Paratimmus, Baniyamuddin & Ahmad, 2009

Baniyamuddin, M. & Ahmad, Wasim, 2009, Paratimmus provulvatus gen. nov., sp. nov. (Dorylaimida: Mydonomidae) from natural forests in Arunachal Pradesh, India, Journal of Natural History 43 (37 - 38), pp. 2357-2363 : 2358

Paratimmus gen. nov.

Diagnosis

Mydonomidae . Medium-sized nematodes. Lip region hemispherical, continuous; papillae not raised. Amphids with stirrup-shaped fovea. Odontostyle tiny, asymmetrical, but with distinct lumen. Guiding ring single, distinctly sclerotized, thick. Odontophore simple, rod-like. Pharynx slender, gradually expanding to form basal bulb, constituting about one-quarter of its entire length; a thin sheath (not spiral) present around basal bulb. Cardia elongate, conoid. Female genital system monodelphic–opisthodelphic; short anterior uterine sac present. Vulva transverse, distinctly anterior. Males with dorylaimoid spicules and three to four spaced ventromedian supplements. Tail long filiform, similar in sexes.

Type and only species. Paratimmus provulvatus gen. nov., sp. nov.

Relationships

The new genus, as the name indicates, closely resembles the genus Timmus Goseco, Ferris and Ferris, 1976 but differs in some definite morphological features (see Goseco et al. 1976). These include the shape of its lip region, the nature of guiding ring and odontostyle. The type of pharynx is similar to Timmus , but the odontophore is simple in Paratimmus (versus sclerotized in Timmus ). The new genus further differs from Timmus in having a monodelphic–opisthodelphic gonad (versus amphidelphic), an unusually anteriorly placed vulva and a thin sheath (not spiral) (versus sheath absent) around the basal pharyngeal bulb. The new genus also resembles the genus Calolaimus Timm, 1964 in the nature and shape of lip region, odontostyle and pharynx (see Timm 1964) but differs in having a thick but simple guiding ring (versus strongly sclerotized, thick, beltlike); odontophore not sclerotized (versus sclerotized); a thin sheath around the basal pharyngeal bulb (versus sheath around basal pharyngeal bulb absent); monodelphic– opisthodelphic gonad (versus amphidelphic), the unusual anterior position of the vulva (V = 22.5–25% versus 40–45.5%); lateral guiding pieces straight (versus constricted); and fewer ventromedian supplements (versus series of ventromedian supplements). In the shape of its lip region, the nature of the odontostyle and odontophore, and the nature of pharynx and gonad, the new genus closely resembles the genus Paraqudsiella Siddiqi, 1982 (see Siddiqi 1982). However, it differs from it in having a thick guiding ring (versus guiding ring indistinct); a thin sheath (not spiral) around basal pharyngeal bulb (versus sheath absent); and cardia not spatulate (versus cardia spatulate).