MYXOBOLUS MOLNARI SP-N AND M-MOKHAYERI SP-N (MYXOSPOREA, MYXOZOA) INFECTING A MESOPOTAMIAN FISH, CAPOETA-TRUTTA HECKEL, 1843

A new Myxobolus species is described from the gills and another from t he fins of Capoeta trutta Heckel, 1843 caught in the River Karun in th e southwestern part of Iran. The two species differ from each other bo th in location and in morphology. Myxobolus molnari forms plasmodia in the tunica adventitia of blood vessels of the primary gill filaments, directly beneath the endothelium, in a cyst surrounded by connective tissue cells. The plasmodia of M. mokhayeri develop in the fins, aroun d the soft fin rays, beneath the stratum spongiosum of the skin and al so in cysts surrounded by connective tissue cells.