زمان تخم ريزي و مراحل باروري خارجي در خرچنگ پهن آب شيرين جاجرود

Spawning season and maturity stages of Potamon persicum in Jajroud River

Jajroud river with 140km length, inhabits various species of aquatics of which one of the main identified one is freshwater crab belongs to POTAMIDAE family with scientific name of Pozaman persicum. In this study, 388 specimens from 5 sampling stations (Latian dam, Taraghion, Khojir, Giahan daroie and Mamloo dam) were collected since November 1998. All samples were transfered to the laboratory for reproduction studies and determination of spawning season, with studying the maturity stages of gonads and external eggs. The results showed that the spawning season of this species occuring in middle of spring, it was also found that P. persicum is a total spawner. The external maturity (of eggs) was classified to 7 stages. On the other hand the maturity stages of gonad was recongnized in accordance with the color, size and egg diameter and classified to 5 stages.