Gonad morphology and histology of the a endemic Hormuz cichlid, Iranocichla hormuzensis Coad, 1982 from Mehran River, southern Iran

Abstract

The gonad morphology and histology of the Hormuz cichlid Iranocichla hormuzensis, a maternal mouthbrooder endemic fish species from Mehran River, southern Iran was investigated. Based on the size, shape and weight of the gonads, degree of occupation of the body cavity, presence or absence of ripe oocytes, or milt, diameter of the oocytes in the ovary, and histological observations, six typical gonad maturation stages were described for both males and females using macroscopic and microscopic criteria. Based on the percentage of late gonad maturation stages (IV, V, VI) and high frequency of large oocytes it was concluded that the Iranian cichlid spawns at the end of winter and beginning of spring. These stages were correlated to the gonadosomatic index.