Dendropsophus kubricki, Rivadeneira, C. Daniel, Venegas, Pablo J. & Ron, Santiago R., 2018

Rivadeneira, C. Daniel, Venegas, Pablo J. & Ron, Santiago R., 2018, Species limits within the widespread Amazonian treefrog Dendropsophusparviceps with descriptions of two new species (Anura, Hylidae), ZooKeys 726, pp. 25-77 : 46-52

Dendropsophus kubricki sp. n. Figs 1, 7C, 13, 14

Holotype.

CORBIDI 15778, an adult male from Peru, Loreto Department, Requena Province, Campamento Wishuincho-Rio Tapiche (7.1914°S, 73.9781°W), 120 m above sea level, collected on 11 October 2014 by P. J. Venegas.

Paratypes.

Nine adult males and an adult female from Peru, Loreto Department, Requena Province, Campamento Wishuincho-Rio Tapiche (7.1914°S, 73.9781°W), 120 m above sea level: CORBIDI 15775 77, adult males, collected on 9 October 2014 by P. J. Venegas; CORBIDI 15779 84, adult males, collected on 12 October 2014 by P. J. Venegas; CORBIDI 15785, adult female, collected on 12 October 2014 by P. J. Venegas. Three adult males and four adult females from Peru, Loreto Department, Requena Province, Sierra del Divisor (6.9187°S, 73.8461°W), 500 m above sea level: CORBIDI 3762, 3970, 3983, adult males, collected in January 2009 by R. Santa Cruz; CORBIDI 2281, adult female, collected on 1 November 2008 by D. Vasquez; CORBIDI 3743 44, 3780, adult females, collected in January 2009 by R. Santa Cruz.

Referred specimens.

An adult male and three adult females from Peru, San Martin Department, Picota Province, Area de Conservacion Municipal Chambira (7.0375°S, 76.0900°W), 679 m above sea level: CORBIDI 8863, adult male, collected on 27 November 2010 by P. J. Venegas; CORBIDI 8861 62, 8864, adult females, collected on 27 November 2010 by P. J. Venegas.

Etymology.

The specific name kubricki is a noun in the genitive case and is a patronym for Stanley Kubrick, an American filmmaker who is one of the most brilliant and influential film directors of all time. We dedicate this species to him for his legacy to film culture and science fiction.

Diagnosis.

Throughout the species description, coloration refers to preserved specimens unless otherwise noted. The new species is assigned to the genus Dendropsophus based on our phylogenetic results (Fig. 1) and the overall similarity with D. parviceps and other species of the genus (Figs 13 14). Dendropsophus kubricki is a medium-sized species, relative to other species in the D. parviceps group and is characterized by the following combination of traits: (1) size sexually dimorphic; mean SVL 19.4 mm in males (range 18.3 20.1; n = 14), 26.0 mm in females (range 22.0 28.4; n = 8); (2) throat with white flecks posteriorly in males and white blotch with stripes posteriorly in females (Fig. 14); (3) snout truncate in dorsal view, rounded and inclined posteroventrally in lateral view; (4) nostrils slightly prominent; (5) tympanum distinct, rounded, concealed posterodorsally, tympanic membrane non-differentiated and annulus evident; (6) low tubercles on upper eyelid can be distinct or ill-defined; (7) thoracic fold slightly evident or indistinct; (8) ulnar tubercles and outer tarsal tubercles low; (9) axillary membrane present; (10) skin on dorsal surfaces smooth with scattered tubercles mainly on head; skin on throat areolate, skin on chest, belly, posterior surfaces of thighs, and subcloacal area coarsely areolate; (11) dark brown markings on dorsum consisting of chevrons and transverse blotches in variable arrangements (Fig. 14); (12) thenar tubercle distinct; (13) hand webbing formula II1-?2+III1-?1-IV, foot webbing formula I1-?2-II1-?2-III1- 2IV2?1-V; (14) in life, dorsal surfaces reddish brown, brown, or grayish tan; (15) orange to amber blotch on the proximal ventral surface of shanks and under arms, from the axillae to near elbow, in life (white to creamy white in preserved); (16) one suborbital white bar present both in life and preserved; (17) anterodorsal surfaces of thighs are black to dark brown with two or three white spots, both in life and preserved; (18) iris in life is reddish brown, brown or silver gray.

Comparisons with other species.

Dendropsophus kubricki is most similar to D. kamagarini and D. parviceps . It is distinguished from D. parviceps by its larger size (Fig. 2; see Morphological comparisons), lower dominant frequency in advertisement call (Fig. 4A B, E F; see Bioacoustic comparisons), throat with white flecks or white medial spot posteriorly in males, both in life and preservative (dark flecks posteriorly in males both in life and preservative in D. parviceps ), and scattered low tubercles on the upper eyelids (smooth in D. parviceps ). Dendropsophus kubricki differs from D. kamagarini by lacking a prominent conical tubercle on the distal edge of the upper eyelid (present in D. kamagarini ; Fig. 12). Dendropsophus kubricki also differs from D. parviceps and D. kamagarini by having a more rounded snout in profile (Fig. 12). Dendropsophus kubricki differs from other species of the D. parviceps group (sensu Fouquet et al. 2015) by having, in life, an orange blotch on the proximal ventral surface of shanks and arms [orange blotches are absent in D. bokermanni ( Goin 1960; Duellman and Crump 1974), in D. brevifrons ( Duellman and Crump 1974), in D. counani ( Fouquet et al. 2015), in D. frosti ( Motta et al. 2012) and in D. koechlini ( Duellman and Trueb 1989)]. Dendropsophus kubricki also resembles D. pauiniensis , but it differs by the presence of an orange blotch on the proximal ventral surface of shanks (absent in D. pauiniensis ; Heyer 1977).

Description of holotype.

Adult male (Fig. 7C), SVL 19.0 mm. Head as wide as body, slightly wider than long, widest below eyes; snout truncate and short in dorsal view, moderately rounded and slightly inclined posteroventrally in lateral view; loreal region concave; lips thin; internarial region slightly concave; nostrils slightly protuberant dorsally and laterally; interorbital area flat; tympanum rounded and distinct, tympanic annulus evident, tympanic membrane non-differentiated, supratympanic fold thin, covering tympanum posterodorsally. Arms slender, not hypertrophied; axillary membrane extending along proximal one third of arm; ulnar fold distinct, low ulnar tubercles present; fingers short, bearing small, round discs; relative length of fingers I <II <IV <III; subarticular tubercles small, round on fingers I and II, bifid on finger III, and divided on finger IV; supernumerary tubercles small, slightly evident; thenar tubercle distinct; palmar tubercle flat, round; webbing basal between fingers I and II; hand webbing formula II1-?2-III1- 1IV. Hindlimbs long, slender; tarsal fold absent, low outer tarsal tubercles present; calcar and heel tubercles absent; toes moderately long, bearing round discs, smaller than those of fingers; relative length of toes I <II <III <V <IV; subarticular tubercles small, round; supernumerary tubercles indistinct; inner metatarsal tubercle small, flat, elliptical; outer metatarsal tubercle absent; foot webbing formula I1- 2II1- 2III1- 2IV2 1-V. Skin on dorsum and head smooth with scattered tubercles, skin on dorsal surfaces of limbs, flanks and groins smooth; skin on venter, posterior surfaces of thighs and subcloacal area coarsely areolate; skin on chest and throat areolate; skin on other surfaces smooth. Cloacal opening directed posteriorly at upper level of thighs; cloacal sheath short; cloacal folds and tubercles absent. Tongue cordiform, barely free posteriorly; dentigerous process of vomers small, prominent, adjacent medially, each bearing three and five vomerine teeth (left/right), positioned obliquely to choanae; choanae small, rounded; vocal slits long, extending from midlateral base of tongue to angle of jaws; vocal sac single, median, subgular.

Color of holotype in preservative

(Fig. 7C). Dorsal surfaces of head, body, and limbs brownish gray with scattered reddish brown flecks with melanophores and leucophores on dorsum, dark brown markings on dorsum consisting of a median blotch anteriorly and transverse bar posteriorly; dark brown broad transverse bars on the forelimbs and shanks; snout brown dorsally; scapular region gray; thighs black with three white spots on the anterodorsal surfaces; one small white suborbital bar. Ventral surface of belly dark brown mottled with white anteriorly and with translucent white posteriorly and laterally; chest white; throat dark brown anteriorly and white with dark brown flecks posteriorly; ventral surfaces of the forelimbs translucent white; thighs translucent white anteriorly and dark brown posteriorly.

Measurements of holotype (in mm).

SVL 19.0, HW 6.6, HL 6.3, END 1.8, IN 1.5, FL 9.1, TL 10.0, FL 7.3.

Variation.

Morphometric variation of the paratype series is summarized in Table 3. Variation in dorsal and ventral coloration of preserved specimens is shown in Figure 14. Dorsal coloration in alcohol varies from gray (e.g., CORBIDI 15777) to grayish tan (e.g., CORBIDI 2281, 15775), reddish brown (e.g., CORDIBI 15779), brown (e.g., CORBIDI 8864), grayish brown (e.g., CORBIDI 15780), dark brown (e.g., CORBIDI 8862), or pinkish gray (e.g., CORBIDI 15785); some specimens have scattered reddish brown low tubercles and slightly black flecks (e.g., CORBIDI 15775, 15777, 15784). Occipital region with dark brown median blotch, one blotch in scapular region and dark brown transverse bar in sacral region extending onto flanks (e.g., CORBIDI 15779, 15780, 15784); some specimens have two)(shaped dorsolateral stripes beginning on the upper eyelids and ending on the posterior flanks (e.g., CORBIDI 8862, 8864). The dorsum has tubercles mainly on head and upper eyelid (e.g., CORBIDI 8864, 8861, 15776, 15785), but some specimens have a smooth dorsum without tubercles (e.g., CORBIDI 2281, 3744; Fig. 14). Some specimens have postrictal tubercles, posteroventrally to tympanic annulus (e.g., CORBIDI 15775, 15780).

The venter of preserved specimens (Fig. 14) varies from black (e.g., CORBIDI 15780, 15785) to dark brown (e.g., CORBIDI 8864) with scattered white or creamy flecks. The throat anteriorly (Fig. 14) varies from brown (e.g., CORBIDI 8863, 15784), dark brown (e.g., CORBIDI 8862), grayish tan (e.g., CORBIDI 2281, 15775) to black (e.g., CORBIDI 15779, 15780) with white flecks (e.g., CORBIDI 15779), one irregular white stain (e.g., CORBIDI 2281, 8862) or stripes (e.g., CORBIDI 8864, 15785) posteriorly. The subcloacal area is white in most specimens (e.g., CORBIDI 15775, 15780, 15785), but it is black in some (e.g., CORBIDI 8862, 8863, 8864).

Color in life.

Based on digital photographs (Fig. 13): dorsum varies from reddish brown, brownish gray, brown to creamy tan suffused with gray and brown with scattered white flecks, with or without reddish brown or brown low tubercles; some individuals have few scattered dark brown flecks on the dorsum; flanks are white with black or dark brown vertical bars; dorsal markings are dark brown, some individuals are mustard brown dorsolaterally; dorsal surfaces of forelimbs and shanks have dark brown transversal bars; anterodorsal surfaces of the thighs are black to dark brown with two or three spots. The single suborbital bar is white. The venter is black to dark brown mottled with translucent gray, and with white flecks anteriorly; some individuals have scattered white flecks on venter; chest is white; throat is brown, reddish brown, or dark brown with white flecks posteriorly in males (posterior part of throat with white blotch with or without stripes in females), some individuals have a white medial spot adjacent to the chest; the ventral surfaces of the limbs are translucent gray, the thighs are mottled with black or dark brown anteriorly; posteriorly the thighs are black with white flecks; the proximal ventral surface of shanks and arms, from the axillae to near the elbow, have an orange or amber blotch. The iris is reddish brown, brown, or silver gray.

Calls

(Fig. 4E?F). Descriptive statistics of acoustic variables are provided in Table 7. We recorded three males (two not collected and CORBIDI 15778) at Campamento Wishuincho-Rio Tapiche (Loreto Department, Requena Province, Peru) on 11 October 2014 at 12:53h and 12 October 2014 at 21:53h. We also recorded one male (not collected) at Cordillera Azul (7.8103°S, 75.9928°W, 725 m, San Martin Department, Picota Province, Peru).

The advertisement call is a pulsed note (Fig. 4E?F). The amplitude of the advertisement call increases gradually until three-quarters of the note duration to decrease abruptly until the end. This call may be followed by one or more click notes. These clicks sometimes are emitted alone. Moreover, the click notes are pulsed, except for the last one which is unpulsed.

Distribution and ecology.

Dendropsophus kubricki is distributed in the Amazon basin in northeastern and central Peru (Fig. 9), at elevations between 106 (Jenaro Herrera) and 725 m (Cordillera Azul). Dendropsophus kubricki was found in flooded forest. Specimens from Chambira were collected in a small pond in a Terra Firme forest. Males call at night while perching on leaves of bushes and trees. They were observed between 0.3 and 0.4 m above the water.

Conservation status.

Extent of occurrence (B1) is 53,548 km2. Dendropsophus kubricki occurs in the following protected areas: Sierra del Divisor National Park, Cordillera Azul National Park, and Cordillera Escalera Regional Conservation Area. Because its distribution range is large and occurs in protected areas, we recommend that D. kubricki is assigned to the Least Concern category, following IUCN (2001) criteria.

Remarks.

Specimens from Chambira (Picota Province) are closely related to Rio Tapiche and Jenaro Herrera specimens (both localities from Requena Province) (Fig. 1); genetic distances between these populations are low (mean p-distances 1.3% in mitochondrial gene 12S). Therefore, we include them tentatively in Dendropsophus kubricki . However, individuals from Chambira and Tarapoto (Picota and San Martin provinces, respectively) show differences in coloration because their dorsal tubercles have the same color as the background, white flecks and reddish brown low tubercles on the dorsum and dorsal surfaces are absent both in life and preservative (present in Rio Tapiche and Jenaro Herrera individuals; Figs 13 14). In addition, there is segregation in acoustic space between advertisement calls from Cordillera Azul (Picota Province) and the type locality (Fig. 5; Table 7). Therefore, it is conceivable that they represent a separate species.