Dendrophryniscus oreites, Recoder, Renato Sousa, Junior, Mauro Teixeira, Cassimiro, José, Camacho, Agustín & Rodrigues, Miguel Trefaut, 2010

Recoder, Renato Sousa, Junior, Mauro Teixeira, Cassimiro, José, Camacho, Agustín & Rodrigues, Miguel Trefaut, 2010, A new species of Dendrophryniscus (Amphibia, Anura, Bufonidae) from the Atlantic Rainforest of southern Bahia, Brazil, Zootaxa 2642, pp. 36-44 : 37-41

Dendrophryniscus oreites sp. nov.

( Figs. 1 , 2 , and 3)

Holotype. MZUSP 142493, M.T. Rodrigues field number MTR 16368, adult male, collected in “Parque Nacional de Serra das Lontras (a national park) (15o 09' 41" S, 39o 20' 38" W; datum WGS 84; ca. 850 m a.s.l.), Municipality of Arataca, State of Bahia, Brazil; 6 March 2009, collected by A. Camacho, J. Cassimiro, M. Teixeira Jr. and R.S. Recoder.

Diagnosis. The new species is assigned to Dendrophryniscus by the following suite of characters: small size, habitus atelopodiform, hind limbs well developed (THL+TL/SVL> 0.80), parotoid glands absent, cranial crests indistinct, external tympanum absent, vocal slits absent, foot basally webbed, relative toe length I<II<III<V<IV, and skin uniformly granulose.

The new species is diagnosed from other Dendrophryniscus spp. by: (1) large size for the genus (SVL 25.0 mm); (2) elongate body; (3) snout largely pointed and truncate in dorsal view; (4) thumb short and robust; (5) presence of a dark nuptial pad in males; (6) toe tip of fourth finger expanded; (7) presence of transversely elliptical subarticular tubercles on hands; (8) hands not webbed; (9) highly granulose body surfaces, with numerous rounded warts; (10) colour in life pale yellow, with a discrete dorsal pattern; (11) use of epiphytic bromeliad as perch site.

Description of holotype. Body small, elongate ( Figure 2 ); head triangular, longer than wide. Head length 37% of SVL. Snout pointed and truncate in dorsal view, acute in profile ( Figure 3 ). Nostrils located near the tip of the snout, laterally and slightly below canthus rostralis in dorsal view. Internarial distance smaller than eye diameter, eye-to-nostril distance, and interorbital distance, and slightly smaller than upper eyelid width. Eye-to-nostril distance slightly smaller than eye diameter, smaller than interorbital distance and larger than upper eyelid width, and about two thirds of the eye-snout distance. Canthus rostralis straight, and loreal region vertical. Eye diameter about 70% of the interorbital distance, upper eyelid about 55% of the interorbital distance. Tympanum absent. Tongue long, narrow and free in the anterior half, with posterior margin rounded. Choanas small and circular, maxillary and palatine teeth absent. Vocal sac and vocal slits absent. Dorsal surface of body highly granulose, with numerous large rounded warts irregularly distributed. Warts forming lines or clusters of enlarged granules in the dorso-lateral region, sacral region and nuchal region. Ventral and lateral surfaces highly granulose, but with shallow and smaller warts. Forelimbs long. Forearms longer and more robust than arms. Hands with slender fingers, not webbed and not fringed, with distal end slightly enlarged and truncate, without discs. Inner finger short and robust, with a distinct dorsal dark nuptial pad. Relative lengths of fingers: II<III<V<IV. Subarticular tubercles single, globular and transversally ovoid; supernumerary tubercles present; outer metacarpal tubercle globular, large and rounded; inner metacarpal tubercle small and ovoid, with size correspondent to the basal subarticular tubercles. Ventral and lateral surfaces of forelimbs highly granulose. Hind-limbs slender, thigh length just slightly larger than tibia length. Sum of thigh and tibia length about 85% of SVL. Tarsal length 25% of SVL. Foot with slender toes, basally webbed, not fringed, distal end rounded, slightly enlarged, without discs. Relative lengths of toes: I<II<III<V<IV. Subarticular tubercles single and rounded; supernumerary tubercles and accessory plantar tubercles present; inner metatarsal tubercle large and elliptical, outer metatarsal tubercle small and ovoid. Ventral and lateral surfaces of hind-limbs granulose.

Colour of the holotype. General colour in life yellow to yellowish-brown, lighter on ventral surfaces. Dorsum with a darker X-shaped blotch on the scapular region, and two posteriorly diverging chevron-like diagonal bars with the same colour, extending transversally from sacral region to hind limbs. Presence of a less evident longitudinal band in the dorsolateral regions. In preservative, tan or pale brown dorsal colour, lighter in ventral surfaces.

Measurements of holotype. SVL 25.00; HL 9.15; HW 7.42; IND 2.01; ESD 3.92; END 2.65; ED 2.75; IOD 3.80; UEW 2.10; THL 10.67; TL 10.38; TAL 6.23; FL 9.53; UAL 4.85; FAL 5.90; HL 6.70.

Comparisons. Dendrophryniscus oreites sp. nov. is distinguished from D. minutus and D. bokermanni by (features of compared taxa in parentheses): presence of expanded tip on fourth finger (tip not expanded); inner finger reduced (slightly reduced or longer than third finger); presence of transversely elliptical subarticular tubercles (longitudinally elliptical subarticular tubercles); and ventral surfaces pale coloured (ventral bright coloured with pattern of blotches or ocelli). Dendrophryniscus oreites sp. nov. is distinguished from the remaining Dendrophryniscus species by: larger size (male size less than 22 mm), body surfaces with numerous enlarged warts (body with small warts to finely granular), and yellowish coloration with a discrete dorsal pattern (greyish to brownish colour, with a well defined dorsal pattern in most species). Furthermore, Dendrophryniscus oreites sp. nov. is distinguished from D. brevipollicatus by having a fourth finger less expanded, with tip width corresponding to 1.33 times the width at the middle of the finger (tip width 1.53 + 0.1 of width at the middle, N=12), and palms of hands without grooves (palms with grooves); from D. leucomystax by the absence of a white stripe on lips (present); from D. carvalhoi by the dark coloration of nuptial pads in males (unpigmented); from D. berthalutzae by presenting a reduced inner finger with nuptial pads in males (inner finger slightly reduced, with nuptial pads indistinct), and no distinct subrostral crests on snout (subrostral crests present); from D. stawiarskyi by the presence of a dark nuptial pad in males (absence of nuptial pads); and from D. krausae by having an elongate body (body robust and slightly enlarged posteriorly).

Distribution and natural history. Dendrophryniscus oreites sp. nov. is known solely from the type locality, Parque Nacional de Serra das Lontras, in the Atlantic Forest of the southern portion of the state of Bahia ( Figure 4 ). This is the northernmost record for the genus in the Atlantic Forest domain (extending ca.

540 km north of Santa Teresa, state of Espírito Santo, where D. carvalhoi occurs), and the only species known for the state. The single specimen was collected perching on a leaf of an epiphytic bromeliad, 1.2 to 1.5 meters high, at the border of a trail, between 12:00 pm and 13:00 pm. When approached, the individual hid within the sheaths of the leaves of the bromeliad. The habitat consisted of a steep and tall rainforest, with closed canopy, at the slope of a hill, about 850 m a.s.l. ( Figure 5 ). Bromeliads and palms were abundant at the site, as well as mosses and lichens covering trunks and fallen logs. Dense leaf-litter covered the soil. Near the summit (950 m a.s.l.) the vegetation becomes lower, with several thin-trunk small trees. At this altitude there is almost no soil, and the vegetation grows on a tangle of leaves, roots and peat. Neither the call nor the tadpole of the new species are known.

Etymology. The specific epithet is a noun in apposition from the Greek word oreites which means mountaineer. It is a reference to the locality of the holotype, a steep forest on the slope of a hill summit. Although the species may occur through lowland forests, it is more likely that the species would persist at mountainous forests in the future, due to the current high rates of vegetation conversion in lowlands of the Atlantic Rainforest.

Remarks. Based on hand morphology (expanded toe tips, reduced inner finger, and transversely elliptical subarticular tubercles), body colour (pale ventral colour), ecology (use of epiphytic bromeliads as perch site) and geography, Dendrophryniscus oreites sp. nov. appears to be more related to the Atlantic Forest brevipollicatus group than to Amazonian species.

Figures

FIGURE 1. Dendrophryniscus oreites sp. nov., holotype (MZUSP 142493) in life, adult male from Parque Nacional de Serra das Lontras, municipalities of Una and Arataca, state of Bahia, Brazil. Photo by Mauro Teixeira Jr.

FIGURE 2. Dendrophryniscus oreites sp. nov. (Holotype, MZUSP 142493, SVL 25.0 mm), dorsal and ventral views.

FIGURE 3. Dendrophryniscus oreites sp. nov., holotype, MZUSP 142493. Left: ventral view of hand (up) and foot (bottom). Right: lateral view of head (up), and dorsal view of the head (bottom). Dark scale bar represent 1 mm.

FIGURE 4. Geographic distribution of Dendrophryniscus oreites sp. nov. in the context of its congeners. Blue dots: distribution of formerly known species in the genus; star: type locality of D. oreites sp. nov.

FIGURE 5. Habitat and landscape where the new species was found. Upper left: rain forest habitat at the slope of the Peito de Moça hill, at 850 m a. s. l. Upper right: the Peito de Moça hill (to 950 m a. s. l.), placed at Parque Nacional de Serra das Lontras, municipalities of Una and Arataca, state of Bahia. Bottom: panoramic view of the landscape in the surroundings of the type locality, showing the typical undulating relief of southern Bahia. Photos by Mauro Teixeira Jr.