VARIATION IN ABUNDANCE AND SURVIVAL OF FISH LARVAE IN SHALLOW EUTROPHIC LAKE-TJEUKEMEER

Variations in abundance and survival of larvae of the major fish speci es, bream, roach, pikeperch, perch and smelt were studied in shallow e utrophic lake Tjeukemeer (1986-1988). Except for smelt, the size of th e spawning stock and the abundance of larvae were not related. Both th e timing of appearance of larvae and their growth rate were determined by water temperature as was shown by a growth model developed earlier for Tjeukemeer fishes. In cyprinids and percids the survival of the l arvae was hypothesized to be negatively related to the duration of the earliest stages. Except in cyprinids, the abundance of 0+ juvenile fi sh could be explained by the number of larvae. In cyprinids 0+ juvenil e abundance at the end of the year was not related to the number of la rvae in May and June. The cyprinid juvenile survival rates are hypothe sized to be related to the size of the main cyprinid predator, 0+ pike perch.