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 (P setta maxima) and brill (Scophthalmus rhombus), in the Adriatic Sea was inv estigated by histology and macroscopic analysis of gonads. Different patter ns of vitellogenesis and spawning were observed in the two species. In turb ot. gonad development culminates annually from March to May and the seasona l egg hatch develops synchronously. the eggs becoming ready at about the sa me time. In brill, the ovary contains several oocyte batches in different s tages of maturity, indicating intermittent release of ripe eggs in the cour se of a long spawning season (January-July). These data are discussed and c ompared with observations on reproduction of turbot and brill for other are as of their distribution ranges.