Sacrimarinema gen. n. from Lake Baikal with descriptions of three new species (Nematoda, Monhysterida: Xyalidae)

Abstract. Sacrimarinema gen. n. and three new species from Lake Baikal are described. The new genus is close to Penzancia de Man, 1889, from which it differs in the presence of 14 cephalic setae, complicated supplements, and very long spicules and vagina. Its type species, S. tatushae sp. n., is characterized by the presence of 6-7 supplements and length of spicules equal to 2.3-3.0 anal diameters. S. ljajiae sp. n. differs from S. tatushae sp. n. in the longer body, longer spicules (3.3-3.5 anal diametrs) and vagina, higher number of supplements. S. allae sp. n. differs from S. tatushae sp. n. in the extremely long spicules (6.9-9.2 anal diametrs) and vagina (2.2-2.5 body diametrs), lower number of supplements.