Meeting Abstract

P3.214  Sunday, Jan. 6  Life in Hot Waters: Live Fast and Die Young CAMP, N*; MARTINEZ, E; PHILLIPS, C; PORCERRA, A; TORRES, J; COLOMBO, R; MENZE, MA; Eastern Illinois University; University of South Florida mmenze@eiu.edu

Thermal variation has profound implications for the physiology and life histories of ectotherms, influencing individual performance and population dynamics. Aquatic ecosystems are especially strongly affected by alterations in the thermal environment. Coffeen Lake, a cooling source for a central Illinois coal-power plant, has temperatures in excess of 35°C during the summer months due to discharge of thermal effluent. Lake Mattoon is a comparable lake system that is not impacted by thermal discharge. Previous studies demonstrated the average length and weight of Lepomis macrochirus in Lake Mattoon (132 ± 2 mm, 59.9 ± 2 g; p < 0.05) to be greater than Coffeen Lake (75.1 ± 1.1mm, 9.4 ± 0.51g; p < 0.05), and the average age to be significantly younger in Coffeen Lake (1 year) than in Lake Mattoon (2.3 years). However, the molecular, cellular, and whole-organism aspects of thermal adaptation in Coffeen Lake bluegill remain uncharacterized. We captured L. macrochirus from Coffeen Lake and Lake Mattoon and adapted the animals to two different temperatures (15° C and 30 °C) for two weeks in laboratory tanks. No significant difference was found between the upper thermal maximum of either population, adapted to 30 ˚C, after two weeks of acclimation [Mattoon = 39.7 ± 0.1 ˚C, Coffeen = 41± 0.1 ˚C, n = 6-9 ± SE; p > 0.05). Additionally, no differences were observed among oxygen consumption rates of animals adapted at 15 °C or 30 °C captured from either lake system. However, acute exposure of 15 °C adapted animals to 30 °C from both lakes led to a 1.7-fold increase in oxygen consumption rates. These results indicate broad plasticity in temperature tolerance for L. macrochirus , and oxidative stress will be discussed as possible factor in the reduced life span in Coffeen Lake.