Bolitoglossa (Nanotriton) chinanteca, Rovito, Sean M., Parra-Olea, Gabriela, Lee, Dana & Wake, David B., 2012

Rovito, Sean M., Parra-Olea, Gabriela, Lee, Dana & Wake, David B., 2012, A new species of Bolitoglossa (Amphibia, Caudata) from the Sierra de Juarez, Oaxaca, Mexico, ZooKeys 185, pp. 55-71 : 60-62

Bolitoglossa (Nanotriton) chinanteca sp. n. Figure 3 A– 3I

Bolitoglossa occidentalis (in part). Duellman 1960.

Bolitoglossa rufescens (in part). Larson 1983.

Bolitoglossa rufescens . Campbell et al. 2010. Fig. 28A

Vernacular name:

Chinanteca Salamander

Salamandra chinanteca

Holotype.

Colección Nacional de Anfibios y Reptiles IBH 24708, field number SMR1401, an adult female from 10.3 km south (by rd) of center of Valle Nacional on Hwy. 175, Sierra de Juárez, Oaxaca, Mexico, 676 m elevation, 17.72390°N, 96.32100° W (WGS84 datum), collected by Sean M. Rovito and Dana Lee on 26 October, 2010.

Paratypes.

Thirteen specimens, all from Oaxaca, Mexico. 7 females: Sierra de Juárez: IBH 24709, same locality data as holotype; KU 136428, 4.6 km N Vista Hermosa; KU 86616-86617, Villa Hermosa [=Vista Hermosa]; MZFC 5323, Vista Hermosa; MVZ 131152, along Mexico Hwy. 175, vicinity of Vista Hermosa, Distrito Ixtlán; Sierra Mixe: MZFC 16085, Carretera Coconales-Zacatepec; 6 males: Sierra de Juárez: IBH 22535, IBH 24711, IBH 24712, same locality data as holotype. KU 86618, Villa Hermosa [=Vista Hermosa]; UCM 52439, UMMZ 119647, Vista Hermosa.

Referred specimens.

None.

Diagnosis.

Distinguished from species of all other genera of Neotropical salamanders by the lack of a sublingual fold. Distinguished from species of Bolitoglossa ( Magnadigita ) and Bolitoglossa ( Oaxakia ) ( Parra-Olea et al. 2004) by the presence of fully webbed, pad-like feet and smaller size. Distinguished from species of Bolitoglossa ( Pachymandra ) and Bolitoglossa ( Bolitoglossa ) by smaller size, smaller hands and feet, and shorter tail, from species of Bolitoglossa ( Mayamandra ) by less broad feet, and from Bolitoglossa ( Eladinea ) by having a complex tail base in which the transverse processes of the first caudal vertebrae extend forward and cross those of the more anterior vertebra ( Parra-Olea et al. 2004). Distinguished from all species of Bolitoglossa ( Nanotriton ) by more robust body. Distinguished from Bolitoglossa nympha by the presence of maxillary teeth, a relatively wider head (HW/SVL females: Bolitoglossa chinanteca : 0.17 + 0.018 vs. Bolitoglossa nympha 0.15 + 0.0063, Wilcoxon test, Z = -3.44, p = 0.0006; males: Bolitoglossa chinanteca : 0.17 + 0.010 vs. Bolitoglossa nympha 0.15 + 0.008, Wilcoxon test, Z = -2.78, p = 0.0055), relatively longer forelimbs (FLL/SVL females: Bolitoglossa chinanteca : 0.24 + 0.014 vs Bolitoglossa nympha : 0.18 + 0.010, Wilcoxon test, Z = -3.79, p = 0.0002; males: Bolitoglossa chinanteca : 0.24 + 0.0067 vs. Bolitoglossa nympha : 0.19 + 0.014, Wilcoxon test, Z = -3.77, p = 0.0002), and relatively wider feet (RFW/SVL females: Bolitoglossa chinanteca : 0.10 + 0.0081 vs Bolitoglossa nympha 0.089 + 0.0077, Wilcoxon test., Z = -2.70, p = 0.0070; males: Bolitoglossa chinanteca : 0.10 + 0.0009 vs Bolitoglossa nympha : 0.09 + 0.073, Wilcoxon test, Z = -2.87, p = 0.0041). Distinguished from Bolitoglossa occidentalis by having more maxillary teeth in males ( Bolitoglossa chinanteca : 29.8 + 10.7 vs. Bolitoglossa occidentalis : 11.4 + 9.1; Wilcoxon test, Z = -3.43, p = 0.0006), a wider head in females (HW/SVL Bolitoglossa chinanteca : 0.17 + 0.018 vs. Bolitoglossa occidentalis 0.16 + 0.0054, Wilcoxon test, Z = -2.85, p = 0.0043), relatively longer forelimbs (FLL/SVL females: Bolitoglossa chinanteca : 0.24 + 0.014 vs Bolitoglossa occidentalis : 0.20 + 0.017, Wilcoxon test, Z = -4.40, p <0.0001; males: Bolitoglossa chinanteca : 0.24 + 0.0067 vs. Bolitoglossa occidentalis : 0.21 + 0.017, Wilcoxon test, Z = -3.55, p = 0.0004), and relatively wider feet in females (RFW/SVL Bolitoglossa chinanteca : 0.10 + 0.0081 vs Bolitoglossa occidentalis : 0.092 + 0.0074, Wilcoxon test., Z = -2.14, p = 0.0326). Distinguished from Bolitoglossa rufescens by having more maxillary teeth (females: Bolitoglossa chinanteca : 23.1 + 10.8 vs. Bolitoglossa rufescens : 1.4 + 2.9, Wilcoxon test, Z = 4.19, p <0.0001; males: Bolitoglossa chinanteca : 29.8 + 10.7 vs. Bolitoglossa rufescens : 3.6 + 5.7, Wilcoxon test, Z = 6.50, p <0.0001), relatively longer forelimbs (females: Bolitoglossa chinanteca : 0.24 + 0.014 vs Bolitoglossa rufescens : 0.20 + 0.015, Wilcoxon test, Z = -4.31, p <0.0001; males: Bolitoglossa chinanteca : 0.24 + 0.0067 vs. Bolitoglossa rufescens : 0.21 + 0.015, Wilcoxon test, Z = -3.55, p = 0.0004), relatively wider feet (RFW/SVL females: Bolitoglossa chinanteca : 0.10 + 0.0081 vs Bolitoglossa rufescens : 0.088 + 0.0079, Wilcoxon test., Z = -3.24, p = 0.0012; males: Bolitoglossa chinanteca : 0.10 + 0.0009 vs Bolitoglossa rufescens : 0.09 + 0.0074, Wilcoxon test, Z = -3.03, p = 0.0025), and a relatively wider head in females (HW/SVL Bolitoglossa chinanteca : 0.17 + 0.018 vs. Bolitoglossa rufescens 0.16 + 0.0075, Wilcoxon test, Z = -2.81, p = 0.0049).

Description of the holotype.

A large adult female (SVL 37.2). Head broad (HW/SVL 0.15); snout truncate; eyes weakly protuberant, not visible when viewed from below. Maxillary teeth numerous (40 maxillary teeth), 6 premaxillary teeth anterior to line of maxillary teeth, do not pierce lip. Vomerine teeth numerous (29), extending in an irregular row to below the center of the internal nares, forming a more numerous patch near internal nares. Labial protruberances moderately developed. Tail fairly rectangular at base, becoming more rounded only at tip and tapering more sharply on posterior one-third; very weakly constricted at base; relatively short (SVL/TAL 0.78). Limbs relatively short (FLL/SLV 0.24, HLL/SVL 0.22); adpressed limbs separated by approximately 2 costal folds. Hands and feet strongly webbed, with only digit 3 emerging from web. Digits poorly defined except near distal tips; third digit on hands and feet pointed, others rounded; subterminal pad not evident; digits in order of increasing length I-II-IV-III on hands and I-V-II≈IV-III on feet.

Measurements

(in mm), limb interval and tooth counts of the holotype. SVL 37.2; HW 5.6; SG 9.8; HD 2.8; eyelid length 2.5; eyelid width 1.6; eye-nostril distance 2.0; ED 1.8; IO 3.8; IN 2.2; RL 3.0; snout to forelimb 10.6; snout to anterior angle of vent 34.2; AG 19.3; TL 29.2; tail width at base 3.0; tail depth at base 2.8; FLL 8.8; HLL 8.3; width of right hand 2.8; RFW 3.8; length of third toe 0.6; length of fifth toe 0.2; maximum nostril diameter 0.4; SW 5.1. Limb interval 2. Maxillary teeth 40; premaxillary teeth 6; vomerine teeth 29.

Coloration (in life)

of the holotype (Fig. 3A, 3B, 3E). Dorsum nearly uniform orange-brown with scattered darker brown specks. Dorsal surface of head slightly darker brown between interorbital region and dorsal midline behind eyes, forming a triangle of darker coloration. Rostrum pale brown. Iris coppery. Labial surfaces and sides of head to insertion of forelimb pale brown with tiny cream spots. Dorsal surface of tail similar to dorsum. Dorsal surface of legs, lateral surfaces of body and tail brown with tiny pale flecks scattered throughout. Gular surface pale with cream and brown mottling. Ventral surface pale brown with fine cream mottling. Underside of tail and limbs pale brown with tiny cream and darker brown specks throughout. Underside of feet pale brown.

Coloration (in alcohol)

of the holotype. Dorsum and dorsal surface of tail dark golden brown with scattered dark brown specks. Head and upper surface of limbs brown. Upper surface of feet golden brown. Sides of body and tail, and head grey-brown with scattered pale flecks. Gular region, underside of forelimbs, and anterior portion of venter (to approximately 2 costal grooves past insertion of forelimbs) cream colored with light brown mottling. Brown mottling more extensive on posterior portion of venter, underside of tail, and underside of hind limbs. Underside of hands pale, underside of feet slightly darker brown.

Color variation.

Several of the paratypes exhibit lighter grey dorsal coloration with more dark brown or black specks in alcohol. MZFC 21178 has a lighter reddish brown dorsum, becoming lighter yellow-brown towards the sides of the body, with numerous dark brown flecks throughout. MZFC 21178 has a more yellowish venter, with extensive brown mottling, while IBH 22523 has a darker brown venter with some pale yellow mottling, and a yellowish gular region with brown mottling.

Osteology.

A radiograph of a single adult paratype (UMMZ 119647) shows that the species has osteology typical of Nanotriton . The hands and feet bear foreshortened digits that taper strongly to their tips. The terminal phalanges are irregular in shape and even number, with a maximal formula of 1-2-3-2 and 1-2-3-2-2. The skull is well formed and has a small dorsal fontanelle between the frontal and parietal bones. The nasal bones are well formed and relatively protuberant from the rest of the skull. Prefrontal bones appear to be present. The preorbital processes of the vomer are long and relatively straight. The vertebral column includes an atlas, 14 trunk, one sacral, two caudosacral and 27 caudal vertebrae. The first caudal vertebra has very elongate transverse processes that arise near the anterior end of the vertebra and extend sharply anterolaterally, strongly overlapping the processes of the last caudosacral vertebra. The long process of the first caudal is bifurcated near its base on one side but less evidently so on the other.

Distribution.

This species is known from the Sierra de Juárez, between the small settlement of Vista Hermosa (at approximately 1500 m elevation) and the type locality to the north, along Hwy. 175, as well as from the Sierra Mixe, near the town of Santiago Zacatepec. The two known localities are approximately 70 km (by air) apart. The species presumably occurs on the Atlantic slopes of the Sierra de Juárez and the Sierra Mixe between known populations, and perhaps more widely in the Sierra Mixe.

Natural History.

All specimens of Bolitoglossa chinanteca for which information is available were collected in the axils of banana plants during the day, and on vegetation at night. The species is presumably arboreal, like other members of the subgenus Nanotriton .

Etymology.

This species is named after the Chinanteco people from the municipalities of Santiago Comaltepec and San Pedro Yolox (Sierra de Juárez) in the Chinantla region of Oaxaca, where most specimens were collected. The language spoken in Santiago Comaltepec is also called Chinanteco.