Bioacoustics of Ololygon feioi

Diagnosis . The new species belongs to the genus Scinax by sharing morphological synapomorphies known for the genus: webbing between toes I and II that does not extend beyond the subarticular tubercle of Toe I, m. pectoralis abdominalis originates at well-defined tendons, and m. pectoralis abdominalis overlaps the m. obliqus externus ( Faivovich 2002 ; Faivovich et al . 2005 ). Also, we include the new species in the S. catharinae clade by the absence of a pectoral fold. This combination of characters differentiates adults of species of the S. catharinae clade from all those of the S. ruber clade ( sensu Faivovich 2002 ). Furthermore, the new species shares with members of the S. catharinae species group a m. extensores brevis distalis digit III with a laterodistal origin (synapomorphy of this group; Faivovich 2002 ) and the lack of a bromeligenous reproductive mode (synapomorphy of the S. perpusillus group; sensu Peixoto 1987; Favivovich et al . 2005). Males (n=12) SVL 26.6–32 (29±1.5) HL 10–11.7 (10.9±0.5) HW 8.1–9.9 (9.1±0.5) END 2.9–3.7 (3.4±0.2) IND 2.3–2.8 (2.5±0.2) ED 3.8–4.8 (4.4±0.3) IOD 3.1–3.7 (3.3±0.2) TD 1.0–1.6 (1.3±0.2) THL 12.6–15 (14±0.7) TL 14.7–16.5 (15.6±0.6) FL 7.6–10.0 (8.2±0.5) Scinax feioi sp. n. is diagnosed by the following characters: (1) SVL in males 26.6–33.0 mm, n = 12 (females unavailable); (2) snout mucronate in dorsal view; (3) canthus rostralis marked; (4) vocal slits in males present; (5) males with vocal sac externally distended ( Fig. 2 a–c); (6) light-yellow gular region in live males ( Fig. 3 ); (7) glandular acini on the medial region of forearm in males present; (8) light colored, protruded nuptial pad on finger II; (9) glandular acini on the dorsal region of the fingers II and III in males; (10) skin on dorsum covered by scattered tubercles; (11) inguinal gland in males absent; (12) webbing between toes II and III reaching the subarticular tubercle of Toe II; (13) webbing between toes IV and V reaching the second subarticular tubercle or at most half of the penultimate phalanx of Toe V; (14) narrow irregular band, restricted to the median interocular region present; (15) orange-yellow coloration on inguinal region and hidden portions of thigh and shank ( Fig. 3 ); and (16) m. depressor mandibulae with an origin on the dorsal fascia at the level of the m. dorsalis scapulae ( Fig. 4 ). Comparison with other species . Scinax feioi sp. n. differs from S. agilis , S. argyreornatus , S. aromothyella , S. berthae , S. caissara , S. cardosoi , S. carnevallii , S. centralis , S. garibaldiae , S. heyeri , S. luizotavioi , S. machadoi , S. melanodactylus , S. pombali , S. ranki , S. skuki , and S. tripui by the larger male SVL ( Scinax feioi sp. n. 26.6–33.0 mm; combined SVL in males of these species 12.0–26.2 mm). Scinax feioi sp. n. differs from all species of the S. catharinae group (except S. garibaldiae , S. obtriangulatus , and S. skaios ) by its light-yellow coloration on the gular surface in life, contrasting with its overall color pattern (the gular region of S. garibaldiae is bright yellow; topotypes of S. obtriangulatus and S. skaios were not analyzed in this study). The gular region of all other species is entirely beige or has irregular brown spots on a beige background in life. Males of S. aromothyella , S. hiemalis , S. littoralis , S. luizotavioi , and S. rizibilis present yellow pigmentation spread throughout body, including the gular region, but it happens only at night and in vocalization activity. Males of the new species have an externally distended vocal sac ( Fig. 2 a–c), characteristic that promptly dis- tinguishes it from all other species of the S. catharinae group, except from S. aromothyella , S. berthae , S. cardosoi , S. garibaldiae , and S. rizibilis (all other species do not have a distended vocal sac). Scinax feioi sp. n. is also distinguished from S. agilis , S. albicans , S. argyreornatus , S. aromothyella , S. berthae , S. machadoi , S. ranki , and S. rizibilis by its marked canthus rostralis (not marked in these species); and from S. ariadne and S. skaios by the presence of vocal slits (absent in these species). The new species differs from almost all species of the S. catharinae group (except S. argyreornatus , S. cardosoi , S. carnevallii , and S. kautskyi ) by its mucronate snout in dorsal view (subovoid in S. caissara , S. canastrensis , S. centralis , S. longilineus , S. goya , S. machadoi , S. rizibilis , S. skaios , and S. melanodactylus ; sub-elliptical in S. aromothyella , S. berthae , and S. pombali ; rounded in S. ariadne , S. catharinae , S. brieni , S. garibaldiae , S. obtriangulatus , and S. ranki ; rounded with mucronate tip in S. albicans , S. angrensis , S. flavoguttatus , S. hiemalis , S. heyeri , S. humilis , S. littoralis , S. muriciensis , S. strigilatus , S. trapicheiroi , and S. tripui ; and sub-elliptical with acute tip in S. jureia and S. luizotavioi ). Scinax feioi sp. n. differs from most species of the S. catharinae group (except S. argyreornatus , S. aromothyella , S. caissara , S. cardosoi , S. catharinae , S. kautskyi , S. flavoguttatus , S. heyeri , S. luizotavioi , S. muriciensis , S. skuki , S. strigilatus , and S. tripui ) by its webbing between toes IV and V reaching the second subarticular tubercle or at most half of the penultimate phalanx of Toe V (more developed webbing between toes IV and V in the remaining species, reaching the base of the disc of the Toe V). Webbing between toes II and III reaching only the subarticular tubercle of Toe II, differs the new species from S . agilis , S . albicans , S. ariadne , S. brieni , S. canastrensis , S. centralis , S. flavoguttatus , S. garibaldiae , S. goya , S. hiemalis , S. jureia , S. longilineus , S. melanodactylus , S. obtriangulatus , and S. trapicheiroi (webbing reaching the base of the disc or the half of the penultimate phalanx of the Toe II in these species). The narrow irregular band (looking a subtle W-shaped) restricted to the median interocular region differs the new species from almost all species of the S. catharinae group, except S. angrensis , S. humilis , and S. littoralis ( S. agilis and S. melanodactylus with a black longitudinal line or no mark on the interocular region); S. argyreornatus , S. caissara , S. carnevallii , S. flavoguttatus , S . garibaldiae , S. heyeri , S. kautskyi , S. machadoi , S. muriciensis , S. rizibilis , S. strigilatus , and S. tripui with a trapezoid mark or a W-shaped blotch reaching or slightly exceeding the posterior margin of the eyes; S. ariadne , S. brieni , S. canastrensis , S. catharinae , S. centralis , S. goya , S. hiemalis , S. jureia , S. longilineus , S. luizotavioi , S. obtriangulatus , S. pombali , S. ranki , and S. skaios with an inverted triangle or an irregular trapezoid mark on this region, reaching or slightly exceeding the posterior border of the tympanum; S. trapicheiroi with a W-shaped blotch, which is very long, reaching the posterior half of the body; and S. cardosoi with a longitudinal band in the interocular region, sometimes interrupted, that extends posteriorly through the dorsal surface). The new species also differs from some species of the group, except S. agilis , S. albicans , S. angrensis , S. aromothyella , S. cardosoi , S. carnevallii , S. catharinae , S. brieni , S. flavoguttatus , S. garibaldiae , S . humilis , S. littoralis , S. luizotavioi , S. obtriangulatus , S. trapicheiroi , and S. tripui by having a light-colored, protruded nuptial pad with respect to the surrounding skin in males (nuptial pad is particularly enlarged in S. rizibilis , black colored in S. melanodactylus , and not protruded in the other species). Furthermore, Scinax feioi sp. n. differs from S. agilis , S. ariadne , S. aromothyella , S. berthae , S. caissara , S. cardosoi , S. canastrensis , S. garibaldiae , S. goya , S. longilineus , S. pombali , and S. skaios by having scattered tu- bercles on dorsum (rough in S. ariadne , S. canastrensis , S. goya , S. longilineus , S. pombali , and S. skaios ; smooth in S. agilis , S. aromothyella , S. berthae , S. caissara , S. cardosoi , and S. garibaldiae ). The absence of inguinal gland distinguishes S. feioi sp. n. from S. ariadne , S. brieni , S. canastrensis , S. catharinae , S. centralis , S. flavoguttatus , S. garibaldiae , S. jureia , S. hiemalis , S. longilineus , S. luizotavioi , S. obtriangulatus , S. ranki , S. rizibilis , S. skaios , and S. tripui (externally evident inguinal gland in these species and particularly hypertrophied in S. centralis ). The new species differs from most species of the S. catharinae group, except S. canastrensis , S. carnevallii , S. flavoguttatus , S. goya , S. kautskyi , S. longilineus , S. machadoi , S. muriciensis , S. skaios , S. strigilatus , and S. tripui by the glandular acini on the medial region of forearm in males (glandular acini absent on the medial region of forearm in these species). In addition, the presence of glandular acini on the dorsal region of the Finger III in males distinguishes S. feioi sp. n. from S. agilis , S. argyreornatus , S. ariadne , S. berthae , S. carnevallii , S. centralis , S. garibaldiae , S. heyeri , S . hiemalis , S. melanodactylus , S. ranki , S. rizibilis , S . skuki , and S. strigilatus (glandular acini absent on Finger III in these species). The yellow-orange coloration of the inguinal region and hidden areas of the thigh and shank ( Fig.3 a–c) differs the new species from almost all species of the S. catharinae group [ S. ariadne has light brown irregular blotches on violet or pink background; S. brieni has brown irregular blotches on light blue background; S. catharinae , S. humilis , and S. trapicheiroi have dark brown irregular blotches on light blue or white background; S. hiemalis , S. jureia , S. ranki , S. skaios ( Pombal et al . 2010 ) , S. strigilatus , and S. tripui has brown irregular blotches on greenish background; S. obtriangulatus has “dull grayish violet” (B. Lutz 1973 )]. Moreover, other species of the S. catharinae group have no bright coloration on these regions, they have dark brown spots on light pale background: S. agilis , S. albicans , S. angrensis , S. caissara , S. carnevallii , S. kautskyi , S. luizotavioi , and S. littoralis . Furthermore, the m. depressor mandibulae with an origin on the dorsal fascia at the level of the m. dorsalis scapulae differs Scinax feioi sp. n. from all species of the S. catharinae group, except from S. goya , S. jureia , and S. muriciensis that were not examined (without origin on the dorsal fascia in all other species of the group; see also Faivovich, 2002 ).

Distribution and Natural History. Scinax feioi sp. n. is currently known from its type locality: Fazenda Duas Barras ( 16° 24’ 36.82” S , 40° 2’ 42.35” W ; 757 m a.s.l.), Santa Maria do Salto municipality, northeastern of Minas Gerais state , southeastern Brazil ( Fig. 5 ). This region belongs to the Jequitinhonha river basin and it is one of the last remaining fragments of Atlantic rainforest in northeastern of Minas Gerais . The type locality has a peculiar geomorphic feature, with many huge granite inselbergs towering over forest. Males of the new species were found on leaves (about 1 m above the water) of the marginal vegetation of a stream that have connections with several water bodies. They were observed calling during the wet season (on October) and after rainy days during the dry season (on April).