EUTOBRILUS GODLEWSKII SP. NOV. AND TOBRILUS GIGAS SP. NOV. (NEMATODA: TRIPLONCHIDA) FROM LAKE BAIKAL, RUSSIA

Eutobrilus godlewskii sp. nov. and Tobrilus gigas sp. nov. are described and illustrated based on the material collected from Lake Baikal, Siberia, Russia. The species Eutobrilus godlewskii sp. nov. morphologically is close to E. fortis (Tsalolikhin, 1972) and E. prodigiosus Shoshin, 1988. From the former species it differs in the narrower labial region, longer outer labial setae, longer spicules and the absence of crystalloids. It differs from E. prodigiosus in the comparatively longer pharynx, another structure of stoma, longer spicules, another arrangement of precloacal supplements and the absence of crystalloids. Another new species, Tobrilus gigas sp. nov. is the largest among valid species of the genus Tobrilus. Morphologically it is close to T. undophylus Shoshin, 1988 and T. kamtschaticus Gagarin, 2004. From the former species it differs by having a narrowed male body, longer outer labial setae and spicules. From T. kamtschaticus it differs in wider labial region, longer outer labial setae and spicules. This article presents two tables showing the morphological characteristics of males among valid species of the genus Eutobrilus and Tobrilus from Lake Baikal.