CULLUM, A.J.*; GONSALVES, W.; Creighton University, Omaha, NE; Creighton University, Omaha, NE: Effects of developmental temperature on growth in Teleogryllus oceanicus: a test of acclimation hypotheses

The capacity of an animal to acclimate to changes in environmental factors such as temperature may have potentially significant fitness consequences. One long-held assumption was that such consequences would generally be positive; for example, development at a particular temperature would increase later fitness at that temperature. However, this �Beneficial Acclimation� hypothesis is only one of a number of patterns of acclimation that might occur. Huey and Berrigan (1996) identified four additional hypotheses concerning the relationship between acclimation or developmental temperature and fitness at different temperatures: �Cooler is Better,� �Warmer is Better,� �Optimal Developmental Temperature� and �Developmental Buffering.� They then proposed a strong inference approach to testing all five hypotheses simultaneously. In this study, we are using this approach to examine the fitness consequences of early development at one of three temperatures in the cricket Teleogryllus oceanicus. In the work reported here, cricket eggs were allowed to develop from laying until hatching at one of three temperatures: 24°C, 28°C or 32°C. After hatching, juvenile crickets from each temperature were divided among the same three temperatures, providing a three-by-three factorial design. The growth of blocks of crickets was then followed until adult size was reached. Although we found no consequences of either egg development or growth temperature for final adult size, we did find significant difference in the growth patterns associated with growth temperature (the direct effect of temperature) and also egg development temperature (the �acclimation� effect). However, the pattern of differences observed did not support any of the five hypotheses tested.