Daptonema Cobb, 1920

Timchenko, Anna I. & Portnova, Daria A., 2024, A new sympagic nematode species Daptonema gelida sp. n. (Monhysterida, Xyalidae) from the White Sea landfast ice, Zootaxa 5433 (2), pp. 183-206 : 185-186

Genus Daptonema Cobb, 1920

Diagnosis (modified from Fonseca & Bezerra 2014 and Leduc 2015): Cuticle striated or annulated. The set of anterior sensilla consists of six inner sensilla papilliform, six outer labial papillae/setae, and four cephalic setae or papillae forming a single circle. Additional subcephalic setae may occasionally be found at the level of the cephalic and outer labial setae. Somatic setae typically present and 1.5 times shorter than corresponding body diameter. Amphideal fovea in circular shape of varying sizes and in variable positions from the anterior end. Buccal cavity conical in shape, slightly cuticularized. Small cardia surrounded by intestine. Ventral gland absent. Post- and prevulval sac may be present. Pairs of spicules typically short 1.5–2.0 anal body diameter long and strongly curved, L-shaped. Gubernaculum usually present, often with lateral guiding pieces and rarely with dorso-caudal apophysis. Tail conico-cylindrical, with terminal swelling and 2 (rarely 3 or 4) terminal setae.

Here we present a comparative list of valid species of Daptonema with their key morphological traits (i.e., body length, de Man’s ratios (a, b, c) ( de Man 1881), spicule and gubernaculum length) (Appendix).