Centrolene mariaelenae Cisneros­Heredia & McDiarmid, 2006

Cisneros-Heredia, Diego F. & Mcdiarmid, And Roy W., 2006, A new species of the genus Centrolene (Amphibia: Anura: Centrolenidae) from Ecuador with comments on the taxonomy and biogeography of Glassfrogs, Zootaxa 1244, pp. 1-32 : 4-12

Centrolene mariaelenae Cisneros­Heredia & McDiarmid , new species

( Fig. 1–4 )

Holotype

DFCH­USFQ D125, an adult male taken along a small stream, tributary of the Jambue River, ca. 16 km S from Zamora, Podocarpus National Park (ca. 04º15’S, 78º56’W, 1820 m), on the western slope of Contrafuerte de Tzunantza, Cordillera Oriental, eastern slopes of the Andes, Provincia de Zamora­Chinchipe, Republic of Ecuador ( Fig. 5 ), on 0 3 March 2002 by F. Smith and L. Wesch.

Diagnosis

This new taxon possesses a humeral spine thus it is placed in the genus Centrolene ( Ruíz­Carranza & Lynch 1991a), and it is assigned to the gorzulai species group because the parietal peritoneum is transparent and the hepatic peritoneum is covered by guanophores ( Noonan & Harvey 2000; Duellman & Señaris 2003). Centrolene mariaelenae is diagnosed from other species of the family by the combination of the following characters: (1) vomerine teeth absent; (2) bones white in preservative (unknown in life); (3) parietal peritoneum clear without guanophores in a bib­like fashion; guanophores covering on the pericardial, hepatic and visceral peritonea, except for the clear gall bladder; (4) color in preservative, dorsal and flank surfaces cream with many small dark lavender punctuations and scattered larger dark flecks; (5) webbing absent between fingers I and II, basal between fingers II and III, outer fingers III2 ½­2½IV; (6) webbing on feet I2 ­–2½ II2­3III2­3IV2 %­1%V; (7) snout bluntly truncate in dorsal view and truncate in profile; notch in lower lip absent; nostrils elevated, indentation between the nostrils; loreal region concave; (8) dorsal skin shagreen; (9) no dermal folds on hands, forearms, feet, or tarsus; (10) humeral spine present in male holotype; (11) tympanum oriented posterolaterally with light dorsal inclination; tympanic annulus rather indistinct; supratympanic fold weak; (12) snout­vent length in male holotype 19.0 mm; females unknown; (13) prepollical spine not protruding externally; unpigmented nuptial pad Type I; (14) pair of large, round, flat tubercles on ventral surfaces of thighs below vent; other anal ornamentation absent, ventral skin granular and not enameled; (15) first finger longer than second, (16) liver apparently bulbous (but see Discussion); (17) eye diameter larger than width of disc on finger III; (18) iris grey in preservative; (19) melanophores absent on fingers and toes except for a few at the base of Toe V; (20) the advertisement call is unknown for this species.

Comparisions

Centrolene mariaelenae is the only known Andean centrolenid frog that has a humeral spine, transparent parietal peritoneum, and guanophores covering the pericardial, hepatic and visceral peritonea. These characteristics are currently shared only with members of the gorzulai species group ( Centrolene gorzulai [Ayarzagüena], C. lema Duellman & Señaris , and C. papillahallicum Noonan & Harvey ) endemic to the Guayanan Region of eastern Venezuela and adjacent Guayana (Table 1 and 2, Fig. 5 ). All other members of the gorzulai species group differ from C. mariaelenae by having guanophores on the parietal peritoneum in a bib­like fashion covering only the heart and by its color in preservative. Further, C. gorzulai differs from C. mariaelenae by its subtruncate snout in dorsal view, glandular nuptial pad, prepollical spine protruding externally, and long snout (EN>IOD). Centrolene lema is distinguished from C. mariaelenae by having more hand webbing, visceral peritoneum clear, tympanum barely evident, and melanophores on toes IV and V. Centrolene papillahallicum differs from C. mariaelenae by having a subtruncate snout in dorsal view; anal ornamentation consisting of small enameled tubercles below vent; first finger equal in length to second; and scattered melanophores on fingers and toes. The distribution of salient characters among species in the Centrolene gorzulai group is presented in Table 1. Members of the genus Hyalinobatrachium have a clear parietal peritoneum, white visceral and hepatic peritonea, and a bulbous liver, but differ by lacking humeral spines in males, usually having a cream dorsal coloration in preservative with pale spots or reticulations and no dark flecks, and having a clear pericardium (visible heart) in some species.

Description of the holotype

Adult male, SVL = 19.0 mm ( Fig. 1 ). Body slender. Head distinct, slightly wider than long, and wider than body; HW/HL = 1.12, HW/SVL = 0.40, HL/SVL = 0.35. Snout short, bluntly truncate in dorsal view and truncate in profile, EN/HL = 0.26; indentation at internarial region between protuberant nostrils; canthus rostralis rounded, rather indistinct, a shallow platform between the canthus rostralis; concave loreal region; lips slightly flared. Eyes large, ED/HL = 0.35, directed anterolaterally at about 39° from midline, eyes can be seen when viewed from below, interorbital area wider than eye diameter, IOD/ED = 1.39, EN/ED = 0.74, EN/IOD = 0.53. Tympanum oriented posterolaterally with light dorsal inclination, separated from orbit by distance nearly equal to tympanum diameter; tympanic annulus rather indistinct, slightly elevated interiorly and ventrally; supratympanic fold weak, TYD /ED = 0.61 ( Fig. 2 ). Dentigerous processes of vomers absent, choanae small, rather elliptical, widely separated medially; tongue elongately ovoid, not indented posteriorly, free posteriorly and laterally; vocal slits paired, elongated (around 2/3 of the tongue length), extending from mid­lateral base of tongue to angles of jaws.

Skin of dorsal surfaces of head, body, and limbs shagreen; belly granular, all other ventral surfaces shagreen. Cloacal opening directed posteriorly at upper level of thighs; no distinct cloacal sheath; a pair of large, round, flat tubercles on ventral surfaces of tights below vent, other anal ornamentation absent, ventral skin granular and not enameled.

Upper arm thin, forearm robust, breadth of upper arm about half that of forearm. Humeral spine present ( Fig. 3 ); ulnar fold and tubercles absent. Relative lengths of fingers II <I <IV <III; webbing absent between fingers I and II, basal between finger II and III, III 2 ½–2½ IV; bulla absent in fingers web, lateral fringes present on fingers III and IV; finger discs wide, nearly truncate; disc on third finger slightly larger than those on toes, and shorter than eye diameter, 3DW/ED = 0.61, 3DW/ TYD = 1.0; subarticular tubercles rounded and elevated; supernumerary tubercles small, rather indistinct; palmar tubercle large, ovoid, flat, tenar tubercle indistinct. Protruding prepollical spine absent; nuptial excrescences Type I, unpigmented.

Eye diameter versus diameter of third finger disc; 2: for species where it is known; 3: dark and light

green are coded as green.

Hind limbs slender; heels of adpressed limbs perpendicular to body touch but do not overlap; TL/SVL = 0.57, FL/SVL = 0.46. Fringes and tarsal fold absent; inner metatarsal tubercle small, elliptical, rather indistinct, outer metatarsal tubercle absent; subarticular tubercles; supernumerary tubercles small, rather indistinct. Webbing on foot I2 ­–2½ II2­ 3III2­3IV2 %­1%V; lateral fringes distinct on toe IV; disc on toe I round not expanded, all other discs bluntly truncate, pointed projection on disc of toe I absent.

Coloration of holotype

In preservative, all dorsal surfaces cream with many small, dark, lavender punctuations and scattered bigger dark flecks ( Fig. 1–2 ); venter cream. Bones white in preservative but possibly green in life as in other members of the group. Parietal peritoneum clear, without guanophores in a bib­like fashion; pericardial, hepatic, and visceral peritonea, sclera and testes white (covered by guanophores); gall and urinary bladders clear ( Fig. 4 ).

Measurements (in millimeters)

SVL 19.0; HW 7.4; HL 6.6; ED 2.3; IOD 3.2; EN 1.7; TL 10.8; FL 8.7; TYD 1.4; IN 2.0; 3DW 1.4.

Etymology

The specific name of this Glassfrog is a noun in the genitive case and a patronym for María Elena Heredia, D.F. Cisneros­Heredia’s mother, who will always be grateful for her permanent support of his work in herpetology, her friendship, field companionship, and infinite love.

Distribution and ecology

Centrolene mariaelenae is known only from a single specimen collected in the province of Zamora­Chinchipe, Ecuador ( Fig. 5 ). The holotype is an adult male found at night on a leaf ca. 2 m above water in the immediate vicinity of a small stream in old secondary­growth Low Montane Evergreen Forest at 1800 m elevation. The small stream is tributary of the Jambue River on the western slope of the Contrafuerte (Cordillera) de Tzunantza, a ridge part of the Cordillera Oriental (Cordillera Real), southeastern E cuadorian Andes. The Contrafuerte de Tzunantza is separated to the north by the Nangaritza river valley from the Cordillera del Cóndor. Centrolene mariaelenae may be distributed over the nearby slopes of the Cordillera Oriental or in the mountain ranges of Cordillera del Cóndor or Cordillera del Cutucú. It could have even a wider distribution to the south, reaching northern Peru.

Centrolene mariaelenae was collected sympatrically with two other centrolenid frogs, Cochranella cochranae Goin and an undescribed species of Centrolene . Several areas near the type locality have been surveyed but only C. cochranae and Hyloscirtus phyllognathus (Melin) were found in riverine areas (Smith and Wesch, unpubl. data, Almeida and Nogales, unpubl. data).

Figures

FIGURE 1. Dorsal view of the holotype of Centrolene mariaelenae (DFCH­USFQ D 125), SVL = 19.0, adult male. Photo by Sebastián Cruz.

FIGURE 2. Dorsal view of the head of the holotype of Centrolene mariaelenae (DFCH­USFQ D 125), SVL = 19.0, adult male. Photo by Sebastián Cruz.

FIGURE 3. Humeral spine of the holotype of Centrolene mariaelenae (DFCH­USFQ D 125), SVL = 19.0, adult male. Photo by Sebastián Cruz.

FIGURE 4. Internal morphology of the holotype of Centrolene mariaelenae (DFCH­USFQ D 125), SVL = 19.0, showing the guanophores covering the pericardium, and the hepatic and visceral peritonea. Photo by Sebastián Cruz.

FIGURE 5. Map of Ecuador with the position of the type­locality of Centrolene mariaelenae. Lower insert with the northern portion of South America showing the distribution of the taxa of the Centrolene gorzulai species group in the Guayana Shield and in southeastern Ecuador.