Bolitoglossa mucuyensis, García-Gutiérrez, Javier, Escalona, Moisés, Mora, Andrés, Pascual, Amelia Díaz De & Fermin, Gustavo, 2013

García-Gutiérrez, Javier, Escalona, Moisés, Mora, Andrés, Pascual, Amelia Díaz De & Fermin, Gustavo, 2013, A new species of salamander (Caudata: Plethodontidae, Bolitoglossa) from Sierra Nevada de Mérida, Venezuela, Zootaxa 3620 (1), pp. 179-191 : 184-186

Bolitoglossa mucuyensis sp. nov.

( Fig. 3 A–E)

La Mucuy salamander (English) Salamandra de La Mucuy (Spanish)

B. orestes Barrio-Amorós y Fuentes-Ramos 1999:29 (in part, MCNC7557) B. orestes Díaz de Pascual et al. 2010:41 (in part, CVULA IV-7099)

Holotype. ULABG 1772, adult female from Parque Nacional ‘Sierra Nevada’, La Mucuy, nearby a stream located between a trout farm and a place called Mesa de Los Pinos, 2225 masl, Santos Marquina municipality, Mérida state, Venezuela. Collected in August 7th, 1987 by Enrique La Marca (field number ELM 1772), Abraham Mijares (AMU), Juan Elías García Pérez and Maricela Sosa.

Paratypes. Same data as the holotype, ULABG 1771 (field number ELM 1771); Parque Nacional ‘Sierra Nevada’, La Mucuy stream, close to a trout farm and the national park facilities (INParques), 2225 masl, adult males ULABG 1797, 1798, 1800,1805-1809, adult females ULABG 1799, 1801, 1803, 1804, collected in October 8th, 1987 by Abraham Mijares and Enrique La Marca (field numbers ELM 1797-1809); National Park Sierra Nevada, La Mucuy cloud forest, sector Bosque del Silencio, 2250 masl, juveniles ULABG 3032, 3034, adult female ULABG 3033, collected in June 21st, 1989 by Abraham Mijares (field numbers AMU 2223-2225); Parque Nacional ‘Sierra Nevada’, La Mucuy forest, nearby a trout farm and the national park facilities (INParques), 2200 masl, ULABG 3413, collected in January 7th, 1993 by Enrique La Marca (field number ELM 3413); Parque Nacional ‘Sierra Nevada’, La Mucuy Alta, adult female, CVULA IV-7099, collected in June 17th, 2008.

Diagnosis. Species of reduced size belonging to the adspersa group of species of the Eladinea subgenus as defined by Parra-Olea et al. (2004), and corroborated by the molecular data reported by Fermin et al. (2012) and those derived from the present work ( Fig. 2 ). Assigned to Bolitoglossa because it lacks a sublingual fold. B.

mucuyensis sp. nov. differs from all other Venezuelan salamanders, except B. orestes , by a larger SVL/TL ratio (calculated as the mean of the individual ratios, Fig. 4 ): 1.36±0.38, n=17 for B. mucuyensis sp. nov. (1.70±0.61, n=6 for females and 1.33±0.09, n=12 for males), 1.35±0.13, n=23 for B. orestes (1.44±0.12, n=13 for females and 1.25±0.25, n=10 for males), 1.20±0.17, n=8 for B. borburata (1.27±0.17, n=5 for females and 1.08, n=3 for males), 0.96, n=3 for B. guaramacalensis (0.89, n=2 for females and 0.88, n=1 for males), and 1.12±0.25, n=8 for B. altamazonica (1.13±0.33, n=5 for females and 1.12, n=3 for males). Data for B. altamazonica do not derive from specimens collected in Venezuela. Differs from B. altamazonica (Brame & Wake, 1963) by more rounded digit ends, which also show reduced webbing. Differs from B. borburata and B. guaramacalensis by a lower SVL (females: mean 40.3mm, range 33.7–45.4mm, n=7; males: mean 37.9mm, range 34.1–40.6mm, n=12), and lesser number of VT and MT (females: mean 12, range 6–17, n=7; males: mean 12, range 8–16, n=12, and females: mean 20, range 14–26, n=7; males: mean 19, range 14–28, n=12, respectively). B. mucuyensis sp. nov. differs from B. orestes by having a reduced webbing between the hand digits 1 and 2 and the tip of digit 3, a diminished webbing between the foot digits 1 and 2 and between 3 and 4; it can also be distinguished from B. orestes by presenting more rounded toe tips ( Fig. 5 ). B. mucuyensis sp. nov. differs from B. orestes by 3.12% in terms of the nucleotide sequence of the 16S rRNA gene (Fermin et al. 2012) and by 8.1% in the cytb gene as reported here. Finally, B. mucuyensis sp. nov. differs from B. tamaense sp. nov. in that females of B. mucuyensis sp. nov. (40.3mm) are smaller than B. tamaense sp. nov. (47mm); webbing of B. tamaense sp. nov. is more pronounced than in B. orestes , and hence, than in B. mucuyensis sp. nov.; 16S rRNA gene sequence between both species differ ca. 3% (not shown).

Description of the holotype. Female with a rounded snout in dorsal view; tip of the snout blunt and narrow. In ventral view, the snout protrudes beyond the jaws. Small, rounded nostrils from whose posterior margin emerges the nasolabial groove. Labial protuberances are slight and separated 2.5mm. Canthus rostralis small and rounded. Standard length 7 times the head width and 4.5 times the head length. Presence of a postorbital groove that extends at the level of the posterior angle of the eye, like a small depression of 2.5mm long, and extends parallel to the gular region, 3.4mm anterior to the gular fold. Vomerine teeth 16 (9 right and 7 left) that protrude laterally to the posterior edge of the choanae, and in the middle part between the choanae these teeth protrude parallel towards the parasphenoid, approaching the patch of parasphenoid teeth. Maxillary teeth 28 (13 right and 15 left) which protrude posteriorly to the mid level of the eyes. Premaxillary teeth 2. The lip is not cleft, but it looks concave due to the presence of labial protuberances. Standard length 1.5 times the tail length. In transverse section, the tail looks rectangular with rounded angle edges, higher than wide when it is compressed laterally, and constrained at the base. Short limbs: fore limbs 5.7 times smaller and hind limbs 5.5 times smaller than the standard length. Digital tips free of web, which is quite notable for digit 3; obvious subterminal pad. Digital tips flattened dorsoventrally and rounded. Digital tips moderately robust. Decreasing order of the hand phalanges 3, 2, 4 and 1. Decreasing order of the foot phalanges 3, 4, 2, 5 and 1.

Measurements of the holotype (in mm). Head length 9.9; head depth at posterior angle of jaw 3.8; eyelid length 3.2; eyelid width 1.7; anterior rim of orbit to tip of snout 1.8; horizontal orbit diameter 2.3; interorbital distance between angle of eyes (intercanthal distance) 2.4; distance between vomerine teeth and the patch of parasphenoid teeth 0.6; snout to forelimb 11.5; distance separating external nostrils 1.9; interchoanal distance 1.5; snout projection beyond mandible 0.9; snout to posterior angle of vent (standard length) 44.3; limb interval 22.2; tail length 29.3; tail width at base 2.8; tail girth at base 2.8; forelimb length (to tip of longest finger) 7.8; hind limb length 8.0; right hand width 2.5; right foot width 3.0.

Coloration of the holotype in life ( Fig. 3 A). According to the field notes of Enrique La Marca (August 7th, 1987), dorsal ground color dark with brownish stripes, and venter black mottled with light punctate gray.

Coloration of the holotype in 70% ethanol ( Fig. 3 B and C). The snout is reddish brown on the right and dorsal sides; the left side is more yellow and the area surrounding the nostrils is like the yellowish brown ground color. The head is reddish brown (except for the lids which are like the yellowish brown ground color), a coloration that extends through the vertebral region of the neck and the right flank above the insertion region of the limb; the rest shows the ground color. Dorsum is ground color, but alternates irregularly with the reddish brown tone, conferring the thoracic and sacral regions a “marbled” aspect with a predominance of the reddish brown hue on the right flank. Base of the tail is predominantly of the ground color and remains reddish brown on its right side. The entire dorsal-caudal region is solid reddish brown. In the ventral region the tips of the labial protuberances are ground color. Lips are reddish brown, and the rest of the body is ground color with some reddish brown dots in the gular region. The ventral-caudal region is ground color but lighter than the dorsal-caudal region. Dorsal coloration of limbs is reddish brown, except for the left hind limb and the digit tips which are ground color. Ventral coloration of limbs is predominantly yellowish brown with some reddish brown dots, except for hands and feet which are almost totally ground color.

Measurement variation in the type series. The typical sexual dimorphism of the genus was observed in terms of SVL, being females larger than males: the SVL mean for females was 40.3mm (n=7), while in males was 37.9 (n=12). Although SVL variation range between males and females overlap, the highest SVL value matches to a female (45.4mm). The highest SVL value for males was 40.6mm. Males are easily recognizable by the presence of the hedonic gland, absent in females. Females show a proportionally shorter tail (higher SVL/TL ratio) than males, although this character, considering males and females together, allows to differentiate B. mucuyensis sp. nov. from all other Venezuelan salamanders (except for B. orestes ; in the case of B. altamazonica , their comparison values were taken from specimens not collected in Venezuela since the only reported specimen of this species in the country, by Schargel & Rivas-Fuenmayor (2003), did not allow making further comparisons).

Coloration variation of the type series in life ( Fig. 3 D and E). The coloration pattern of these caudates is highly variable: some specimens are dark brown (almost black) in the dorsal region with some light brown spots, venter uniformly dark brown like the flanks and limbs, while others show light ochre dorsal stripes from head to tail on an otherwise dark brown ground color. It was also observed that some others can have light paravertebral spots that coalesce at the base of the tail, while the venter shows a solid light brown tone. Some specimens show a dorsal black line from the tail to the shoulders over the spine; flanks and venter dark brown. Finally, some specimens present a solid dark dorsum with two diffuse light brown spots and dark venter with some whitish dots.

Coloration variation of the type series in 70% ethanol. The coloration patterns of the animals preserved in ethanol and analyzed here show slight variations as compared to the general pattern described for the preserved holotype. Some specimens present a uniform dark brown dorsum from head to tail; flanks are uniformly light brown while the venter is even slightly lighter; fore and hind limbs present a degradation of brown tones, being darker at the region where the limbs join the trunk, and then vanish when approaching the distal regions. Other specimens have some dark brown dorsal stripes of a light ochre ground from head to mid body, or from there to the tail base; flanks can be uniformly light brown, or in some cases dark brown with some discontinuous more intense, colored stripes; venter uniformly light brown, like fore and hind limbs. In other salamanders a third coloration pattern is characterized by light ochre tones on the head and the mid region of the body with some dark ochre spots; the tail is solid dark brown; flanks with clear or uniform light ochre spots; venter uniformly light ochre with darker spots at the tail base and hind limbs. Finally, a group of specimens present in dorsal view dark brown tones from head to mid body; this color gradually turns lighter when approaching the base and distal region of the tail where it becomes uniformly light brown; flanks dark brown with some thin, dark brown lines; limbs solidly light brown; venter either solid dark brown like the flanks, or uniformly light brown with limbs light ochre at the distal end and dark brown at the proximal region.

None of the specimens analyzed here showed guanophores in the ventral region, nor laterally.

Distribution, some ecological data and natural history. We are only aware of specimens of this species, collected by different researchers at different times, in its type locality between 1870 and 2250 masl ( Fig. 1 C).

Specimens used for the designation of the typical series were collected during nocturnal samplings (between 21:00 and 23:00 hours) in places close to disturbed forest patches with some introduced species like Pinus sp., Eucalyptus sp., and secondary vegetation dominated by diverse Euphorbiaceae . Other amphibians found at the same site during collection times included Nephelobates cf. alboguttatus , Pristimantis vanadisae , Hyloscirtus platydactylus and Hyalinobatrachium duranti (data from La Marca, August 7th 1987). Other specimens have been found under mosses or in rotten logs.

A female (paratype CVULA IV-7099) showed 56 whitish eggs of different sizes, and the oviduct was straight (Díaz de Pascual et al. 2010). In the same study, stomach content was analyzed and the authors identified the presence of ants, pseudoscorpions, spiders, acari, beetles and isopods which might constitute a part of the diet of the salamander specimens found at the type locality.

Etimology. The use of the Latin suffix – ensis (‘native of’) in the specific designation of mucuyensis stresses the fact that the salamanders described here have only been found so far in La Mucuy (Mérida state). In the aboriginal language of the Timotes (Mérida state, Venezuela), ‘mucuy’ means “the place of waters”—which was also the name of a tribe, the Mucuyúes, that inhabited the sector known today as La Mucuy.

Figures

FIGURE 1. Type locality of Bolitoglossa mucuyensis sp. nov. (A) The type locality of the species is placed in the proximities of La Mucuy, Mérida state (white asterisk); the line oriented NW / SE is shown in ‘ B’ with more details. (B) Relief profile from south Lake Maracaibo, passing through Sierra La Culata and Sierra Nevada de Mérida with the homonymous city between them, to the Llanos of Barinas; modified from Vivas (2007). (C) A detailed depiction of La Mucuy in Sierra Nevada de Mérida, very close to the capital city of the state to the left (the type locality is shown with a white asterisk).

FIGURE 2. The original ML tree (1000 bootstrap pseudoreplicates) of the concatenated sequences of cytb + rRNA 16 S, showing the location of the related salamander species from Cordillera de Mérida (Mérida state) Bolitoglossa mucuyensis sp. nov. (Sierra Nevada de Mérida) and B. orestes (Sierra La Culata) was used to generate the 50 % supported tree shown here. The analysis was performed using the GTR model of nucleotide substitution. The tree is drawn to scale, with branch lengths measured in number of substitutions per site (968 sites). The vertical line to the right encompasses the species belonging to the group adspersa.

FIGURE 3. Bolitoglossa mucuyensis sp. nov. (A) Holotype in life (picture taken by Pascual J. Soriano). (B) Dorsal view of the preserved holotype and (C) Ventral view of the preserved holotype (pictures taken by Moisés Escalona). (D and E) Paratypes of B. mucuyensis sp. nov. (pictures taken by Pascual J. Soriano).

FIGURE 4. SVL vs TL plot (in mm) of the specimens of salamanders belonging to Bolitoglossa mucuyensis sp. nov. (red triangles), B. orestes (black triangles), B. altamazonica (orange circles), B. borburata (blue diamonds) and B. guaramacalensis (green squares). The mean of the SVL / TL individual ratios for each group of data (i. e., specimens of the same species) is shown inside the corresponding ovals.

FIGURE 5. Webbing of the front and hind limbs of the two species of salamanders present in Mérida state (Venezuela), Bolitoglossa Mucuyensis sp. nov. and B. orestes (pictures taken by Moisés Escalona).