Site preference of myxosporean spp. on the fins of some Hungarian fish species.

Some species of the known fish myxosporeans select fins as type location for their development. During the plasmodial development of Myxobolus, Henneguya and Thelohanellus species in cyprinid fishes and eels, 3 main locations of plasmodial development were distinguished inside the fins. M. portucalensis, M. alburni, M. caudatus and a Myxobolus sp. formed plasmodia in the dermis of the skin doublets between finrays, while plasmodia of M. diversus and H. cutanea developed inside the lumen of the cartilaginous finrays. The third type of development was represented by T. nikolskii, which started its development on the outer surface of the finrays. Plasmodia both in the lumen and on the surface of the finrays were surrounded by a cartilaginous capsule, but plasmodia of T. nikolskii also had a thick connective tissue capsule containing pieces of cartilage.