Ichthyophis sendenyu, Kamei, Rachunliu G., Wilkinson, Mark & Gower, David J., 2009

Kamei, Rachunliu G., Wilkinson, Mark & Gower, David J., 2009, Three new species of striped Ichthyophis (Amphibia: Gymnophiona: Ichthyophiidae) from the northeast Indian states of Manipur and Nagaland, Zootaxa 2267, pp. 26-42 : 37-38

Ichthyophis sendenyu sp. nov.

( Figs. 1 , 6–7 ; Tables 1–2)

Holotype. BNHS 5221, an adult female, collected by SDB and RGK on 26 June 2007 from Dhyütere (25°54’55’’N, 94°06’19’’E; 782 m asl), New Sendenyu village, Tseminyu sub-division, Kohima District, Nagaland, India.

Paratypes (n = 4). BNHS 5222–5224, three adult females; BNHS 5225 an adult male, all collected along with holotype.

Diagnosis. Ichthyophis with broad (W/S <4) regular, mostly solid lateral yellow stripes from about level of posterior of disc to at least eye level on upper jaw and midway between TAs and nares on lower jaw, broad anterior gap expanded and visible or not ventrally on collars, connected by spurs to disc; arched yellow stripes extending halfway from TAs to nares, tapering towards latter; not known to attain lengths greater than 350 mm, 21 <L/W <27; fewer than 315 AGs, paler than adjacent skin; head U-shaped, short (L/H> 20); TAs less than twice as far from nares than from eyes (TN/TE <2); collars of similar lengths; scales present in anteriormost grooves, five to eight rows posteriorly on dorsum; similar numbers of IMs and dentary teeth.

Description of holotype. Some morphometric and meristic data given in Table 1. Good condition, several annular scale pockets opened, c. 30 mm midventral longitudinal incision c. 70 mm anterior to vent. 112 vertebrae. Head, nuchal region and trunk slightly dorsoventrally compressed. Girth maximal near midbody, decreasing gradually, more substantially over posteriormost c. 20 mm, L/W = 20.8. Tail upturned towards tip. Head short (L/H = 23.9). In lateral view, CM approximately equidistant from top and bottom of head. In ventral view, lower jaws inset from upper, scarcely more so anteriorly than at level of TAs. Eye marginally closer to top of head than to lip in lateral view, surrounded by asymmetric (thicker anteriorly) whitish ring, eye diameter c. 0.8 mm, lens larger than naris. TAs much smaller than eyes, about as large as nares, a little less than twice as distant from nares than from eyes, very close to lips, below imaginary lines between nares and CMs. Nares slightly posterior to level of anterior margin of mouth; in lateral view equidistant from tip and top, further from bottom of snout, inset about one naris diameter from sides in dorsal view. Teeth very slender, recurved, dentary series extend about one sixth the length of the IM series (with 2 or 3 teeth) behind posteriormost IM. Tongue strongly plicate posteriorly, margin overlying only posteriormost IMs. Choanae relatively wide, with elevated margins, distance between them about three times their greatest width. Collar region somewhat more massive than adjacent head and body, delimited by constrictions. C1 and C2 approximately equal length measured laterally. Dorsally, NG3 complete but offset with strong anteromedial flexure. One TG on dorsum of C2, close to NG3 with strong anteromedial flexure.

Few anteriormost AGs incomplete midventrally, many offset, nine (right) or eight (left) interrupted in disc region, four more on tail, first two complete last two incomplete dorsally and ventrally. Dorsally, anteriormost c. 30 and posteriormost c. 15 AGs curve anteromedially, the former strongly and latter more gently. Ventrally, anterior AGs angulate, degree of posteromedial curvature about length of two annuli up to midbody, decreasing posteriorly, orthoplicate by c. 45th annulus anterior to disc. Very small (0.3 x 0.5 mm) scales in TG, single row of slightly larger scales in shallow pockets in anteriormost AGs. Posteriorly seven or eight rows of larger scales (up to 1.7 x 1.4 mm) in very deep pockets on dorsum, six or seven rows in deep pockets on venter. No papillae on disc. Seventeen irregular denticulations around vent.

In preservation, dorsum dark brown, venter paler grey-brown. Broad, fairly regular, solid, bright yellow lateral stripes, width varying 3.1–5.1 mm, thickest at midbody, extending unbroken from about fourth last annulus to the CMs then narrowing and ending on upper jaws at eye level, extending further along lower jaws to midway between TAs and nares in lateral view, with wide gap at mandible tip giving the darker area between stripes on throat a distinctive ('mushroom') shape, slightly expanding ventrally on C2 but barely visible ventrally on collars, with ventral spurs connecting to anterior of disc. Yellow lines extending dorsally then curving anteriorly from TAs to half way between TAs and nares, thickest near TAs. AGs paler especially on venter. In life, dorsum uniformly bright orange-brown; venter pale lilac-grey; lateral stripe bright yellow; disc whitish.

Variation. Morphometric and meristic data for the type series are given in Table 1, and summarised in Table 2 . There are between two and four dentary teeth posterior to the last IM on each side. The distance between the choanae ranges from 2.5 to four times the maximal choanal width. The number of denticulations around the vent ranges from 16 to 18. Compared to the holotype, the paratypes have mostly incomplete AGs ventrally on a much larger proportion of the body, fewer (between about 19–38) AGs orthoplicate on venter anterior to the vent, and fewer anterior and posterior AGs that curve anteromedially on the dorsum (14–21 and 10–13, respectively). The stripe is mostly solid throughout but narrowly broken on one side posteriorly in a single specimen (BNHS 5225). Papillae on the disc are present in the single male paratype (BNHS 5225). The tail is upturned (only slightly) in a single paratype (BNHS 5223).

Squamation investigated in BNHS 5223. Small (1.0 x 0.4 mm) scales present dorsally in TGs on collars; dorsally at midbody five rows of large (1.7 x 1.3 mm) scales per annular groove; ventrally at midbody three rows of scales (1.0 x 0.6 mm) in shallow pockets; posteriorly slightly larger scales (1.8 x 1.7 mm) in five rows on dorsum, smaller scales (1.5 x 1.0 mm) in five rows on venter. All pockets shallow.

Etymology. Named after Sendenyu village, Nagaland state, where the type series was collected. The specific epithet is considered to be a noun in apposition.

Suggested common name. Sendenyu striped Ichthyophis .

Distribution and natural history. This species is known only from the type locality. All specimens were dug from a small banana plantation on the fringe of paddy field near a secondary forest.

Figures

FIGURE 1. Distribution map of Ichthyophis species from northeast India: 1. I. khumhzi, 2. I. moustakius, 3. I. sendenyu, 4. I. sikkimensis, 5. I. husaini, 6. I. garoensis. Positioning of symbols is approximate.

FIGURE 6. Holotype of Ichthyophis sendenyu, BNHS 5221.

FIGURE 7. Holotype of Ichthyophis sendenyu, BNHS 5221. A. Anterodorsal view in life, B. Dorsolateral view of head in life, C. Ventral view in life, D. Dorsal view of head in preservation, E. Ventral view of head in life, F. Ventral view of body terminus in life.