Bioacoustics of Scinax haddadorum

Description of holotype . Body moderately robust; head as large as wide, 40.1% of SVL. Snout rounded in profile, slightly acuminated in dorsal view. Nostrils dorsolateral, elliptical, slightly protruded; distance between nostrils 79.3% of IOD. Canthus rostralis slightly evident and convex. Loreal region slightly concave. Eyes protuberant, ED 34.5% larger than IOD, almost equal to END . Tympanum nearly rounded, separated from eye by a distance almost half TD. TD 59% of ED. Tympanic annulus rounded, with upper portion hidden by supratympanic fold. Supratympanic fold barely evident, from the upper portion of the tympanum to the insertion of the arm. Vocal sac single, median, subgular, externally evident by the loose skin on the sides of jaw, ventrally not reaching the pectoral region. Vocal slits present, located diagonally to the longitudinal body axis, originating laterally to the tongue and running towards the corner of the mouth. Tongue ovoid, free laterally and posteriorly notched. Vomerine teeth in two slightly convex series between and only just posterior to the choanae, each bearing seven (right) and six (left) teeth. Choanae oval. Axillary membrane absent. Upper arm more slender than forearm. A series of small, round, low, and enameled ulnar tubercles (right forearm: one tubercle; left forearm: five tubercles in row). Fingers, short and slender, fringed. Relative finger length I<II<IV<III. Discs elliptical, wider than long; disc on Finger I smaller than the others. Subarticular tubercles single, conical on fingers I and II; rounded and quadrangular on fingers III and IV, respectively. Subarticular tubercle on Finger IV larger than the others. Supernumerary tubercles small, single, and rounded. Inner metacarpal tubercle single, medium-sized, elliptical; outer metacarpal tubercle flat, bilobed (right hand) or divided (left hand), the two parts are elongated in the latter condition. Webbing absent between fingers I and II; basal between fingers II, III, and IV. The lateral fringe on Finger IV is continued in the lateral margin of the palm by an enameled dermal ridge, from the penultimate subarticular tubercle back to the level of distal margin of outer metacarpal tubercle. Thick, wide, light colored nuptial pad covering only the medial margin of Metacarpal I, and obscuring the outer margin of the inner metacarpal tubercle ( Fig. 3 A–B). Hind limbs robust; TL 51.6% of SVL. Toes slender, fringed. Relative toe length I<II<V≈ III<IV. Discs elliptical, wider than long. Subarticular tubercles single, conical, and rounded. Supernumerary tubercles small, single, and rounded. Inner metatarsal tubercle single, oval; outer metatarsal tubercle simple, elliptical, one third the size of inner metatarsal tubercle, located with distal margin at the level of distal margin of inner metatarsal tubercle or slightly offset posteriorly. Webbing formula I 2 -–2+ II 1 1/3 –2 III 1 1/2–2+ IV 2 +– 1 V. Fringe on lateral margin on Toe V continued along the margin of the sole by a poorly developed ridge that reaches the base of the metatarsal. Along the medial margin of the tarsus, an inconspicuous medial tarsal ridge, barely evident as a thickening of the skin. A series of small, round, inconspicuous tarsal tubercles. Three discrete, low tubercles, next to the tibiotarsal articulation on the right tarsus; tubercles absent on the left tarsus. Skin on dorsum, upper eyelid, and dorsal region of limbs smooth, with small, scattered, rounded tubercles on head and upper eyelid. Small, round, and white pigmented tubercles present on the posterior portion of the tympanum, near the insertion of the arm. Vocal sac smooth; pectoral region, abdomen and subcloacal regions densely covered with rounded, low granules. Ventral surfaces of arms and tibiae smooth. Pectoral fold with pre- and postaxillar elements. There is a white, slightly thickened area in the pectoral region that is apparently glandular, but this requires histological corroboration. Coloration in life of the holotype . There are no notes of coloration in life of the holotype . Coloration in preservative of the holotype . Dorsum light brown with scattered round, irregular, and elongate dark blotches; tympanic membrane finely spotted; canthus rostralis dark brown, loreal region with same coloration as dorsum. Two diagonal dark brown blotches on upper eyelid. Upper lip light cream with diffuse limits. Dorsal surface of fore- and hindlimbs with irregular, transverse dark brown markings. Dorsal surface of hands and discs with dark brown dots and irregular transversal blotches on fingers III and IV, like those on forearms. Flanks and inguinal region lighter with irregular dark blotches. Hidden area of thigh and shank dark brown with some large and irregular light blotches. Ventrally, soles brown, palms light brown; other ventral areas creamy white, immaculate, but margins of the gular region, around arm insertion, and bordering areas with the dorsal coloration finely spotted with brownish gray. The iris is black, with many thin, silver reticulations. Measurements of the holotype (mm). SVL 30.4; HL 12.2; HW 11.8; IND 2.3; IOD 2.9; ED 3.8; END 3.6; TD 2.3; TL 15.7; FL 13.7; 3FD 1.7; 4TD 1.6. Variation in the type series. Some measurements are presented in Table 1 . The number of vomerine teeth in males varies between four and seven on both the right and left processes. In one male paratype (MZUSP 152329) the right process (five teeth) and the left process (six teeth) are more separated than those of the other specimens (about half of the process size). Dorsally, small, scattered, round tubercles are evident mainly on head and body, sometimes on upper eyelid, and less commonly on limbs. Ulnar tubercles are absent in two individuals; when present they can be arranged in line (seven individuals; between two and six tubercles), or scattered (three individuals; between two and five tubercles). In six individuals these tubercles are white. The white dermal ridge on lateral margin of the palm is complete (five individuals) or interrupted (eight individuals). Two specimens (MZUSP 152188; 152191) have the nuptial pad thicker than those of other individuals. The granules on the subcloacal region are white in nine individuals. Measurements Males ( n = 12) Females ( n = 1) Mean ± SD Range SVL 31.8 ± 2.1 29.4–35.4 35.7 HL 12.3 ± 0.6 11.1–13.3 13.7 HW 11.6 ± 0.5 10.8 – 12.4 13.1 IND 2.2 ± 0.1 2.1 – 2.5 2.4 IOD 3.2 ± 0.3 2.9 – 3.9 3.8 ED 3.8 ± 0.3 3.2 – 4.2 4.1 END 3.5 ± 0.2 3.0 – 4.0 4.3 TD 2.2 ± 0.1 2.0 – 2.3 2.4 TL 16.9 ± 1.3 15.6 – 19.0 18.6 FL 14.0 ± 1.1 12.8 – 16.0 15.5 3FD 1.5 ± 0.1 1.4 – 1.8 1.6 4TD 1.5 ± 0.1 1.3 – 1.7 1.5 Tarsal tubercles on the external surface of the tarsus are absent in four individuals. When present these tubercles can be enameled (two individuals). The number of tubercles present on the internal margin of the tarsus, next to the tibio-tarsal articulation, varies from one to five; the distal one is elongated in MZUSP 152331; and the tubercles are enameled in five individuals. Small calcar tubercles, round and low are present in six individuals. Webbing formulae among paratypes varies as follows: I (2+–2-) – (2+–2) II (1 1/2–1-) – (2+–2) III (1 1/2–1-) – (2 ½–2) IV (2+–2-) – (1+–1-) V. The only available female (SVL 35.7 mm ) is slightly larger than the largest male paratype (MZUSP 152188; SVL 35.4 mm ). Similar to Scinax rupestris (see Araujo-Vieira et al. 2015 ), some specimens have a thickening of the ventral portion of the webbing between toes IV and V that is also evident on the dorsal aspect as a number of wrinkles or an ampulla-like swelling. Unidentified eggs are present in the webbing in two individuals (MZUSP 152330– 152331). This is apparently common in several species of Scinax (Faivovich pers. obs.). A photograph in life is available only from paratype MZUSP 152190 ( Fig. 6A ). The specimen is dorsally yellowish tan with brown markings. Two diagonal blotches on upper eyelid, an interocular fragmented blotch continuous to the diagonal blotches. Loreal region with the same coloration as dorsum, and a light brown canthal line. Small round blotches, and larger, irregular blotches in the dorsum with a pair of elongate, irregular blotches on scapular and sacral regions. Hidden surfaces of thigh light brown with irregular yellow blotches. Iris golden yellowish, with many thin, darker reticulations. In preservative, the dorsal color pattern of head, body and limbs varies from light and dark gray to dark brown, with round and irregular dark blotches ( Fig. 4 ). A dark brown canthal line is present in seven individuals, and it is fragmented in two individuals (MZUSP 152192; 152330). The diagonal dark blotches on the upper eyelids can be lighter or darker than in the holotype . They are absent in MZUSP 152326–152327 and 152330. The interocular region can show an inverted triangular or V-shaped dark blotch, sometimes fragmented. Upper lip light cream with diffuse limits finely or conspicuously pigmented. A pair of elongate blotches is present in the scapular and sacral regions of some individuals. Transversal blotches on limbs are continuous or fragmented. They are absent on the shanks in MZUSP 152326–152327. Flanks and inguinal region light colored, with irregular dark blotches. Hidden surfaces of thigh and shank light or dark brown, with lighter, large and irregular blotches. Ventrally, soles and palms, margins of the gular region, arm insertion, and bordering areas with the dorsal coloration vary from creamy white to dark brown. The pectoral region can be finely pigmented with dark brown in some individuals. One individual (MZUSP 152329) has a series of lighter regions on the body, as if the dorsal pattern has faded, with several lightly pigmented areas; we are uncertain if this represents a natural condition or a fixation artifact. Tadpoles and advertisement call. The tadpole is unknown, and the advertisement call has not been recorded. Geographic distribution and Natural history. Scinax haddadorum sp. nov. has been found in four different localities in the Municipality of Barra do Garças, State of Mato Grosso, Brazil ( Fig. 5 ). All streams where they occur flow to either Pindaíba or Araguaia rivers, both in Araguaia-Tocantins River Basin, a major tributary of the Amazon River. The headwaters of Pindaíba and Araguaia rivers are located in the Cerrado domain, forming a complex landscape. In this scenery, small streams flow from their headwaters at the top of low mountain ranges (less than 1000 m a.s.l.) to floodplains, where marginal lagoons and flooded forests along rivers cross the prevailing savannah vegetation. Males of the new species were found calling from vegetation or rocks at the margins of small streams ( Fig. 6A –B). Vegetation varied from open (scarce bushes) to dense (gallery forest), and, in one occasion this species was found calling from young buriti palm tree ( Mauritia flexuosa ) in a Vereda , a riparian Cerrado vegetation type characterized by a line of buriti palm trees along a flooded headwater, a swamp or a seasonally flooded area ( Figs. 5 C–D). No male was found calling perched above 1.5 m high. All individuals were found above 500 m a.s.l., near the headwaters of permanent or temporary streams, although several areas below 400 m were also sampled during the same fieldwork season. Aquatic environments below 400 m comprised ponds, wide rivers and flooded forests/grasslands. The other anuran species found in the same localities where Scinax haddadorum sp. nov. has been collected are Ameerega berohoka (Dendrobatidae) , Leptodactylus furnarius , Leptodactylus syphax , Pseudopaludicola ameghini (Leptodactylidae) , and Pristimantis ventrigranulosus (Craugastoridae) .