Study of the sexual maturation time in Neogobius Pallasi (Berg, 1916) of the Gobiidae Family in Gomishan wetland

The reproductive biology of the Neogobius pallasi (Berg، 1916) was examined from Gomishan wetland a period of one year (2006-2007). This species are as important food for economic fish species in Caspian sea، specially for Acipenserid species. Different samples were taken from Gomishan wetland during one-year period of study. At this stage، the number of undifferentiated، previtellogenic stage، vitellogenic stage and postvitellogenic oocytes، and oocytes were counted. The number and diameter of ovary، nucleus and nucleolus were also measured. Data were analyzed using Systat statistical software. Results indicated that Neogobius pallasi was (p <0. 05) with respect to the numbers of differentiated and previtellogenic oocytes، and the diameter of chorion layers. GSI measurement showed that peak of sexual maturity in this species occurred in June.