were carrying eyed embryos.
The percentage of females 30 mm or more in length bearing eyed embryos
increased linearly with water temperature.
Size structure was also altered as indicated by the curvilinear decrease
in the ratio of median to maximum length with increasing water temperature.
Secondary productivity was higher in heated environments.
SREL Reprint #0387
Ferens, M.C. and T.M. Murphy Jr. 1974. Effects of
thermal effluents on populations of mosquito fish. p. 237-245. In
Thermal Ecology, edited by J.W. Gibbons and R.R. Sharitz.
CONF 730505. Atomic Energy Commission.
