Phelsuma borai, Glaw, Frank, Köhler, Jörn & Vences, Miguel, 2009

Glaw, Frank, Köhler, Jörn & Vences, Miguel, 2009, A new species of cryptically coloured day gecko (Phelsuma) from the Tsingy de Bemaraha National Park in western Madagascar, Zootaxa 2195, pp. 61-68 : 62-66

publication ID	https://doi.org/ 10.5281/zenodo.275114
DOI	https://doi.org/10.5281/zenodo.6215116
persistent identifier	https://treatment.plazi.org/id/03AC87F2-FFC8-C866-38F3-5A25FD4DFE8D
treatment provided by	Plazi
scientific name	Phelsuma borai
status	sp. nov.

Treatment

Phelsuma borai sp. nov.

( Figs. 1–2 View FIGURE 1 View FIGURE 2 )

Phelsuma sp. "Bemaraha" ― Glaw & Vences 2007: 400–401 Phelsuma sp. (Bemaraha) ― Hallmann et al. 2008: 220 –221 Phelsuma sp. aff. mutabilis ― Rocha et al. 2009: 533 –536

Holotype. ZSM 103/2006, adult male, collected at Andafiabe, Beboka River, 18°47'03'' S, 44°46'46'' E, 177 m above sea level, Tsingy de Bemaraha National Park, western Madagascar, on 24 March 2006 by P. Bora, H. Enting, F. Glaw & J. Köhler.

Diagnosis. Phelsuma borai sp. nov. is a medium-sized day gecko with greyish-brown ground colouration and without any green or red colours. It differs from most other Phelsuma species by the combination of (1) absence of green and red colours on the dorsal surface in life and (2) a low number of lamellae below the fourth toe (11 in P. b o r a i vs. 12–28 in most other species). It differs from P. p ro n k i which has a smilar low number of lamellae by a very different life-colouration and smaller size (42 vs. 49–50 mm SVL). P. borai shares most characteristics with P. b re v i c e p s and P. m u t a b i l i s, but differs from both species by a higher number of supralabials (9–10 vs. 6–8), a higher number of internasals (3 vs. 1–2), a distinctly concave groove between the nasals (vs. not concave), a triangular mental scale (vs. mostly bell-shaped mental), and the configuration of the throat scalation (see Fig. 3 View FIGURE 3 ). Furthermore, it differs from P. mutabilis by the absence of a dark stripe along the infralabials. In addition, P. borai is characterized by a very strong differentiation from all other Phelsuma species in the studied mitochondrial genes (16S rRNA and cytochrome b) and by a substantial divergence in the nuclear (C-mos, Rag-1 and Rag-2) gene fragments (see Rocha et al. 2009 and Discussion below).

Description of the holotype. Well preserved, with largely complete original tail with the terminal 13.8 mm regenerated. Fourth toe of left foot missing. Hemipenis not extruded. Body and head flattened dorsoventrally. Head slightly wider than neck, about as wide as body. Ear opening roundish. Tail longer than snout-vent length, dorsoventrally flattened in cross section. No distinct tail whorls recognizable. Digits strongly expanded at tips, first finger and first toe vestigal, comparative finger and toe length 1<2<5<3<4. Rostral scale wider than tall, less wide as mental. Distinct rostral cleft in dorsal process of rostral scale. Three internasals, the central one in a deep depression. Nostril in contact with four scales, the first supralabial, the nasal and two small postnasals, but no contact with rostral. Pupil round. Dorsal and lateral scales of head smooth, nearly flat, becoming increasingly rounded in profile on the posterior regions of the head. Dorsal and lateral scales of body semi-spherical, dorsal scales of tail flattened in profile. All ventral scales smooth. The median row of subcaudal scales distinctly enlarged transversely, more than twice as long as wide. Mental scale triangular, bordered posteriorly by a pair of elongate, irregular hexa- and pentagonal postmentals. Postmentals contact mental, first infralabial and two or three, relatively large gulars. Gulars decrease gradually in size posteriorly.

Measurements: Snout-vent length 41.7 mm; tail length 46.4 mm; head length 14.5 mm; head width (at widest point) 9.6 mm; snout length (anterior edge of eye to tip of snout) 6.4 mm; horizontal eye diameter 2.6 mm; ear opening diameter 1.0 mm; eye-ear distance 3.3 mm; internarial distance 2.4 mm; nostril-eye distance 5.1 mm, axilla-groin length 15.4 mm; forelimb length (from axilla to tip of longest finger) 12.1 mm; hindlimb length (from groin to tip of longest toe) 15.6 mm. Several additional measurements and counts are given in table 1.

TABLE 1. Morphological variation in Phelsuma borai and the related species P. breviceps and P. mutabilis ( P. androyense and P. micropholis being junior synonyms of P. mutabilis ). Abbreviations: Status (HT, holotype; LT, lectotype; PLT, paralectotype; ST, syntype), Sex (M, male; F, female), SVL, snout-vent length (in mm); TL, total length (in mm), in parenthesis if tail regenerated; SL, number of supralabials (left/right); IL, number of infralabials (left/right); IN, number of internasals (c, concave groove between nasals; nc, no concave groove between nasals); NC, nostril contact (0, in contact with rostral and first supralabial; 1, in contact with first supralabial only); PFP, number of preanofemoral pores; RC, rostral cleft above (+, present; -, absent);

ME, mental (1, bell-shaped; 2, triangle-shaped; 3, trapezoid); DO, dorsals (s, smooth; k, keeled), VE, ventrals (s, smooth; k, keeled); SC= subcaudals (s, smooth; k, keeled); SCE, subcaudals enlarged transversely +, present; -, absent), SL4, number of (transversely enlarged) subdigital lamellae under fourth toe; TS, dark throat stripe below infralabials (+, present; -, absent).

Colour after more than two years in alcohol partly similar to that of the splendid colour-phase in life ( Fig. 1 View FIGURE 1 B). Ground colour of head, body and dorsal parts of the limbs dorsally and laterally grey-brown with blackish spots and dots. A purplish middorsal band (largely without black spots) runs from the middle of the back to the tip of the tail. A black band from the nostril to anterior eye and from posterior eye to a point above the ear opening. Supralabials and infralabials white. Throat, chest, venter, and ventral parts of forelimbs and hindlimbs whitish; ventral side of tail whitish with a purplish shade, especially in the anterior part. No dark stripe on throat recognizable along the lower suture of infralabials, although scattered dark pigment is present. In life, colouration was extremely variable ( Fig. 1 View FIGURE 1 ), see also additional colour photographs of the holotype in Glaw & Vences (2007: 401) and Hallmann et al. (2008: 221). One cryptic colour phase resembled the bark of tree, with a beige or brownish-greyish ground colouration with irregular grey-blue and blackish pigment and with a series of three pairs of light spots (one pair in neck, one pair on anterior back, one pair on posterior back). The dorsal surface of the tail was olive-green with dark grey and bluish flecks, reminding to the colour of lichens ( Fig. 1 View FIGURE 1 A). Labials were light. When exposed to sunlight the same individual changed colour to a whitish-greyish ground colour with black reticulations, a blue tail and a broad blue middorsal band, here called splendid colour phase ( Fig. 1 View FIGURE 1 B). The ventral surfaces were white, with exception of the yellowish area of the preanofemoral pores and the anteriormost part of the tail which showed an orange spot ( Fig. 1 View FIGURE 1 C). No dark stripe on throat was recognizable along the lower suture of infralabials, although scattered dark pigment is present when examined after preservation ( Fig. 3 View FIGURE 3 ).

Distribution and conservation. Phelsuma borai is reliably known only from the Tsingy de Bemaraha National Park in western Madagascar. However, Mori et al. (2006) and Mori & Ikeuchi (2006), in publications on the herpetofauna of the Ankarafantsika National Park in northwestern Madagascar, provided a total of three different photographs of a Phelsuma species identified as P. mutabilis which—based on its life-colouration—is likely to represent P. b o r a i. It is therefore reasonable to assume that P. borai might be distributed in the dry forests between the Tsingy de Bemaraha and Ankarafantsika. It is also possible that other records of P. mutabilis from northwestern Madagascar, especially the localities Ankarafantsika, Namoroka, Andranomanintsy and Maevatanana ( Hallmann et al. 2008, Ramanamanjato & Rabibisoa 2002, Raselimanana 2008) actually refer to P. b o r a i or to both P. mutabilis and P. borai . The confirmed northernmost record of P. mutabilis is from Antsalova (UADBA uncatalogued [FGCZ 971]) where we observed this species abundantly on trees. All records of P. mutabilis from further north should be revised in order to determine the extent of occurrence of P. borai and the northern range limits of P. m u t a b i l i s. Due to the very limited current knowledge on this species we suggest to consider the conservation status of P. b o r a i as "Data Deficient" according to the IUCN criteria as used for the Malagasy amphibians (see Andreone et al. 2005).

Habitat and habits. The holotype of Phelsuma borai was captured after dusk in karstic dry forest in the rainy season, roosting in the vegetation close to a cave entrance. The specimens from Ankarafantsika (Mori et al. 2006) considered by us to possibly represent P. borai were found on trees and in a pitfall. Before preserving the holotype we noticed its extraordinary ability to change the colouration ( Fig. 1 View FIGURE 1 ) and the unusual cryptic nature of one colour phase ( Fig. 2 View FIGURE 2 ). Two other Phelsuma species, P. abbotti chekei and P. kochi were found around the type locality and two additional species, P. mutabilis and P. cf. dubia , were found at Antsalova, just outside of the Tsingy de Bemaraha National Park. Sympatric occurrence of P. borai and P. mutabilis is, therefore, likely but still needs confirmation.

Etymology. We dedicate this new species to our student, colleague and friend Parfait Bora who captured the holotype and was of invaluable help during several expeditions in Madagascar.

Available names. Two available names are currently considered as junior synonyms of Phelsuma mutabilis (see Hallmann et al. 2008): The original description of Phelsuma androyense Mocquard, 1901 was based on two males from Androy Nord ( Mocquard 1901), both studied by us (see table 1). In the original description of Phelsumia micropholis, Boettger (1913: 293–294) mentioned a total of 28 specimens (20 specimens from Tulear, one adult male from Andranohinaly, one adult male from Tsimanampetso and five males and one female from Menabe). He also stated that the original description was based on one male from Tsimanampetso (= Tsimanampetsotsa) as well as one male and one female from Menabe and provides measurements for these three specimens. Four paralectotypes, including the male from Tsimanampetso and three specimens from Menabe were identified by Bauer & Günther (1991) in the Zoological Museum at Berlin (ZMB). Boettger (1913) provides partial data of at least 18 specimens in his description and we consider the whole series of 28 specimens as type material. However, Mertens (1962), in a review of the genus Phelsuma , listed only five of these specimens, SMF 9470-9473 (studied in this paper) and the male from Andranohinaly, indicating that many paralectotypes were exchanged or lost. Although Mertens (1962) already considered the male SMF 9473 from Menabe as " Typus " and SMF 9470-9472 as " Paratypen " he later considered SMF 9473 as lectotype ( Mertens 1967), indicating that SMF 9470-9472 are paralectotypes. Upon examination these four specimens were morphologically homogeneous (Table 1). Based on the throat scalation and further morphological data (Table 1), it is evident that both Phelsuma androyense Mocquard, 1901 and Phelsumia micropholis Boettger, 1913 are indeed junior synonyms of Phelsuma mutabilis (see also table 1) and not conspecific with Phelsuma borai .