Oreobates sanderi, (PADIAL ET AL., 2005)

Padial, José M., Chaparro, Juan C. & Riva, Ignacio De La, 2008, Systematics of Oreobates and the Eleutherodactylus discoidalis species group (Amphibia, Anura), based on two mitochondrial DNA genes and external morphology, Zoological Journal of the Linnean Society 152 (4), pp. 737-773 : 763

OREOBATES SANDERI (PADIAL ET AL., 2005)

Ischnocnema sanderi Padial et al., 2005

Oreobates sanderi – Caramaschi & Canedo (2006) ( Fig. 3N)

Ischnocnema sanderi Padial, Reichle, & De la Riva, 2005: 187 . Holotype: CBF 5385 . Type locality: ‘Arroyo Bilunto (14°38′24″S, 68°31′45″W), Chunirumi Valley , Bilunto Mountains, Área Natural de Manejo Integrado Madidi, near Santa Cruz de Valle Ameno, Province Franz Tamayo, Departament La Paz, Bolivia, 1800 m’ ( Fig. 4 ).

Diagnosis: A medium-sized Oreobates (SVL of adults, 28–38 mm) characterized as follows: (1) skin of dorsum granular, with round keratinized granules and small, sparse, low, flat warts, only some of them slightly enlarged; warts on flanks slightly larger than those of dorsum; occipital W-shaped fold and/or x-shaped fold on mid-dorsum; venter smooth; posterior surfaces of limbs smooth, groin areolate; discoidal fold present; dorsolateral folds weak; large postrictal glands; (2) tympanic membrane and annulus distinct, both with length of about half of the eye length; supratympanic fold weak, short; (3) head large, as wide as long; snout short, round in dorsal and lateral views; canthus rostralis slightly convex or sinuous in dorsal view, round in profile; (4) cranial crests absent; upper eyelid covered by small warts; (5) dentigerous process of vomers large, oblique, almost in contact, situated posteromedial to choanae; (6) males with vocal slits and nuptial pads; (7) hands with long and slender fingers, first finger longer than second; subarticular tubercles large, prominent, round to conical; supernumerary tubercles large or small, round to conical, smaller than subarticular tubercles; tips of fingers III and IV round, not enlarged, lacking circumferential grooves and ungual flap; lateral fringes and keels weak; (8) ulnar tubercles absent; (9) no tubercles on heel or tarsus; (10) inner metatarsal tubercle ovate, prominent; outer metatarsal tubercle smaller, round, prominent; supernumerary tubercles conspicuous, conical; (11) toes long and slender (foot length 50% of SVL), lateral fringes weak or absent, webbing absent; tips of toes round, with ungual flap not indented; (12) axillary glands present; (13) dorsal coloration pale brown to dark brown with cream flecks, sometimes with W-shaped occipital and/or mid-dorsal X-shaped dark marks, or a pair of cream dorsolateral stripes and a short longitudinal sacral stripe; throat and chest cream with fine brown mottling; belly cream with brown mottling or reticulations on anterior margin.

Among the medium-sized and large species of Oreobates , O. sanderi is most similar to O. granulosus , from which it can be distinguished by having conspicuous supernumerary tubercles (weak or absent), shorter feet, FL/SVL = 50% (50–60%), and incipient dorsolateral folds (absent). It can be distinguished from small species of Oreobates by the combination of keratinized granules on dorsum, and fingertips round and not enlarged.

Remarks: The original description and diagnosis are accurate ( Padial et al., 2005a). For distinguishing this species from other members of Oreobates see the operational key below. Its advertisement call is unknown.

Distribution: Oreobates sanderi inhabits the humid montane forests and cloud forests of the Andean slopes of northern Bolivia, in Department La Paz, at elevations of 1300–2000 m a.s.l. ( Figs 4 , 5 ). Two specimens from Department Puno, Peru, one from Abra de Maruncuna, 10 km south-west of San Juan del Oro, 1650 m a.s.l. ( KU 206101 ), and one from Juliaca (AMNH 6063; locality in error given that Juliaca lies in the dry Altiplano – this specimen was probably sent to Juliaca from somewhere else in the humid montane forests of Department Puno, Peru), are tentatively assigned to this species.

Figures

Figure 4. Type localities of members of Oreobates: (1) O. quixensis, San José de Moti, Prov. Napo, Ecuador; (2) O. simmonsi, Río Piuntza, 1830 m a.s.l., Cordillera del Cóndor, Prov. Morona-Santiago, Ecuador; (3) O. saxatilis, Ponga de Shilcayo, 470 m a.s.l., Department San Martín, Peru; (4) O. lehri, Apurimac River Valley, 2445 m a.s.l., Department Cusco, Peru; (5) O. granulosus, Santo Domingo, Carabaya, Department Puno, Peru, 1800 m a.s.l.; (6) O. madidi, Arroyo Huacataya, Serranía Eslabón, 1500 m a.s.l., Department La Paz, Bolivia; (7) O. sanderi, Arroyo Bilunto, Chunirumi Valley, 1800 m a.s.l., near Santa Cruz de Valle Ameno, Department La Paz, Bolivia; (8) O. zongoensis, Valle de Zongo, 1250 m a.s.l., Department La Paz, Bolivia; (9) O. choristolemma, Serranía de Bellavista c. 1000 m a.s.l., Department La Paz, Bolivia; (10) O. cruralis, Department La Paz, Bolivia, 4000 m a.s.l. (in error); (11) O. heterodactylus, gruta Facendinha, State Mato-Grosso, Brazil; (12) O. ibischi, km 68.5 on Santa Cruz de la Sierra-Samaipata road c. 750 m a.s.l., Department Santa Cruz, Bolivia; (13) O. sanctaecrucis, El Chapé, Department Santa Cruz, Bolivia, 2060 m a.s.l.; (14) O. discoidalis, Tucumán, Prov. Tucumán, Argentina.

Figure 5. Altitudinal distribution across habitat types of members of the genus Oreobates.