Meeting Abstract
Some teleosts will intentionally strand themselves on land to escape poor conditions, while others may become accidentally stranded. Do some species travel farther than others when stranded on land? Many small teleosts perform a tail-flip jump to move about on land. During this behavior, a fish rolls its head over the tail, extends the posterior body to push against the substrate, and launches into ballistic flight. We predicted that species with takeoff angles of approximately 45° (“good jumpers”) would jump more frequently and travel a greater distance, relative to species with takeoff angles greater than 45° (“poor jumpers”). To test this prediction, we stranded six species with varying jumping abilities (Gambusia affinis, Betta splendans, Umbra lima, and Oryzias latipes, “good” jumpers vs. Pseudomugil signifer and Danio rerio, “poor” jumpers) on a moist surface for two minutes and the response to stranding was recorded from overhead with digital video. Trials were analyzed by overlapping before/after images of each jump and net displacement was measured with ImageJ. During the trials, “good” jumpers moved very little, jumping approximately five times in two minutes, while “poor” jumpers moved continuously, jumping approximately fifty times (10x more often). Because they jumped infrequently, “good” jumpers covered less distance during a trial, relative to so-called “poor” jumpers. We hypothesize that these responses are a consequence of the natural history of each species: good jumpers may be predisposed to jump out of the water and rest immobile until an aquatic threat is gone, whereas, poor jumpers are unlikely to voluntarily leave the water. Consequently, “poor” jumpers may jump repeatedly in an effort to return immediately to the aquatic environment when stranded on land.
