Rana eschatia, Inger & Stuart & Iskandar, 2009

Inger, Robert F., Stuart, Bryan L. & Iskandar, Djoko T., 2009, Systematics of a widespread Southeast Asian frog, Rana chalconota (Amphibia: Anura: Ranidae), Zoological Journal of the Linnean Society 155 (1), pp. 123-147 : 134-135

RANA ESCHATIA SP. NOV.

(Previously referred to as Thailand morphotype)

Rana labialis Smith, 1916: 168 .

Rana chalconota Smith, 1930: 109 .

Holotype

THNHM 05677 (field number 66721), an adult female from Ngao Falls National Park (9°56′N / 98°43′E), Ranong Province, Thailand. Collected on a gravel bank 0.1 m from the edge of a stream in secondary forest, 26.xi.2004, by Jennifer Sheridan and Tanya Chan-ard.

Paratypes

From the type locality FMNH 268523, 268526-28, 268530 (adult males with nuptial pads) FMNH 268524, 268529 (adult females with convoluted oviducts), FMNH 268521, 268525 (juveniles).

Etymology

Specific name from eschatia, Gr. , outskirt, referring to distribution at the edge of the geographical range of the group.

Referred material

Thailand: FMNH 268852-54 , 268856-57 Khao Luang National Park (8°30′N / 99°45′E), Nakhon Si Thammarat Prov. ; FMNH 268858 , 268860 , 268869 Khao Phanom Bencha National Park (8°14′N / 99°E), Krabi Prov. ; FMNH 268872 , 268874-84 Khao Sok National Park (8°56′N / 98°34′E), Surat Thani Prov. ; FMNH 268531-4 , 268536-9 , THNHM 05690 , 05695 Kaeng Krung National Park (9°34′N / 98°49′E), Surat Thani Prov..

Diagnosis

A moderate-sized species of the chalconota group with males up to 40 mm SVL, females up to 57 mm, no dorsal spotting, relatively wide head ( HW / SVL usually> 0.305), relatively long leg ( T / SVL usually> 0.575) and males with constricted or divided nuptial pads.

Description

Habitus slender, head slightly wider than trunk, legs long. Head triangular; snout obtusely pointed, rounded in profile, projecting beyond lower jaw, longer than diameter of eye; nostril lateral, very close to tip of snout; canthus angular, not constricted; lores concave, vertical; interobital wider than upper eyelid and internarial; tympanum distinct, about two-thirds eye diameter in females, slightly larger in males, inside its rim the tympanum is slightly depressed relative to the surface of the temporal region; vomerine teeth in oblique groups, gap between groups less than length of one group and equal to distance from choana.

Fingers long, third finger longer than snout; fingers without webbing; second and third fingers with narrow, movable fold of skin along medial margins; tips of three outer fingers with wide discs, that of third finger almost equal diameter of tympanum in female; disc of first finger much narrow than that of second; all discs with circummarginal grooves; subarticular tubercles conspicuous; third finger with two small supernumerary tubercles, bases of second and fourth fingers with a single supernumerary tubercle. Tips of toes expanded into discs smaller than those of outer fingers, but with circummarginal grooves; webbing extensive, reaching discs of first three toes on lateral margins and disc of fifth toe medially; fourth toe webbed to distal subarticular tubercle medially and slightly beyond that laterally; no dermal ridge along outer margins of first and fifth toes; a low oval inner metatarsal tubercle and a round outer one.

Skin of back granular, in males granules weakly spinose; dorsolateral fold distinct, low; ventral surfaces smooth, except weakly rugose at rear of abdomen; rictal glands present.

Colour in preservative dark brown dorsally and laterally; no black spots on dorsal surfaces; ventral surfaces cream-coloured or white; in some individuals throat with round dark spots; limbs without dark crossbars; rear of thigh dark brown with indistinct lighter round areas.

Measurements (mm) of holotype: SVL 55.6, T 31.0, HW 16.0, HL 19.8, TYM 4.6, DF3 3.2.

Variation

Adult females 42.8–56.6 mm, mean 47.57 ± 0.96 mm (N = 17), males 30.6–39.6 mm, mean 34.14 ± 0.39 mm (N = 22). Variation in body proportions given in Table 8. Relative tympanum diameter in females 0.077 –0.095, in males 0.096 –0.127. The sexes do not differ in relative head width; HW/ SVL in females 0.288 –0.325 (median 0.308), in males 0.275 –0.326 (median 0.310). All males have constricted or divided nuptial pads and vocal sac openings at the corners of the mouth.

Comparisons

Males of Rana eschatia are most similar in size to those of R. labialis (Selangor) and R. parvaccola ( Table 2), but females of eschatia are larger than females of those two ( Tables 2 and 6). Rana eschatia also differs from those two species in the absence of black spots on the back and in having a wider head in both sexes ( Tables 2 and 6). Rana eschatia is larger than R. raniceps (both sexes) and has a longer leg ( T / SVL) and a smaller tympanum in males ( Tables 2 and 6). Rana eschatia is smaller than R. megalonesa , R. rufipes and R. chalconota and differs from the latter two in the length of the tibia ( T / SVL) and in the form of the nuptial pad, which is constricted or divided only in eschatia .