Graphonema Cobb, 1898

Datta, Tridip Kumar & Al-Helal, Md. Abdullah, 2023, Review of Euchromadorinae (Nematoda: Chromadorida) with description of a new species of Trochamus Boucher & De Bovée, 1971 from the Sundarban, India, Zootaxa 5278 (3), pp. 493-510 : 496

Graphonema Cobb, 1898 (emended after Warwick & Coles 1975 and Shimada et al. 2019)

Body cuticle with complex heterogeneous ornamentation. Anterior part of the body with hexagonal blocks and afterward the pattern changes with alternate hooking between rings. The rings are externally smooth and with crenate edges. Lateral differentiation, if present, like simple smooth band without forming elevated lateral ridge or wing-shaped form. Amphideal fovea either transverse slit-like without a double contour, or not observed. Six outer labial and four cephalic setae. Buccal cavity with a hollow dorsal onchium (tooth) and two lateral or ventrosublateral onchia, without rows of denticles. Pharynx without posterior terminal bulb. Spicules not jointed. Gubernaculum containing a dorsal piece and a pair of hammer- or L-shaped lateral pieces. Precloacal supplement absent. Pre- and postcloacal cuticular elevation also absent.

Type species: G. vulgare Cobb, 1898

List of valid species:

G. achaeta Platonova, 1971

G. amokura e (Ditlevsen, 1921) Inglis, 1969

G. antarcticum Shimada, Tsujimoto & Watanabe, 2019

G. arctica ( Filipjev, 1946) Warwick and Coles, 1975

G. georgei Inglis, 1969

G. mediterranea ( Allgén, 1942) Warwick & Coles, 1975

G. metuliferum Kito, 1981

G. northumbriae Warwick & Coles, 1975

G. parafricana ( Gerlach, 1958) Warwick & Coles, 1975

G. scampae ( Coles, 1965) Warwick & Coles, 1975

G. vulgare Cobb, 1898

Taxon inquirendum: G. sabangensis ( Steiner, 1915) Wieser, 1954