Reproductive biology of turbot(Psetta maxima)and brill(Scophthalmus rhombus)(Teleostei, Pleuronectiformes) in the Adriatic Sea

The reproductive biology of two commercially important flat fish, turbot (Psetta maxima) and brill (Scophthalmus rhombus), in the Adriatic Sea was investigated by histology and macroscopic analysis of gonads. Different patterns of vitellogenesis and spawn ing were observed in the two species. In turbot, gonad develop ment culminates annually from March to May and the seasonal egg batch develops synchronously, the eggs becoming ready at about the same time. In brill, the ovary contains several oocyte batches in different stages of maturity, indicating intermittent re lease of ripe eggs in the course of a long spawning season (Janu ary‐July). These data are discussed and compared with observa tions on reproduction of turbot and brill for other areas of their distribution ranges.