Scinax tigrinus, Nunes & Carvalho Jr & Pereira, 2010

Nunes, Ivan, Carvalho Jr, Ronald R. & Pereira, Emiliane G., 2010, A new species of Scinax Wagler (Anura: Hylidae) from Cerrado of Brazil, Zootaxa 2514 (1), pp. 24-34 : 25-31

publication ID	https://doi.org/ 10.11646/zootaxa.2514.1.2
persistent identifier	https://treatment.plazi.org/id/03DC8789-DA32-FFE6-5A94-FB7089CA29BA
treatment provided by	Felipe
scientific name	Scinax tigrinus
status	sp. nov.

Treatment

Scinax tigrinus View in CoL sp. nov.

( Figures 1 View FIGURE 1 and 2 View FIGURE 2 )

Holotype. MNRJ 54464, adult male, from Palmital District (16º19'20''S, 47º13'10''W; 970m altitude), Municipality of Cabeceira Grande, Minas Gerais State, Southeastern Brazil, collected on 16 January 2007, by R.R. Carvalho Jr. and T.P. Paula. GoogleMaps

Paratopotypes. MNRJ 54465-66, adult males, collected with the holotype; MNRJ 54467–54469, adult males, collected on 12–21 December 2006, by E.G. Pereira and D.S. Giovanardi; MCNAM 9144–9147, adult males, collected on 21–30 March 2007, by E.G. Pereira and M.A.S. Canellas.

Referred specimens. MNRJ 53190, Municipality of Jaraguá , Goiás State ; MNRJ 58893, Municipality of Santo Antônio do Descoberto , Goiás State .

Diagnosis. Scinax tigrinus sp. nov. is a member of the S. ruber clade (sensu Faivovich et al. 2005), and is diagnosed by the following combination of characters: moderate size (males 28.4–30.8 mm SVL); presence of several flash orange-yellowish transversal stripes on thigh; vocal sac well developed; snout acuminate in profile; advertisement call with one note, 4–15 pulses, and dominant frequency 2.93–3.27 kHz.

Comparison with other species. The dorsal drawing pattern and color of background beige, with many brown blotches with irregular shape, distinguishes S. tigrinus sp. nov. from S. acuminatus , S. cabralensis , S. camposseabrai , S. curicica , S. eurydice , S. fuscomarginatus , S. fuscovarius , S. maracaya (see Fig. 3 View FIGURE 3 ), S. nasicus , S. pachycrus , S. parkeri , S. rogerioi , and S. squalirostris (see photos and/or color descriptions in B. Lutz 1973; Cardoso & Sazima 1980; Izecksohn & Carvalho-e-Silva 2001; Pugliese et al. 2004; Caramaschi & Cardoso 2006; Juncá 2006; Drummond et al. 2007; Uetanabaro et al. 2008; Pugliese et al. 2009). By the presence of yellow flash color on posterior surfaces of the thigh and hidden portion of the shanks, S. tigrinus sp. nov. differs from S. acuminatus , S. cabralensis , S. fuscomarginatus , S. pachycrus , S. parkeri , and S. squalirostris . The smaller SVL of S. tigrinus sp. nov. adult males (28.4–30.8 mm; n=10) distinguishes it from S. acuminatus (38.9–43,7 mm; n=8), S. eurydice (39.6–51.2 mm; n=21), and S. fuscovarius (39.0– 47.9 mm; n=7); by its larger SVL it is distinguished from S. cabralensis (22.5–25.0 mm; n=4), S. fuscomarginatus (17.1–22.0 mm; n=13), S. maracaya (26.7–28.0 mm; Cardoso & Sazima 1980), and S. parkeri (21.0– 22.6 mm; n=3). The dorsal view of the snout of S. tigrinus sp. nov. is oval in dorsal view and differs from S. eurydice , S. fuscovarius , and S. similis (rounded in these species), and from S. squalirostris (pointed). The snout profile of S. tigrinus sp. nov. is acuminate, while the snout profile of S. cabralensis , S. curicica , S. eurydice , S. maracaya , and S. pachycrus is rounded; in S. camposseabrai is truncate; and in S. fuscomarginatus , S. nasicus , S. parkeri , and S. squalirostris is protruding. Scinax tigrinus sp. nov. presents vocal sac more developed than S. cabralensis , S. camposseabrai , S. curicica , S. eurydice , S. fuscomarginatus , S. fuscovarius , S. maracaya , S. pachycrus , S. parkeri , S. similis , and S. squalirostris . The dorsal skin texture smooth or scattered granulated differs S. tigrinus sp. nov. from S. acuminatus , S. cabralensis , S. maracaya , S. nasicus , and S. rogerioi (more rugose dorsal skin in these species). Scinax tigrinus sp. nov. presents smooth skin texture in vocal sac, while S. acuminatus , S. curicica , S. maracaya , and S. pachycrus presents granulose skin texture in vocal sac. The smooth tarsal region distinguishes S. tigrinus sp. nov. from S. acuminatus , S. cabralensis , S. eurydice , S. maracaya , and S. pachycrus (presence of dermal fold or/and tubercles on tarsus in these species). Scinax tigrinus sp. nov. can be distinguished from the Scinax maracaya , the most closer related species, also by the outer metacarpal tubercle bigger with both elongated (smaller, with outer rounded in S. maracaya ), and by the outer metacarpal tubercle very more developed (almost vestigial in S. maracaya ). The number of notes (n=1) distinguishes S. tigrinus sp. nov. from S. cabralensis (n=6–9; Drummond et al. 2007), S. fuscovarius (n=9–10; Pombal et al. 1995b), and S. squalirostris (n=11–13; Pombal et al. 1995b). The smaller number of pulses per note (n=4–15) distinguishes S. tigrinus sp. nov. from S. curicica (n=29–43; Pugliese et al. 2004), S. eurydice (n=3; Pombal et al. 1995b, where the pulses were called notes), S. fuscomarginatus (n=85–104; Toledo & Haddad 2005), S. pachycrus (n=17–32; Carneiro et al. 2004), S. parkeri (17–21; De La Riva 1994), and S. perereca (n=21–24; Pombal et al. 1995a). The dominant frequency (2.93–3.27 kHz) of S. tigrinus sp. nov. is lower than in S. cabralensis (3.70–4.22 kHz; Drummond et al. 2007), S. fuscomarginatus (4.1–4.7 kHz; Toledo & Haddad 2005), and S. squalirostris (3.9–4.6 kHz; Pombal et al. 1995b), and higher than in S. nasicus (0.97 kHz; De La Riva 1994), and S. parkeri (2.7–2.8 kHz; De La Riva 1994).

Description of holotype. Body slender; medium size (30.5 mm SVL); head slightly longer than wide; snout subovoid in dorsal view ( Fig. 1 View FIGURE 1 ), acuminate in profile ( Fig. 2 View FIGURE 2 ); nostrils dorsolateral, elliptical; canthus rostralis weakly marked, concave; loreal region slightly concave; eyes protuberant; tympanum visible, rounded ( Fig. 1 View FIGURE 1 and 2 View FIGURE 2 ); supratympanic fold slightly evident, from the posterior corner of eye to shoulder; vocal sac single, median, subgular, well developed; vocal slights laterally on mouth floor; tongue large, cordiform, notched posteriorly, barely free; vomerine teeth in two straight series closer to each other, below the oval choanae. Pectoral fold present. Arm slender, forearm moderately robust; fingers slender, medium– sized, poorly fringed, webbing barely visible, without evident nuptial asperities; relative lengths I≤II<IV<III; finger disks nearly rounded, medium–sized, the first finger disk smaller; inner metacarpal tubercle single, elliptical; outer metacarpal tubercle divided, both elongated ( Fig. 2 View FIGURE 2 ); sub–articular tubercles simple, small, rounded; supranumerary tubercles rounded, small. Legs moderately robust; toes slender, long, relative lengths I<II<V≈III<IV; toe disks medium sized, I−II rounded, smaller than toe disks III-V, nearly elliptical; webbing formula I 2–2 II 1–2 + III 1–2 IV 2 + –1 V (webbing little folded in the holotype; see Fig. 2 View FIGURE 2 ); foot with inner metatarsal tubercle single, oval, medium-sized; outer metatarsal tubercle simple, conic, rounded ( Fig. 2 View FIGURE 2 ); subarticular tubercles single, rounded; supranumerary tubercles simple, small, rounded. Skin on dorsum smooth; gular region, undersurfaces of arms, and tibia smooth; venter and thighs strongly granulated.

Color. The following description is based on the uncollected adult male in the Figure 4 View FIGURE 4 . Dorsum background beige with brown and cream blotches of irregular shape; presence of an interorbial brown blotch surrounding by cream. Presence of several flash orange-yellowish and brown transversal stripes on the hidden portion and dorsal region of thighs; the dorsal surfaces of tibia and forearm presents the same pattern, but the transversal stripes are beige on brown background. The inguinal region presents some small flash orangeyellowish blotches. Ventral region beige. In preservative ( Figs. 1 View FIGURE 1 and 2 View FIGURE 2 ), the color pattern is the same, but the colors are faded.

Measurements of the holotype (in mm). SVL 30.5, HL 11.1, HW 10.0, ED 3.0, END 3.0, TD 1.9, UEW 2.5, IOD 3.3, IND 2.5, NSD 2.0, FAL 5.5, HAL 7.9, 3FD 1.2, THL 14.7, TL 16.3, FL 22.8, 4TD 1.3.

Variation. The morphology of the specimens of the type series is very similar. Some paratypes have the nostrils upon a smaller elevation than that of the holotype; the shape of finger disks can be more rounded; there is a short variation in the number of supranumerary tubercles. The shape of the transversal stripes on the hidden portion and dorsal region of thighs varies from well defined shape to stripes with irregular shape. Males morphometric variation are in Table 1.

Advertisement call. The following description is based on unvouchered calls of two adult males from the type-locality at Municipality of Cabeceira Grande , Minas Gerais State, Brazil. The males were recorded while they were perched on a bush at the edge of a pond approximately 20 cm from the water. The advertisement call is a single periodic pulse train comprised of 4 to 15 pulses (n=40 calls; Fig. 5 View FIGURE 5 ). The call duration ranged from 0.08 to 0.34 s (0.21±0.06; n=40 calls), emitted in irregular intervals from 0.60 to 6.53 s (1.07±0.95; n=37 intervals). The dominant frequency ranged from 2.93 to 3.27 kHz (3.06±0.03; n=40 calls). The call does not have amplitude or frequency modulation ( Fig. 5 View FIGURE 5 ) .

Habitat and natural history. Individuals of this new species have been observed active during twilight and nocturnal hours in the rainy season (October to March). Males used branches and broad leaves of grass and shrubs as calling sites in a vertical stratification from the ground to 1.5 m high. Individuals were observed in a wetland near ponds of open areas featuring abundant emergent and marginal vegetation. This area is close to forest edge fragments isolated from each other by crops and pastures. Also, individuals have been observed to enhance the note duration when in antiphony.

Nineteen other species of anurans have been observed living in the type-locality of Scinax tigrinus sp. nov.: Aplastodiscus perviridis Lutz , Barycholos ternetzi (Miranda-Ribeiro) , Dendropsophus minutus (Peters) , Eupemphix nattereri Steindachner , Hypsiboas albopunctatus (Spix) , H. lundii (Burmeister) , Leptodactylus furnarius Sazima & Bokermann , L. fuscus (Schneider) , L. labyrinthicus (Spix) , L. mystacinus (Burmeister) , L. syphax (Bokermann) , Leptodactylus sp. (gr. marmoratus ), Phyllomedusa azurea Cope , Physalaemus cuvieri Fitzinger , P. marmoratus Reinhardt & Lütken , Pseudopaludicola sp. , Rhinella rubescens (Lutz) , Scinax fuscomarginatus (Lutz) , and S. fuscovarius (Lutz) .

The micro-environments, in which the new species has been recorded, are part of fragments with different types of Cerrado vegetation in the midst of an agricultural matrix, where the main uses for crops are soybean, maize, and sorghum. Although the Cerrado degradation, and we do not aware about much more populations of this new species, we expect that S. tigrinus sp. nov. has a wide distribution because of the known localities are in the South American open formations corridor (Caatinga-Cerrado-Chaco region). These known sites are areas protected by the Brazilian Forest Code (Áreas de Preservação Permanente or APP, “Permanent Preservation Areas” in English) or Reservas Legais (“Legal Reserves” in English), indicating the importance of conservation and maintenance of amphibian populations.

Geographic distribution. Known from three localities: Cabeceira Grande, in Minas Gerais State (typelocality), and Jaraguá and Santo Antônio do Descoberto , both in Goiás State, Central Brazil ( Fig. 6 View FIGURE 6 ) .

Etymology. The specific epithet, “ tigrinus ” (English “tigerlike”), is a Latin adjective, in allusion to the color pattern of the thighs.

Remarks. According to Faivovich et al. (2005), the morphological synapomorphy for the Scinax ruber clade is the proctodeal tube positioned above the margin of the lower fin in tadpoles. We do not have larval data for Scinax tigrinus sp. nov., but the external morphology agree with the classification of the S. ruber group, in a taxonomic context, proposed by Pombal et al. (1995a), and this new species has a very similar external morphology with S. maracaya (primarily identified as such by some researchers; J. Faivovich pers. comm.), but can be distinguished from S. maracaya by morphology, SVL, and dorsal coloration pattern (see comparisons).

According to Pugliese et al. (2009), nowadays there are eleven available names in the synonymy under Scinax species belonging to the S. ruber clade (sensu Faivovich et al. 2005) known from southeastern and central Brazil. Hyla phrynoderma Boulenger, 1889 , and Hyla fiebrigi Ahl, 1927 , are synonyms of S. acuminatus , and the new species can be distinguished from them by its smaller size, dorsum being smooth or scattered with very small granules (very rugose in H. phrynoderma and H. fiebrigi ; B. Lutz 1973; Duellman 1974). Hyla madeirae Bokermann, 1964 , is a synonym of S. fuscomarginatus and is smaller (males SVL 10.0–22.0 mm) than S. tigrinus sp. nov. and has dorsum with a pair of continuum longitudinal stripes ( Bokermann 1964). The examination of the lectotype (MNRJ 229) and paralectotype (MNRJ 5221) of H. megapodia Miranda-Ribeiro, 1926 , a synonym of S. fuscovarius , shows an undistinguishable morphology and color pattern from their senior synonym, confirming the results of Almeida and Cardoso (1985) about the similarity of both sperm morphology, and junior synonym status by Faivovich et al. (2005) in the last Scinax taxonomic review. The other available synonym of S. fuscovarius is H. trachythorax Müller & Hellmich, 1936 . Norman and Naylor (1994) studied the anurans of the Paraguayan Chaco and reported that the SVL of the males of S. fuscovaius ranged from 41.0–48.0 mm. The type locality of S. trachythorax (= S. fuscovarius ) is “Apa-Bergland, Centurion (San Luis)" in Paraguay ( Frost 2010), showing that it differs from S. tigrinus sp. nov. by its smaller size. Duellman (1974) and Langone (1991) considered Hyla nigra Cope, 1887 , and Hyla anisitsi Méhely, 1904 , as synonymies of Scinax nasicus ; herein, we follow these early authors. According to Gallardo (1961), H. lindneri Müller & Hellmich, 1936 , and H. evelynae Schmidt, 1944 , are synonyms of S. squalirostris and have the same dorsal color pattern (see Müller & Hellmich 1936; Schmidt 1944); so, as the dorsal color pattern with a pair of continuum longitudinal stripes differs S. tigrinus sp. nov. from S. squalirostris , it also differs the new species from H. lindneri and H. evelynae . Hyla affinis Spix, 1824 , and H. coerulea Spix, 1824 , are synonyms of S. x-signatus (see Frost 2010); the type specimen of S. x-signatus is lost ( Hoogmoed & Gruber 1983) and distinct forms are currently identified as S. x-signatus , which precludes a correct identification (see Pombal et al. 1995a; Pugliese et al. 2009). The type localities of H. affinis and H. coerulea are in the Amazonian region ( S. x-signatus is on the Atlantic Forest), while S. tigrinus sp. nov. is on the Cerrado Domain. In addition, Scinax dolloi (Werner) (a species inquirenda according to Pugliese et al. 2009) cannot be associated with any known natural population as pointed out by Faivovich et al. (2005). Werner (1903) reported the total length of Scinax dolloi as 45 mm, but the two syntypes have SVLs of 34.9 and 42.9 mm, male and female, respectively ( Pugliese et al. 2009).