Thermoregulatory behavior of bluegill, Lepomis macrochirus from a thermally stressed ecosystem. [Lepomis macrochirus]

Technical Report · Sat Dec 01 04:00:00 EST 1984

OSTI ID:5563637

Fischer, Jr, R U

Bluegills, Lepomis macrochirus were used as a representative aquatic ectotherm to determine the importance of behavior in thermoregulation of fish inhabiting a thermally stressed ecosystem. In the first part of the study, the mean final temperature preferenda for small bluegills from the heated and normothermic sites (25.2/sup 0/C vs 25.0/sup 0/C) were not significantly different. In the second part of the study, the acute preferred temperatures of large L. macrochirus (anti X = 26.3/sup 0/C) showed a statistically significant difference from that of small bluegills (anti X = 25.2/sup 0/C). There was no significant difference in the acute preferred temperatures for bluegill from the heated and normothermic sites. In the last phase of the study L. macrochirus from both a thermally stressed and normothermic site were tested for upper avoidance temperature in the absence of and in the presence of two sizes of predators (Micropterus salmoides, largemouth bass). In the absence of a predator the small bluegill had a mean upper avoidance temperature of 30.0/sup 0/C as compared to 29.8/sup 0/C for the large bluegills. In the presence of a small and large predator the small bluegills had a mean upper avoidance temperature of 34.0/sup 0/C and 33.9/sup 0/C respectively, while the large bluegills had mean upper avoidance temperatures of 33.8/sup 0/C and 33.1/sup 0/C. In the presence of a predator bluegill upper avoidance temperatures were significantly higher, however, predator size did not influence this relationship. During the determinations of final temperature preferendum, acute preferred temperature, and upper avoidance temperature, the fish from the heated site always exhibited less variability in temperature measurements than those from the control site. 41 refs., 9 figs., 10 tabs.

• Research Organization: State Univ. of New York, Buffalo (USA). Dept. of Biology
• DOE Contract Number: AC02-76EV02502
• OSTI ID: 5563637
• Report Number(s): DOE/EV/02502-T1; ON: DE86012570
• Country of Publication: United States
• Language: English

Related Subjects

520100* -- Environment
Aquatic-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ANIMALS
AQUATIC ECOSYSTEMS
AQUATIC ORGANISMS
BIOLOGICAL ADAPTATION
BIOLOGICAL STRESS
CONTROL
DATA
ECOSYSTEMS
EXPERIMENTAL DATA
FISHES
INFORMATION
NUMERICAL DATA
TEMPERATURE CONTROL
THERMAL EFFLUENTS
THERMOREGULATION
VERTEBRATES