Stereocyclops palmipes Caramaschi, Salles & Cruz, 2012, sp. nov.

Stereocyclops palmipes sp. nov.

Figures 1–2

Stereocyclops incrassatus — Feio and Ferreira 2005.

Holotype. MNRJ 31579 (Fig. 1), adult male, collected near the head of the Zona da Mata Regional Airport (21o31’S, 43o11’W; 408 m a.s.l.), Municipality of Goianá, State of Minas Gerais, Brazil, by H. de Niemeyer and U. Caramaschi, on 20 November 2001.

Paratypes. MNRJ 31578, adult female, and MNRJ 31580, juvenile, collected with the holotype; MZUFV 4333–4334, adult males, collected in the borders of the municipalities Goianá/Rio Novo (21o30’S, 43o09’W; 398 m a.s.l.), State of Minas Gerais, Brazil, by R. N. Feio and J. L. Pontes, on 0 5 November 2001; MZUFV 5318–5319, adult females, collected in the Municipality of Tombos (21o08’S, 42o22’W; 219 m a.s.l.), State of Minas Gerais, Brazil, by D. S. Ferraz, on 25 November 2003.

Diagnosis. Stereocyclops was not addressed by modern phylogenetic analyses (Frost et al. 2006; Van der Meijden et al. 2007; Pyron & Wiens 2011) and a thorough morphological study of the genus still needs to be done. Thus, we assign S. palmipes sp. nov. to this genus on the basis of overall similarity to other species. Stereocyclops palmipes sp. nov. is characterized by: (1) medium size (SVL 43.7–48.5 mm in males; SVL 48.4–56.7 mm in females); (2) in males, large, numerous dermal spines concentrated in the inferior border of mandible, forming a band; (3) dermal spines scattered on ventral surfaces of body, arms, fingers, legs, toes, and pericloacal region of males, and agglomerate only in pericloacal region and ventral surfaces of thighs in females; (4) fringes and interdigital membranes of toes developed, slightly larger in males (plantar webbing formula I 2 + – 3+ II 2 - – 4+ III 3 – 3 - IV 3 - – 2+ V) than in females (plantar webbing formula I 2 + – 3 II 2 - – 4+ III 4 + – 4+ IV 4 + – 2+ V); (5) color pattern composed by two mid-dorsal, poorly defined, dark brown stripes from the inguinal regions to head, passing on the occipital dermal fold and reaching the upper eyelid.

Comparisons with other species. The presence of well developed interdigital membranes on feet distinguishes Stereocyclops palmipes sp. nov. from both S. incrassatus and S. parkeri, in which webbing is absent or vestigial. Additionally, S. palmipes sp. nov. is distinguished from S. parkeri by the presence of large mandibular, ventral, and pericloacal dermal spines (dermal spines small, visible only under magnification, few, very scattered in S. parkeri) and by the color pattern (mid-dorsal dark stripes converging and uniting before the occipital dermal fold, forming an arrow-shaped dorsal pattern in S. parkeri).

Description of holotype. Body robust, ovoid (Fig. 1); head small, larger than long, head length 69.3% of head width; head length 36.3% of SVL, head width 37.9% of SVL; snout short, rounded in dorsal view (Fig. 2 A), protruding in lateral view (Fig. 2 B); nostrils at the tip of snout, directed laterally; internarial distance 20.5% of head width, 14.3% of interorbital distance; canthus rostralis poorly developed; loreal region oblique; eye to nostril distance 93.1% of internarial distance; eyes small, not prominent, eye diameter 15.7% of head width, 77.6% of internarial distance, 82.7% of eye to nostril distance; upper eyelid width 80.8% of eye diameter, 30% of interorbital distance; interorbital distance 42.2% of head width; occipital dermal fold developed; supratympanic dermal fold developed, from the posterior corner of eye to just before the arm insertion; tympanum indistinct; tongue large, ovoid, without posterior notch; choanae small, rounded, widely separated; maxillary and vomerine odontoids absent; two palatal folds present; vocal slits under the tongue, located anteriorly on the mouth floor; vocal sac not expanded, single, subgular. Arms robust, forearm length 17.4% of SVL; hand large (Fig. 2 C), robust, forearm length 66.7% of hand length; fingers slender, tips small, rounded, not expanded; relative length of fingers, II <III <V <IV; inner metacarpal tubercle small, elliptical; outer metacarpal tubercle large, unique, about four times the inner metacarpal tubercle; subarticular tubercles developed, rounded; supernumerary tubercles and nuptial pad absent; fringes poorly developed, with small dermal spines; interdigital membranes absent. Legs robust, tibia length slightly smaller than thigh length; tibia length 40.2% of SVL and 95.1% of thigh length; thigh length 42% of SVL; sum of thigh and tibia lengths 82.5% of SVL; tarsal length smaller than foot length, sum of tarsal and foot lengths 86.1 of the sum of thigh and tibia lengths. Foot (Fig. 2 D) robust; relative lengths of toes, I <II <V <III <IV; tips of toes small, rounded, not expanded; inner metatarsal tubercle developed, elliptical; outer metatarsal tubercle absent; subarticular tubercles developed, rounded; supernumerary tubercles absent; fringes developed, with small dermal spines; interdigital membranes developed, webbing formula I 2 + – 3+ II 2 - – 4+ III 3 – 3 - IV 3 - – 2+ V. Dorsal surface smooth. Dermal spines numerous, evident, concentrated on the inferior border of mandible, forming a band; gular region, chest, ventral surfaces of body, arms, legs, and pericloacal region with scattered dermal spines.

Dorsum background color grayish light brown and venter dark brown, laterally well delimited among them; color pattern composed by two mid-dorsal, poorly defined, dark brown stripes from the inguinal regions to head, passing on the occipital dermal fold and reaching the upper eyelid.; a cream line from the tip of snout to vent; dorsal surfaces of thighs and tibiae with transversal brown bars; gular region gray; a longitudinal cream line on ventral surface, from the anterior border of mandible to vent; a transversal, V-shaped cream line on the pectoral region; cream lines bordering the posterior surfaces of arms, thighs, tibiae, and feet.

Measurements of the holotype (mm). SVL 43.7; HD 11.5; HW 16.6; IND 3.4; END 3.1; UEW 2.1; ED 2.6; IOD 7.0; FAL 7.6; HAL 11.4; THL 18.5; TL 17.6; TAL 11.1; FL 20.0.

Variation. Females are larger than males; variations in measurements are presented in Table 1. The dorsal background color ranged from light gray to dark brown; dorsal anastomosed brown marks may be delimited by dark brown lines; ventral color varied from dark brown to dark gray; small cream spots may be present scattered on ventral region.

Males (n = 3) Females (n = 3)

Range Mean SD Range Mean SD SVL 43.7–48.5 46.3 1.96 48.4–56.7 53.2 4.29 HL 11.5–13.6 12.4 0.87 11.7–14.0 13.2 1.28 HW 16.6–20.2 18.3 1.48 17.6–21.9 20.1 2.19 IND 3.3–4.5 4.0 0.49 3.1–4.3 3.7 0.59 UEW 2.1–2.3 2.2 0.06 2.0–2.2 2.1 0.14 ED 2.5–3.4 2.8 0.39 2.1–2.6 2.3 0.28 IOD 7.0–7.8 7.4 0.32 7.6–9.2 8.6 0.84 FAL 7.6–9.9 9.0 0.99 8.9–13.0 11.2 2.07 HAL 11.4–12.8 12.3 0.61 11.8–14.5 13.1 1.35 THL 18.5–23.1 21.2 1.99 21.8–27.4 24.9 2.80 TL 17.6–20.9 19.6 1.45 20.1–25.4 23.0 2.67 TAL 11.1–12.8 12.2 0.74 12.3–15.2 13.9 1.50 FL 20.0–22.4 21.6 1.13 21.8–27.0 25.1 2.85 Etymology. The name, a Latin adjective, refers to the webbed feet of the species.

Remarks. The type locality is located in the region called “Zona da Mata ”, in the State of Minas Gerais, Southeastern Brazil, in the Pomba River sub-basin, a tributary of the Paraíba do Sul River. The general vegetation type is classified as Low Montane Semidecidual Forest. Specimens were obtained in a locality called “ Mata de Cabeceira” by Feio and Ferreira (2005), a forest fragment with approximately 12 ha, involving ciliary forests of the right margin of the Novo River. In the forest occur flooding depressions, forming small pools bordering the river. In addition to Stereocyclops palmipes, for the same general area, Feio and Ferreira (2005) reported the occurrence of the following anurans species (up to dated nomenclature): Rhinella pombali (Bufonidae), Dendropsophus anceps, D. bipunctatus, D. branneri, D. elegans, D. minutus, Hypsiboas albomarginatus, H. faber, H. semilineatus, Itapotihyla langsdorffii, Scinax argyreornatus, S. eurydice (Hylidae), Leptodactylus (Adenomera) sp., L. fuscus, Leptodactylus latrans, L. spixi (Leptodactylidae), Physalaemus cuvieri, Physalaemus gr. signifer (Leiuperidae), and Elachistocleis cesarii (Microhylidae).