Capitellum mariagalantae, 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 : 59-63

Capitellum mariagalantae sp. nov.

Marie-Galante Skink

( Figs. 18A , 19A , 20 )

M[abuia] aenea —Cope, 1862:186 (part).

Mabuya mabouia —Barbour, 1930:105 (part).

Mabuya mabouia — Barbour, 1935:129 (part).

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

Mabuya mabouia — Barbour, 1937:147 (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, 1999:87 (part).

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

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

Mabuya mabouya —Miralles, 2005:49 (part).

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

Holotype. ANSP 9413 , an adult female from Marie-Galante , Guadeloupe, containing 6 fetuses. Initially in the MNHN but donated to the ANSP at some time prior to 1862. No other collection information is available, but it was possibly collected in the 1830s (see Remarks).

Paratypes (n = 6). Guadeloupe. Fetuses of the holotype, ANSP 9413 .

Diagnosis. Capitellum mariagalantae sp. nov. is characterized by (1) maximum SVL in males, not available; (2) maximum SVL in females, 78.3 mm (only known specimen); (3) snout width, 2.55% SVL; (4) head length, 15.8% SVL; (5) head width, 12.3% SVL; (6) ear length, 2.12% SVL; (7) toe-IV length, 9.52% SVL; (8) prefrontals, two; (9) supraoculars, four; (10) supraciliaries, five; (11) frontoparietals, five; (12) supralabial below the eye, six (83%), seven (17%); (13) nuchal rows, one; (14) dorsals, 62; (15) ventrals, 63; (16) dorsals + ventrals, 125; (17) midbody scale rows, 30; (18) finger-IV lamellae, 10; (19) toe-IV lamellae, 14; (20) finger-IV + toe-IV lamellae, 24; (21) supranasal contact, Y (67%), N (33%); (22) prefrontal contact, N; (23) supraocular-1/frontal contact, N; (24) parietal contact, Y (point); (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 Capitellum , C. mariagalantae sp. nov. differs from C. metallicum by having a higher number of supralabial scales (supralabial six or seven below the eye versus supralabial five below the eye in C. metallicum ), a wider head (head width 12.3% SVL versus 11.5% SVL in C. metallicum ), and three (versus two) lower preoculars. In pattern ( Fig. 19A–B ), C. mariagalantae sp. nov. is a more boldly patterned species than C. metallicum (pattern information for C. metallicum based on original description and figures because the lectotype has faded). It has pale and dark lateral and dark ventrolateral stripes that extend the full length of the body and onto the tail, whereas C. metallicum has only a dark lateral stripe in the anterior one-third of the body. Capitellum mariagalantae sp. nov. is more similar to C. parvicruzae sp. nov. in pattern ( Fig. 19A, C ), although comparison of pattern is difficult because of the poor state of preservation of the holotype of C. mariagalantae sp. nov. and relies mostly on traces of pattern in the fetuses. It can be seen that the two species share bold lateral dark and pale stripes, both of which run the length of the body and onto the tail. They also have pale dorsolateral stripes anteriorly. Other than these general similarities, it is not possible to make a detailed comparison of patterns in the two species. In scalation C. mariagalantae sp. nov. differs from C. parvicruzae sp. nov. in having five supraciliaries (versus six), parietal contact (versus no contact), a larger auricular opening (ear length 2.12% SVL versus 1.44% SVL), and 169 (versus 190) total digital lamellae.

Capitellum mariagalantae sp. nov. also differs from species in other genera inhabiting nearby islands in the Lesser Antilles ( Tables 3–5). For example, from the species in the same island bank (genus Mabuya ; see below), C. mariagalantae sp. nov. differs by having five supraciliaries (not four); four supraoculars (not 2–3); fewer finger-IV (10 versus 12–15), toe-IV (14 versus 16–21), and combined (24 versus 29–35) lamellae; and no supraocular-1/ frontal contact (versus contact present in Mabuya from Guadeloupe).

Description of holotype ( Figs . 18A, 20 ). An adult female in poor state of preservation, without injuries and with an abdominal slit. SVL 78.3 mm; tail length not measured (broken); HL 12.4 mm; HW 9.66 mm; SW 2.00 mm; EL 1.66 mm; and toe-IV length 7.45 mm; ear-opening large in size and round or slightly oval; toe length in the following order: I <V <II <III <IV.

Head scalation. Rostral wider than high, contacting first supralabials, nasals and supranasals. Paired supranasals not 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 and moderately lanceolate, in contact with the second supraoculars and paired frontoparietals. secondary and tertiary temporal scales. Four supraoculars, the second one being the largest. Five supraciliaries, approximately equal in length. Nostril in posterior part of the nasal. A small postnasal, bordered by supranasal, anterior loreal and first supralabial. Anterior and posterior loreals squarish with posteromedial projection on latter. Four upper preoculars and three 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. Six infralabials (seven on the left). Mental scale wider than long, posterior margin straight. Postmental scale and two pairs of adjoining chin shields in contact with anterior infralabials. Both pairs of chin shields separated by smaller cycloid scales. similar to dorsals; 63 in a longitudinal row; 30 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, 10 under finger-IV and 14 under toe-IV, 38 on hands, 47/46 (L/R) on feet, 169 total lamellae. Preanal scales similar to ventrals. No enlarged median subcaudal scales on tail.

Pattern and coloration. Dorsal ground color dark gray-brown without visible dark brown spots (dorsal pattern has faded). Dark dorsolateral stripes absent. Dark lateral stripes present, medium brown, extending from loreal region past hindlimbs to tail. Pale middorsal stripe absent. Pale dorsolateral stripes present. Pale lateral stripes present, whitish, extending from behind eye to last third of body, bordered below by a narrow (ventrolateral) dark line. Ventral surface of body without pattern. Palmar and plantar surfaces dark brown. No information is available on color in life of the holotype.

Variation. Despite their early stage of development and fragile condition, some information on scalation and pattern of the fetuses could be ascertained ( Tables 4–5). They appear to have four supraoculars, five supraciliaries, and no prefrontal contact, as in the holotype. Parietal contact is obvious in one fetus but not scorable in the others. A few could be scored for supralabial scale below the eye, and they showed some variation (scale six or seven below the eye). The lateral pale and dark stripes and the ventrolateral dark lines of the adult are even more evident in the fetuses, probably because they have been obscured from ambient light for two centuries. All extend past the hindlimbs and continue to at least one-third of the length of the tail. The bold lateral pale (white) stripe also forms a ring around the ear opening. Anteriorly, the white lateral stripe extends along the supralabial scales (all pure white) to the nasal. Pale dorsolateral stripes also are evident anteriorly on nape but fade out just past the hindlimbs. Faint traces of dark dorsolateral stripes are evident bordering the pale dorsolateral stripes for a short distance on the nape, but they would have been barely noticeable in life. A pale ventrolateral stripe is faintly visible passing below the forelimbs.

Distribution. The species is distributed on Marie-Galante, Guadeloupe, 158 km 2 ( Fig. 11B ).

Ecology and conservation. No information is available on the ecology of this species (see Remarks for the genus suggesting that the species were likely terrestrial and cryptozoic). Aside from this single specimen collected at least 150 years ago, there are no other specimens or observations of skinks from this island. The mongoose was introduced to Marie-Galante, and rats undoubtedly are present as well, thus probably explaining the subsequent

Based on IUCN Redlist criteria ( IUCN 2011), we consider the conservation status of Capitellum mariagalantae sp. nov. to be Critically Endangered and possibly extinct (CR A2ace). It faces a primary threat from the introduced mongoose, which has probably led to its extinction. Secondary threats include habitat destruction from agriculture and urbanization, and predation from other 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. The female holotype (78.3 mm SVL) contained six fetuses. No specific month of collection is available .

Etymology. The species name ( mariagalantae ) is a feminine genitive singular noun referring to the distribution of the species on the island of Marie-Galante. The island was named for Santa Maria Galanda, the flagship of Christopher Columbus, who discovered the island in 1493.

Remarks. The first mention of the existence of skinks on Marie-Galante was a footnote in a paper by Cope (1862, p. 186), who remarked, "I have supposed a specimen from the Paris Museum labeled as Eumeces mabuia from Marie Galante, to belong to M. aenea , while new Grenadian and Trinidad specimens have been referred to the Duméril and Bibron (1839) mentioned two collectors who supplied specimens of skinks from Guadeloupe: Joseph L'Herminier (1802–1866) and M. Beaupertuis. The botanical literature records both being active collectors in the 1830s, just prior to the publication of Duméril and Bibron (1839). Thus it is possible that the Marie-Galante specimen was collected in the 1830s, examined by Duméril and Bibron (1839) for their description of Eumeces mabouia (= redescription of Mabuya mabouya ), and later exchanged with the ANSP prior to 1862. This is supported also by Cope's (1862) mention that the MNHN labeled the specimen as " Eumeces mabuia ." The MNHN syntype of S. fulgidus , a species described by Cope (1862) in the same paper that included his footnote on the Marie-Galante specimen, may have been in exchange for that specimen. Unfortunately the description of E. mabouia Duméril and Bibron (1839) does not include sufficient detail on scalation to determine if the Marie- Galante specimen was available to them, and taxonomically it would not matter in any case. Dunn mentioned this specimen in the first sentence of his revision of "American Mabuyas" ( Dunn 1936): "the following notes are an attempt to name Mabuyas from the islands of St. Martin, Redonda, and Marie Galante, in the collection of the Academy."

Figures

FIGURE 11. Map showing the distribution of mabuyine skinks occurring in the Lesser Antilles and Trinidad and Tobago. See Fig. 1 for location of the islands. The islands and species are: (A) Anguilla, Dog Island, and St. Barts (Spondylurus powelli sp. nov., squares), and St. Martin (S. martinae sp. nov., circle); (B) Guadeloupe: Basse-Terre (Mabuya guadeloupae sp. nov., square), Grande-Terre (Mabuya grandisterrae sp. nov., triangle), Îlet à Cochons (Mabuya cochonae sp. nov., star), La Désirade and Terre de Bas, Petite-Terre (Mabuya desiradae sp. nov., diamonds), and Marie-Galante (Capitellum mariagalantae sp. nov., circle); (C) Martinique (Mabuya mabouya, circles; Capitellum metallicum, triangle); (D) St. Vincent, the Grenadines, and Grenada (Copeoglossum aurae sp. nov., circles; Marisora aurulae sp. nov., triangles); (E) Redonda (Copeoglossum redondae sp. nov., circle) and Montserrat (Mabuya montserratae sp. nov., square); (F) Dominica (Mabuya dominicana); (G) St. Lucia (Alinea luciae), (H) Barbados (Alinea lanceolata); (I) Trinidad (Copeoglossum aurae sp. nov., circles; Marisora aurulae sp. nov., triangle), and (J) Tobago (Copeoglossum aurae sp. nov., circles; Marisora aurulae sp. nov., triangles). Hollow symbols in A and J are literature records (specimens not examined). Where no specific localities within an island are known for a species, a symbol is placed centrally on the island: Alinea luciae, Capitellum mariagalantae, Capitellum metallicum, and Copeoglossum redondae sp. nov. The scale in (A) applies to all islands.

FIGURE 18. Head scalation in species of the Genus Capitellum (left, side view; right, dorsal view). (A) C. mariagalantae sp. nov. (ANSP 9413, holotype); (B) C. metallicum (MNHN 5424, lectotype); and (C) C. parvicruzae sp. nov. (ZMUC-R 99, holotype).

FIGURE 19. Representative patterns in species of the Genus Capitellum (top, dorsal view; bottom, side view). (A) C. mariagalantae sp. nov.; (B) C. metallicum; and (C) C. parvicruzae sp. nov.

FIGURE 20. Capitellum mariagalantae sp. nov., from Marie-Galante, Guadeloupe. (A–C, E–F) ANSP 9413, holotype, Marie- Galante (no specific locality). (D) fetus of ANSP 9413, paratype, Marie-Galante (no specific locality).