Melanophryne barbatula, Lehr & Trueb, 2007

Lehr, Edgar & Trueb, Linda, 2007, Diversity among New World microhylid frogs (Anura: Microhylidae): morphological and osteological comparisons between Nelsonophryne (Günther 1901) and a new genus from Peru, Zoological Journal of the Linnean Society 149 (4), pp. 583-609 : 588-592

MELANOPHRYNE BARBATULA SP. NOV.

FIG. 5

Holotype: MHNSM 19904 , male, collected in 1994 at Parque Nacional Yanachaga-Chemillen, at approximately 2500 m, Distrito de Oxapampa , Provincia de Oxapampa, Departamento de Pasco, Peru, by J. Icochea.

Paratypes: MHNSM 19903 (female, cleared-andstained) , MHNSM 19905 (male) , MTD 45944 (female) , MTD 45945 (male), all collected with the holotype .

Diagnosis: (1) Female SVL to 27.0 mm, male SVL to 24.9 mm. (2) Females with spines only in region of tympanum; males with spines on ventral surface of lower jaw, dorsal and lateral surfaces of head, dorsum, body flanks, dorsal surface of upper arms, on ventral surface on tarsus, on lateral surface of Toe V, and ventral surface of Toe V; vocal sac and vocal slits absent, large nuptial pad present. (3) Dorsal skin of males and females smooth except for regions covered by spines. (4) Dorsum and venter uniform brown and lacking pattern. (5) Tongue oval. (6) Terminal phalanges Y- shaped; prominent heterotopic cartilage at tibiofibular-tarsal joint; eight presacral vertebra with Presacrals I and II separate; clavicles straight, narrow and not reaching coracoids. (7) Hyoid corpus flat, lacking projections. (8) Laminar nasal bone present.

Description of holotype: Adult male ( Fig. 5 ); SVL 23.7 mm; tibia length 9.2 mm; foot length 10.8 mm; head length 7.6 mm; head width 8.5 mm; eye diameter 2.2 mm; interorbital distance 2.8 mm; upper eyelid width 1.9 mm; internarial distance 1.8 mm; eye– nostril distance 1.8 mm. Ventral skin smooth, dorsal skin with numerous small (0.05 mm in diameter) conical, white spines; large conical spines (up to 0.25 mm in diameter and 0.15 mm in height) on ventral surface of lower jaw ( Fig. 6A ), dorsal and lateral surfaces of head, dorsum, body flanks, dorsal surface of upper arms, on ventral surface of tarsus, on lateral surface of Toe V, and ventral surface of Toe V. Head nearly as broad as body; occipital fold absent. Snout truncate in dorsal and lateral profiles ( Fig. 6B ); nostrils positioned laterally close to tip of snout, equidistant from each other and from the eyes; loreal region nearly vertical, slightly concave; supratypmanic fold moderate, extending to insertion of arm, broad and thick above arm insertion; canthus rostralis slightly angular; eyes relatively large, eye diameter 29% of head length; width of upper eyelid 68% of interorbital distance; pupil round in preserved specimen. Tympanic annulus and tympanic membrane absent. Tongue large, oval, posterior half free. One palatal ridge visible when mouth open. Relative lengths of fingers: IV> V> III> II; digital tips rounded, flattened and slightly expanded, terminal grooves, lateral fringes and webbing absent; subarticular tubercles prominent, round, elevated; inner metacarpal tubercle ovoid, elongate, elevated, one-third size of outer metacarpal tubercle; outer metacarpal tubercle ovoid, elongate, elevated ( Fig. 7 ); prominent nuptial pad covering dorsal surfaces of Fingers II, III and inner dorsolateral surface of Finger IV ( Fig. 8A ). Relative lengths of toes: IV> III> V> II> I, tips rounded, flattened and slightly expanded, terminal grooves and lateral fringes absent, webbing basal; subarticular tubercles prominent, ovoid, elongate, more prominent on Toes II and III than on others; inner metatarsal tubercle prominent, oval, elevated; outer metatarsal tubercle absent ( Fig. 7 ); prominent heterotopic cartilage at tibiofibular-tarsal joint ( Fig. 9 ).

Coloration of holotype in preservative: Dorsal, lateral and ventral surfaces dark brown with no pattern. Conical spines white to pale grey. Nuptial pad pale brown.

Coloration of holotype in life: Unknown.

Variation: No variation in respect to coloration and external morphology was observed. For variation in meristic characters, see Table 2.

Etymology: The specific name barbatula is the diminutive of the Latin word barbatus, meaning bearded. The name is used in reference to the large spines of the ventral surface of the lower jaw, which resemble a beard.

Remarks: Chromosome number, call, and tadpole unknown.

Distribution and ecology: Melanophryne barbatula is known only from Parque Nacional Yanachaga- Chemillén, which is located in the valley of the Río Palcazu in the Amazon Basin of central Peru. The park is 122 000 ha in area and consists primarily of the Cordillera de Yanachaga, which reach an elevation of 3643 m. On the eastern side of the park, the Cordillera de Yanachaga descends gradually into the valley of the Río Palcazu. On the western flank, the Cordillera de Santa Barbara reaches an elevation of 3400 m and is separated from the Cordillera de Yanachaga by the deep Huancabamba Canyon. The zoological collection of the Parque Nacional Yanachaga-Chemillén administration (INRENA) contains one unnumbered specimen of M. barbatula collected along with specimens of Eleutherodactylus sagittulus Lehr, Aguilar & Duellman at San Alberto (c. 10°32′53″S, 75°22′17″W, 2200 m).

The ovary of MHNSM 19903 contained 22 pigmented eggs with an average diameter of 1.6 ± 0.09 mm (n = 10).

One stomach of Melanophryne barbatula (MHNSM 19903) contained arthropods belonging to the following families: Blattelidae , Carabidae , Cryptorhynchinae, Galumnidae , Oribatidae and Formicidae , and an unidentified insect larva. The arthropod composition indicates a leave litter habitat for M. barbatula .

Figures

Figure 5. Adult male Melanophryne barbatula (MHNSM 19904, holotype) in dorsal (A) and ventral (B) views. Photos by F. Höhler.

Figure 6. Ventral (A) and lateral (B) views of head of adult male Melanophryne barbatula (MHNSM 19905) to show distribution of spines on head.

Figure 7. Ventral views of hand (A) and foot (B) of Melanophryne barbatula (MHNSM 19005). omt, outer metatarsal tubercle.

Figure 8. Dorsal views of hand of (A) male Melanophryne barbatula (MHNSM 19904) and (B) female M. barbatula (MTD 45944).

Figure 9. Prominent heterotopic cartilage at tibiofibular– tarsal joint (heel) in Melanophryne barbatula (MHNSM 19903, A, right heel; B, left heel with skin removed).