HABITAT SELECTION BY JUVENILE LEMON SHARKS, NEGAPRION BREVIROSTRIS

We surgically implanted ultrasonic transmitters in 38 lemon sharks, Negaprion brevirostris, and manually tracked the sharks for 1-153 days. This yielded 2281 positional fixes recorded at 15-min intervals. We used these positional data with availability data of four environmental variables (water depth, temperature, salinity, and bottom type), sampled at 213 stations along 15 transects, to examine usage of habitat. All sharks used contours of water depth, water temperature, and bottom type disproportionately to the availability of these variables in the study site. Specifically, juvenile lemon sharks selected shallower, warmer water with an underlying rocky or sandy substrate, perhaps for predator avoidance. This is the first report on habitat selection by any elasmobranch.