Dendropsophus frosti, Motta, Ana P., Castroviejo-Fisher, Santiago, Venegas, Pablo J., Orrico, Victor G. D. & Padial, José M., 2012

Motta, Ana P., Castroviejo-Fisher, Santiago, Venegas, Pablo J., Orrico, Victor G. D. & Padial, José M., 2012, A new species of the Dendropsophus parviceps group from the western Amazon Basin (Amphibia: Anura: Hylidae), Zootaxa 3249, pp. 18-30 : 22-25

Dendropsophus frosti sp. nov.

( Figs. 3–4 )

Dendropsophus koechlini , Fig. 6 H—Von May and Venegas (2010).

Holotype. ANDES-A1025 (field number JMP 1986), an adult male from Km 11 on the road from Leticia to Tarapacá (04° 06' 24.2" S, 69° 56' 57.4" W; 103 m. a.s.l.), Departamento Amazonas, Colombia ( Fig. 3 ), collected on December 28, 2009 by Santiago Castroviejo-Fisher, José M. Padial, Björn Rogel, and Linn Fenna Groeneveld.

Paratypes. ANDES-A1024 (field number JMP 2014) an adult male, same data as the holotype; ANDES- A1026 and ANDES-A1027 (field number AJC 3586–5 respectively) adult female and male with same data as the holotype but collected on December 9, 2011 by Justin Touchon. CORBIDI 05882–05883 (males), CORBIDI 0 5884 (female), from Peru: Loreto, Provincia de Maynas, Piedras (between the community of Nueva Vida and San Pablo de Totolla) (02.79278° S, 72.91750° W; 150 m) collected on October 25, 2009 by Pablo J. Venegas.

Diagnosis. We assigned the new species to the genus Dendropsophus on the basis of our phylogenetic results ( Fig. 2 ) and the overall similarity with other species of the genus ( Fig. 1 ). We could not evaluate the two putative synapomorphies of the genus suggested by Faivovich et al. (2005). Dendropsophus frosti sp. nov. is a mediumsized member of the Dendropsophus parviceps group (sensu our phylogenetic results), (SVL 21.1–23.0 mm in adult males, 25.9–28.8 mm in a single female), diagnosed by the following combination of traits: slender body, head wider than body; snout truncate in dorsal and lateral views; nostrils slightly protuberant; large prominent eyes (EL/HW=0.4); palpebral membrane bearing brownish pigmentation on its border; small tympanum ( TYD / DF3=1.1); moderately developed axillary membrane; bifid distal subarticular tubercles on finger IV; prepollex concealed by skin, attached to finger I; nuptial excrescences not visible under a magnifying stereoscope in adult males; hands webbing formula I 2 ¯ —2¯ II 2 ½—2¯ III 2 +— 2 IV, feet webbing formula I 2 ½—2 II 1 +—2+ III 1—2 + IV 2 +— 1¯ V; no inner tarsal fold, tarsal tubercles absent; heel and calcar tubercles absent; cloacal opening covered by a cloacal sheath on its dorsal third; in life, dorsal surfaces presenting plain light brown coloration, ventral surfaces pale yellow, thighs and internal region of foot (through fingers III and IV) dark brown; lateral surfaces of body and head dark brown, darker in groin region; fingers I and II, and the tip of finger III pale, iris copper. In alcohol, dorsal surfaces pale brown; venter creamy white; iris gray.

Comparison to other species. Dendropsophus frosti sp. nov. differs from all other members of Dendropsophus by at least the combination of the following traits: plain light brown dorsal coloration, contrasting with dark brown flanks; fingers III and IV dark brown; fingers I and II and tip of finger II pale, and copper iris in life ( Fig. 3 ). It specifically differs from species of the D. parviceps group (sensu Faivovich et al. 2005) as follows: from D. allenorum , D. giesleri , D. koechlini , D. microps Peters 1872 , D. parviceps , D. pauiniensis , D. ruschii Weygoldt and Peixoto 1987 , and D. timbeba by having a plain ventral coloration; from D. grandisonae by having a pale venter instead of gray. D. grandisonae also differs from the new species by presenting dorsal surfaces of the arms white and a more developed patagium. Dendropsohus frosti sp. nov. differs from D. bokermanni , D. pauiniensis , and D. subocularis Dunn 1934 by having ventral surfaces granular; from D. allenorum , D. giesleri , D. microps , D. pauiniensis , and D. ruschii by lacking any kind of tubercles, spiculae or warts on dorsum. The absence of blotches, spots or bars on surfaces of thighs and groin differentiates D. frosti sp. nov. from D. bokermanni , D. brevifrons , D. luteoocellatus , D. microps , D. pauiniensis , D. timbeba , and D. subocularis . The new species also differs from all the species in the D. parviceps group, except D. giesleri , D. grandisonae , and D. timbeba , by lacking suborbital bars. Females of D. brevifrons present a broad dorsolateral light stripe, which is absent in females of D. frosti sp. nov.

Description of holotype. Adult male, SVL 22.8 mm; body slender; head wider than body, slightly wider than long, HW/HL 1.1, widest below eyes; snout truncate in dorsal and lateral views; canthus rostralis present, curved; loreal region flat; lips thin; nostrils slightly protuberant, directed anterolaterally. Interorbital area flat; eyes large (EL/HW=0.4) and protuberant; palpebral membrane translucent, with brown pigmentation on its border. Tympanum small ( TYD /DF3=1.1), distinct, directed laterally. Tympanic annulus and membrane evident, supratympanic fold absent. Forearm slender, not hypertrophied, bearing a slight axillary membrane; fingers short, bearing round discs; relative length of fingers I <II <IV <III; subarticular tubercles small, round, bifid on finger IV, most prominent on finger I; supernumerary tubercles absent; inner metacarpal tubercle flat, elongate; outer metacarpal tubercle flat small, round; nuptial excrescences absent; webbing basal between fingers I and II; webbing formula I 2 ¯ — 2¯ II 2 ½— 2¯ III 2 +— 2 IV. Hind limb long and slender; TL/SVL = 0.5; no tarsal fold; calcar and heel tubercles absent; toes bearing round discs, smaller than those on fingers; relative lengths of toes I <II <III <V <IV; subarticular tubercles, round, elevated; supernumerary tubercles absent; inner metatarsal tubercle flat, elongate; outer metatarsal tubercle flat, round; webbing formula I 2 ½—2 II 1 +—2+ III 1—2 + IV 2 +—1¯ V. Skin on dorsum, head, dorsal surfaces of forearms and thighs, flanks and groin smooth; skin on belly and ventral surfaces of thighs granular. Cloacal opening directed posteriorly at midlevel of thighs, covered by cloacal sheath dorsally; cloacal tubercles absent. Tongue cordiform, barely free behind; dentigerous process of vomers evident, in two transverse series, positioned obliquely to choanae, each having two vomerine teeth; choanae large, rounded; vocal slits moderately long, extending from midlateral base of tongue, almost reaching to angle of jaws; vocal sac single, median, subgular. In life, dorsal surfaces of body, head, arms and tibia, and the external region of foot (including toe V) light brown; thighs and internal region of foot (including toes III and IV) dark brown; lateral surfaces of body and head dark brown, darker than dorsal surfaces, with darkest region on groin; fingers I and II, and the tip of Finger III pale; venter pale yellow; iris copper. In alcohol, dorsal surfaces pale brown; venter creamy white; iris gray. The holotype is missing the right foot because it was cut at the level of heel as a tissue sample for molecular studies.

Measurements of holotype (in mm): SVL 22.8, HL 8.1, HW 8.8, ED 3.8, ELW 1.8, ES 2.9, TYD 1.4, DF3 1.4, TL 12.3, THL 11.9, FL 9.9.

Variation of type series. Type series is morphologically concurrent with the holotype, although the two females are larger than the males. Measurements of the type series are summarized in Table 1 . The female COR- BIDI 0 5884 has four vomerine teeth per dentigerous process of vomer. At night the dorsal coloration of the Peruvian specimens is yellow in males and pale brown in females without a contrasting coloration in the flanks or thighs. By day, the dorsal coloration of males and females are brown, ventral surfaces pale yellow, thighs and internal region of foot (including toes IV and V) and shanks dark brown (nearly black); toes I-III pale; lateral surface of body and head dark brown, with darkest region on groin; fingers I and II, and the tip of fingers III pale, iris copper. In life, all Peruvian paratypes presented a pale vertical stripe in the rostrum extending posteriorly as a pale narrow stripe from the rostrum to the tympanum through the canthus rostralis and eyelids, fading from the posterior margin of the eyelid over the dorsal margin of the tympanum ( Fig. 4 ). Coloration in preservative resembles that of coloration in life during daylight. The pale vertical stripe in the rostrum of the Peruvian specimens is also apparent in preservative.

Distribution and ecology. The two localities are in terra firme Amazonian lowland forests close to large river channels ( Fig. 5 ). Justin Touchon (pers. comm.) placed the amplectant pair ANDES-A1026– 7 in a semi-natural enclosure consisting of a 1m diameter pool, floating vegetation and emergent vegetation, and surrounded by a nylon mesh cage supported by PVC poles ~ 2m tall. A thin, black cloth to increase shade covered the cage. The pair was left in the cage overnight and laid a single clutch of 70 eggs, 80 cm above the surface of the water, attached to the PVC supports. Although only a single observation, this indicates that they can and will lay terrestrial eggs attached to a rigid surface (such as a tree trunk in nature). Of course, they may also lay clutches on leaves or other arboreal substrate under different conditions. Justin Touchon carefully removed 5 eggs from the jelly, photographed them on 5mm grid paper and measured their diameters in ImageJ. Average egg diameter was 1.9 mm (0.17 SD). The Peruvian locality is in an extensive complex of high terraces forest, at elevations of 90– 170 m.a.s.l., close to the Algodoncillo River, which drains in the Algodón River, of the Putumayo basin. Specimens were found at night perching on low vegetation around ponds in primary forest. Several males were calling and two amplectant pairs were observed in the Peruvian locality, but calls were not recorded. Other Dendrosophus species occurring in the same area at both localities were D. rhodopeplus , including in the same ponds where the new species was collected.

Etymology. The name is a patronym for Darrel Frost—a well-known North American herpetologist— in recognition of his contribution to amphibian systematics, his encouragement, and for sharing his ample knowledge with us.

Figures

FIGURE 1. Living specimens of 11 species of the Dendropsophus parviceps group sensu Faivovich et al. (2005): A) D. allenorum from Madre de Dios, Peru (photo: W. E. Duellman); B) D. bokermanni from Sucumbios, Ecuador (photo: W. E. Duellman); C) D. luteoocellatus from Venezuela (photo: A. Acevedo); D, E) D. brevifrons from Leticia, Colombia (photos: J. M. Padial); F) D. microps from Brazil (photo: M. Sacramento); G, H) D. giesleri from Brazil (photos: L. Drummond); I) D. ruschii from Espirito Santo, Brazil (photo: P. Peloso); J, K) D. koechlini from Cruzeiro do Sul, Acre, Brazil (photos: T. Grant); L) D. schubarti from Cuzco Amazónico, Madre de Dios, Peru (photo: W. E. Duellman); M, N) D. parviceps from Leticia, Colombia (photos: J. M. Padial); O) D. subocularis from Santander, Colombia (photo: C. Hernandez-Jaimes). Photographs A, B and L are courtesy of the Biodiversity Institute, University of Kansas. Photographs are not at the same scale (i. e. they have no morphometric value) and are presented for coloration, shape, and skin structure comparisons.

FIGURE 3. Adult male holotype of Dendropsophus frosti sp. nov. ANDES-A 1025, SVL = 22.8 mm. Photos of the live specimen illustrate coloration during daylight. Photos: preserved specimen S. Castroviejo-Fisher, live specimen J. M. Padial.

FIGURE 4. Peruvian paratypes of Dendropsophus frosti sp. nov. presenting the rostral stripe. Photos illustrate coloration during daylight. Photos: P. J. Venegas.

FIGURE 5. Map of western Amazon Basin showing the type (dot) and paratype (square) localities of Dendropsophus frosti sp. nov.

FIGURE 6. Accumulation curve of named species of Dendropsophus according to Frost (2011).

FIGURE 2. A) Maximum parsimony and B) Maximum likelihood best trees for 42 terminals, including 38 samples of 36 species of Dendropsophus, inferred from the 16 S and 12 S rRNA genes (see methods). Numbers above nodes are bootstrap values. In red are members of the D. parviceps group, and Dendropsophus frosti sp. nov. is highlighted in bold red.

Tables

TABLE 1. Measurements (mm) and proportions of adult specimens of Dendropsophus frosti sp. nov. (mean and ± standard deviation in parentheses).

	males (n=4*)	females (n=1*)
SVL	21.1–25.2 (22.1 ± 0.9)	25.9–28.8
HL	7.1–8.1 (7.5 ± 0.4)	8.6
HW	7.3–8.8 (8.0 ± 0.7)	8.2
ED	3.4–3.8 (3.6 ± 0.2)	3.2
TYD	0.9–1.4 (1.2 ± 0.2)	1.5
DF3	1.0–1.4 (1.2 ± 0.2)	1.0
TL	11.8–12.3 (12.0 ± 0.2)	12.9
TH	11.5–12.0 (11.8 ± 0.3)	12.3
FL	9.5–9.9 (9.7 ± 0.2)	10.3
TL/SVL	0.5–0.6 (0.6 ± 0.0)	0.5
FL/SVL	0.4–0.5 (0.5 ± 0.0)	0.4
HL/SVL	0.3–0.4 (0.3 ± 0.0)	0.3
HW/SVL	0.3–0.4 (0.4 ± 0.0)	0.3
HW/HL	1.0–1.1 (1.1 ± 0.1)	1.0
EL/HW	0.4–0.5 (0.5 ± 0.0)	0.4
*We only included	SVL for paratypes ANDES-A1026–7.