Ontogeny of feeding habits in northern pike, Esox lucius (Esocidae), larvae reared in illuminated cages

Feeding habits of larval pike, Esox lucius L., was studied at three stockin g densities in illuminated cages. Developmental patterns of larval feeding on zooplankton were independent of larval density. During the first week of rearing, larvae fed mainly on rotifers, small cladocerans, nauplii and cop epodites of Cyclopidae. After second week they selected small cladocerans ( Bosmina spp.), and adult copepods (Cyclops and Mesocyclops spp.). Higher st ocking densities resulted in lower survival and growth rates. This was pres umably due to increased competition for food, as the composition of the die t was independent of stocking density.