Ramphotyhlops hatmaliyeb, Wynn, Addison H., Reynolds, Robert P., Buden, Donald W., Falanruw, Marjorie & Lynch, Brian, 2012

Wynn, Addison H., Reynolds, Robert P., Buden, Donald W., Falanruw, Marjorie & Lynch, Brian, 2012, The unexpected discovery of blind snakes (Serpentes: Typhlopidae) in Micronesia: two new species of Ramphotyphlops from the Caroline Islands, Zootaxa 3172, pp. 39-54 : 46-48

Ramphotyhlops hatmaliyeb sp. nov.

( Figs. 5 , 7 C)

Holotype. USNM 558300, from Giilab (= Gielap, Gielop) Island, Ulithi, Caroline Islands ( Federated States of Micronesia), collected by Marjorie Falanruw on 0 4 August 2007.

Paratypes. USNM 558301–558303, Giilab Island; USNM 558304, Iaar Island; USNM 558305, Bulbul Island; USNM 558306, Piig Island; and USNM 558307–558310, Soong Island; all part of Ulithi, Caroline Islands ( Federated States of Micronesia).

Referred specimen. USNM 558311, Dorooleng Island, Ulithi, Caroline Islands ( Federated States of Micronesia).

Diagnosis. Ramphotyhlops hatmaliyeb can be distinguished from other Indoaustralian and Philippine typhlopids by the combination of 22 scale rows over the length of the body; the wedge-shaped snout, without a keratinized keel; and its broad, ovate rostral.

Description of holotype. Female, total length 331 mm, tail length 10.5 mm, midbody diameter ca. 8 mm, body diameter at vent 6.6 mm, diameter near midpoint of tail 5.5 mm. Middorsal scale rows 462 (not including intercalary scales), 466 (including intercalary scales—1 on left, 3 on right). Middorsocaudal scales 21 (count approximate due to irregularities in scale pattern of middorsal row, excludes one intercalary scale in middorsal row). Twentytwo scale rows around head (beginning about four transverse scale rows posterior to fourth supralabial) and continuing for length of body to about 3.3 mm anterior to vent, then 24 rows around body for last six transverse rows anterior to vent due to division of both paramidventral scale rows. Head tapered with a rounded anterior tip when viewed from above; dorsal surface of snout sloped to give head a wedge shape in lateral profile; a keratinized beak absent ( Fig. 5 ). Eyes distinct, ca. 0.4 mm in diameter, lying beneath unpigmented windows in ocular scales.

Details of the head scalation can be seen in Fig. 5 . Salient features are: superior internasal suture short, incompletely dividing the nasal, extending forward obliquely from the nostril and extending under the rostral free-edge (but not penetrating the gland row under the rostral free edge) with a small, oval gland underlying it; inferior internasal suture extending from the nostril to the second supralabial, with a broad underlying gland row. Rostral ovate viewed from above, 2.5 mm in width at its broadest (51% head width), then tapering to a rounded posterior tip. Four supralabial scales, increasing in size from first to last, with the third and fourth nearly equal in size and much larger than the first and second. The first supralabial (not visible in Fig. 5 ) is overlapped by the prenasal and overlaps the second supralabial. The second supralabial is about twice the size of the first, overlapped by the prenasal, postnasal, and preocular, and overlaps the third supralabial. The third supralabial extends dorsally to the level of the nostril, is overlapped by the preocular and overlaps the ocular and fourth supralabial. The fourth supralabial also extends dorsally to the level of the nostril, and is overlapped by the ocular. There are two postoculars on each side.

The dorsum is covered with brown melanophore pigmentation. On the head, this pigmentation is restricted to the posterior half of the dorsal surface of the rostral (although there is a patch of amber coloration on the rostral at the tip of the snout, apparently a keratinized thickening of the rostral); the prefrontal, frontal, interparietal, supraoculars, and parietals; the dorsalmost apex of the postnasals; the dorsal half of the preoculars; the oculars surrounding the unpigmented eye-window (although only sparsely below the eye on the left); the dorsoanterior apex of the third supralabial on the right; and the dorsal apex of the fourth supralabials. Behind the fourth supralabial, pigmentation in about three transverse rows extends as far laterally as the seventh lateral row on the right, and the sixth row on the left, with a gap of six unpigmented ventral rows. Posterior to this, the body has a brown longitudinal stripe 11 scale rows in width (the middorsal and five scale rows lateral to it on either side), with the scales in the middorsal and four rows lateral to it continuously pigmented for the length of the body, but with scattered unpigmented scales, or groups of scales, occurring in the fifth lateral row. (At the level of the 18th to 22nd middorsals, there is an anomalous irregular transverse band of unpigmented scales, one to three transverse rows in width, that extends to the second lateral row on the right, and completely across the dorsal stripe on the left.) Outside of this stripe, a few pigmented scales are scattered along the sixth lateral row, especially in the vicinity of the vent. The dorsal stripe continues along the length of the tail, 11 rows in width for about the first third of the tail length, then gradually decreases in width along the remaining tail length to include only the middorsal and one row on either side immediately anterior to the terminal scale. The terminal scale is pigmented on its dorsal and lateral surfaces. Other scales on the ventral head, body, and tail lack melanophore pigmentation.

The dorsal stripe is darkest middorsally and gradually becomes lighter laterally due to decreasing pigment density in the scales, especially the posterior portion of the lateralmost rows, and pigmentation is absent in the posterior half of many scales in the fifth row, giving the dorsal stripe an indistinct appearing edge.

The tail decreases in width only slightly over roughly its first half, then tapers more abruptly just before the tail tip; the terminal scale is cone shaped with a sharp, keratinized spine, curved downward to give a slightly hook-like appearance.

Variation. Total length 178–416 mm, middorsal scales 452–472. Tail length appears to be sexually dimorphic. The three male paratypes have tails that have more middorsocaudals and are proportionately longer than that of the holotype and female paratypes (Table 1, Fig. 3 ). Tail shape, however, does not appreciably differ between the sexes. Postocular number is variable, with four paratypes having two postoculars on both sides of the head, four having three on both sides, and two that each have three on the left and two on the right (Table 1). All specimens have 22 scale rows around the body posterior to the head until just anterior to the tail where the paramidventral scale rows divide five to seven transverse rows anterior to the vent to increase the number of rows around the body to 24 (or 26 in USNM 558302).

The color pattern of all paratypes is similar to that of the holotype. Two specimens (USNM 558307 and 558309, both from Soong Island) differ in having a completely pigmented rostral (rather than having pigmentation limited to the dorsal surface), and pigmentation was more extensive on the head of these two specimens, most notably more extensive pigmentation of the postnasals and preoculars to include all of these scales except the right postnasal of USNM 558309.

Most of the paratypes have a dorsal stripe that is 11 rows in width, as in the holotype, with only scattered pigmented scales in the sixth lateral row. Four specimens (USNM 558303, 558307, 558308, and 558310), however, have more extensive pigmentation in the sixth lateral row, with roughly half or more of the scales lightly pigmented, and with a few scattered pigmented scales occurring in the seventh lateral row. Tail coloration is similar to the holotype in all paratypes, although unlike the holotype, most specimens have a few pigmented scales in the seventh lateral row near the vent in addition to an increased frequency of pigmented scales in the sixth lateral row in the vicinity of the vent. In two specimens (USNM 558303 and 558307) pigmentation in the sixth lateral row extends for about half the length of the tail. In the other specimens, the stripe is 11 rows in width for at least half the tail length, with pigmentation in the fifth lateral row either continuing to near the tip or pigmentation in the fourth lateral row continuing to near the tip. Both USNM 558302 and USNM 558305 have a protruded tongue, neither tongue with visible lateral spines. A rectal caecum could not be found in three specimens examined (USNM 558304, 558305, and 558306). Retrocloacal sacs are present in USNM 558302, extending about 7 mm anterior to the level of the vent into the body cavity (2% of the body length). Exposed by dissection of the tail, the left inverted hemipenis of USNM 558302 is straight for its proximal half followed by four coils in its distal half.

Life history note. Although blind snakes are typically regarded as fossorial in habit, Gaulke (1995), Das and Wallach (1998), and Bickford and Wynn (2005) have documented climbing behavior in Ramphotyphlops . In addition to being collected crawling on the ground and under debris and rocks, as well as in green sea turtle nests, two individuals of R. hatmaliyeb were found under circumstances similar to many of the records reported by Das and Wallach (1998) in their review of arboreality in blind snakes. USNM 558302 was observed at night crawling upward in a crease in the trunk of a Pisonia tree, about two meters off the ground. Another animal (not collected) was observed about five meters up the trunk of another Pisonia tree.

Etymology. " Hatmaliyeb " is one transliteration of the Ulithian name for this snake (likening it to a large worm from Yap), used here as a noun in apposition.

Figures

FIGURE 3. The relationship between relative tail length (tail length / total length) and the number of middorsocaudal scales in male and female specimens of Ramphotyphlops adocetus and R. hatmaliyeb.

FIGURE 5. Dorsal (top) and left lateral (bottom) views of the head of the holotype of Ramphotyphlops hatmaliyeb (USNM 558300). The illustration of the scale pattern on the left is based on the free edge of the scale plates. The scale bar represents three millimeters.

FIGURE 7. Radiographs of the head of Ramphotyphlops adocetus: (A) lateral view of USNM 529971, (B) dorsal view of USNM 558296; and the head of R. hatmaliyeb: (C) lateral view of USNM 558300, (D) dorsal view of USNM 558303. The arrows indicate the anterior projection of the premaxilla.