Osteocephalus mimeticus

This frog has been confused many times since its description. One reason may be the fact that the type specimens are juvenile frogs with rows of bold paravertebral spots on the dorsum lacking many characteristic features of adult male Osteocephalus. Trueb & Duellman (1971) referred an adult specimen from Yaupi, Río Paucartambo, Departamento Pasco, Peru (KU 136312) to O. pearsoni and illustrated it as such. The dorsal coloration of the holotype apparently led Duellman (1974) to synonymize Hyla mimetica with Hyla triangulum Günther, 1869 (= Dendropsophus triangulum). However, the lectotype (he mentions a frog of 23.5 mm SVL; apparently the other syntype) lacks the axillary membranes and glandular thoractic patches of frogs of the Dendropsophus leucophyllatus group, which triangulum is a member of. Henle (1981) described Hyla elkejungingerae on the basis of juveniles collected as tadpoles and raised in captivity from Boquerón del Padre Abad, Departamento Ucayali, Peru. He later transferred it to Osteocephalus when frogs raised to adult size and more specimens were available (Henle 1992). Before, Frost (1985) had listed the taxon under Hyla elkejungingerae, but added a note by Hoogmoed that it was likely to be a synonym of Osteocephalus taurinus. Eric Smith (pers. comm. 2002) and I independently inspected the holotype of Hyla mimetica and agree that it is a valid taxon in the genus Osteocephalus. Earlier, Smith & Noonan (2001), without further comment, had referred to material examined by them as Osteocephalus mimeticus in their description of Osteocephalus exophthalmus. The species (as Osteocephalus elkejungingerae) was described in detail by Henle (1992), so it need not be repeated here. The lectotype agrees with the holotype of Hyla elkejungingerae, also a subadult (22 mm SVL) as well as with the large series of “ topotypes ” at the ZFMK, namely the subadult specimens (e. g. ZFMK 39164, 40152 – 3). The lectotype of Hyla mimetica has still retained some juvenile characters: Large white supralabial spots (reduced to a large subocular mark in many adults), dark paravertebral markings (a uniform dorsum or variable markings on the entire dorsum in adults), light elbows, knees and tibiotarsal articulations (dark like the rest of the extremities in adults). But the iris coloration, black with some golden blotches (a character shared among the genus only with the allopatric Colombian O. carri) is already reminiscent of that of an adult. In contrast, recently metamorphosed juveniles have bright red irises. Live subadults have intermediate irises with black blotches on light red ground. The red color quickly fades in preserved frogs. Sexes at this stage can already be identified by dorsal skin structure. The specimen’s back is smooth, indicating that it is a female. The ontogenetic change in this species has been described and illustrated several times (Henle 1981, Henle et al. 1983, Schütte and Spieler 1993) under various names. Females from the type locality of Hyla elkejungingerae that I placed together with a male from Tarapoto, about 45 km east of the type locality of Hyla mimetica, laid eggs that were fertile. Frogs raised from these eggs were also fertile. The maximum size for males measured is 62.7 mm SVL from Boquerón del Padre Abad, Departamento Ucayali, Peru (Henle 1992), the largest female, KU 209454 from the Río Cainarache, 33 km NE Tarapoto, San Martín, Peru, is 82.7 mm in SVL. Measurements of the lectotype of Hyla mimetica (in mm): SVL 34.0; HL 12.5; HW 12.0; TL 23.0; FL 12.6; ED 4.3; TD 2.1; FD 1.8; EN 3.6; IN 2.8; TE 1.9.