Stegelleta Thorne, 1938

Boström, Sven & Holovachov, Oleksandr, 2014, Descriptions of species of Stegelleta Thorne, 1938 (Nematoda, Rhabditida, Cephalobidae) from California, New Zealand and Senegal, and a revision of the genus, European Journal of Taxonomy 87, pp. 1-19 : 3

Genus Stegelleta Thorne, 1938

Stegella Thorne, 1937: 4 [junior homonym of Stegella Stechow, 1919 ].

Stegelleta Thorne, 1938: 64–65 .

Type species

Stegella incisa Thorne, 1937 .

Diagnosis (emended after Holovachov et al. 2009)

Cuticle annulated, without distinctly annulated internal layer; annuli with longitudinal incisures (tessellated). Lateral field with two or four wings (appearing as three, four or five incisures); ending at tail terminus in females and in males. Lip region weakly offset, consisting of six globular lips arranged in three pairs: one dorsal and two subventral. Pairs of lips separated by primary axils; guarding processes absent; secondary axils undeveloped. Cephalic probolae absent or in the shape of one acute tine extending along the primary axil occurring only on lateral lips or on all six lips. Labial probolae elongate-conoid with broad basis, bifurcated about halfway forming two slender prongs, in some species further bifurcated apically. Six labial and four cephalic papilliform sensilla arranged in a cephaloboid manner. Amphidial aperture slit-shaped, located on lateral lips. Stoma divided into cheilo-, gymno- and stegostom: cheilostom barrel-shaped with strongly sclerotized bacilliform cheilorhabdia; gymnostom weakly developed, as wide as stegostom, with weak gymnorhabdia; stegostom consists of a funnel-shaped prostegostom and variably shaped mesostego-, metastego- and telostegostom parts. Metastegostom denticle present. Pharynx cephaloboid: pharyngeal procorpus and metacorpus cylindrical, lining of procorpus and metacorpus are of same thickness; isthmus narrower than metacorpus; basal pharyngeal bulb oval, with strongly developed valves. Nerve ring encircling posterior part of metacorpus or anterior part of isthmus. Excretory pore opens at level of nerve ring, at posterior part of metacorpus or anterior part of isthmus. Deirids present. Female reproductive system cephaloboid; posterior part of ovary straight; spermatheca present; postvulval uterine sac present; vagina straight; vulva flat, vulval flap absent or present. Male reproductive system cephaloboid; spicules cephaloboid with manubrium and corpus of approximately equal width; gubernaculum plate-like or wedge-shaped; cornua crurum present. Male genital papillae: at least one ventrosublateral pair located anterior to cloaca; one ventrosublateral pair located at the level of cloacal opening; two pairs located at middle of tail length; and three pairs (lateral, subventral and subdorsal) near tail terminus; there is a midventral papilla on anterior cloacal lip. Rectum short (1–2 times longer than anal body diameter). Phasmids located at about one-third to half of tail length in both sexes. Female tail conoid or subcylindrical, straight, tail terminus bluntly rounded or truncate; male tail conoid, arcuate ventrad, tail terminus bluntly rounded.

Valid species

Stegelleta arenaria Boström & Holovachov, 2012

Stegelleta georgica Bagaturija, 1973

Stegelleta iketaia Yeates, 1967

Stegelleta incisa ( Thorne, 1937)

Stegelleta ophioglossa Andrássy, 1967

= Stegelleta cylindrica Mavljanov, 1978: 1889 , figs 1–6

Stegelleta tuarua Yeates, 1967