Centrolenidae

Guayasamin, Juan M. & Funk, Chris, 2009, The amphibian community at Yanayacu Biological Station, Ecuador, with a comparison of vertical microhabitat use among Pristimantis species and the description of a new species of the Pristimantis myersi group, Zootaxa 2220, pp. 41-66 : 43-46

Family: Centrolenidae

Glassfrogs have a Neotropical distribution and are particularly diverse in the northern Andes. All centrolenids have a partial or complete ventral transparency, a dilated medial process on Metacarpal III, and deposit their eggs out of water (usually on the upper or under sides of leaves; Hayes & Starrett 1980; Ruiz-Carranza & Lynch 1991; Guayasamin et al. 2009). They are usually found at night on vegetation along streams when reproducing. Herein, we follow the taxonomy proposed by Guayasamin et al. (2009) that recognizes 12 genera and 147 species within Centrolenidae . In YBS, there are five identified ( Centrolene bacatum , C. buckleyi , Nymphargus posadae , N. siren , N. wileyi ) and two unidentified ( Centrolene sp, Cochranella sp) species of glassfrogs.

guacamayo

Rhinella margaritifera 2000 –2200 Open pasture, Small ponds, ditches, 3/4/2/0/1 Nocturnal

disturbed habitat and pools in pasture

Centrolenidae Centrolene bacatum 2000 –2200 Primary forest and Leaves 1/9/0/0/0 Nocturnal

bamboo along streams

Centrolene buckleyi 2000 –2200 Primary forest along Leaves 0/2/0/0/1 Nocturnal

streams

Centrolene sp 1 2100 Primary forest along Leaves 0/3/0/0/0 Nocturnal

streams

Cochranella sp 1 2100 Primary forest along Leaves 1/0/0/0/0 Nocturnal

streams

Nymphargus posadae 2000 –2200 Primary forest along Ferns, leaves 1/3/0/0/0 Nocturnal

streams

Nymphargus siren 2100 Primary forest along Leaves 0/2/0/0/0 Nocturnal

streams

Pristimantis eriphus 2000 –2300 Primary and secondary Leaves, ferns, 10/ 3/9/14 / Nocturnal

forest bromeliads 27

Pristimantis cf. eriphus 2000 –2200 Primary and secondary Leaves 0/1/1/0/1 Nocturnal

forest

Pristimantis inusitatus 2000 –2200 Primary and secondary Leaves, ferns 10/7/ 2/2/14 Nocturnal

forest

Pristimantis gladiator 2270 –2500 Primary forest Low vegetation, 0/0/0/0/2 Nocturnal

forest floor

Pristimantis leucopus 2000 –2200 Primary forest High leaves above 1/2/0/0/0 Nocturnal

streams

Pristimantis cf. petersi 2000 –2200 Primary forest Leaves and low 7/ 6/9/49 /27 Nocturnal

vegetation

Pristimantis w-nigrum 2000 –2200 Pasture, forest edge, Hidden in grass in 0/7/3/7/8 Nocturnal

secondary and primary pastures, forest floor,

forest low vegetation

Pristimantis sp 1 2000–2200 Primary forest Low vegetation 0/0/0/36/0 Nocturnal Caeciliidae Caecilia orientalis 2100 Pasture and secondary Fossorial, under 1/3/0/1/2 Unknown

forest rotten logs, comes to

surface during hard

rains

Centrolene bacatum (Plate 1). Described by Wild (1994). This species is easily distinguished from other amphibians in YBS by having a green dorsal coloration with few white tubercles, some of which form a line that extends from below the eye to the insertion of the arm ( Wild 1994; Guayasamin et al. 2006a). As all species included in the genus Centrolene , C. bacatum has a venter that is posteriorly translucent. Also, adult males of this species have a humeral spine (absent in all Nymphargus species, except N. grandisonae and some individual in N. griffithsi , both species found on the western slope of the Andes). Centrolene bacatum is smaller than C. buckleyi [25.3–30.5 mm (n = 23) in adult males of C. buckleyi ]. In YBS, SVL in C. bacatum males, 19.3–21.8 mm (n = 11); SVL = 20.4 mm in one adult female. Active, calling males of Centrolene bacatum are frequently heard in YBS during the night; however, they usually call from areas close to the canopy; females deposit the egg masses on the upper and undersides of leaves, in vegetation along streams.

Centrolene buckleyi (Plate 1). — Described by Boulenger (1882). Among the glassfrogs found at YBS, Centrolene buckleyi is easily distinguished by having green dorsal surfaces sharply demarcated laterally from white lower flanks, a humeral spine (in males), white upper lip, a moderate adult size (SVL in males 25.3– 30.5 mm; in females 29.8–34.4 mm) and a sloping snout in lateral profile ( Guayasamin et al. 2006a).

Remarks: Genetic analyzes suggests that Centrolene buckleyi represents a species complex ( Guayasamin et al. 2008), a hypothesis that needs further examination with a dense sampling in Ecuador and Colombia.

Nymphargus posadae (Plate 2). — Described by Ruiz-Carranza and Lynch (1995). This species can be differentiated from other glassfrogs by lacking webbing between fingers, lacking humeral spines, having a green dorsum with small greenish-white warts, and by having a white upper lip, and a white line on the ventrolateral border of arm, Finger IV, tarsus and Toe V ( Guayasamin et al. 2006a). Nymphargus posadae is differentiated from Centrolene buckleyi and C. bacatum mainly by lacking humeral spines, which are present in the adult males of the two Centrolene species. Also, N. posadae lacks webbing between fingers, whereas there is some webbing between the two externalmost fingers of C. bacatum and C. buckleyi . At YBS, there are two additional glassfrogs that belong to the genus Nymphargus (i.e., N. siren and N. wileyi ). These three species share the absence of webbing between fingers. Nymphargus siren differs from the other two species (and any other amphibian in YBS) by presenting small yellow spots on the dorsum, whereas N. wileyi has a uniform green dorsum (in N. posadae , green dorsum with small greenish-white warts). SVL in males is 30.7– 34.1 mm (x = 32.3, n = 6); in females 30.2–33.3 mm (x = 31.4, n = 4).

Remarks: Males of Nymphargus posadae collected in YBS are smaller (SVL = 30.7–31.9 mm, n = 3) than Colombian specimens (SVL = 32.7–34.1 mm, n = 3; Ruiz-Carranza & Lynch 1995; Guayasamin et al. 2006a).

Nymphargus siren (Plate 2). — Described by Lynch and Duellman (1973). In YBS, this glassfrog is the only amphibian that has a green dorsum with small yellow spots. Additionally, N. siren lacks webbing between fingers, lacks humeral spines, and is relatively small (SVL <22.0 mm). Nymphargus siren seems to be a rare species in YBS; only two males have been found during the two years of surveys.

Nymphargus wileyi (Plate 2). — Described by Guayasamin et al. (2006a). Nymphargus wileyi differs from other Glassfrogs by having a uniform green dorsum, white renal peritoneum, and by lacking membranes between Fingers III and IV. In adult males, SVL 23.4–26.5 mm (x = 24.6; n = 11); 25.1–28.1 mm in adult females (x = 26.3; n = 4).