FOOD PATHWAYS ASSOCIATED WITH PENAEID SHRIMPS IN A MANGROVE·FRINGED ESTUARY

STONER, A. W. & ZIMMERMAN, R. J. 1988. Food pathways associated with penaeid shrimps in a mangrove-fringed estuary. Fisheries Bulletin 86:543-551.

Abstract: 
High abundance and production of juvenile Penaeus spp. in tropical estuaries has been attributed to high concentrations of mangrove-derived detritus in the nursery habitats. Examination of the diets of Penaeus notialis, P. subtilis, and P. brasiliensis in the mangrove-fringed Laguna Joyuda, Puerto Rico showed that even the smallest juveniles are predators consuming capitellid polychaetes (20-38% of diets) and amphipods (20-76%). Less than 25% of the diets was detritus. Ontogenetic variation in diets was greater than interspecific variation, and there was no evidence for dietary separation among the sympatric species. Seasonal shifts in foods reflected abundance patterns of macrobenthic prey species. Despite the consumption of prey organisms generally classified as detritivorous, stable carbon isotope ratios in the penaeids (-18.1 to -15.0%0), their food items (-18.8 to -17.7°/00), and primary producers indicated that shrimps and the majority of sediment dwellers in Laguna Joyuda obtain most of their carbon from benthic a1gae (-14.4°/00) and not from mangrove detritus (- 25.0 to - 22.9°/00).