Rana parvaccola, 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 : 138-139

RANA PARVACCOLA SP. NOV.

(Previously referred to Padang Small morphotype)

Rana chalconota Inger & Iskandar, 2005: 138 .

Rana cf. chalconota Stuart et al., 2006: 473 .

Holotype

FMNH 268605 (field tag 16279) adult female from Sarasah Buntah 528 m (0°06′S / 100°40′E), Paya- kumba, West Sumatra. Collected in disturbed forest on 8.viii.2001, by Djong Hon-Tjong and David Gusman.

Paratypes

FMNH 268604 , 268606-47 , 27 adult males, ten adult females, six juveniles from same locality and elevation as holotype, 9–17.viii.2001 ; FMNH 268589-92 , four adult males from Limau Manis 373 m (0°54′S / 100°28′E), Padang , West Sumatra, 2–9.vii.2001 ; FMNH 268593 , one juvenile from Padang Jernih 340 m (0°52′S / 100°28′E), Padang , West Sumatra, 27.vii.2001 ; FMNH 268594-603 , ten adult males from Batang Harau 566 m (0°04′S / 100°39′E), Payakumbuh , West Sumatra, 5–7.viii.2001 ; FMNH 268648-50 , one adult male, two adult females from Akar Berayun 546 m (0°06′S / 100°39′E), Payakumbuh , West Sumatra, 20–21.viii.2001 . All with same collectors as the holotype.

Etymology

Specific name from parvus L., meaning small, and accola L., meaning neighbour, referring to its size relative to the co-occurring species rufipes .

Diagnosis

A small form of the Rana chalconota group, SVL of females <45 mm, of males <40 mm. Dark spots present on back. Nuptial pad of males not constricted.

Description

Habitus slender, head very slightly wider than trunk, legs long. Head triangular, longer than broad; snout narrowly rounded, projecting slightly beyond lower jaw, longer than diameter of eye; nostril on side of snout, much closer to tip of snout than to eye; canthus angular, not constricted; lores concave, weakly oblique; interorbital wider than upper eyelid, wider than internarial; pineal body visible, in line with front borders of upper eyelids; tympanum distinct, about two-thirds diameter of eye in females, larger in males; vomerine teeth in short, oblique groups, distance between groups equal to or slightly greater than distance between groups and choanae.

Fingers long, length of third finger less than distance from rear of eye to nostril; without webbing; second and third fingers with narrow, movable dermal fold on medial margins; tips of three outer fingers with wide discs, that of third finger about two-thirds diameter of tympanum in females, disc of first finger about half width that of second finger, all discs with circummarginal grooves; subarticular tubercles conspicuous; three outer fingers with a supernumerary tubercle; finger lengths 3> 4> 2> 1. Tips of toes expanded into discs smaller than those of fingers, but with circummarginal grooves; webbing extensive, to base of discs on lateral margins of first three toes and medial margin of fifth, medial edge of fourth toe fully webbed to distal subarticular tubercle; narrow dermal ridge along outer edge of last joint of fifth toe and medial edge of last joint of first toe; a low, oval inner metatarsal tubercle and a distinct, round outer one.

Skin of back granular, those on back of males tipped with small, colourless spinules; similar spinules present on eyelid and lower portion of lores in males; a distinct, low dorsolateral fold; rear of abdomen rugose, rest of venter smooth.

Males with paired vocal sac openings on floor of mouth. Whitish, velvety nuptial pad on dorsal and medial surfaces of first finger, nuptial pad not constricted. A weak humeral gland detectable by folding back skin of upper arm.

Colour in preservative brown dorsally and on sides; side of head darker; upper lip lighter, but dusted with melanophores; dorsal surfaces with small black spots; ventral surfaces of body whitish, lightly dusted with melanophores; hind limb without dark crossbars in most individuals; ventral surface of webbing black.

Measurements (mm) of holotype: SVL 41.8, tibia 23.7, head width 12.2, head length 15.4, diameter of tympanum 3.8, width of disc of third finger 2.3.

Variation

Mature females 37.8–43.0 mm, mean 41.54 ± 0.68 mm (N = 15), males 29.0– 38.1 mm, mean 32.39 ± 0.76 mm (N = 13); T / SVL 0.523 –0.608, median 0.574; HW/ SVL of females 0.268 –0.309, of males 0.273 – 0.330; HL/ SVL of females 0.344 –0.403, of males 0.376 –0.418; TYM/ SVL of females 0.081 –0.101, of males 0.103 –0.130; DF3/ SVL 0.046 –0.064, median 0.056.

Comparisons

Comparisons with the co-occurring species, R. rufipes , have been made under the heading of that species. Rana parvaccola is one of the smallest members of the chalconota group. The females are larger than those of R. raniceps , and R. parvaccola differs from the latter species in higher frequency of dark spotting on the back and in absence of constriction of the nuptial pads. Females of R. parvaccola are smaller than those of R. labialis and R. eschatia ( Tables 2 and 6). Relative tympanum diameter is larger in R. parvaccola than in Selangor labialis . Both sexes of this species are smaller than those of the larger members of the group – R. chalconota , R. megalonesa and R. rufipes . The uncorrected pairwise sequence divergence between R. parvaccola and the co-occurring R. rufipes is 14.75–14.93% (Table 4).