Oxybelondira paraperplexa Ahmad & Jairajpuri, 1979

Nguyen, Duong Thi Anh, Vu, Tam Thi Thanh, Bonkowski, Michael & Pena-Santiago, Reyes, 2014, New data of three rare belondirid species (Nematoda, Dorylaimida, Belondiridae) from Vietnam, with the first record and description of the male of Oxybelondiraparaperplexa Ahmad & Jairajpuri, 1979, Biodiversity Data Journal 2, pp. 1156-1156 : 1156

Oxybelondira paraperplexa Ahmad & Jairajpuri, 1979

Materials

Type status: Other material. Occurrence: recordedBy: Nguyen T.A.D; individualCount: 21; sex: 1 male, 20 females; Location: country: Vietnam; stateProvince: Cuc Phuong National Park in Ninh Binh, Huu Lien Nature Reserve in Lang Son, Phong Nha - Ke Bang National Park in Quang Binh; verbatimLocality: Soil samples of karst forest; verbatimElevation: 300-500m; Event: eventDate: Ninh Binh: in August, 2009; Lang Son: in May, 2013; Quang Binh: in July, 2010; Record Level: collectionID: Cuc Phuong 5.1 (10); Cuc Phuong 1.1 (20); Cuc Phuong 3.2 (11); Cuc Phuong 3.2 (15); Huu Lien 15.1; PN-KB 27.1; institutionCode: IEBR; collectionCode: Nematode

Description

Specimens examined (n=21): Twenty females and one male in good condition (Figs 4, 5).

Mesurements: See Table 2.

Adult: Very slender nematodes of medium size. Habitus slightly curved ventrad after fixation. Body cylindrical, gradually tapering towards both extremities, but more so towards the posterior end. Cuticle thin, with fine transverse striations. Lateral chords 9-12 µm wide, occupying ca one-third of mid-body diameter. Lip region continuous, somewhat truncate, 1.7-2.0 times as wide as high and ca one-fifth (20%) of body diameter at neck base; labial framework well developed, having distinct labial and post-labial sclerotizations; lips amalgamated, with low papillae. Amphid fovea cup-shaped. Cheilostom a truncate cone, lacking any differentiation. Odontostyle rather strong, 1.2-1.4 times the lip region width long, with distinct lumen and aperture, which occupies ca one-fourth of its length. Guiding ring simple, located at 7 µm or one lip region diameter from the anterior end. Odontophore rod-like, 1.3 times the odontostyle length. Pharynx consisting of a slender part that enlarges gradually, and the basal expansion nearly cylindrical, occupying 50-56% of total neck length and surrounded by a distinct spiral muscular sheath. Cardia rounded conoid, as long as wide.

Female: Genital system mono-opisthodelphic. Anterior branch nearly lacking or reduced to a very short, vestigial sac. Posterior branch well developed: ovary 72-90 µm long, reaching and occasionally surpassing the oviduct-uterus junction, with oocytes first in several rows and then apparently in one row; oviduct joining the ovary subterminally and consisting of a slender portion with prismatic cells and moderately developed pars dilatata with distinct lumen; a marked sphincter separates oviduct and uterus; uterus 60-70 µm long or 2.0-2.5 times the corresponding body diameter. Vagina 13-16 µm long or extending inwards ca one-half of body diameter: pars proximalis as long as wide, with somewhat sigmoid walls and enveloped by weak circular musculature; pars refringens lacking; pars distalis well developed. Vulva a pre-equatorial, transverse slit. Prerectum 6.3-6.5 anal body widths long. Rectum as long as one anal body width. Tail elongate, made of two sections of about equal length: the anterior onewider, and tapering gradually the posterior narrower and cylindrical, visibly clavate at the end; hyaline portion one-third to two-fifths of tail length.

Male: Genital system diorchic, with opposite testes. In addition to the ad-cloacal pair, situated at 9 µm from the cloacal aperture, one ventromedian supplement within the range of spicules, located at 15 µm from ad-cloacal pair. Spicules dorylaimoid, slightly curved ventrad and relatively slender, 7 times as long as wide and 2 times as long as anal body diameter. Lateral guiding pieces not well seen. Tail elongate, made of two sections of about equal length:anterior one wider and tapering gradually at both sides, posterior narrower and cylindrical, visibly clavate at the end; hyaline portion one-third to two-fifths of tail length.

Distribution

Oxybelondira paraperplexa was collected in Cuc Phuong National Park and Huu Lien Nature Reserve in North Vietnam, and Phong Nha - Ke Bang National Park in central Vietnam, collected in soil samples from karst forests.

Taxon discussion

This is the first record of Oxybelondira paraperplexa after its original description from Manipur, India by Ahmad and Jairajpuri (1979), the the male is described for the first time. The Vietnamese females are identical to the type material, but new morphological data are herein provided and the ranges of the morphometrics appreciably widened.