Meeting Abstract
71.1 Thursday, Jan. 6 The Influence of Temperature on the Physiology and Feeding Behavior of the Invasive Pike Killifish, Belonesox belizanus KERFOOT, J.R.*; TURINGAN, R.G.; Union University; Florida Institute of Technology jkerfoot@uu.edu
A series of studies were designed to determine the role of thermal adaptation as a plausible physiological mechanism allowing the invasive Belonesox belizanus to spread northward from its original point of introduction. Stage-specific variation in temperature tolerance exists in natural populations and underscores the need to determine if the variation in the ability of B. belizanus to tolerate different levels of temperature regimes throughout ontogeny influences its distribution and abundance in south Florida. The first study investigated the life-history stage specific thermal tolerances of B. belizanus. Upper lethal and lower lethal thermal tolerances were measured for individuals from each life-stage (neonate, juvenile, and adult) by increasing or decreasing the temperatures in experimental tanks 1 oC day-1. Results indicated that juveniles had a significantly lower thermal tolerance range and have the potential to disperse further than either adults or neonates, especially during seasonal thermal stress events. The objective of the second study sought to determine the effect of temperature on feeding behavior and physiological performance across ontogeny of this invasive species. Investigating the kinematics of prey-capture, individuals from each of the three life-stages where filmed feeding on live prey at three separate temperatures, 20, 25, and 30 oC. Results of the Q10 (temperature coefficient) analyses indicated the potential ability of juveniles to successfully modulate their prey-capture abilities across temperatures compared with neonates and adults. The ability of juveniles to modulate their feeding behavior and tolerate lower temperatures may facilitate the spread of this invasive species to heterogeneous thermal environments in Florida.
