Alternate Title

Foods of Juvenile Spotted Seatrout in Seagrasses at Seahorse Key, Florida


Early juvenile [ <1 yr; 10-100 mm total length (TL)] spotted seatrout in the shallow seagrasses at Seahorse Key, Florida, in the Northeast Gulf of Mexico, fed on 12 kinds of foods. Although the total diversity of major food items of juvenile seatrout is about the same as 50 years ago, for some unexplained reasons, the juvenile diets have apparently switched to other invertebrate species and to small fish. The 10-30 mm TL seatrout ate small Crustacea, e.g., amphipods and grass shrimps, and fed mostly in the Halodule seagrass zone (average depth 0.5 m). In addition to these species, the 50-80 mm TL seatrout, feeding primarily in the Halodule and Thalassia (average depth 0.8 m) zones, consumed copepods, a combination of decapod shrimps (Mysidopsis bahia, Palaemonetes pugio, P. vulgaris, Periclimenes longicaudatus, Penaeus duorarum), and small fish. Seatrout of 80-100 mm TL appeared to feed only in Thalassia, and larger juveniles (not collected) probably fed in the mixed-grass zone beyond our study area (>1 m depth). Seatrout food resources at the Keys were robust. Peak densities and diversities of hyperbenthic invertebrates in the seagrasses were inversely proportional (maximum average number of individuals = 12,000/sled trawl, Sep.; maximum average number of taxa = 35 spp., March).