ABSTRACT
Goussia obstinata sp. n. is described from the intestine epithelium of the Amur sleeper Perccottus glenii Dybowski, 1877 from Russia and Moldova. The species was examined in an optical microscope. Merogonic, gamogonic and sporogonic stages of the species are located in cells of the gut epithelium. Sporulation is endogenous; oocysts are released in the gut lumen. Non-sporulated oocysts are spherical or ellipsoidal; sporulated oocysts are rounded, 6.7-11.4 µm in diameter, with a colorless, single-layer, very fine and easily ruptured wall. Micropyle and oocyst residuum is absent; 1-2 small polar granules of 1.0-2.5 µm are sometimes present. Oocysts contain four compact widely oval, slightly narrow-ended sporocysts. The sheath of the sporocyst is formed of two folds divided by a slightly S-shaped longitudinal suture. Coarsely granulated, globular or oval compact sporocyst's residuumis located between sporozoites. Sausage-shaped sporozoits are subdivided by a bend into two unequal parts, being 6.4-9.8 µm (long part) and 2.6-4.8 µm (short part) long, arranged in a top-to-tail position. Our preliminary data suggests that infestation of the sleeper with the examined parasite is not associated with the morbidity and mortality of the fish. A new combination Goussia marmorata (Molnár, 1996) comb. n. is proposed for a species originally described in the content of the genus Eimeria Schneider, 1875 from the Western tubenose goby Proterorhinus semilunaris.
