Meeting Abstract

P1.102  Tuesday, Jan. 4  How do small teleost fishes respond to being stranded on land? Terrestrial movements by Danio rerio and Gambusia affinis AKLAND, M. K.*; GIBB, A. C.; University of Northern Arizona mka36@nau.edu

Fish may become stranded on land when they jump out of water to escape predators or seek more favorable conditions; once stranded, the ability to return to the water is critical for individual survival. We have recently described a terrestrial jumping behavior in several fully-aquatic small teleost species. Here, we examine jumping in response to stranding by two species of teleost Danio rerio and Gambusia affinis. Because previous work in our laboratory suggests that Gambusia have a take-off angle of ~45 degrees, whereas the take-off angle of Danio approaches 90 degrees, we predicted that Gambusia would jump farther than similarly-sized Danio. To test this hypothesis, we placed individuals (n=10-12) of each species in a circular arena (~0.1 m diameter) lined with wetted lab-bench liner-paper and recorded their response for two minutes using a commercial-grade camcorder. We found that the average distance per jump for Danio was ~0.10 m, while Gambusia jumped only ~0.07 m, although maximum jump distances were similar for both species (~0.27 m). Danio jumped an average of over 40 times during a two minute trial, while Gambusia only jumped ~7 times. Consequently, over the course of the trial, Danio moved an average of >1.5 m, whereas the Gambusia moved <0.5 m. Although both fish have similar capacities for jumping, Danio showed a greater propensity to jump and traveled greater distances when stranded, relative to Gambusia. However, it is also possible that Gambusia employ a different strategy when stranded under natural conditions, such that they jump less frequently, but in a more directed manner.