Dendropsophus manonegra Rivera-Correa & Orrico, 2013, sp. nov.

Dendropsophus manonegra sp. nov.

(Figs. 1–3)

Holotype. MHUA-A 7336; an adult male from kilometer 60 road Florencia — Altamira, 1° 47' 42.2'' N, 75° 38' 48.7'' W, 1040 m a.s.l., vereda Sucre, municipio de Florencia, departamento de Caqueta, Colombia, collected on November 14, 2010 by Marco Rada.

Paratypes. All adults. MHUA-A 7337, female; MHUA-A 7668, male; both with same data as the holotype. ICN 23973–24000; 28 males from kilometer 19 of the road Florencia —El Paraíso, 740 m a.s.l., vereda El Paraíso, municipio de Florencia, departamento de Caquetá, Colombia, collected by Pedro Ruiz, John Lynch and Ricardo Sánchez on May 28, 1990. ICN 39875, 39877–80; five males from Serranía de los Churumbelos, mouth of the Rio Intiyaco on the Rio Caquetá, 1º 5' 57.7'' N, 76º 34' 5.8'' W, 400 m a.s.l., municipio de Mocoa, departamento de Putumayo, Colombia, collected by José V. Rueda (unknown date).

Referred specimens. TG 1815; an adult male from kilometer 28 of the road Florencia — Suaza, municipio de Florencia, departamento de Caquetá, Colombia, 800 m a.s.l.; TG 1850; an adult male from kilometer 20 of the road Florencia — Suaza, municipio San José de la Fragua, departamento de Caquetá, Colombia, 720 m a.s.l.; both vouchers deposited at ICN but not yet catalogued.

Diagnosis. We assigned the new species to the genus Dendropsophus on the basis of our phylogenetic results (see below). Furthermore, we assigned it to the Dendropsophus leucophyllatus species group based on the close phylogenetic relationship with D. bifurcus and its relatives. Males and females of the new species exhibit a pair of oval pectoral glands, a character that is considered a putative morphological synapomorphy of the D. leucophyllatus species group (Cochran & Goin 1970; Duellman, 1970; Faivovich et al. 2005).

Dendropsophus manonegra sp. nov. (Figs. 1–3), can be distinguished from all its congeners by the following combination of traits: (1) SVL in males 22.7–25.1 mm (N = 12), female (N = 1) SVL of 32.5 mm; (2) very short snout, approximately 28% of head length, truncate in dorsal and lateral views; (3) head wider than long; (4) canthus rostralis straight and indistinct, loreal region flat; (5) tympanum rounded, tympanic annulus distinct except for its uppermost part, tympanic membrane indistinct; (6) vomerine teeth absent; (7) skin on dorsal surfaces smooth; (8) axillary membrane present, reaching the first proximal third of the arm; (9) finger discs round, about five thirds of the width of the finger; (10) webbing formulae of fingers I – II (1-–1 1/2) – (2 1/3–2 1/2) III (2-–2) – (1 1/2–2) IV, webbing formulae of toes I (1-–1) – (1–1 3/4) II (1–1+) – (1 1/2–2) III (1-–1) – (1 1/2–1 3/4) IV 2 – (1-–1+) V; (11) oval pectoral glands present; (12) inner tarsal fold present; (13) tarsal, heel, and calcar tubercles absent; (14) dorsum ground color brown with black spots and with dorsal yellow light markings consisting of a triangular head blotch connected to narrow or broad dorsolateral bands along the anterior two thirds of body (composing an inverted U-shape), often connected posteriorly at the groin, producing a pattern resembling a frame; (15) one yellow light blotch on heel present; (16) ventral surfaces white, being the mental region smoky gray; (17) digits, webbing, axillary membranes, groin, and hidden surfaces of arms and legs bluish-black; (18) iris coppery brown with fine brown reticulations and a narrow homogeneous, non reticulated copper ring around the pupil.

Comparison with other species of the D. leucophyllatus species group. The new species is distinguishable from all species of the Dendropsophus leucophyllatus group by having, in life, bluish-black coloration on digits, webbing, axillary membranes, groin and hidden surfaces of arms and legs (Figs. 1, 2). This color pattern fades to grayish black in preservative. All other species of the D. leucophyllatus group have yellow, orange, pink or red surfaces in life, fading to cream in preservative.

Dendropsophus manonegra sp. nov. is distinguishable from all other species of the group by the absence of vomerine teeth (present in other species of the D. leucophyllatus group, except in D. bifurcus) and a single blotch over the heel (D. elegans and D. leucophyllatus having a pair of blotches, reticulated blotches, or a blotch that covers the dorsal surface of the shank completely). From D. sarayacuensis and D. rossalleni, D. manonegra sp. nov. can be distinguished by the presence of a triangular interorbital blotch (“T-shaped” in D. sarayacuensis; two small, not connected, transversal bars in D. rossalleni). The dorsolateral bands of D. manonegra sp. nov. are regular, homogeneously filled, with straight borders while D. ebraccatus have irregular dorsolateral bands that can be interrupted by brown blotches. Many specimens of D. triangulum have and uniform dorsal color pattern, sometimes punctuated by one or two small brown blotches or even, reticulated—the favosa pattern (D. manonegra sp. nov. exhibit the frame pattern), the pectoral glands of D. triangulum are large and in contact or nearly so (pectoral glands are more inconspicuous and distinctly apart in D. manonegra sp. nov.).

Dendropsophus manonegra sp. nov. males (22.7–25.1 mm) are smaller than males of D. anceps (31.0–40.0 mm, Lutz 1973), D. leucophyllatus (30.4–36.0 mm, Duellman 1978; Caldwell & Araújo 2005), and D. salli (25.4– 30.1 mm, Jungfer et al. 2010) and are larger than males of D. rossalleni (19.0– 22.3 mm, De la Riva & Duellman 1997). The single known female of D. manonegra sp. nov. (32.5 mm) is smaller than females of D. anceps (39.0– 42.0 mm, Lutz 1973), D. leucophyllatus (37.7–50.0 mm, Caldwell & Araújo 2005; Lescure & Marty 2000), D. sarayacuensis (34.0–37.0 mm, Rodriguez & Duellman 1994), and D. triangulum (36.0–42.0 mm, Rodriguez & Duellman 1994). The female of D. manonegra sp. nov. is larger than females of D. rossalleni (28.2–28.7 mm, De la Riva & Duellman 1997).

Description of the holotype. An adult male of 23.7 mm SVL. Head as wide as body, slightly wider than long, head lenght representing 33% of SVL. Snout very short, approximately 28% of head length, truncate in both dorsal and lateral views. Internarial region subtly depressed. Nostril openings directed anterolaterally, not protuberant. Loreal region flat. Canthus rostralis indistinct. Lips thin and barely flared. Eye large, ED 1.6 times the distance between the eye and nostril, palpebral membrane translucent, with brown pigmentation at its border. A faint supratympanic fold, extending posteriorly from the posterior corner of the eye to an area above the anterior part of the arm insertion. Tympanum round, slightly wider than high, directed laterally. Tympanic annulus distinct, except for the uppermost part (about 1/4 of its diameter) that is obscured by the supratympanic fold; its diameter equals the diameter of the digital disc of finger III and is only slightly smaller (84%) than the distance between the eye and the tympanum. Digital discs round. Digital disc of finger III about 1.6 to 1.8 times the width of the finger. Relative length of fingers I <II <IV <III. Subarticular tubercles round, distal tubercle on finger IV bifid. Supernumerary tubercles on the proximal segments of digits present. Palmar tubercle flat, divided, inconspicuous. A flap-like fold extends from the palmar tubercle to the base of the digital disc of finger IV. Inner metacarpal tubercle flat, elongate. Prepollex lacking nuptial excrescences. Webbing formula of the hand: I – II 1 ¼–2 1/ 3 III 2-–1 1/ 2 IV. Vocal sac single, median, subgular, externally evident by the loose skin on the sides of the jaw and immediately below the mental region. Axillary membrane reaches the first proximal third of the arm. Two glandular patches visible on the chest, separated from each other by about half their width. Hind limbs long, TL equaling 54% of SVL. Toes bearing round digital discs, slightly smaller than those on fingers. Inner metatarsal tubercle large, ovoid. Outer metatarsal tubercle indistinct. Subarticular tubercles round, subconical. Few supernumerary tubercles on proximal segments of digits, indistinct. Relative lengths of toes I <II <III <V <IV. Webbing formula of the foot: I 1–1 II 1 +–1 1/2 III 1– 1 3/4 IV 2–1 + V. External tarsal fold and tubercles absent. Internal flap-like tarsal fold present, extending from the inner metatarsal tubercle to the tibiotarsal articulation. Calcar and heel tubercles absent. Cloacal opening directed posteriorly, situated at the level of the upper edges of thighs. Small cloacal sheat present, dorsal to the cloaca, not covering it completely. Skin smooth, except for the oval pectoral patches, which are finely granular, and the belly that is coarsely granular. Tongue oval, free laterally and posteriorly, shallowly notched behind. Vocal slits present, longitudinal, and long, originating below the rim of the central part of the tongue and running towards the corner of the mouth. Choanae small, rounded, separated by a distance almost five times its diameter. Process and vomerine teeth absent.

In life, dorsal ground color of the body, flanks and limbs dark brown with black, small, regularly disposed, well defined spots. Interocular blotch on head, dorsolateral bands, blotches on the heel and the rump are light yellow. Upper lips gray. Belly and pectoral glands are white. Digits, webbing, axillary membranes, groin, and hidden surfaces of the arms and legs are bluish-black. Chin, throat, and ventral areas of arms and legs are smoky gray. Ventrally, the pads of the digits are blue-gray. Iris coppery brown with tiny dark brown reticulations and a narrow non-reticulated copper ring around the pupil.

In preservative the dorsum is dark brown. Interocular and dorsolateral bands are creamy white, axillary membranes, groin, thigh, webbings, and digits are grayish black. Venter is creamy white and iris dark gray.

Measurements of holotype (in mm). SVL 23.7, HL 7.6, HW 8.4, ED 3.3, END 2.1NSD 1.2, IND 2.1, AMD 5.7, TD 1.4, FAL 5.7, FAB 1.7, HAL 8.7, THL 12.9, TL 12.7, TAL 6.9, FL 11.1, TFD 1.2, FFD 1.0.

Variation. Measurements of the type series are summarized in Table 1. The body is slightly wider than the head in some specimens. In some specimens the dorsolateral bands are connected posteriorly to the spot in the rump forming a frame, the color varies from light yellow to bright yellow; the dorsum may be light brown to dark brown. The bluish-black color is more intense and more exposed on the flanks in the only known female (MHUA- A 7337, Fig. 3 B). Variation exists with respect to the amount of black spots on the dorsum, more abundant at ICN 39877–39980 then on ICN 23973–24000. Few scattered yellow dots are present in some specimens (TG 1850, Fig. 3 A). Webbing on the hand varies slightly among specimens II (1-–1 1/2) – (2 1/3–2 1/2) III (2-–2) – (1 1/2–2) IV and variation of webbing between toes is I (1-–1) – (1–1 3/4) II (1–1+) – (1 1/2–2) III (1- -1) – (1 1/2–1 3/4) IV 2 – (1-–1+) V. The pectoral glands are more elliptical in the female when compared to the glands of males, which are oval. Subarticular tubercles of finger IV may be simple, bifid or divided.

Geographic distribution and natural history. Dendropsophus manonegra sp. nov. is known from three localities of the upper Amazon basin at the eastern foothills of the Andes in southern Colombia (Fig. 4), departamentos de Caquetá, Cauca and Putumayo, approximately between 400 and 1200 m a.s.l. The type locality is a temporary pond in a pasture without forest cover in the immediate vicinity. Males were calling perched on vegetation on the edge of the pond or on floating or emergent vegetation. One amplectant pair was observed (MHUA-A 7336–37). Tadpoles and advertisement calls are currently unknown. The only sympatric anuran species found at the site was Hypsiboas lanciformis.

Phylogenetic relationships. Tree search retrieved 10 equally most parsimonious trees with 6833 steps. The consensus tree is shown in Fig. 5. Most of the conflict among the shortest trees occurs at the species group-level relationships. Of the species groups retrieved by Faivovich et al. (2005) only the Dendropsophus leucophyllatus and the D. marmoratus groups were recovered as monophyletic. Overall Jackknife values are low except in some internal nodes such as the least inclusive clade containing the new species. All tree topologies depict D. manonegra sp. nov. as sister species to D. bifurcus. See Table 2 for genetic distances between species of the D. leucophyllatus species group.

Etymology. The specific name manonegra is used as a noun in apposition and is Spanish for “black hand” making reference to the unusual black flash colors of the species, especially in the webbing. It is concurrently a tribute to Mano Negra, a rock band of the 80’s and 90’s. The band was in contact with the nature, culture and society of Colombia through their project “El Expreso del Hielo” (The Train of Ice), a fantastic train ride that crossed Colombia.