Tripylina manurewa, Zhao, Zeng Qi, 2009

Zhao, Zeng Qi, 2009, A review of the genus Tripylina Brzeski, 1963 (Nematoda: Triplonchida), with descriptions of five new species from New Zealand, Zootaxa 2238, pp. 1-24 : 10-12

Tripylina manurewa sp. nov.

( Fig. 4 A–G)

Measurements. Table 2.

Material examined. Holotype: NNCNZ, slide No. 260.

Paratypes: eight females. NNCNZ, slide Nos 2546–2553.

Description. Female. Body ventrally arcuate when fixed ( Fig. 4 A), posterior more curved than anterior. Cuticle smooth, about 1–2 μm thick anteriorly, no distinct layering observed. Maximum body diameter generally near ovary, occasionally near vulva or base of pharynx. Body pores small, numerous, indistinct.

Head rounded, continuous with body contour ( Fig. 4 A). Labial papillae short, conical. Six long and four short cephalic setae in a single whorl ( Fig. 4 F); the six setae 11–14 μm long, or 50–60% of head diameter, more or less arcuate, directed anteriorly; the four setae 6–8 μm long, thinner than the six setae, more or less arcuate. A single ventromedian cervical seta, thin, 78–86 μm, or 41–47% of pharyngeal length, from anterior end of body ( Fig. 4 B). Two pairs of lateral cervical setae, one anterior and one posterior to nerve ring ( Fig. 4 C). Stoma walls thickened, dorsal tooth relatively large, triangular; two small subventral denticles in stomatal chamber 2–4 μm anterior to dorsal tooth, difficult to observe ( Fig. 4 B). Amphids cup-like with transverse oval opening, 15–19 μm from anterior end of body ( Fig. 4 B).

Excretory pore 101–113 μm, or 54–62% of pharyngeal length, from anterior end of body ( Fig. 4 B). Nerve ring 88–91 μm, or 44–51% of pharyngeal length, from anterior end of body. Three prominent cells at pharyngo-intestinal junction. In intestinal region, 5–6 oval to fusiform ventrolateral coelomocytes, each 11–12 x 34 –58 μm; positions variable, in holotype one coelomocyte near pharyngo-intestinal glands and the rest, fusiform, spread from mid-body to anus.

Female genital system mono-prodelphic, ventral to intestine, 138–172 μm long, or 13–16% of total body length from vulva to point of flexure ( Fig. 4 D), reflexed 1/2–3/4 of the way back to vulva. No eggs observed. Vulva simple, without protuberant lips, pore-shaped in lateral view, with weakly sclerotised pieces in vaginal area.

No distinct prerectum. Rectum length less than anal body diameter (20 vs 27 μm). Tail usually bent ventrad ( Fig. 4 E), narrowing evenly, with one pair of subdorsal caudal setae on anterior part ( Fig. 4 E). Three tandem caudal glands ( Fig. 4 E), spinneret terminal, 2.8–3.4 μm long ( Fig. 4 G).

Male. Not known.

Locality and habitat. Holotype and paratypes from soil and litter, 0–10 cm depth under a native Dacrycarpus dacrydioides tree, Auckland Botanic Garden, South Auckland, New Zealand (37˚ 0.657 S, 174˚ 54.491 E). Coll. Zeng Qi Zhao, 23. iv. 2008.

Diagnosis and relationships. Tripylina manurewa sp. nov. is characterised by having a single ventromedian seta and two pairs of lateral setae in the cervical region ( Fig. 4 B & C), thickened stoma walls, large triangular dorsal tooth, two small subventral denticles in stomatal chamber 2–4 μm anterior to the dorsal tooth, and cup-like amphids with transverse oval opening located 15–19 μm from the anterior end of the body.

Females of T. manurewa sp. nov. are close to those of T. tearoha sp. nov., T. tamaki sp. nov., T. sheri , T. arenicola and T. ursulae in body length. However, they are longer than T. macroseta and shorter than all other species ( T. longa , T. stramenti , T. yeatesi sp. nov. and T. kaikoura sp. nov.) ( Table 3).

T. manurewa sp. nov. is similar to T. tearoha sp. nov., T. tamaki sp. nov., T. sheri , and T. macroseta in having two subventral denticles anterior to dorsal tooth, but differs from T. arenicola and T. ursulae which have two subventral denticles posterior to dorsal tooth ( Table 3).

T. manurewa sp. nov. is more similar to T. tearoha sp. nov. and T. tamaki sp. in having a single ventromedian seta and two pairs of lateral setae in the cervical region. It differs from T. sheri and T. macroseta which has no setae present in the cervical region ( Table 3).

T. manurewa sp. nov. differs from T. tamaki sp. nov. in body diameter (37–43 vs 51–60 μm), de Man’s Index a (24–29 vs 20–23). It differs from T. tearoha sp. nov. in the distance of ventromedian seta from the anterior end of the body (78–86 vs 62–77 μm).

Based on SSU and LSU molecular phylogenetic studies, T. manurewa sp. nov. is different from T. tearoha sp. nov. and T. tamaki sp. nov. ( Fig. 1 & 2 ).

Etymology. Manurewa refers to the type locality. It is used here as a noun in apposition.

Figures

FIGURE 1. Bayesian tree inferred from SSU gene DNA sequences. Posterior probabilities exceeding 50 % are given on appropriate clades. Nematode species, GenBank numbers, locations are listed for each taxon if known.

FIGURE 2. Bayesian tree inferred from LSU gene DNA sequences. Posterior probabilities exceeding 50 % are given on appropriate clades. Nematode species, GenBank numbers, locations are listed for each taxon if known.

FIGURE 4. Tripylina manurewa sp. nov. female. A: Entire body. B: Pharyngeal region, lateral, showing the single cervical seta. C: Pharyngeal region, ventral, showing two pairs cervical setae. D: Genital region, lateral. E: Tail. F: En face view. G: Spinneret. Scale bars: A, B, C, D, E = 50 μm; F, G = 25 μm.