Mabuya montserratae, Hedges & Conn, 2012

Hedges, S. Blair & Conn, Caitlin E., 2012, A new skink fauna from Caribbean islands (Squamata, Mabuyidae, Mabuyinae) 3288, Zootaxa 3288 (1), pp. 1-244 : 115-117

publication ID	https://doi.org/ 10.11646/zootaxa.3288.1.1
persistent identifier	https://treatment.plazi.org/id/39191A7F-077B-FF89-2DA9-EEAA7DDBF9DF
treatment provided by	Felipe
scientific name	Mabuya montserratae
status	sp. nov.

Treatment

Mabuya montserratae sp. nov.

Montserrat Skink

( Figs. 31D View FIGURE 31 , 32H View FIGURE 32 , 45 View FIGURE 45 )

Mabuya mabouya mabouya — Dunn, 1936:544 (part).

Mabuya mabouia — Barbour, 1937:147 (part).

Mabuya mabouya mabouya —Peters & Donoso-Barros, 1970:200 (part).

Mabuya mabouya mabouya — Schwartz & Thomas, 1975:141 (part).

Mabuya mabouya mabouya — MacLean et al., 1977:38 (part).

Mabuya mabouya mabouya — Schwartz & Henderson, 1988:150 (part).

Mabuya mabouya mabouya — Schwartz & Henderson, 1991:457 (part).

Mabuya bistriata — Powell et al., 1996:82 (part).

Mabuya bistriata — Malhotra & Thorpe, 1999:75 (part).

Mabuya sloanii — Mayer & Lazell, 2000:883 (part).

Mabuya mabouya — Breuil, 2002:267 (part).

Mabuya mabouya — Henderson & Powell, 2009:292 (part).

Holotype. MCZ R-125464, an adult male, collected 6 August 1970 between Killecrankie Mydram, Waterworks Estate, and Molyneux Village , Montserrat, by J. Boos.

Paratypes (n = 7). Montserrat. BMNH 94.9 .20.8, F. Watts, no specific locality, accessioned 20 September 1894; and USNM 30850 About USNM (n = 6), July 1902 (no additional collection information available) .

Diagnosis. Mabuya montserratae sp. nov. is characterized by (1) maximum SVL in males, 85.3 mm; (2) maximum SVL in females, 98.0 mm; (3) snout width, 2.80–3.33% SVL; (4) head length, 17.1–18.6% SVL; (5) head width, 12.3–13.2% SVL; (6) ear length, 1.49–1.55% SVL; (7) toe-IV length, 9.51–11.4% SVL; (8) prefrontals, two; (9) supraoculars, three; (10) supraciliaries, four (only three appear to be present in some fetuses, but they are in poor condition); (11) frontoparietals, two; (12) supralabial below the eye, five (63%), six (38%); (13) nuchal rows, one (88%), two (13%); (14) dorsals, 57–63; (15) ventrals, 64–71; (16) dorsals + ventrals, 123– 134; (17) midbody scale rows, 32–34; (18) finger-IV lamellae, 14–15; (19) toe-IV lamellae, 16–18; (20) finger-IV + toe-IV lamellae, 30–33; (21) supranasal contact, Y (25%), N (75%); (22) prefrontal contact, N; (23) supraocular- 1/frontal contact, Y; (24) parietal contact, Y; (25) pale middorsal stripe, N; (26) dark dorsolateral stripe, N; (27) dark lateral stripe, Y; (28) pale lateral stripe, Y; and (29) palms and soles, dark ( Tables 3–5).

Within the Genus Mabuya , M. montserratae sp. nov. differs from all other species by having a shorter frontonasal (frontonasal length 16.5–16.8% HL versus 17.8–23.9% in those other species; Fig. 34 View FIGURE 34 ). It differs from M. dominicana , M. grandisterrae sp. nov., M. guadeloupae sp. nov., and M. mabouya by having a lower supraciliary-2/supraciliary-3 length ratio (1.39–1.66 versus 1.67–2.40 in those other species; Fig. 36 View FIGURE 36 ). It differs from M. dominicana and M. mabouya in having a wider supranasal (supranasal length/supranasal width 3.19–3.58 versus 3.61–6.57 in those other species; Fig. 35). It is separated from M. hispaniolae sp. nov. by having a larger ear (ear length 1.49–1.55% SVL versus 1.11–1.46% in M. hispaniolae sp. nov.). Additionally, M. montserratae sp. nov. tends to have more midbody scale rows than M. hispaniolae sp. nov.: 32 (four individuals) and 34 (four) versus 30 (six) and 32 (two). Also, the fetuses of M. montserratae sp. nov. are spotted and lack dark dorsolateral stripes whereas the fetuses of M. hispaniolae sp. nov. have dark dorsolateral stripes, at least anteriorly. Although hard to quantify in old specimens, the ear of M. montserratae sp. nov. also differs in shape from other species in being dorsoventrally elongated, versus more rounded.

Description of holotype ( Figs. 31D View FIGURE 31 , 45A–C View FIGURE 45 ). An adult male in good state of preservation, with an injury (in the first half of the body posterior to the left forelimb) and without an abdominal slit. SVL 85.3 mm; tail length not measured (complete); HL 15.9 mm; HW 11.0 mm; SW 2.70 mm; EL 1.32 mm; and toe-IV length 9.71 mm; earopening average in size and oval; toe length in the following order: I <II = V <III <IV.

Head scalation. Rostral wider than high, contacting first supralabials, nasals and supranasals. Paired supranasals in median contact, contacting anteriormost loreal. Frontonasal diamond-shaped, wider than long, laterally in contact with anterior loreal scale. A pair of quadrilateral prefrontals, separated medially, and in contact with frontonasal, both anterior and posterior loreals, first supraciliary, first supraoculars, and frontal. Frontal heptagonal, in contact with the first supraoculars and paired frontoparietals. Frontoparietals also in contact with parietals and gest and largest. Four supraciliaries, the second the longest. Nostril in posterior part of the nasal. A small postnasal, bordered by supranasal, anterior loreal and first supralabial. Anterior and posterior loreals rectangular with posterodorsal projection on latter. One upper preocular and two lower preoculars. Eight supralabials, the sixth being the widest and forming the lower border of the eyelid. Four moderately enlarged scales behind eye comprising the postoculars; similar to temporal scales but smaller. One primary temporal, two secondary temporals, and three tertiary temporals; all imbricate, smooth, cycloid, not distinctly delimited from the scales on the nape and the sides of the neck. Seven infralabials. Mental scale wider than long, posterior margin curved toward the tip of the snout. Postmental scale and three pairs of adjoining chin shields in contact with anterior infralabials. First pair of chin shields in contact medially; second and third pairs separated by smaller cycloid scales.

Body and limb scalation. One row of two fused nuchal scales. Other scales on nape similar to dorsals. On lateral sides of neck, scales slightly smaller. Dorsal scales cycloid, imbricate, smooth, 58 in a longitudinal row; ventrals similar to dorsals; 67 in a longitudinal row; 34 scales around midbody. No distinct boundaries between dorsals, laterals and ventrals. Scales on tail and limbs similar to dorsals, except smaller on limbs. Palmar and plantar regions with small tubercles, subequal in size and delimited by a surrounding region of flatter scales. Subdigital lamellae smooth, single, 15 under finger-IV and 17 under toe-IV. Preanal scales larger than ventrals. No enlarged median subcaudal scales on tail.

dorsolateral stripes absent. Dark lateral stripes present, dark brown with pale spots between forelimbs and midbody, continuous from loreal region to midbody and broken into a series of dark brown spots from midbody to hindlimbs. Pale middorsal stripe absent. Pale dorsolateral stripes essentially absent; faintly evident in fetuses. Pale lateral stripes present, whitish, extending from below ear to last third of body, bordered below by a series of dark brown spots. Limbs brownish with darker brown mottling on dorsal surfaces and gray on ventral surfaces. Ventral surface of body without pattern. Palmar and plantar surfaces dark brown. No information is available on color in life of the holotype.

Variation. In coloration and scalation, other specimens resembled the holotype ( Tables 4–5), and the photograph of the live specimen ( Fig. 45D View FIGURE 45 ) is similar in showing a nearly uniform brown dorsum with spots and faint traces of pale dorsolateral stripes. Pattern and coloration of the fetuses are consistent with adults.

Distribution. The species is distributed on Montserrat ( Fig. 11E View FIGURE 11 ). Only two localities are known. The holotype was collected in the central uplands above the abandoned town of Plymouth. That region was severely affected by the recent volcanic eruptions on the island, and satellite imagery shows no remaining forest in that area. Woodlands ( Fig. 45D View FIGURE 45 ) is the other locality, and it is on the central west coast, close to the area affected by the volcanic eruptions.

Ecology and conservation. Although the mongoose is absent, introduced rats are present in the forests of Montserrat, and these mammals are known to have a significant negative effect on native reptiles ( Young 2008). Also, forest habitats in the southern and central portions of Montserrat were considerably affected by the volcanic eruptions that began on 26 April 1995. The two known localities of this species are in that zone, and only two other individuals have been seen or collected, the most recent one being photographed in 1984 ( Fig. 45D View FIGURE 45 ). All native species of lizards recorded from Montserrat were sighted in a recent and extensive biodiversity survey, except Mabuya ( Young 2008) .

Based on IUCN Redlist criteria ( IUCN 2011), we consider the conservation status of M. montserratae sp. nov. as Critically Endangered (CR A2ace) and possibly extinct. It faces a primary threat from predation by introduced predators, including black rats. Studies are needed to determine if the species still exists, the health of any remaining populations, and threats to the survival of the species. Captive breeding programs should be undertaken, if the species still exists, because eradication of introduced mammalian predators is not possible on large islands.

Reproduction. One female (98.0 mm SVL) contained five developing young. The date of collection for that specimen was July, 1902.

Etymology. The species name ( montserratae ) is a feminine genitive singular noun, referring to the distribution of the species on the island of Montserrat.

Remarks. Two of the three known specimens of Mabuya from Montserrat were in museum collections at the beginning of the 20th century, but they were overlooked by Barbour (1914:355) in his detailed review of the zoogeography of the West Indian herpetofauna. Dunn (1936) was the first to note the presence of Mabuya on Montserrat, but he considered them to be members of his wide-ranging species, M. mabouya . Underwood (1963) omitted the island from the distribution of M. mabouya , but it was reinstated again by Schwartz and Thomas (1975) and Schwartz and Henderson (1988, 1991). Most recently, Miralles (2005) inadvertently omitted Montserrat from the distribution of M. mabouya . Mabuya montserratae sp. nov. is the northernmost species in the Genus Mabuya , in the Lesser Antilles.

MCZ	Museum of Comparative Zoology

Copyright notice

No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.

Taxonomy

Kingdom	Animalia
Phylum	Chordata
Class	Reptilia
Order	Squamata
Family	Scincidae
Genus	Mabuya