MANUEL ANDRES SOTO, G. JOAN HOLT, AND SCOTT A. HOLT, University of Texas Marine Science Institute, 750 Channel View Drive, Port Aransas, Texas 78373, USA

Red drum Sciaenops ocellatus and Atlantic croaker Micropogonias undulatus spend most of their adult lives offshore and congregate near tidal passes to spawn. Pelagic larvae of both species are transported by oceanographic and tidal currents to nursery habitat in bays and estuaries. Larval and juvenile red drum and Atlantic croaker concurrently occupy seagrass beds in the fall and interactions may affect trophic dynamics. A study was undertaken to: 1) describe quantitatively the diet of larval and juvenile red drum and Atlantic croaker, 2) determine ontogenetic patterns in diet for the two species, and 3) determine dietary overlap of red drum and Atlantic croaker when they co-occur in seagrass beds. A total of 274 red drum (4.00 - 19.99 mm SL) and 205 Atlantic croaker (8.00 - 17.99 mm SL) guts were examined of which 8.4 % and 28.8 % were empty, respectively. The primary prey taxa consumed (% IRI) by both species were calanoid copepods, harpacticoid copepods, and mysid shrimp. More discrete ontogenetic trophic patterns were detected for red drum than for Atlantic croaker. Four of the five size classes (8.00 - 15.99) examined had high dietary overlap values (> 0.7).