Telmatobius ventriflavum, Catenazzi, Alessandro, Garcia, Victor Vargas & Lehr, Edgar, 2015

Catenazzi, Alessandro, Garcia, Victor Vargas & Lehr, Edgar, 2015, A new species of Telmatobius (Amphibia, Anura, Telmatobiidae) from the Pacific slopes of the Andes, Peru, ZooKeys 480, pp. 81-95 : 83-89

Taxon classification Animalia Anura Telmatobiidae

Telmatobius ventriflavum sp. n.

Holotype

(Figs 2-4). CORBIDI 14685, an adult male (Figs 2-4) from 13.5806 S, 75.2449 W (WGS84), Chicchobamba, upstream of Represa Negrayccassa, upper drainage of the Huaytará river, 3900 m, Provincia Huaytará, Región Huancavelica, Peru, collected by A. Catenazzi, V. Vargas García, and M. Jaico Huayanay on 18 October 2012.

Paratypes

(Fig. 2). Two females (CORBIDI 14684, 14686) collected at the type locality along with the holotype by A. Catenazzi, V. Vargas García and M. Jaico Huayanay on 18 October 2012.

Referred specimens.

Six juveniles (MUSM 12748-12750, 12752-12754) and one sub-adult female (MUSM 12755) collected near the type locality ( Huaytará; precise location, collector, and date unknown).

Diagnosis.

The new species is characterized by (1) snout–vent length of males to 48.5 mm, females to 52.9 mm; (2) head in profile moderately low, with rounded snout; (3) snout rounded in dorsal view; (4) lips not flared; (5) post-commissural gland present, small; (6) tympanum and tympanic annulus not visible; supratympanic fold present; (7) forelimb slender, males lack humeral crest and spine; (8) nuptial spicules minute, closely arranged; nuptial pad on dorsal and medial surface of thumb; no spicules on other fingers; (9) foot fully webbed; palmar and plantar surfaces smooth; (10) tarsal fold present; (11) dorsal skin smooth with small, flat pustules; (12) dorsal surfaces of body and legs golden yellow to golden tan mottled with dark brown, golden yellow and red spots; (13) ventral parts of body yellow, ventral surfaces of limbs marigold or orange; (14) iris light gray with fine black flecks, eye bordered by thin turquoise ring; (15) skull moderately flat, median head length ~78% of head width at the level of the quadratojugal-maxillary articulation, eye-to-nostril distance ~20% of head length.

Comparisons.

Telmatobius ventriflavum is readily distinguished from all other central Peruvian Andean species ( Telmatobius arequipensis , Telmatobius atahualpai , Telmatobius brachydactylus , Telmatobius brevipes , Telmatobius brevirostris , Telmatobius culeus , Telmatobius jelskii , Telmatobius latirostris , Telmatobius macrostomus , Telmatobius marmoratus , Telmatobius mayoloi , Telmatobius peruvianus , Telmatobius punctatus , Telmatobius rimac , and Telmatobius truebae ) but Telmatobius carrillae and Telmatobius intermedius by the absence of premaxillary and maxillary teeth. Furthermore, the species differs from Telmatobius carrillae by having vomerine teeth. The new species is readily distinguished from Telmatobius intermedius by its larger size reaching 55.7 mm in snout–vent length in females and 48.5 mm in males (45.0 mm in both sexes of Telmatobius intermedius ), flatter head, the absence of cutaneous keratinized spicules (spicules on dorsal surfaces of skin even in immature females), and in males by the presence of minute, densely packed nuptial spines on dorsal and medial surfaces of thumbs (Fig. 3: large, sparsely packed nuptial spines on dorsal, medial and ventral surfaces). The morphologically similar Telmatobius peruvianus is distinguished by having pre-maxillary teeth, skin of dorsum rugose, and by males having large and scattered nuptial spines on thumbs, and keratinized spicules on chest, throat, lower jaw, forearms, hind limbs, and sometimes dorsum. Another species found in coastal river valleys, Telmatobius rimac has a much larger body size (to 70.5 mm in males and 86.9 mm in females, Lehr 2005), robust body and limbs, ventral coloration of body brown and of limbs yellow. Males of Telmatobius arequipensis have nuptial spines on fingers I and II. The other Telmatobius species known to occur in Región Huancavelica, Telmatobius jelskii has larger body size (to 68.6 mm in males and 84.7 mm in females), large and conical nuptial spines on thumb and spines on chest and throat in males, and ventral coloration white or light gray, with yellow-orange blotches on hindlimbs.

Description of holotype.

An adult male with a SVL of 48.5 mm; body slender; head slightly wider than long, its length 31.5% of SVL; head width 34.6% of SVL; head length 91.1% of head width. Head flat; snout rounded in lateral and dorsal views; nostrils not protuberant, oriented dorsally; internarial distance 20.2% of head width; nostrils closer to margin of orbit than to tip of snout; internarial region slightly convex; eye large, 30.7% of head length; loreal region moderately concave; lips not flared; tympanum and tympanic annulus indistinct; supratympanic fold well developed, extending from behind eye to level of shoulder; distinct dermal fold from supratympanic fold to post-commissural gland; post-commissural gland small, oval. Maxillary and premaxillary teeth absent; dentigerous processes of vomers between choanae, each bearing two small, fanglike teeth; choana width 1.6 mm, subcircular; tongue rounded, attached anteriorly through about one third of its length; vocal slits absent.

Forelimb slender; humeral crest absent (Fig. 4A); relative lengths of fingers: I = II <III> IV (Fig. 4A); Finger II notably shorter than Finger IV; palmar webbing absent; tips of fingers spherical; fingers lacking lateral fringes; inner palmar (prepollical) tubercle oval, distinct; outer palmar tubercle slightly larger than inner, oval; subarticular tubercles rounded; five or six rounded supernumerary palmar tubercles, palmar surface smooth; nuptial excrescence on medial surface of thumb, composed by minute, keratinized, brown spicules closely arranged, forming a pad in contact with inner palmar tubercle posteriorly; keratinized spicules not covering surfaces of Finger II. Hind limbs long and slender; tibia length 50.7% of SVL; foot length 55.7% of SVL, combined lengths of tibia and foot 106.4% SVL; upper surfaces of hind limbs smooth; relative lengths of toes: I <II <III <IV> V (Fig. 4B); Toe V slightly longer than Toe III; toes fully webbed; tips of toes spherical, about the same size of those of fingers; inner metatarsal tubercle moderately flattened, oval; outer metatarsal tubercle round, about two-thirds the size of inner metatarsal tubercle; subarticular tubercles round or slightly oval; four supernumerary tubercles small and rounded, plantar surface smooth.

Skin on dorsum smooth with small, flat pustules; keratinized spicules or spines absent; loose folds of skin absent; ventral skin smooth; cloacal opening approximately at dorsal level of thighs.

Measurements of holotype provided in Table 1.

Coloration of holotype in alcohol.

Dorsal surfaces of head, body, and limbs grayish-brown, with dark spots discernible on dorsum; spots that are golden yellow and red in life discernible as light grey spots; throat and venter light yellowish-gray; ventral surfaces of limbs tan yellow with yellowish-gray spots; plantar and palmar surfaces gray; tips of digits cream.

Coloration of holotype in life.

Dorsal surfaces golden tan mottled with dark brown, golden yellow and red spots especially on scapular region and on head; flanks tan yellow; throat and venter golden yellow to marigold, fading into depigmented spots on chest; ventral surfaces of limbs at points of insertion quickly transitioning from tan yellow or marigold to orange distally and posteriorly; iris light gray with fine black flecks; eyes bordered by a thin turquoise ring.

Variation.

Coloration in life is based on field notes and photographs taken by A. Catenazzi (Fig. 2) of six females (the two paratypes and four uncollected females) and one male (the holotype) found at the type locality. The only captured male is smaller than females (Table 1) and weighted 13.6 g. The SVL of females averaged 52.5 ± 1.1 mm (49.3-55.7 mm), whereas their weights averaged 16.2 ± 1.3 g (11.5-19.7 g). A juvenile with 43.4 mm in SVL weighed 8.4 g. Some individuals (e.g., paratype CORBIDI 14686, Fig. 2E) had much lighter, predominantly golden yellow dorsal coloration than the holotype, whereas most individuals (e.g., paratype CORBIDI 14684, Fig. 2C) had dorsal mottling similar or darker than the coloration of the holotype. The ventral coloration seemed to vary with sex. Whereas the male had extensive and bright marigold to orange coloration on the ventral parts of the limbs, in females such coloration was more suffused, and much of the ventral parts of the limbs presented the same yellow coloration of venter and throat. In all captured individuals the irises were light grey and the eyes were surrounded by a thin turquoise ring.

Etymology.

The specific name ventriflavum is derived from Latin nouns venter, meaning belly, and flavus, meaning yellow. The species epithet refers to the golden yellow and orange coloration on the ventral parts of the body and limbs.

Distribution, natural history, and threats.

The new species is only known from the type locality (Fig. 5), a stream tributary of the Huaytará river, which is in the upper drainage of the Pisco river watershed. The Pisco watershed drains directly into the Pacific Ocean, and is dominated by arid and hyper-arid environments, especially at elevations below 3000 m. The habitat surrounding the type locality at 3900 m is sparse puna. Rainfall is concentrated during the months from January to March, with very little precipitation occurring during the remaining months. The type locality is a stream ~10 m wide, with a rocky substrate that alternates pebble and gravel pools with small waterfalls and riffles. However, 500 m downstream of the type locality, the stream has been dammed to build a reservoir. The habitat downstream of the reservoir is not suitable to Telmatobius , although the reach was not inspected during our visit. The reach upstream of the type locality has not been surveyed and extends up to 4300 m in elevation. This reach appears to be in good condition and could be used by the species for reproduction.

The valley of the type locality and adjacent central Peruvian coastal valleys are dominated by arid environments that likely limit dispersal of the species. Therefore, and considering that other species ( Telmatobius rimac to the north, and Telmatobius intermedius to the south) are known from nearby coastal regions, it is very likely that the new species is endemic to the upper Pisco watershed and adjacent river basins. It is unknown whether the species overlaps geographically with Telmatobius rimac or Telmatobius intermedius , or with the highland species Telmatobius jelskii which occurs in the adjacent Región Ayacucho. During the visit on 18 October 2012, three observers searched 100 m of the stream reach during 60 minutes (search effort of 180 person-minutes), and encountered 43 tadpoles, one juvenile, 6 females and one male. The tadpoles were in developmental stages 25 to 45 (following Gosner 1960), suggesting that the species is breeding successfully over extended periods of time including during the dry season (October is at the end of the dry season when stream levels are low).

We detected the presence of the pathogenic fungus Batrachochytrium dendrobatidis Longcore, Pessier & Nichols, 1999 at the type locality. The prevalence of infection during our visit on 18 October 2012 was 53.5% for tadpoles (n = 43) and 40.0% for adults (n = 5); the only juvenile found was infected. Among tadpoles, prevalence was 23.1% for larval stages (Gosner stages 25 to 39, n = 13), and 66.7% for pre-metamorphic stages (Gosner stages 40 to 45, n = 30). Among infected individuals, infection loads were very small for adults and the juvenile (0 <ze <1 zoospores), and ranged from 1.6 to 2162.4 zoospores for tadpoles (average ze = 177.3 ± 66.4 zoospores; median = 76.1 zoospores).