Bioacoustics of Physalaemus orophilus

Diagnosis. (1) Body length small (SVL 21.1–24.8 mm in males, 25.5–28.1 mm in females); (2) skin texture shagreened; (3) head as long as wide; (4) snout subelliptical in dorsal view, protruding in lateral profile; (5) a lateral black stripe extending from the postorbital region to the inguinal region; (6) inguinal gland poorly developed; (7) an oblique white line from posterior corner of the eye to the arm insertion; (8) a white line weakly marked, extending from the tip of the snout, through the canthus rostralis and margin of upper eyelid, absent on the dorsolateral fold; (9) annulus of tympanum weakly marked; (10) vocal sac developed, gray marbled with scattered white dots; (11) tarsal tubercle absent; (12) tarsal fold present; (13) advertisement call composed by one note with 56 to 87 pulses (pulse rate 16 to19 pulses per second); (14) mean value of the dominant frequency 3.18 kHz. Comparison with other species. Physalaemus orophilus sp. nov. is distinguished from P. aguirrei and P. insperatus by the absence of a white line outlining the inferior margin of the mandible (present in those species) and by the presence of an oblique white line from the posterior corner of the eye to the arm insertion (absent in those species). Moreover, it is distinguished from P. i n s p e r a t u s by the vocal sac not expanded laterally to the supratympanic fold (expanded laterally in P. i n s p e r a t u s ).

Physalaemus orophilus sp. nov. is distinguished from P. feioi by having smaller body length (SVL 21.2–31.2 mm in males, 23.5–31.2 mm in females of P. f e i o i ), tarsal tubercle absent (present in P. f e i o i ), advertisement call with pulse emission rate of 16 to 19 pulses per second (8 to 16 pulses per second in P. feioi ), and mean dominant frequency 3.18 kHz (2.56 kHz in P. feioi ) From P. olfersii and P. lateristriga , P. orophilus sp. nov. is distinguished by having smaller body length (SVL 22.1–37.8 mm in males, 26.9–40.3 mm in females of P. lateristriga ; SVL 26.2–36.4 mm in males, 21.7– 41.1 mm in females of P. olfersii ), callosities on heel absent (present in those species), and advertisement call with mean dominant frequency 3.18 kHz (1.24 kHz in P. olfersii ; 1.68 kHz in P. lateristriga ). Physalemus orophilus sp. nov. has smaller body length than P. maximus (SVL 41.1–46.5 mm in males, 42.2–51.5 mm in females of P. m a x i m u s ), tarsal tubercle present (absent in P. maximus ), advertisement call with dominant frequency 3.18 kHz (mean dominant frequency 0.73 or 0.76 kHz in P. maximus ; Baêta et al. 2007 ). Finally, P. orophilus sp. nov. is distinguished from P. soaresi by the larger body length (SVL 17.9–22.8 mm in males, 19.9–21.5mm in females of P. soaresi ), head as long as wide (wider than long in P. s o a re s i ), an oblique white line from the posterior corner of the eye to the arm insertion (absent in P. s o a re s i ), vocal sac developed (vocal sac weakly developed in P. s o a re s i ), tarsal tubercle absent (present in P. s o a re s i ), advertisement call composed by 56 to 87 pulsed notes (one multipulsed note in P. s o a re s i ; Bokermann 1966a ; Weber et al. 2005 ), and longer call duration, from 3.07 a 5.18 seconds (1.34 a 2.40 seconds in P. soaresi ; Bokermann 1966a ; Weber et al. 2005 ). Description of the holotype . Body robust; head longer than wide; snout subelliptical in dorsal view, protruding in lateral profile; nostril elliptical, protuberant, oriented laterally, closer to the tip of the snout than to the eye; canthus rostralis distinct; loreal region oblique; eyes protuberant; tympanum distinct; supratympanic fold developed; parotoid glands well developed; dorsolateral fold present, from the posterior corner of eye, delimiting the dorsal region from flanks, and ending at the anterior margin of the inguinal gland; vocal sac subgular, well developed, extending to the chest; choanae medium–sized, rounded, well distinguished from each other; tongue narrow, long, free posteriorly; maxillary and premaxillary teeth visible; vomerine teeth absent. Arms short, slender; forearms slightly more robust and as long as the arms; fingers thin, long, not fringed; fingers length I <II <IV <III; nuptial pad divided, one part covering 2/3 of the inner metacarpal tubercle and other part enclosing all the thumb, except the inner side; subarticular tubercles large, single, rounded; outer metacarpal tubercle medium–sized, rounded, covering 1/3 of carpal region; inner metacarpal tubercle medium–sized, elliptical, with the same size of the outer metacarpal tubercle; few supernumerary tubercles well developed; fingers tip slightly expanded. Legs moderately robust; tibia slightly longer than thigh; the sum of tibia and thigh lengths slightly shorter than SVL; tarsal fold present; toes thin, long, weakly fringed; toes length I <II <III = V <IV; subarticular tubercles small, single, protruding; inner metatarsal tubercle large, elliptical; outer metatarsal tubercle small, ovoid, approximately half of the size of the inner metatarsal tubercle; tarsal tubercle absent; supernumerary tubercles absent; toes tip slightly expanded. Dorsal surface shagreened, ventral surface smooth. Color in preservative (70% ethanol). Color pattern gray or brown; small, irregular shaped, scattered light brown blotches on dorsum; a light gray or light brown blotch at the center of the dorsal surface; dorsal median line extending on posterior third of the dorsum; an interorbital dark brown line; loreal region gray anteriorly with white dots dispersed and white on the region under the eye; a white line weakly marked on canthus rostralis and border of upper eyelid, absent on dorsolateral fold; a rectangular dark brown blotch on dorsum of the forearm; a dark brown line on the lateral of the ventral surface of the forearms; transversal brown bars on dorsum of thighs; gular and anterior region of the abdomen marbled with light gray blotches and white dots; posterior region of the abdomen and ventral surfaces of thighs white; inguinal gland not distinguished from the color pattern of dorsum; tubercles of palmar and plantar surfaces white; nuptial pads brown or light brown. Measurements of the holotype (mm). SVL 25.3; HL 9.4; HW 8.3; ED 2.9; UEW 2.2; IOD 2.8; IND 2.2; END 2.1; TL 12.2; SL 12.6; FL 20.2. Variation (n = 26). All specimens analyzed agree in morphology and color; females are slightly larger than males (range, mean, and standard deviation of SVL of males and females are in table 4); nuptial pad vary in size, covering half or 2/3 of the inner metacarpal tubercle; interorbital brown line complete or incomplete; few specimens present snout pointed in dorsal view; few individuals present vocal sac brown marbled. Advertisement call. Advertisement calls (n = 124 calls) were obtained from six males in the municipalityof Mariana, and in the Reserva Particular do Patrimônio Natural da Serra do Caraça, state of Minas Gerais, Brazil . The advertisement call ( Fig. 24 , table 3) is composed by one note with 56 to 87 pulses (each pulse is composed by 8 to 11 subpulses), pulse duration of 42 to 50 miliseconds; non–harmonic structure, with an ascendant frequency modulation; mean duration of 3.85 seconds (SD = 0.58, amplitude = 3.07 to 5.18 seconds); pulse rate ranges from 16 to 19 pulses per second; mean duration between calls 1.59 seconds (SD = 0.46, amplitude = 1–2.86 seconds), and mean value of the dominant frequency 3.18 kHz (SD = 0.09, amplitude = 3–3.39 kHz).