Ecnomiohyla sukia, Savage, Jay M. & Kubicki, Brian, 2010

Savage, Jay M. & Kubicki, Brian, 2010, A new species of fringe-limb frog, genus Ecnomiohyla (Anura: Hylidae), from the Atlantic slope of Costa Rica, Central America, Zootaxa 2719, pp. 21-34 : 23-31

Ecnomiohyla sukia sp. nov.

Shaman Fringe-limb Frog (Figs, 1, 2, 3, 4)

Hyla fimbrimembra Duellman, 2001:898 , pl. 74, fig. 3 (in part).

Holotype. UCR 14119, an adult male from Costa Rica: Provincia de Limón: Cantón de Siquirres: Distrito de Siquirres: Guayacán: Alto Colorado, 710 m (N 10˚ 02’ 13.7” W 83˚31’ 22.4”) obtained by Miguel Solano on the 25th of March, 1999.

Paratypes. All from Costa Rica: Provincia de Limón: UCR 10966, an adult female: 5km from Moravia de Siquirres toward Turrialba (= Guayácan area) (N 10˚ 02’ W 83˚31’); UCR 15361, an adult female and UCR 15561, an adult female: Guayacán: Alto Colorado, 710 m (N 10˚ 02’ W 83˚31’); UCR 16753, an adult male & UCR 17024, an adult female: S Río Blanco (town): Fila Asunción, (N 9° 54’ W 83° 10’) 400– 500 m.

Referred specimen. Costa Rica: Provincia de Alajuela: UCR 11176 (metamorph), Reserva San Ramón: Colonia Palmeraña, (no coordinates available) 900 m.

Diagnosis. A moderate sized species of the genus Ecnomiohyla , adult males 56.7–63.3 mm in standard length, females 58.1–68.7 mm, differing from other species in the genus by the following combination of characters: 1) fingers extensively webbed (fig. 1a), web reaching base of disk on one margin of two fingers (see Table 1 ); 2) toes extensively webbed (fig. 1b), web reaching base of disks on one margin of three or four toes (see Table 1 ); 3) skin on dorsum with many scattered tubercles; tips of granules on venter not tipped with black keratin; 4) cranial and dorsal osteoderms present; 5) skin on upper surface of the head not co-ossified with cranium; 6) humerus without enlarged crista lateralis; 7) prepollex well developed, without keratinzed, black spinous excrescences in adult males; 8) prepollical bony projection directed laterally, pointed but not forming a sharp spine; 9) fleshy fringe on foot continuing onto heel as a series of fleshy flaps; 10) upper surfaces uniform brown, tan or gray or with irregular darker and/or green markings in life; capable of considerable metachrosis.

FINGERS TOES C = considerable = not to base of disk on any digit; S = substantial = to base of disk on one digit; EX = extensive = to base of disk on two to four but not all digits; F = full = to base of disk on all digits.

Diagnostic comparisons are made below to other members of Ecnomiohyla with contrasting features for E. sukia presented in parentheses (see Tables 1–2 for summary). Ecnomiohyla echinata ( Duellman, 1962) of Mexico and E. fimbrimembra ( Taylor, 1952) from Costa Rica and Panama are immediately distinguishable from the new form by having substantially less finger and toe webbing (see Table 1 ). In addition they have heel tubercles, blunt, rounded prepollical bony projections and keratinized black spinous prepollical excrescences in adult males (fleshy heel flaps, prepollical bony projection pointed, no keratinized, black spines on prepollex). Other species having less extensive finger webbing than E. sukia but sharing extensive toe webs with the new form are E. phantasmagoria ( Dunn, 1943) of Colombia, E. rabborum Mendelson, Savage, Griffith, Ross, Kubicki , and Gagliardo, 2008 of Panama, E. tuberculosa ( Boulenger, 1882) from the upper Amazon Basin and E. valancifer ( Firschein and H. M. Smith, 1956) of Mexico. Ecnomiohyla phantasmagoria has less finger webbing, the prepollical bony projection forming a spine in males, and pointed tubercles on the heel (extensive finger webbing, prepollical projection pointed, heel with fleshy flaps). In E. rabborum there is a bony humeral projection and the prepollex is covered with keratinized, black spines in adult males and the heel is without ornamentation (no humeral projection, no keratinized, black spines, heel with fleshy flaps). Hyla tuberculosa (fig. 5) lacks an enlarged prepollical bony projection in males and has large tubercles on the heel (enlarged prepollical bony projection present, heel with flesh flaps). Ecnomiohyla valancifer has a blunt flattened prepollical bony projection in adult males and two to three large tubercles on the heel (prepollical projection pointed, heel with fleshy flaps). Ecnomiohyla minera from Belize and Guatemala and E. salvaje from Guatemala and Honduras ( Wilson, McCranie, and Williams, 1985) have the cephalic skin co-ossified to the skull, the toes fully webbed, and adult males have a humeral projection, a blunt prepollical projection and keratinized, black spines on the prepollex (no co-ossification, toes with less webbing, no humeral projection, a pointed prepollical projection, no keratinized, black spines on prepollex). The two remaining species of fringe-limb hylids placed in Ecnomiohyla having extensive finger and toe webs are E. thysanota ( Duellman, 1966) of Panama and E. miliaria (Cope, “1885”, 1886) of Honduras to Panama. The former differs trenchantly from E. sukia in having a granular dorsum and a smooth heel and being uniform green in life (tuberculate dorsum, fleshy flaps on heel, not uniform green). The very large species, E. miliaria (to 110 mm in males, 86 mm in females) has the prepollical projection recurved and terminating in a sharp spine in adult males, pointed large tubercles on the heel which are tipped with black keratin in males, and many large tubercles on the upper head surface and eyelids some of which are tipped with black keratin and others with a light horny material in males, and black keratin tipped over most of the venter and flanks (prepollex not recurved, prepollical projection not terminating in a sharp spine, fleshy flaps on heel, and only a few tubercles on upper surface of head and eyelids, and no ventral and flank black-tipped tubercles).

Description. Head as wide as body, upper lip round in dorsal outline; raised snout truncate in dorsal outline and profile; snout short with nearly terminal protuberant nostrils directed laterally. Top of head flat; internarial area slightly concave; canthus rostralis concave; loreal region concave; upper lip not flared. Upper and lateral surface of head and upper eyelids with scattered tubercles, a few black tipped; a discrete series of tubercles running from midpoint of posterior margin of eye to tympanum; a continuous supratympanic and postympanic series of large tubercles, under laid by bone, that overlap the upper and posterior margin of the raised tympanum and terminate in a cluster of tubercles near angle of jaw; tympanum prominent, opaque, separated from eye by a distance slightly greater than width of tympanum; TY/E 160–180% in males, 126– 148 in females. Upper surfaces of body and limbs tuberculate with scattered larger tubercles. Flanks and venter granulate without black tipped tubercles. Arms short and upper arm hypertrophied in males; no distinct transverse dermal fold on wrist; a fleshy scalloped fringe extends from the elbow along the ventrolateral margin of forearm and continues along the outer edge of Finger IV to base of disk; scallops of fringe relatively weak, not deeply incised or pointed, largest on forearm, smaller scallops along finger.

Hands very large; fingers moderately long and robust; disk on Finger I much smaller than disks on Fingers II–IV; disk on Finger III largest, about equal in size to tympanum. Distal subarticular tubercles on fingers large, somewhat elliptical, larger than proximal subarticular tubercles on Fingers II–IV; accessory palmar tubercles numerous, low, small; thenar tubercle cordate, prepollex enlarged, protuberant, greatly enlarged and obtuse in males; bony prepollical projection bluntly pointed in males and directed laterally; tip rounded in females; fingers extensively webbed, web extending to base of disk on at least two fingers; web margin nearly even between Fingers II–IV; modal webbing formula: I 1 3/4 - 2 II 3 /4 - 1 III 1 - 3/ 4 IV. Legs relatively long and robust, heel of adpressed limbs overlapping about one-quarter length of crus; tibiotarsal articulation extends to eye when limb adpressed along side of body; distinct fleshy, scalloped fringe begins on heel and extends along ventrolateral margin of tarsus and outer margin of Toe V to base of disk; scallops relatively weak, not deeply incised or pointed, largest on tarsus, smaller scallops along toe; several small tubercles dorsal to fleshy scallops on heel; no tarsal fold. Disks on toes smaller than those on fingers, moderate on Toes III–V, smaller on Toes I–II; Subarticular tubercles under toes, small, round; inner metatarsal tubercle elongate, slightly raised, outer not distinct from accessory tubercles which are tiny and numerous; toes nearly fully webbed, webs extending to base of disks on at least three toes; web margin slightly concave between Toes II–V; modal webbing formula: I 3 /4 - 1 II 3 /4 - 1 III ¾-1 IV 1 + - 3/ 4 V. Chin, chest, venter and undersides of arms and thighs strongly granulate and lacking keratinized tips; cloacal opening directed posteriorly at mid-level of thighs with a distinct flap, many small tubercles below cloaca. Tongue broadly cordate; prevomerine tooth patches transversely elongate, narrowly separated, lying between the posterior margins of the moderately large ovoid choanae; paired vocal slits in adult males extending posterior from posterior lateral base of tongue towards angle of jaws; single partly distensible, median subgular vocal sac.

Coloration in life. Dorsal ground color varies from reddish-brown to brown or tan to gray, uniform or with irregular darker markings of brown, black, and/or green; usually a definite narrow interorbital dark band; dark bands often present on dorsal surfaces of arms and legs. Substantial metachrosis evident, with color and intensity varying with level of activity and environmental factors. Throat, chest, abdomen and ventral surfaces of arms and legs cream to white with irregular medium sized tan to brown spots; ventral spots often larger and more diffuse on the arms and legs; similar brown spots present on flanks and upper portion of posterior thigh. Posterior surface of thigh brown, usually with large pale spots. Iris pale tan to gold, finely reticulated with copper to dark brown and divided into upper and lower halves by solid brown horizontal band through center of eye.

Coloration in preservative. Dorsal ground color brownish and dark markings somewhat more emphasized than in life but no green markings evident.

Measurements of holotype in mm. SVL = 56.7; HL = 18.6; HW = 23.5; E = 6.3; TY = 3.5; C = 30.4; FL = 28.5.

Measurements of paratypes in mm. Males (N=2): SVL = 56.7–63.2; HL 32.0–33.0; HW = 40.0–42.0; C = 53.0–55.0; FL = 48.0–51.0; TY/E = 56.0–64.0; females (N=4): SVL = 62.6–68.7; HL = 33.0–40.0; HW = 40.0–46.0; C = 53.0–58.0; FL = 46.0–56.0; TY/E = 71.0–84.0.

Advertisement call. Males of this species generally call at night from high in the forest canopy, often more than 20m above the ground. The call consists of 13 to 20 staccato barks repeated after a time gap of as much or more than an hour. A single male possibly calls only several times during one night.

The accompanying audiospectrograms of E. sukia (fig. 4a–b) are calls of a male that was captured at the type locality of E. sukia . The calls where recorded on the 28th of February, 2006 in the laboratory.

Call 1 (fig. 4a) was recorded at 22.15 hours: ambient temperature 21 C; relative humidity 95–100%. The call consists of 15 separate notes, with a total duration of 7.73 sec. having a dominant frequency of 1.15 kHz. Individual call notes lasted 0.252 sec. (average of four notes selected at random) with a 0. 287 sec. pause between notes (average of four pauses selected at random).

Call 2: (fig. 4b) was recorded at 22:53 hours: ambient temperature 21 C; relative humidity 95–100%. The call consisted of 16 separate notes, with a total duration 0f 8.29 sec. having a dominant frequency of 1.15 kHz. Individual call notes lasted 0.220 sec. (average of four notes selected at random) with a 0.302 sec pause between notes (average of four pauses selected at random).

Heel few small several pointed pointed tubercles smooth pointed tubercles

tubercles tubercles

Color in life red-brown; brown with darker brown to mottled brown to green *brown with light flanks dark markings; juv. mix of brown and green with darker vermiculations brown brown-yellow-green with darker blotches markings

continued.

*color in preservative; M = Male; F = Female.

The only recorded call of E. miliaria (fig. 4c) consists of a series of 29 slurred bar-aks with a total duration of 26.03 sec having a dominant frequency of 1.05 kHz. Individual call notes lasted.323 sec (average of four notes selected at random) with a 0.562 sec pause between notes (average of four pauses selected at random).

Larva. See following paper by Hoffmann and Kubicki (2010).

Etymology. The name sukia is a noun in apposition and is derived from the Costa Rican name for the Amerind shamans of this region. We imagine that the call of the new species speaks, like those of the shamans, to communicate with the mysterious and unknown forces in the forest of the night.

Habitat and ecology. E. sukia is a nocturnal frog that inhabits mature secondary and primary humid broadleaf evergreen forests. It is a habitué of the canopy and individuals have been found in water-filled cavities, on the surface of vegetation and on tree branches. The junior author has seen about 20 individuals captured by Miguel Solano and his associates and heard about 10 individual males calling over the past decade. The species seems to be generally most active at the drier times of the year (February to April) but may be heard calling more or less randomly throughout the year. Five were kept in captivity but only one would feed under conditions in a large terrarium with ample water and hiding places. The single male, whose call was recorded, lived four year in the terrarium and ate crickets. The species uses water-filled cavities in living trees as sites for egg deposition and probably these are the places where amplexus takes place. We wish to point out that no individuals of the larger species, Ecnomiohyla miliaria have been seen nor heard subsequent to 1999 at Guayacán or elsewhere in the larger study area.

Distribution. Definitely known from two localities on the Atlantic slope in Tropical Lowland Wet Forest and Tropical Premontane Rainforest zones (sensu Savage, 2002, modified from Holdridge, 1967), Limón Province, Costa Rica (400–710 m; possibly to 900 m in northeastern Costa Rica). This species was recently found but not collected on the private reserve Las Brisas, at an elevation near 1000 m (Erick Berlin pers. comm.). The private reserve of Las Brisas is located on the Atlantic slopes of the Turrialba Volcano, Limón Province.

Tables

TABLE 1. Modal webbing formulae for species of Ecnomiohyla.

Species Extent	I – II	II – III	III – IV	Extent	I – II	II – III	III – IV	IV – V
E. echinata C	2+ - 2 ½	1–2	2–1 ½	S	1–2	1–2	1–2	2 – ¾
E. fimbrimembra C	2 ¼–3	1–2	2–1 ¼	C	1+–2+	1–2	1–2-	2–1
E. miliaria EX	1 ¾ -2	¾–1 ¼	1 ¼–¾	EX	1–1 ¼	¾–1 ½	¾–1	1–¾
E. minera EX	2–2	¾–2	2–¾	F	¾–¾	¾–¾	¾–¾	¾–¾
E. phantasmagoria C	1 ¼ –2	1 – 1+	1 ½–1	EX	¾–1+	¾–1	½–1	1+–¾
E. rabborum S	2–2 ¼	¾–1 ¼	1–1	EX	1–¼	¾–1 ¼	¾–1	1 ¼–1
E. salvaje EX	2–2 ½	¾–2	2–¾	F	¾–¾	¾–¾	¾–¾	¾–¾
E. sukia EX	1 ¾–2	¾–1	1– ¾	EX	¾–1	¾–1	¾–1	1+–¾
E. thysanota EX	2–2 ¼	¾–1 ½	1–¾+	EX	1–1+	¾–1 ¼	¾–1	1–¾
E. tuberculosa S	2–2 ¼	¾–2 ¼	2–1	EX	¾–2	¾–2	1–2	2–¾
E. valancifer C	2–2 ½	1 ¾–1	1 ¾–1	EX	1–2	¾–1 ¾	1-–1 ¼	2-–¾