Feeding habits of asp Aspius aspius larvae (Cyprinidae) in Lake Maroz, Poland

Feeding development of asp Aspius aspius larvae was studied during rearing in Lake Maroz (north Poland) illuminated cages. The initial rearing occurre d under controlled conditions in a hatchery. After four and half weeks, rea red fish (total length 14.8 mm) were transported to cages maintained in a l ake. The initial stocking density was about 8 830 fish per cage. All experi ments were replicated three times. Fish were fed zooplankton collected duri ng night with a light placed over the cages. During the seven weeks rearing period in lake cages survival was relatively high (over 72%). The observed feeding development pattern was as follow: rotifers, nauplii, copepodites, adult Copepoda, then adult Cladocera. The largest asp larvae also ate imag e forms of insects.