NODULAR COCCIDIOSIS OF THE PIKEPERCH STIZOSTEDION-LUCIOPERCA AND VOLGA PERCH STIZOSTEDION VOLGENSIS

In early spring, coccidiosis often develops in the gut of pikeperch St izostedion lucioperca and Volga perch S. volgensis living in Lake Bala ton, Hungary. Gamonts and oocysts cause nodular infection of enterocyt es in specific portions of the gut. Besides those present in the nodul es, merozoites and gamonts occur diffusely in the epithelium of the in testine and the pyloric sacs. The different developmental stages are l ocated in the apical cytoplasm of enterocytes and are released from th e cells in unsporulated condition. The sporulation of oocysts takes 48 h in tap-water at 20 degrees C. The oocysts, which are 13-13.5 mu m i n diameter in an unsporulated state, grow to 17-20 mu m by the end of the sporulation process, and ellipsoidal sporocysts composed of 2 valv es and containing banana-shaped sporozoites develop in them. On the ba sis of oocysts derived from pikeperch, the parasite is described as Go ussia desseri n. sp.