Ultrastructure and cytochemistry study of Goussia sparis (Protozoa: Apicomplexa) stages from the intestine of the gilthead sea bream Sparus aurata L. (Pisces: Teleostei)

Abstract

The ultrastructure and cytochemistry of merogonial and gamogonial stages and early unsporulated oocysts of Goussia sparis in the intestine of Sparus aurata were studied. The typical pellicle was observed in some stages. The different stages might appear in intraepithelial or supraepithelial positions, but they were always intracellular. First steps of two apparently different endomerogonies were observed in intra- and supraepithelial positions, respectively. An apparent ectomerogony also occurred in supraepithelial stages. Developing macrogamonts showed surface invaginations and were densely packed with ribosomes, well-developed rough endoplasmic reticulum, mitochondria, amylopectin granules, lipidic droplets, and wall-forming-like bodies. The latter could participate in the formation of the oocyst wall. Abundant and large mitochondria, together with residual nuclei, appeared in advanced microgamonts. Microgametes showed two flagella with microtubul arranged according to the typical pattern. An increase in polysaccharide content was observed with coccidian development, reaching a maximum in zygotes and unsporulated oocysts.

Fine structure of sporogonic stages of Goussia clupearum (Apicomplexa: Eimeriidae) in the liver of infected fish (Belone belone L.), using light and electron microscopy

“…In the coccidia, the genera Eimeria and Goussia seem to be among the most important groups of ®sh parasites (Morrison and Hawkins 1984). Although most Goussia species live in the ®sh intestine (Steinhagen et al 1989;LukesÏ and Dykova 1990;Lom et al 1991;LukesÏ et al 1991;LukesÏ 1992;Molna r and Baska 1992;Sze kely and Molna r 1992;Sitja -Bobadilla et al 1996;Alvarez-Pellitero et al 1997), some are found in the liver (Jones 1990;Costa and Mackenzie 1994), or in several organs simultaneously (Morrison and Hawkins 1984;Diouf and Toguebaye 1993). This paper describes some light microscopic and ultrastructural aspects of the life cycle of Goussia clupearum (The lohan, 1894) Labbe , 1896, which infects the liver of the teleost ®sh, Belone belone, from the Portuguese Atlantic coast.…”