Mabuya dominicana Garman, 1887

Hedges, S. Blair & Conn, Caitlin E., 2012, A new skink fauna from Caribbean islands (Squamata, Mabuyidae, Mabuyinae) 3288, Zootaxa 3288 (1), pp. 1-244 : 98-101

Mabuya dominicana Garman, 1887

Dominica Skink

( Figs. 30C , 32C , 39 )

Mabuia dominicana Garman, 1887:52 . Lectotype: MCZ R-6049 (paralectotypes, MCZ R-185619–20), collected by Samuel Walton Garman on Dominica, March, 1879.

Mabuya agilis —Günther, 1888:364 (part).

Mabuya dominicana — Barbour, 1914:321.

Mabuya dominicana —Barbour, 1930:105.

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

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

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

Mabuya mabouia — Underwood, 1963:83 (part).

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

Mabuya mabouya mabouya — Schwartz & Thomas, 1975:141 (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, 1999:34 (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).

Material examined (n = 57). Dominica. MCZ R-6049 (lectotype; photographs); AMNH R 135271, Paul G. Howes, no specific locality, 1929; BMNH 1964.1440, Roseau, 1964 (collector unknown); CAS 112317, B. Malkin, Salibia, 27–30 January 1968; KU 242015, Albert Schwartz, 2 miles west Melville Hall, St. Andrew, 8 March 1962; KU 242016–242018, Albert Schwartz, 0.5 miles west Rosseau, St. David, 23 February 1962; KU 242019, Albert Schwartz, 0.5 miles east Laborie, St. George, 2 April 1961; KU 242020–242026, Albert Schwartz, 1.5 miles north Portsmouth, St. John, 22 February 1962 and 12 March 1963; KU 242027–272028, Albert Schwartz, Clarke Hall Estate, 1.5 miles northeast Layou, St. Joseph, 12–14 March 1963; KU 242029–242034, Albert Schwartz, 1 mile north Morne Raquette, St. Joseph, 16–18 February and 4 March 1962; KU 242035, Albert Schwartz, Geneva, St. Patrick, 28 February 1962; KU 242036–242037, Albert Schwartz, 1 mile east Stowe, St. Patrick, 28 February 1962; KU 242038–242040, Albert Schwartz, Canefield Estate, St. Paul, 11 March 1963; KU 242041, Albert Schwartz, 2.5 miles southeast Layou, St. Paul, 26 March 1961; KU 242042, Albert Schwartz, 1 mile north Pont Casse, St. Paul, 22 March 1961; MCZ R-57814, James Lazell, Moore Park, St. Andrew, 23 June 1958; MCZ R-127759, James Lazell, Dubuc Grand Bay, 26 February 1966; MCZ R-127760, James Lazell, botanical garden, Roseau, 26 February 1966; MCZ R-157108, James Lazell, New Florida Estate, Morne Anglais, 8 June 1973; MCZ R-182281, “W. Lu,” Soufriere, St. John, 19 January 1998; MPM 23266–26267, 4.7 miles NNW Mahout, St. Paul, 1987 (collector unknown); UMMZ 83319, Chester Roys, no specific locality, 20 June 1937; UMMZ 83320–83322 and 239608–239614, Chester Roys, South Central Dominica, 23–26 June 1937; UMMZ 83323 and 239615–239616, Chester Roys, Top of Divide between Roseau and Grand Bay, Dominica, June 1937; USNM 160610–160611, Bredin-Archbold-Smithsonian Biological Survey of Dominica, Clarke Hall, Middle of Plantation, 18 October 1965.

Diagnosis. Mabuya dominicana is characterized by (1) maximum SVL in males, 92.3 mm; (2) maximum SVL in females, 101 mm; (3) snout width, 2.41–3.45% SVL; (4) head length, 16.4–20.9% SVL; (5) head width, 11.5– 15.4% SVL; (6) ear length, 0.771–1.82% SVL; (7) toe-IV length, 8.91–13.4% SVL; (8) prefrontals, two; (9) supraoculars, three (60%), four (40%); (10) supraciliaries, three (2%), four (86%), five (11%), six (2%); (11) frontoparietals, two; (12) supralabial below the eye, five (70%), six (28%), seven (2%); (13) nuchal rows, one (98%), two (2%); (14) dorsals, 54–63; (15) ventrals, 63–73; (16) dorsals + ventrals, 118–136; (17) midbody scale rows, 27–32; (18) finger-IV lamellae, 12–16; (19) toe-IV lamellae, 15–19; (20) finger-IV + toe-IV lamellae, 27–34; (21) supranasal contact, Y (52%), N (48%); (22) prefrontal contact, N; (23) supraocular-1/frontal contact, Y (59%), N (41%); (24) parietal contact, Y; (25) pale middorsal stripe, N; (26) dark dorsolateral stripe, Y (14%; but only as a

Within the Genus Mabuya , M. dominicana differs from all other species by having a longer, narrower supranasal scale (supranasal length/width 4.57–6.57 versus 3.13–4.28 in those other species; Fig. 35). It is also separated from M. montserratae sp. nov. and M. hispaniolae sp. nov. by having a higher supraciliary-2/ supraciliary-3 length ratio (1.77–2.30 versus 1.39–1.66 in those two species; Fig. 36 ). It differs from M. cochonae sp. nov., M. desiradae sp. nov., M. grandisterrae sp. nov., and M. guadeloupae sp. nov. by having a longer frontonasal (frontonasal length 20.5–23.1% head length versus 17.8–19.9% in other species; Fig. 34 ). It differs from M. hispaniolae sp. nov. by having a narrower snout (snout width 13.6–17.5% HL versus 17.4–18.0% in M. hispaniolae sp. nov.; Fig. 40 ). Except for Mabuya guadeloupae sp. nov., M. dominicana has the best-developed stripes in the genus ( Fig. 32 ). These include dark lateral and ventrolateral stripes, dorsolateral and pale lateral stripes (pale lateral stripes in 84% of specimens), and (occasionally) traces of narrow dark dorsolateral stripes on the nape ( Fig. 32C ). These stripes are evident in some fetuses ( Fig. 39D ), although M. hispaniolae sp. nov. has lateral dark and pale stripes that are nearly as well-developed.

Description of lectotype ( Figs . 39A–C). The following is based on our examination of photographs. An adult (sex not determined) in moderate state of preservation, without injuries and with an abdominal slit. SVL, tail length (regenerated), HL, HW, SW, EL, and toe-IV length not measured; ear-opening average in size and round; 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 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, in contact with the second supraoculars and paired frontoparietals. Frontoparietals also in contact with parietals and interparietal. Interparietal tetragonal and acorn-shaped, separated from nuchals by parietals; parietal eye distinct. Parietals in contact with upper secondary and tertiary temporal scales. Four supraoculars, the second one being the longest 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 loreal squarish and posterior loreal rectangular with posterodorsal projection on latter. One upper and two lower preoculars. Seven supralabials, the fifth being the widest and forming the lower border of the eyelid. Three 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. Eight infralabials. Mental scale wider than long, posterior margin straight. Postmental scale and two pairs of adjoining chin shields in contact with anterior infralabials. First pair of chin shields in contact medially; second pair separated by a smaller cycloid scale.

Body and limb scalation. One row of paired 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; 71 in a longitudinal row; midbody scale count not possible with photograph. No distinct boundaries between dorsals, laterals and ventrals. Scales on tail and limbs similar to dorsals, except smaller on limbs and different on regenerated portion of tail. Palmar and plantar regions with small tubercles, subequal in size and delimited by a surrounding region of flatter scales. Subdigital lamellae smooth, single, 18 under toe-IV (finger lamellae not visible in photographs). Four preanals larger than adjacent ventral scales. No enlarged median subcaudal scales on original portion of tail.

Pattern and coloration. Dorsal ground color medium brown with small dark brown spots, distributed uniformly on limbs (slightly darker ground color) and in two dorsolateral bands on body and tail. Dark dorsolateral stripes absent. Dark lateral stripes present, dark brown, extending from loreal region to hindlimbs. Pale middorsal stripe absent. Pale dorsolateral stripes present, pale brown, extending from behind eye onto tail. Pale lateral stripes present, whitish, extending from below ear to hindlimbs, bordered below by a narrow dark line. Ventral surface of body without pattern. Palmar and plantar surfaces dark brown. Garman (1887) noted that the syntypes were brownish-olive (bronzed) in base coloration and that the pale bands were white.

Variation. In coloration, most specimens resembled the lectotype ( Table 5). Dorsal ground color was fairly fairly uniformly across the dorsum posterior to the forelimbs. A distinct white pale lateral stripe bordered below by a dark line was present on some specimens.

Distribution. This species is found only on Dominica ( Fig. 11F ), where nearly all records come from coastal areas, although it may be found inland in higher elevations as well ( Malhotra et al. 2007).

Ecology and conservation. Little is recorded for this species except that it is "widespread in coastal regions of the island" and under "corrugated iron roofs of agricultural sheds" in higher elevations ( Malhotra et al. 2007). Based on the large number of specimens, many of which were collected in the last century, and sightings as recently as 2010 (R. Powell, personal communication), the species appears to be relatively common, related probably to the fact that the mongoose does not occur on Dominica.

Based on IUCN Redlist criteria ( IUCN 2011), we assess the conservation status of Mabuya dominicana as Vulnerable (VU D2). We consider the mongoose to be the primary threat for this species, despite its current absence from the island. An accidental (or not) introduction of the mongoose —which occurs on neighboring islands to the north and south—could be devastating and would likely result in rapid decline and extinction of the species within a short time, based on history (see Discussion). The black rat is a predator of small reptiles ( Young 2008) and is on Dominica, and therefore there is a potential for a negative effect on this species as well (as may have occurred with M. montserratae sp. nov.; see below). Captive breeding now is warranted, for protection of the species in case it were to decline rapidly in the future.

Reproduction. Thirteen females (72.8–100.7 mm SVL) contained 1–6 (mean = 3.0) developing young. The dates of collection for those specimens were June 1937; 22–23 February, 1962; and 11–12 March, 1963. Somma and Brooks (1976) examined seven pregnant females of this species and concluded that litter size averaged 3.3, and that two young lizards at birth measured 29 and 30 mm SVL.

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

Remarks. Shortly after Garman (1887) described Mabuya dominicana, Günther (1888) reported on an additional collection of Mabuya from the island. Günther noted that his specimens showed a wider variation in some standard scale counts (ventrals and supranasal contact) than those of Garman and synonymized M. dominicana with what is here called Brasiliscincus agilis (a taxon that included several species at that time). Günther also went beyond the science and attacked Garman's reputation as well, alluding to a 19th century rivalry or feud. The specifics of the data are not of consequence here because the taxonomic context (species to be compared) is quite different now, and the conventional characters used by Garman (1887) to diagnose M. dominicana from close relatives (e.g., M. mabouya ) are no longer useful. But Günther (1888) was not correct either, because he failed to see that M. dominicana differs considerably from B. agilis , and his low scale count (57 ventrals chin-to-vent) for two specimens of M. dominicana is considerably lower than the lowest we recorded (63) out of 58 specimens. We suspect it was a miscount, or anomaly. Later, Barbour (1914) also pointed to this error by Günther (1888), reinstated M. dominicana as a valid species, and devoted a full page to a quote from Günther, mainly to chastise him for his "invidious remarks" concerning Garman. Since Dunn (1936) synonymized M. dominicana (and many other taxa) into M. mabouya , it has not been recognized as a species until now.

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 30. Head scalation in species of the Genus Mabuya (left, side view; right, dorsal view). (A) M. cochonae sp. nov. (KU 242043, holotype); (B) M. desiradae sp. nov. (KU 242045, holotype); (C) M. dominicana (MCZ R-182281); and (D) M.

FIGURE 32. Representative patterns in species of the Genus Mabuya (top, dorsal view; bottom, side view). (A) M. cochonae sp. nov.; (B) M. desiradae sp. nov.; (C) M. dominicana; (D) M. grandisterrae sp. nov.; (E) M. guadeloupae sp. nov.; (F) M. hispaniolae sp. nov.; (G) M. mabouya; and (H) M. montserratae sp. nov.

FIGURE 34. Graph of frontonasal length versus head length in the eight species of the Genus Mabuya.

FIGURE 36. Graph of supraciliary-2 length versus supraciliary-3 length in the eight species of the Genus Mabuya.

FIGURE 39. Mabuya dominicana, from Dominica. (A–C) MCZ R-6049, lectotype, Dominica (no specific locality). (D) fetuses of UMMZ 239613, "south-central Dominica." (E–F) uncataloged, Batali Beach (live individual, photographed by Robert Powell).

FIGURE 40. Graph of snout width versus head length in two species of the Genus Mabuya.