Distributions of a Larval Fish Community in a Puerto Rico Reservoir

Information regarding spatial and temporal trends in larval fish distributions gives managers insight into recruitment variability and ultimately adult population variability. In Puerto Rico, limited research has been conducted on larval fish distributions and no studies have addressed reservoir systems. We conducted a study to compare efficacy of two larval sampling gears (larval light traps [passive] and bongo-style push nets [active]) and to assess spatial and temporal distributions of larval fish communities in a tropical reservoir. Preliminary results indicate larval light traps collected greater diversities and total numbers of larval fish than push nets for all species except Dorosoma petenense. Inshore light traps collected greatest total number and diversity of the larval fish community, with littoral species such as Tilapia rendalli, Lepomis spp, and Pterygoplichthys pardalis composing the primary catch. Offshore light traps collected greater numbers of pelagic species such as Dorosoma petenense and Ictalurus punctatus, though diversities were lower than inshore light traps. Temporal trends indicate T. rendalli and Centrarchidae numbers peak earlier in the summer, while peak numbers of I. punctatus increased during autumn. These results will allow managers to coordinate larval sampling efforts for specific species with time of year present and within which habitat these species are most likely to occur.