Reproductive biology characteristics of red mullet (Mullus barbatus L., 1758) in Southern Adriatic Sea and management implications

Abstract

The main important reproductive aspects of Mullus barbatus, one of the most important target species for the fishery in the Mediterranean basin, have been studied on the basis of MEDITS trawl survey and sampling of commercial landing. The total length (TL) of females has been demonstrated to be positively correlated with egg sizes and plasmatic concentration of vitellogenin. The possible implications of these aspects on the management of red mullet resources are discussed in this work. Moreover, the relationship between TL and fecundity follows an exponential pattern with a temporal trend during the spawning season. These results represent an important input for more effective management measures, such as the seasonal closure of fishery in summertime. The frequency distribution of the oocytes' diameters showed an asynchronous ovarian organization with batch spawning pattern. Monthly variations in the gonadosomatic index and maturity stages percentage showed that males spawn during almost the entire year showed an increasing trend from November to June and a decreasing trend from July to October, while females in spawning phase are recorded from April to July, with peaks in May and June. The length at 50% maturity (L50) estimated respectively for females and males are 12.1 cm (±0.083) and 10.1 cm (±0.073).