Stripped piggy ( Pomadasys stridends ) is widely distributed in coastal waters of Persian Gulf. However, the reproductive characteristics of this fish were poorly studied. The purpose of present work was to elucidate some features of the sexual cycle, fecundity, nature and spawning period of Pomadasys stridens in the Persian Gulf. Specimens of Pomadasys stridens were collected from the commercial catches at bushehr fishery harbor from May 2010 to April 2011, by regular monthly collections. A total of 540 specimens, including155 males and 385 females were collected and traorted to Bushehr fishery research center and then to Isfahan university of technology for analysis. The total length (cm), as well as, the total weight (g) of the fish was recorded. The total length of mature fish ranged from12.6 to 23 cm in females and from11.7 to 22 cm in males. The weight of mature fish ranged from 27.4 to 144.8 g in females and from 21 to 124.9 g in males. After carrying out biometrical measurements, fish were dissected and gonads were removed, weighed to the nearest mg and thoroughly examined for determination of its sex and maturity stage. For histological examination, pieces of the gonads were fixed in 10% formalin for 24 hours and then moved to 70% ethanol. In both, length and weight, females showed larger size than males. Age groups in both sexes were determined and ranged between 1 and 8 years. Monthly distribution of GSI for female and male P. stridens , showed that the GSI values have two peaks, the first one which was smaller occured in December and the second one, the maximum was in march. The GSI values for females and males fluctuated similarly throughout sampling period. Condition factor for both sexes showed no significant differences. The minimum and the maximum of absolute fecundity were 28597 and 198672, respectively. The relative minimum and maximum fecundity was 288 and 1558, respectively. Oocytes were colourless, spherical-shaped and pelagicous.The curvilinear relationship between fecundity and total weight of fish is explained by the equation: F=776.01W 0.2581 .The minimum and the maximum ova diameter was 65.08 ± 10.13µm (stage 1) and 617.3± 91.63 µm (stage 4). The mean of the sex ratio was 1: 3.3 (M/F). According to the GSI, ova diameter and histological observations, spawning period was determined from December to March .Five sexual maturity stages were determined for females P. stridends as follows: stage 1 (Immature), stage 2 (developing), stage 3 (ripening), stage 4 (spawning), and stage 5 (spent). According to present finding the mode of oocyte development in ovary of P. stridens is considered group synchronous and all of the developing clutch of oocytes release together during spawning season. Key words : Reproduction, Stripped piggy ( Pomadasys stridens ), group synchronous, Persian Gulf, Bushehr province.
