Hyalinobatrachium mesai, Barrio-Amorós & Brewer-Carías, 2010

Barrio-Amorós, César L. & Brewer-Carías, Charles, 2010, Venezuelan Guayana, with the description of five new species, Zootaxa 1942, pp. 1-68 : 18-21

publication ID	https://doi.org/ 10.5281/zenodo.195474
persistent identifier	https://treatment.plazi.org/id/8D57B711-FFD2-4246-FF55-FC1CDEC8F813
treatment provided by	Felipe
scientific name	Hyalinobatrachium mesai
status	sp. nov.

Treatment

Hyalinobatrachium mesai View in CoL sp. nov.

( Figs. 6A, C, D, E, F View FIGURE 6 )

Sarisariñama Glass Frog, Ranita de Cristal de Sarisariñama

Holotype. EBRG 4644 View Materials , an adult male from Locality VI on the southern slope of Sarisariñama-tepui, Estado Bolívar, Venezuela (4º25’ N, 64º7’ W), elevation 420 m, collected on 22 March 2002 by César L. Barrio- Amorós. GoogleMaps

Etymology. The specific name is a patronym in genitive honoring Javier Mesa, a participant of critical importance to the success of our expedition, whose constant help, advice on specimens’ locations, and ability to find good collecting places were always appreciated. It is also to recognize Javier’s long stated love of nature and exploration, particularly of the Venezuelan “Lost World”.

Diagnosis. A species unassigned to any group within the genus Hyalinobatrachium , characterized by the following combination of characters (following Ruiz Carranza and Lynch 1991; Myers and Donnelly 1997, 2001): (1) vomerine teeth absent; (2) bones pale green in life; (3) pericardium transparent; hepatic and visceral peritoneum white; parietal peritoneum transparent; (4) in life head and dorsum pale green with large lime-green spots, dotted with homogeneous black melanophores, and larger black flecks, also present on limbs; in preservative, dorsum cream with white large spots, black melanophores and flecks; (5) no webbing between inner fingers; webbing formula for outer fingers III 2 1/3–1 IV; (6) foot webbing formula I 1–1 2/ 3 II 1–1 1/2 III 1–2 IV 2–1 V; (7) snout rounded in dorsal view, truncate in lateral view; (8) dorsal skin smooth in preservative, finely granular in life; ventral skin areolate; (9) ulnar and tarsal folds absent; (10) humeral spine absent in male; (11) tympanum not visible; tympanic region oriented almost vertically; (12) known size (male) 20 mm SVL; nuptial excrescences absent or inconspicuous.

Hyalinobatrachium mesai can be distinguished easily from other Guayanan species of Hyalinobatrachium (except H. taylori ) by having its bones green in life. The following diagnosis is mostly based in characters tive (black), its webbing is basal between inner fingers (absent), the webbing formula for outer fingers is III 2– 2 IV (III 2 1/3–1 IV), a bulla (see explanation in Myers and Donnelly 2001) is present in the webbing of the outer fingers (absent), and weak ulnar and tarsal folds are present (absent). Hyalinobatrachium eccentricum has a bicolored iris with a brown circumpupillary zone concealing the pupil (iris white with a profusion of black melanophores), it has a bulla in the outer finger webbing (absent), it possesses very weak ulnar and tarsal folds (absent), and the tympanum is concealed but visible through the skin (not visible). Hyalinobatrachium iaspidiense is similar in general appearance, but it has no thenar tubercle (present), smooth ventral skin (areolate), trilobate choanae (oval), a well-defined canthus rostralis (not well defined), both ulnar and tarsal folds present (absent), discs on fingers slightly wider than, or equal in width, to that of the proximal phalanx (always wider), and its toes are approximately two-thirds webbed (three-fourths). Hyalinobatrachium mondolfii has a snout that slopes in profile (truncate), granular dorsal skin (smooth), and a dorsum without black flecks (present). Hyalinobatrachium orientale has a fringe on the interior side of FII (absent), and its dorsal skin is shagreeneded (smooth). Hyalinobatrachium nouraguensis from French Guiana has a dark green dorsum in life with some black flecks (large lime-green spots and black flecks). Hyalinobatrachium ignioculus from Guyana has both ulnar and tarsal folds (absent), and has a distinctive red wide ring around the iris (absent).

Hyalinobatrachium taylori is the only other species with greenish bones. It has a sloping snout when viewed in lateral view (truncate), FI = FII (FI> FII), it has fringes between FII and FIII (absent), is dark green in life (pale green) with small white spots (large lime-green spots and black flecks), appears yellowish in preservative with a dense profusion of arachnoid purple chromatophores (whitish with large white spots and black flecks), and has calls consisting of 5–7 notes (1 or 2).

Hyalinobatrachium mesai is unique among the Guayanan species of Hyalinobatrachium by the following combination of characters: bones pale green in life (character only shared with H. taylori ), white in preservative, parietal peritoneum transparent, pericardium transparent; color in life pale green with large lime-green spots and black arachnoid flecks; dorsal skin smooth and ventral skin areolate, absence of ulnar and tarsal folds.

Description of the holotype. Size small (20 mm SVL); liver bulbous; head wider than long, wider than body; HW about 40% SVL; snout short, rounded in dorsal view, with projecting nares ( Fig. 6C View FIGURE 6 ), truncate in profile ( Fig. 6D View FIGURE 6 ), canthus rostralis indistinct; loreal region sloping towards lip; lips not flared; nostrils terminal, protuberant, directed anterolaterally; internarial region slightly concave. Eyes large, directed anterodorsally, length> EN; UEW about 92% IOD; supratympanic fold absent; tympanum indistinct; tympanic region oriented almost vertically. Vomerine teeth absent; choanae small, oval; tongue round, notched posteriorly, barely free; vocal slits extending from lateral base of tongue toward angle of jaw; distensible subgular vocal pouch.

Humeral spines absent; forearm distinctly broader than upper arm; relative lengths of adpressed fingers III> IV> I> II; webbing absent between inner fingers; webbing formula for outer fingers III 2 1/3–1 IV; bulla (sensu Myers and Donnelly 2001) absent between FIII and FIV; discs on fingers oval, distinctly wider than adjacent phalanx, those on FIII and FIV wider than those on inner fingers; thenar tubercle elliptical, low; palmar tubercle small, oval, low; supernumerary palmar tubercles indistinct; subarticular tubercles small, indistinct, low, round ( Fig. 6F View FIGURE 6 ). Hind limbs slender; tibia length 56% SVL; inner metatarsal tubercle elliptical, low; outer metatarsal tubercle round, small; supernumerary tubercles indistinct, aligned at the base of toe IV; subarticular tubercles low, round, entire. Feet about three-fourths webbed; webbing formula for foot I 1–1 2/3 II 1–1 1/2 III 1–2 IV 2–1 V. Discs on toes rounded to truncate, smaller than those on fingers ( Fig. 6E View FIGURE 6 ).

Skin on dorsal surfaces smooth; that on venter areolate; vent directed posteriorly at upper level of thighs; cloacal opening concealed by a short anal flap; anal ornamentation consisting of inconspicuous folds and arachnoid flecks. Ulnar and tarsal white stripes (but not folds) present, ulnar stripe from elbow to FIV; tarsal stripe from heel to edge of toe V. Ventrally, parietal peritoneum transparent; bones pale green; iris white with profusion of black arachnoid melanophores.

In preservative, dorsum cream with minuscule black melanophores (not seen in life but distinct under the microscope), and large white spots; flecks black; ventral surfaces uniform whitish; skin opaque; internal organs not easily discernible; iris dirty white with black melanophores.

Measurements of holotype. SVL 20.0; TL 11.2; FeL 10.8; FL 9.0; HeL 7.0; HW 8.0; Ind 1.4; UEW 2.6; IOD 2.8; EN 2.0; ED 2.7; FD 1.3; 4TD 1.0; ETS 3.0; 1FiL 3.8; 2FiL 2.4.

Natural history. The holotype (EBRG 4644) is a male that was calling on the upper surface of a Heliconia leaf 2 m aboveground and 2 m from a small stream in the forest. We heard additional males calling away from the stream, and high in the trees and bushes but we did not collect additional specimens. The tadpoles are unknown. The specimen died almost immediately after capture probably by a direct contact with a hand with insect repellent. Mark Moffett was able to photograph the specimen a few minutes after death ( Fig. 6A View FIGURE 6 ).

Vocalization. The recorded call ( Fig. 6B View FIGURE 6 ) is a high-pitched, single note, with a dominant frequency of 4700 Hz (fundamental frequency of 4300 Hz), and duration of 0.17 s. The interval between two calls is 9.3 s. Males call commonly with one note, and sometimes with two. Two-note calls were not recorded.

Remarks. Ruíz-Carranza and Lynch (1991) defined Hyalinobatrachium as having a bulbous liver covered by white peritoneum. They recognized three species groups: (1) the H. pulveratum group (Central America and northern South America) with pale green bones in life, presence of vomerine teeth, and presence of guanophores on pericardium and digestive tract; (2) the H. parvulum group (Atlantic forests of Brazil) with green or white bones, vomerine teeth present or absent, and guanophores on the pericardium and urinary bladder but not on the digestive tract; (3) and the H. fleischmanni group (species-rich and widespread in Central America and in northern and western South America) with white bones, guanophores on the digestive tract but not on the urinary bladder, variable guanophores on pericardium, and no vomerine teeth. Ruíz-Carranza and Lynch (1998) added a life history synapomorphy for the H. fleischmanni group (females laying a single layer of eggs on the undersides of leaves). They also commented that the heart is visible in the H. chirripoi subgroup. Cisneros-Heredia and McDiarmid (2006) considered the pulveratum group ( H. antisthenesi and H. pulveratum ) as Cochranella .

Hyalinobatrachium taylori was assigned tentatively to the H. fleischmanni group, but recently Señaris and Ayarzagüena (2005) concluded that due to its unique bioacoustic and morphological characters, such an assignment would be inappropriate. Hyalinobatrachium taylori and H. mesai are the only species of the genus in the Venezuelan Guayana that have pale green bones in life, a character shared with some species in the H. parvulum group. Furthermore, Ruíz-Carranza and Lynch (1991, 1998) did not consider the possibility of green bones in life for the H. fleischmanni group. Unfortunately, H. taylori is poorly known; and the name possibly involves more than one species. Lescure and Marty (2000) noted that H. taylori in French Guiana has white bones in life and a visible heart, whereas Ayarzagüena (1992) explicitly stated that in Venezuelan animals the bones are green in life and the heart is not visible. However, it is clear than Lescure and Marty’s (2000) H. taylori is actually H. aff. crurifasciatum (C. Señaris and S. Castroviejo, pers. comm.). Noonan and Bonett (2003) also showed inconsistencies in the use of the name H. taylori .

Material examined. Hyalinobatrachium crurifasciatum .— VENEZUELA: Pico Tamacuari, Sierra Tapirapecó , Amazonas, MBUCV 6428 View Materials (paratopotype) .

Hyalinobatrachium ignioculus .— VENEZUELA: Campamento YaKoo, Santa Elena de Uairén , Bolívar, MHNLS 18056 View Materials . La Laja, río Uei, Sierra de Lema , 480–490 m, MHNLS 18057-58 View Materials (males) , 18059 (female). Creek at la Escalera, 470 m, MHNLS 18060-61 View Materials .