ABSTRACT: In early spring, coccidiosis often develops in the gut of pikeperch Stizostedion lucioperca and Volga perch S. volgensis living in Lake Balaton, Hungary. Gamonts and oocysts cause nodular infection of enterocytes in specific portions of the gut. Besides those present in the nodules, merozoites and gamonts occur diffusely in the epithelium of the intestine and the pyloric sacs. The different developmental stages are located in the apical cytoplasm of enterocytes and are released from the cells in unsporulated condition. The sporulation of oocysts takes 48 h in tap-water at 20°C. The oocysts, which are 13-13.5 µm in diameter in an unsporulated state, grow to 17-20 µm by the end of the sporulation process, and ellipsoidal sporocysts composed of 2 valves and containing banana-shaped sporozoites develop in them. On the basis of oocysts derived from pikeperch, the parasite is described as Goussia desseri n. sp.

KEY WORDS: Goussia desseri · Apicomplexa · New species · Pikeperch · Volga perch · Nodular coccidiosis · Histology

Published in DAO Vol. 27, No. 1 (1996) on October 17
ISSN: 0177-5103. Copyright © Inter-Research, Oldendorf/Luhe, 1996