Cryptotriton xucaneborum, Rovito & Vásquez-Almazán & Papenfuss & Parra-Olea & Wake, 2015

Rovito, Sean M., Vásquez-Almazán, Carlos R., Papenfuss, Theodore J., Parra-Olea, Gabriela & Wake, David B., 2015, Biogeography and evolution of Central American cloud forest salamanders (Caudata: Plethodontidae: Cryptotriton), with the description of a new species, Zoological Journal of the Linnean Society 175 (1), pp. 150-166 : 157-162

CRYPTOTRITON XUCANEBORUM , NEW SPECIES

Sierra de Xucaneb Hidden Salamander

Salamandra Escondida de la Sierra de Xucaneb

Figures 6A, 6C

Cryptotriton veraepacis McCranie and Rovito, 2014 (part)

Cryptotriton veraepacis Vásquez-Almazán et al. 2009 (part)

Cryptotriton veraepacis Lynch and Wake, 1978 (part)

Holotype. – MVZ 263575 , male, Guatemala, Departamento Alta Verapaz, Municipio Senahú, 3.8 km S (by road) Finca El Volcán , 15.46102 °N 89.87055 °W ( WGS84 datum), 1370 m, 19 August 2007, S. M. Rovito, C. R. Vásquez-Almazán, E. G. Ruano-Fajardo, and T. J. Papenfuss.

Paratypes. – (n = 4). Three females, MVZ 269516– 269517 , USAC 3496 , one male , USAC 3497 ,

Cryptotriton alvarezdeltoroi Cryptotriton sierraminensis

Cryptotriton monzoni Cryptotriton veraepacis

Cryptotriton nasalis Cryptotriton xucaneborum

Cryptotriton necopinus Cryptotriton sp. Bethel

Guatemala, Alta Verapaz, Municipio Tucurú, Chelemhá Reserve , 15.3558 °N, 90.0775°W ( WGS84 datum), 2045 m .

Referred specimens. – ANSP 28198, ANSP 28199.

Diagnosis. – Distinguished by its very dark grey ventral coloration from Cryptotriton sierraminensis (yellow) and C. veraepacis (lighter grey); gular coloration darker than in C. veraepacis , with no yellow (some yellow in C. sierraminensis ) ( Vásquez-Almazán et al., 2009). Distinguished from C. veraepacis and C. sierraminensis by lack of a tibial spur, and from C. sierraminensis by having prefrontal pierced by nasolacrimal duct, rather than evacuated along anterior margin and by the lack of a postorbital vomerine process ( Vásquez-Almazán et al., 2009). Distinguished from C. necopinus by having prefrontal processes of the premaxillary that arise fused and separate distally, rather than arising separately ( McCranie & Rovito, 2014), and by having a longer tail, more rounded nostrils, a wider foot, and fewer maxillary and vomerine teeth ( Table 1). Distinguished from C. nasalis by having a prefrontal bone pierced by the nasolacrimal duct, rather than evacuated along the anterior margin ( Lynch & Wake, 1978) and smaller nostrils ( Table 1). Distinguished from C. alvarezdeltoroi by its larger size and smaller nostrils ( Table 1).

Description of holotype. – A relatively small adult male (SVL = 25.7 mm). Head moderately sized, ap- proximately same width as body, snout truncate. Eyes extend slightly beyond margin of jaw. Paratoid glands large, relatively well defined. Nostrils large (maximum nostril diameter = 0.6 mm). Well developed hands and feet with little webbing between digits; tips of digits rounded. Limbs relatively long; adpressed limbs separated by approximately two costal folds. Tail longer than body (37.4 mm), approximately rounded in crosssection, constricted at base, gradually tapering to a point. Nasolabial protuberances well developed and wide but not long, extend slightly beyond margin of lip. Large, elliptical mental hedonic gland present. Maxillary teeth (38) small and relatively numerous; premaxillary teeth (3) large, pierce upper lip. Relatively few vomerine teeth (8), arranged in line extending to internal margin of choanae.

Measurements of the holotype (in mm) and tooth counts. – Head width 3.6; snout to gular fold (head length) 5.0; head depth at posterior angle of jaw 2.2; eyelid length 1.8; eyelid width 0.7; anterior rim of orbit to snout 0.9; horizontal orbit diameter 2.2; interorbital distance 1.3; snout to forelimb 7.7; distance separating external nares 0.8; snout projection beyond mandible 0.7; snout to posterior angle of vent (SVL) 25.7; snout to anterior angle of vent 33.7; axilla to groin 13.0; tail length 37.4; tail width at base 1.8; tail depth at base 2.3; forelimb length 5.4; hind limb length 6.5; width of right manus 1.4; width of right pes 2.3; length of longest toe 1.2; length of shortest toe 0.1; maximum nostril diameter 0.6; shoulder width 2.5. Maxillary teeth 38, premaxillary teeth 3, vomerine teeth 8.

Coloration of the holotype in life (based on photos). – Numbers in parentheses refer to colours from Köhler (2012). Dorsal surface of head Flesh Ocher (57) with Burnt Umber (48) in the centre of head from intercanthal region to just anterior to insertion of forelimbs. Dorsal surface of body Salmon Colour (58) with a suggestion of Dark Yellow Buff (54). Chevrons of Burnt

Umber (48) along dorsal midline from insertion of forelimbs to base of tail. Dorsal surface of tail uniform Dark Salmon Colour (58), becoming more reddish along final third of tail. Dorsal surface of limbs Light Pratt’s Rufous (71) and Salmon Colour (58) with Dark Drab (45) speckles and white flecks. Dorsal surface of feet Light Neutral Grey (297) with white flecks; toe tips pinkish. Lateral surface of head and body with same background colours as above, blending ventrally into Dark Greyish Brown (284) with numerous white flecks. Gular region mottled Light Neutral Grey (297) and Sepia (286), becoming nearly uniform Sepia just anterior to gular fold. Ventral surface of body and anterior third of tail Sepia. White flecks on gular region and ventral surface of body and tail, becoming less numerous toward ventral midline. Posterior two-thirds of tail Vinaceous (247), with some Sepia; white flecks throughout tail. Ventral surfaces of limbs Pale Neutral Grey (296) with Tawny Olive (17), small white flecks. Underside of feet Pale Neutral Grey, toe tips pinkish.

Colour of the holotype in alcohol. – Dorsal surface of head Raw Umber (22), with Hair Brown (277) in the centre of head from intercanthal region to just anterior to insertion of forelimbs. Dorsal surface of body Raw Umber with Hair Brown chevrons along dorsal midline. Dorsal surface of tail Buff (5). Dorsal surface of limbs and feet mottled Buff and Raw Umber (23). Gular region mottled Drab-Grey (256) and Hair Brown, becoming nearly all brown towards gular fold. Ventral surface of body Hair Brown. Anterior third of tail Hair Brown, mottled with Buff towards tip. Underside of limbs Buff mottled with Hair Brown, underside of feet Smoke Grey (266). Pale flecks throughout ventral surface of head, body, and tail.

Variation – The male paratype is roughly the same size as the holotype (24.9 mm), while the three female paratypes are slightly larger, reaching a maximum of 32 mm. There is some variation in maxillary teeth in the type series, with the largest female having only 37 maxillary-premaxillary teeth, while another female has a total of 57 maxillary-premaxillary teeth. Similar variation is seen in the vomerine tooth counts; the largest female has only six vomerine teeth, while the smallest male has the most vomerine teeth (13). The female paratypes have nasolabial protuberances that are only very slightly developed and visible only as a slight swelling in the labial margin.

Osteology. – We examined X-rays of the holotype and a paratype (MVZ 269516). Prefrontal bones appear to be pierced by a nasolacrimal duct, as in C. veraepacis and the single known specimen of C. necopinus ( Lynch & Wake, 1978; McCranie & Rovito, 2014). Frontal processes of premaxillary bone arise fused and separate distally. Vomer lacks a postorbital process. Tibial spur absent. As in other species of Cryptotriton , septomaxillary absent and mesopodials unmineralized. Phalangeal formula for manus is 1-2-3-2 and 1-2-3- 3-2 for pes, identical to that of other species in the genus Cryptotriton .

Habitat and distribution. – Known only from two localities separated by 22 km in the Sierra de Xucaneb, Alta Verapaz, Guatemala. The species may occur at a few other points of relatively high elevation in the Sierra de Xucaneb, but extensive deforestation in most areas has eliminated what may have once been suitable habitat for the species. The holotype was found in an arboreal bromeliad, while the four paratypes from Chelemhá were found active at night on vegetation 1–2 m above the ground. The forest at Finca Volcán represents a transition from lower elevation forest to cloud forest, with relatively few bromeliads and other epiphyte growth, and is classified as subtropical rainforest ( Holdridge, 1967), while habitat at Chelemhá is lower montane rain forest ( Holdridge, 1967) with typical cloud forest vegetation and extensive epiphyte cover. The only syntopic species of salamander known to occur with Cryptotriton xucaneborum is Bolitoglossa helmrichi , which occurs at both known sites.

Figures

Figure 6. (A) Holotype of Cryptotriton xucaneborum in life. (B) Ventral view of holotype showing dark grey ventral coloration. (C) Ventral view of an individual of C. veraepacis (USAC 1920) showing lighter grey ventral coloration. (D) View of type locality of C. xucaneborum, showing small forest fragment surrounded by agricultural land. (E) Habitat where holotype of C. xucaneborum was collected.