The ultrastructural characteristics of the sporogenesis of Myxobolus, which infect the brachial arches of Mugil cephalus, is presented. The prevalence of infection was 52.7%. The ultrastructural features of the Myxobolus species studied in general comply with known features of this genus. Based on the ultrastructural morphology and specificity to the host organ, we conclude that this species is Myxobolus ichkeulensis (Bahri and Marques 1996).
