Several new and known species from the families Coninckiidae and Comesomatidae (Nematoda) in the White Sea

Abstract

Ten new and known species of the genera Coninckia, Cervonema, Laimella and Sabatieria are described from the White Sea. Coninckia macroseta sp. n. resembles C. seta Wieser et Hopper, 1967 (Florida coast of U.S.A.) in shape of the amphid and other characters, but differs from the latter by greater body length (2399 μm versus 1300–1400 μm) and by the a-index (83 versus and a 57–58). Cervonema proximamphidum sp. n. differs from all other species of Cervonema by the shape of posterior widening of the pharynx (except for C. allometricum Wieser, 1954 whose original description is too brief). The pharynx of the new species forms posteriorly a conical widening with vague radial striation, whereas the pharynx of other Cervonema species presents posteriorly an oval or elongate thickening with wavy contour and distinct muscular transversal striation. The other diagnostic characters of Cervonema proximamphidum sp. n. are close position of the amphid to the anterior end (distance from the anterior end to the amphid 6–7.5 μm), longer outer labial and cephalic setae (5–5.5 μm), relatively longer and slender body (respectively, 1423–1563 μm and a=30.9–41.1). Specimens Cervonema minutus Muthumbi, Soetaert et Vincx, 1997 largely agree with the original description of Muthumbi et al. (1997) based on the nematodes sampled in the Indian Ocean deep sea; only cephalic setae length (2.7–3.5 versus 2 μm) differ. The White Sea specimens Laimella filipjevi coincide well with the description of Jensen (1979) made on nematodes from the western Baltic Sea, except slight difference in body length (1564–1837 μm versus 1086–1152 μm). Sabatieria kolaensis (Ssaweljev, 1912) is redescribed and restored as valid species. Sabatieria kolaensis was assigned by Platt (1985) to the list of dubious species because of very brief original description lacking some important details. Sabatieria kolaensis belongs to the S. praedatrix species group and is characterized by the greatest number of preanal supplements (31–40). Sabatieria lawsi Platt, 1983 was previously known from the only Antarctic Peninsula shelf; the single White Sea male specimen corresponds well to the original diagnosis of Platt (1983). Sabatieria lawsi is considered to be very close or near identical to S. praedatrix de Man, 1907. The species Sabatieria longispinosa Lorenzen, 1972, S. ornata (Ditlevsen, 1918), S. pulchra (G. Schneider, 1906) and S. strigosa Lorenzen, 1972 are also described and discussed.