Larval Ecology of Atlantic Silversides, Menidia Menidia

The Atlantic silverside (Menidia menidia) is one of the numerically most abundant fish species in estuaries along the East Coast of North America, but its ecology during the first two weeks post-hatch has never been described.  The upper reaches of two Rhode Island, USA, estuaries, Upper Pettaquamscutt River (UPR) and Upper Point Judith Pond (UPJP), with differing levels of anthropogenic inputs, were chosen to study depth distribution, abundance, feeding habits and growth of M. menidia larvae.  Four sampling devices were used.  A circular quadrat, which sampled the land-water interface, an aquarium net, which sampled water from 0.3 – 0.4 m depth, and a small plankton net, which sampled water from 0.4 – 0.5 m depth collected larvae, whereas a large plankton net, which sampled water at greater depths, did not.  Thus, M. menidia larvae can be found predominantly from the shoreline interface to 0.5 m depth. Collection data indicated a zero-inflated Poisson distribution, suggesting a patchy distribution of larvae in the field.  Gut contents of larvae between estuaries differed markedly, with 76.2% of the larval diet at UPR consisting of copepod eggs and 72.5% of that at UPJP consisting of copepod nauplii.  Larval growth rates did not differ between estuaries.