| Body slightly curved ventrally. Cuticle about 1.5 ?m thick, with fine annules. Lateral field with alae separated by two deep incisures extending nearly the entire body length. Often with additional faint areolation and inner two incisures (best visible by SEM). Anterior to the level of the excretory duct, and posterior to the phasmid, inner two lines converging into a single line; faint areolation visible by SEM. Lip region slightly offset, 3-4 ?m high and ca 7 ?m wide, with two or three annules, some of which are incomplete (not extending around the entire circumference of the head).Adjacent subdorsal and subventral lips fused with each other and with the labial disc resulting in a dorso-ventrally elongate bow-tie-shaped lip pattern. Lateral lips distinct and tapering posteriorly where they transect the first lip annule. Orifices of six inner labial papillae surrounding the oral aperture; outer labial and cephalic papillae not visible at surface. Round amphid openings are far anterior on lateral lips. Stylet stout, cone typically slightly longer than shaft plus knobs. Stylet knobs round (not pointed anteriorly or flattened), broad dorsal and subventral knobs about equal to one another in size and shape. Pharyngeal corpus and isthmus about equal in length to gland lobe. In corpus, cuticle-lined lumen slightly offset at the point of junction with the dorsal gland orifice. Throughout the procorpus, vesicles of the dorsal gland process typically distinct. Metacorpus spherical to slightly elongate with conspicuous elongate cuticularised so-called ?valve?. Pair of subventral gland orifices at base of the valve (sometimes obscure in fixed specimens). Isthmus narrow, 10-15 ?m long, surrounded throughout most of its length by commissures and ganglia associated with the nerve ring. Gland lobe broadening abruptly from the isthmus to fill at least the dorsal two thirds of the body cavity. Pharyngo-intestinal junction less than 10 ?m posterior to point of expansion of the gland lobe from the isthmus. Dorsal gland dominating the anterior half of the gland lobe including large nucleus at the level of the excretory duct. Subventral glands with two prominent nuclei posterior to dorsal gland nucleus. Reproductive system didelphic, amphidelphic. Vulva slightly protruding and near the middle of the body; slit ventral, transverse. Branches of reproductive tract about equal in length, but length highly variable among individuals, apparently varying with age. In some specimens, the anterior gonad overlaps and is reflexed in the region of the pharyngeal gland lobe and, in the same specimens, the posterior gonad also may be reflexed and may extend most of the hyaline region of the tail. At the distal ends, each ovary (or ovatestes; see Discussion) includes a cap cell followed by a single row of about ten oocytes, a short region with a double row and then single row of larger ova near the junction with the oviduct. Nearer the uterus, reproductive tract includes a not-offset spermatheca; mature female spermatheca large oval-shaped, and filled with rod-shaped structures and a few vesicle-like spherical elements. Tail tapering, tip conoid, terminating as a sharp point or a minute spike. Phasmid opening in anterior half of tail. Hyaline region of tail variable in length, less than anal body diameter. |
Strongly dimorphic relative to females. Lip region distinctly offset, wider than high, bulbous with large subdorsal and subventral swelling and reduced lateral lips. Obscure amphid openings far anterior on lateral lips; additional labial sense organs not visible at surface. Annulation on lip region weakly defined. Body annulation and lateral field similar to that of female. Stylet weakly developed with little separation between cone and shaft; stylet knobs distinctly separated, about twice diameter of shaft; stylet musculature weak relative to that of female. Pharynx weakly developed relative to female, with corpus longer than isthmus and gland lobe. Pharyngeal lumen of procorpus poorly defined with faint indication of DGO; metacorpus more than twice diameter of procorpus, but with little musculature and poorly defined cuticularised so-called valve. Pharyngeal lumen terminates ca 10 ?m posterior to the metacorpus; transition with intestine unclear. Gland lobe terminating slightly posterior to excretory duct; gland nuclei not visible. Excretory pore faint, duct not visible. Reproductive system monorchic. Anterior end with double row of spermatocytes, and posteriorly with rod-shaped spermatids and a few vesicle like spherical elements. Spicules well developed with distinct manubrium, no vellum, and faint retractor muscles. Gubernaculum flattened with pronounced pair of titillae. Caudal alae elongate and narrow (<7 ?m diam.), terminating ca 15 ?m from the posterior end. Tail nearly cylindrical, except broader between phasmid and cloaca levels, and again near the level of posterior attachment of caudal alae; conical posterior to the caudal alae; terminus is sharply pointed. |
Morphometric characteristics in μm