W. Schneider, 1940
Onchulidae can be recognized from other families of the Tripyloidea (Tripylidae
and Trischistomatidae) by the two whorls of
cephalic setae, the large buccal tooth, shape of the buccal cavity, the
unusual pattern of the esophagus and the lack of a spinneret on the tail.
The genus Stenonchulus is differentiated from Onchulus by the presence of
3 equally developed stomal teeth. Other characters are similar.
From its description in 1940, the genus was represnted by only the type
species, S. troglodytes from Europe. However, in 2013, two new species
were described from Canada and Ireland. The authors (Siddiqi and
Siddiqi, 2013).propsed a new family (Stenonchulidae) to accommodate the
genus based on the presnece of three teeth. However, three teeth occur
in other Tripylida, although not of uniform size, for example
Tripylella mexicana and others, so it will be
interesting to monitor the acceptance of a new family within the order.
Ref: Andrassy, 2007
Spevies have been described from wet soil and "groundwater" in Europe,
Canada and Ireland..
Classified as predators by Yeates et al (1993)
Regulation of opportunistic species through predation.
Andrassy, I. 2007. Free-living nematodes of Hungary (Nematoda, Errantia), II.
Hungarian Natural History Museum, Budapest, Hungary. 496 pp.
Siddiqi, M.R. and Siddiqi, S.E. 2013.
Desacriptions of Stenonchulus longisetosus sp. n. from Canada and S.
eirensis sp. n. from Ireland (Tripylida: Stenonchulidae fam.n.).
Intenational J. Nematology 23:37-42.
Yeates, G.W., T. Bongers, R. G. M. De Goede, D. W. Freckman, and S. S.
Georgieva. 1993. Feeding habits in soil nematode families and genera—An outline
for soil ecologists. Journal of Nematology 25:315-331