Tripylina kaikoura, 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 : 16-18

Tripylina kaikoura sp. nov.

( Fig. 7 A–D)

Measurements. Table 2.

Material examined. Holotype: NNCNZ, slide No. 263.

Paratype: NNCNZ, slide No. 2558.

Description. Female. Body ventrally arcuate when fixed ( Fig. 7 A), posterior more curved than anterior. Cuticle smooth, about 1–2 μm thick anteriorly, without distinct layers. Maximum body diameter one body width posterior to vulva. Body pores not seen. Glandular cells along body scattered, few in number ( Fig. 7 B).

Head rounded, slightly flat, continuous with body contour. Labial papillae short, conical. Six long and four short cephalic setae in a single whorl; the six setae 11 μm long, or 33–37% of head diameter, slightly arcuate, directed anteriorly; the four setae 6–8 μm long, thinner than the six long cephalic setae, more or less arcuate. No setae in cervical region. Stoma walls thickened; dorsal tooth large, triangular; two small subventral denticles in stomatal chamber 4 μm anterior to dorsal tooth. Amphids cup-like (?) with transverse oval opening, 20–22 μm from anterior end of body.

Excretory pore 120–140 μm, or 46–55% of pharyngeal length, from anterior end of body. Nerve ring 118– 120 μm, or 46% of pharyngeal length, from anterior end of body. Prominent cells at pharyngo-intestinal junction, number difficult to determine. Coelomocytes difficult to distinguish.

Female genital system mono-prodelphic, ventral or lateral to the intestine, 303–322 μm long, or 19–21% of body length from vulva to flexure ( Fig. 7 C). Ovary reflexed to vulva. Eggs present. Vulva simple, without protuberant lips, pore-shaped in lateral view, no sclerotised pieces in vaginal area.

No distinct prerectum. Rectum length less than anal body diameter (20 vs 37 μm). Tail bent ventrad, narrowing evenly ( Fig. 7 D). No caudal setae. Three tandem caudal glands ( Fig. 7 A & D), spinneret terminal, 3 μm long ( Fig. 7 E).

Male. Not known.

Locality and habitat. Holotype and paratype from 0–5 cm soil depth from 10 random points under native forest in the Puhipuhi Scenic Reserve, Kaikoura , New Zealand (42˚ 48.782 S, 173˚ 38.996 E). Coll. Gregor W. Yeates, 28. v. 1991.

Diagnosis and Relationships. Tripylina kaikoura sp. nov. is characterised by a long body, absence of ventromedian setae in cervical region, thickened stomatal walls, large triangular dorsal tooth, two small subventral denticles in stomatal chamber 4 μm anterior to dorsal tooth, and cup-like amphids with transverse oval opening, located 20–22 μm from the anterior end of the body.

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

T. kaikoura sp. nov. is similar to T. longa , T. stramenti and T. yeatesi sp. nov. in having two subventral denticles anterior to dorsal tooth. It differs from T. arenicola and T. ursulae which have two subventral denticles posterior to dorsal tooth

T. kaikoura sp. nov. is similar to T. yeatesi sp. nov in not having ventromedian seta or setae in the cervical region, but differs from T. longa which has two cervical setae and T. stramenti which has one cervical seta ( Table 3).

T. kaikoura sp. nov. differs from T. yeatesi sp. nov in having a wider body (68–71 vs 49–55 µm) and de Man’s Indices a (22–23 vs 29–30), b (6.0–6.2 vs 2.9–6.0), c (14–16 vs 18–26) and c’ (2.7–3.0 vs 2.0–2.6), respectively ( Table 3).

Etymology. Kaikoura is a locality name in New Zealand, it is used here as a noun in apposition.

Remarks. Tripylina kaikoura sp. nov. was collected and mounted by Dr Gregor W. Yeates in 1991. After nearly 20 years, the specimens are generally in good condition but as some of the nematode body contents were not clear for identification, some characters of the nematode are difficult to see. However, the body shape of this species is distinctively different from all other species of Tripylina .

Figures

FIGURE 7. Tripylina kaikoura sp. nov. female. A: Entire body. B: Pharyngeal region, lateral. C: Genital region, lateral. D: Tail. E: Spinneret. Scale bars: A, B, C, D = 50 μm; E = 25 μm.