Immature stages and re-description of Henneguya suprabranchiae (Myxosporea: Myxobolidae), an intestinal parasite of the catfish Clarias gariepinus in the River Nile, Egypt.

A new morphological description, supported by light microscopy photographs, is presented for various immature stages and for mature Henneguya suprabranchiae Landsberg, 1987 spores infecting the intestine of the Nile catfish Clarias gariepinus, Burchell, 1822 (Syn.: C. lazera). Large cysts of 2 to 4.5 mm diameter, containing immature and mature stages, were present in the outer layer of the intestine. They caused severe damage to the smooth muscle and atrophy due to the increased size and resultant pressure of the plasmodial mass. From September 2000 to April 2001, 21 infected fishes were detected, with a parasite prevalence of 21.2%. Nine immature stages were distinguished, and these have been measured, sketched and described. In addition, caudal process development was recorded. The mature spores are re-described and compared with previous descriptions of H. suprabranchiae spores. The main new morphological characteristics described are the number of polar filament coils, triangular thickening of the sporoplasm base, and a suture line visible only in lateral view.