Size-Related Variation in the Diet of Juvenile Tautogs from Long Island Sound

Abstract

Juvenile tautogs Tautoga onitis were collected from shallow-water nursery areas along the Connecticut coast of Long Island Sound from June through September of 2000, 2001, and 2003. A total of 164 juveniles (8.9–165 mm standard length) were collected using several different methods. The digestive tracts of 152 (92.68%) juveniles each contained at least one identifiable prey item; 12 (7.32%) stomachs were empty. The number of different identifiable prey taxa in the digestive tracts ranged from one to four. Juvenile tautogs from the study area consumed 21 mutually exclusive prey taxa. Over all size-classes, crustacean prey constituted a major component of the diet. Gammarid amphipods (present in 45.39% of the fish with food in their digestive tracts) and calanoid copepods (16.45%) were the predominant prey. Less commonly consumed prey included hermit crabs Pagurus spp., lady crabs Ovalipes ocellatus, mud crabs (Xanthidae), Asian shore crabs Hemigrapsus sanguineus, eggs of horseshoe crabs Limulus polyphemus, sevenspine bay shrimp Crangon septemspinosa, shore shrimp Palaemonetes spp., polychaete worms (Polychaeta), milky ribbon worms Cerebratulus lacteus, common Atlantic slipper shells Crepidula fornicata, eastern oysters Crassostrea virginica, and blue mussels Mytilus edulis. Hierarchical cluster analysis of prey consumed by young tautogs revealed three distinct size-related feeding groups: (1) small fish (9–30 mm) that consumed calanoid copepods and gammarid amphipods, (2) midsized fish (31–70 mm) that were generalist feeders, concentrating on polychaete worms and crustaceans, and (3) large fish (81–165 mm) that preyed on mollusks, shrimps, and crabs.