Gonads Tissue Changes of Chalcalburnus mossulensis (Heckel, 1843) Infected by Ligula intestinalis (Cestoda)

Chalcalburnus mossulensis from the cyprinidae family is one of the indigenous fish in Gheshlag lake of Kordestan-Iran. Ligula intestinalis is one of the infective parasites among various species offish and causes gonads atrophy. In this study, detectection of species and age of samples, the effects of this parasite on gonads tissues and sexual maturation of Chalcalburnus mossulensis are investigated. By seasonal sampling 144 speciemens of these fish were collected. It was clear that a significant difference was between the means of male and female gonads maturation rate in infected and non infected samples (p< 0.05). The lack of gonads maturation in infected fish may be due to Ligula intestinalis. In addition, the abnormal degenerative changes like absorption follicle, hemorrhage and infiltration of inflammation cells in ovaiy tissue of infected fish were seen. In testicle tissue dispersed hemorrhage, atrophy and MMC (melano-macrophage center) were seen as a pathological signs. So the spread of this parasite in different water sources is important as the point of the maintenance of indigenous species and cultivated fish.