Liopholidophis oligolepis, Glaw & Kucharzewski & Nagy & Hawlitschek & Vences, 2014

Glaw, Frank, Kucharzewski, Christoph, Nagy, Zoltán T., Hawlitschek, Oliver & Vences, Miguel, 2014, New insights into the systematics and molecular phylogeny of the Malagasy snake genus Liopholidophis suggest at least one rapid reversal of extreme sexual dimorphism in tail length, Organisms Diversity & Evolution (New York, N. Y.) 14 (1), pp. 121-132 : 127-129

Liopholidophis oligolepis sp. nov. ( Figs. 3–4 )

Holotype ZSM 153 /2005 (field number FGZC 2796 ), probably adult female, Marojejy National Park , near a campsite locally known as "Camp Mantella" (14°26.260'S, 49°46.533'E; 481 m a.s.l.), northeastern Madagascar, collect- ed on 15 February 2005 by F. Glaw, M. Vences & R. D. Randrianiaina.

Diagnosis A species attributed to Liopholidophis because of its general morphology and its position in the molecular phylogenetic tree. Liopholidophis oligolepis differs from all other lamprophiid snakes of Madagascar except L. baderi by the presence of only 15 dorsal scale rows around midbody. In addition it differs from all other species of Liopholidophis except L. rhadinaea and L. baderi by a uniformly red belly in life that fades in preservative (never red in all other species) and by the presence of a light marking in the neck (versus absence). The new species differs from L. rhadinaea by having fewer ventrals in the female (137 versus 170–179), fewer subcaudals in the female (54 versus 69–88) and probably smaller size. L. oligolepis is most similar in morphology and small size to its sister species L. baderi but differs by having fewer ventrals (137 versus 149–158), fewer subcaudals (54 versus 71–77) and probably details of colouration (neck with two light spots connected to a light band versus three isolated light spots), smaller SVL (179.5 mm versus 205–221.5 mm) and smaller tail length (54.5 mm versus 78–91 mm). L. oligolepis differs furthermore from all other Liopholidophis species by substantial genetic differentiation.

Description of the holotype Female (sex determined by incision at the base of tail). Total length 234.0 mm, snout-vent length 179.5 mm, tail length 54.5 mm (23% of total length). Greatest head width (temporal region) 5.7 mm, head length (tip of snout to end of mandibles) 8.9 mm. Distance between tip of snout and the posterior edge of the parietals 7.2 mm. Body slightly compressed laterally. Head only a little wider than neck. Pupil round. Eye large, diameter horizontally 1.7 mm, larger than the distance between anterior margin of eye and posterior edge of nostril (1.1 mm). Dorsal scales smooth, without apical pits in 15–15–15 rows, but 17 scale rows directly behind the head, scale row reduction from 17 to 15 rows at the level of ventral 7 (left side) and ventral 6 (right side), respectively. Two preventrals, 137 rounded, not angulated ventrals [inserted half ventrals not counted: (1) between ventrals 92–93 on the right side; (2) before the anal scute on the left side]. One gular scale between the posterior inframaxillaries and the first preventral. Anal scute divided. Subcaudals 54/54 all divided plus terminal spine. Reduction of dorsocaudal rows from 8 to 6 at the level of subcaudals 7–8, from 6 to 4 at the level of subcaudals 18–19 and from 4 to 2 at the level of subcaudals 46–47.

Supralabials 8, with 4 th –5 th touching the eye. Infralabials 9, the first pair in contact behind the mental, 1 st –4 th touching the anterior inframaxillary, 4 th –5 th touching the posterior inframaxillary. Two pairs of inframaxillaries both the same width, but the anterior (2.2 mm) pair slightly shorter than the posterior (2.5 mm). Rostral wider (1.8 mm) than high (0.9 mm) and visible from above. Nasal semi-divided (undivided above the nostril, divided below), touching first and second supralabial. One loreal present, higher (0.7 mm) than wide (0.5 mm), touching second and third supralabial. One preocular, scarely visible from above, not in contact with frontal, touching third and fourth supralabial. Two postoculars, lower one slightly larger than upper one, upper postocular in contact with parietal, lower postocular touching parietal, anterior temporal, fifth and sixth supralabial. Temporals 1+2+3. Dorsal surface of head shows the typical lamprophiid scalation consisting of nine shields. Frontal longer (2.8 mm) than wide (2.2 mm), longer than the distance to the posterior margin of rostral (1.6 mm). Parietals longer (3.6 mm) than the frontal.

Dentition: Maxillary teeth 24+2 without diastema, the last two teeth distinctly enlarged and ungrooved. Maxillary reaching beyond the palatine. 16 palatine teeth. Dentary teeth ca. 30, small, equal in size.

Colour in preservative: General dorsal ground colouration entirely dark brown. Lower part of scale row four distinctly darker. At the upper part is a pale dot, situated at the upper basal edge of that scale. Row 5 bears a pale dot at the lower basal edge. These two rows of pale dots appear as a continuous lateral stripe, which starts six scales behind the posterior margin of the parietal and runs continuously on the fourth and fifth row on the body and on the second scale row on the tail nearly until the tip of tail. On the neck there are two distinct white ocelli occupying 4 scales and bordered by a dark ring. Both ocelli were connected by a pale “v”-shaped band, which is also dark bordered. Ground colour of dorsal side of head a little lighter than body. Supralabials whitish, bordered dorsally by a dark brown stripe. This stripe starts at the first supralabial, touches the lower margin of the eye and the lower postocular, running until the angle of the jaws, and then turns transversally on the first dorsal scale row and fades within the body’ s ground colour. A second “stripe” created by little dark spots on the outer edges of the anterior ventrals runs along the whitish throat and becomes the dark outer edge of the subsequent ventrals. Underside of head, body and tail uniform pale in preservative, except the outer margins of ventrals and subcaudals, which show the same dark brown colouration as the first dorsal scale row in sharp contrast to the whitish ventral ground colour. Colouration in life (see Figure 5 and photograph in Glaw and Vences 2007: 448 “ Liophidium sp. ”) dorsally similar to that in preservative. Ventral side of body and tail red in life, beige on throat; ventral colours fading into whitish after preservation.

Habitat, natural history, and conservation status The holotype, so far the only known individual of this species, was collected in a pitfall bucket in a largely undisturbed primary rainforest of the Marojejy National Park . Due to the very limited knowledge we suggest considering this species as "Data Deficient" according to the IUCN criteria used for the recent assessment of Malagasy reptiles .

Etymology The species name oligolepis is derived from the two Greek words, "oligo" meaning "few" and "lepis" meaning "scale," and refers to the very low scale counts of this species (15 dorsal scale rows, 137 ventrals, 54 subcaudals), which are unique among Malagasy snakes. It is used as a noun in apposition.

Remarks The available names in the genera Liopholidophis and Liophidium were discussed by Glaw et al. (2007) and Franzen et al. (2009) indicating that no earlier names are available for L. baderi or L. oligolepis .

Figures

Fig. 3 Head drawings of Liopholidophis oligolepis sp. nov. (holotype, ZSM 153/2005) in (a) dorsal and (b) lateral view

Fig. 4 Holotype of Liopholidophis oligolepis sp. nov. in (a) dorsal and (b) ventral view

Fig. 5 Liopholidophis rhadinaea in life, from Talatakely, Ranomafana National Park (ZSM 1602/2008)