Paedophryne dekot Kraus,

Kraus, Fred, 2011, At the lower size limit for tetrapods, two new species of the miniaturized frog genus Paedophryne (Anura, Microhylidae), ZooKeys 154, pp. 71-88 : 73-76

Paedophryne dekot Kraus, sp. n. Figs 12A, B

Holotype.

BPBM 37753 (field tag FK 15615), alcohol specimen, adult female, collected by F. Kraus and local villagers at Binigun, W slope Mt. Dayman, 9.7071°S, 149.2498°E, 900 m, Milne Bay Province, Papua New Guinea, 1 April 2011.

Paratyp.

(n = 1). BPBM 37754, same data as holotype, except collected 4 April 2011.

Diagnosis.

A minute microhylid (female SV = 8.5-9.0 mm) with smooth dorsal skin; a relatively long leg (TL/SV = 0.45-0.46); short and broad snout (EN/SV = 0.067-0.071, IN/SV = 0.106-0.111, EN/IN = 0.60-0.67); relatively large discs on third and fourth toes (4thT/SV = 0.044-0.052, 3rdF/4thT = 0.43-0.58, Fig. 1E); a uniform brown or red-brown dorsum with two large dorsolateral, downward-pointing, black triangular blotches on each side; and a pale gray venter with brown flecks.

Comparisons with other species.

Paedophryne dekot differs from Paedophryne kathismaphlox and Paedophryne oyatabu , the only two other species currently described in this genus, in its smaller size (female SV = 8.5-9.0 in Paedophryne dekot , 10.4-10.9 mm in Paedophryne kathismaphlox , 11.3 mm in Paedophryne oyatabu ), longer leg (TL/SV = 0.45-0.46 in Paedophryne dekot , 0.35-0.39 in Paedophryne kathismaphlox , 0.40 in Paedophryne oyatabu ), shorter snout (IN/SV = 0.106-0.111, EN/IN = 0.60-0.67, EN/SV = 0.067-0.071 in Paedophryne dekot ; IN/SV = 0.087-0.099, EN/IN = 0.78-0.80 in Paedophryne kathismaphlox ; EN/SV = 0.062, IN/SV = 0.097 in Paedophryne oyatabu ), larger discs on third and fourth toes (4thT/SV = 0.044-0.052 in Paedophryne dekot , 0.032-0.037 in P. kathismaphlox, 0.031 in Paedophryne oyatabu ; 3rdF/4thT = 0.43-0.58 in Paedophryne dekot , 0.66-0.86 in Paedophryne kathismaphlox , 0.80 in Paedophryne oyatabu ), dorsum with two large dorsolateral triangular blotches on each side (dorsum brown vaguely mottled with black or dark brown in Paedophryne kathismaphlox , dorsum brown with two dark mid-dorsal chevrons in Paedophryne oyatabu ), venter pale gray with brown flecks (venter dark brown with scattered light straw-brown or gray flecks in Paedophryne kathismaphlox and Paedophryne oyatabu ), and no brightly colored patch below anus (a burnt-orange patch below anus in Paedophryne kathismaphlox ).

Description of holotype.

An adult female with an incision on right side and across rear of abdomen; liver removed and stored separately for DNA analysis. Head moderately wide (HW/SV = 0.37, Fig. 1A), with steeply oblique loreal region; canthus rostralis rounded, slightly convex when viewed from above; nostrils directed anterolaterally, closer to tip of snout than to eyes; internarial distance much larger than distance from naris to eye (EN/IN = 0.60, IN/SV = 0.111, EN/SV = 0.067); snout rounded when viewed from the side or from above (Fig. 1A, C); eyes moderately large (EY/SV = 0.13; EY/SN = 1.0, Fig. 1C), pupil horizontal; eyelid approximately two-thirds width of interorbital distance; tympanum indistinct and small (TY/SV = 0.044), visible only when skin dries slightly, hidden posterodorsally. Skin smooth; supratympanic fold absent. Fingers unwebbed, flattened; F1 reduced to a vestigial nub; relative lengths 3>2=4>1 (Fig. 1D); discs absent. Subarticular and metacarpal tubercles absent. Toes unwebbed; T3 and T4 with flattened discs and terminal grooves; disc of T4 not wider than penultimate phalanx. Second and fifth toes with round tips and no discs; T1 a vestigial nub; relative lengths of toes 4>3>2=5>1 (Fig. 1E). Subarticular and metatarsal tubercles absent. Plantar and palmar surfaces smooth. Hind legs rather long (TL/SV = 0.46, Fig. 1A). Tongue elongate, straplike, anterior third attached to floor of mouth.

In preservative, dorsum brown with a more-or-less continuous dorsolateral row of black blotchs and flecks; sides and front and rear of thighs pale gray heavily flecked with dark brown. Face dark brown. Ventral surfaces pale gray flecked with dark brown. Iris black.

In life, the holotype was noted as: "Dorsum red brown, sides gray, dorsolateral series of black flecks. Rear of thighs light red brown with black punctations. Face black, posterior to eye spotted with light gray. Venter dark gray with small pale-gray flecks." The iris was black with a red rim around the pupil, and scattered pale blue-gray flecks are apparent on the lower sides and limbs (Fig. 2A).

Measurements (in mm).-SV = 9.0, TL = 4.1, HW = 3.3, HL = 2.9, IN = 1.0, EN = 0.6, SN = 1.2, EY = 1.2, TY = 0.4, 4th T = 0.40.

Variation.

There is little mensural difference between the paratype and holotype, except that the former has a somewhat larger tympanum (TY/SV = 0.059) and a slightly longer snout (EN/IN = 0.67). In coloration, the paratype is similar to the holotype but the black dorsal blotching is not concentrated into dorsolateral lines; there is a pale tan blotch over the rump; and the dark brown on the sides, limbs, and ventral surfaces is reduced to even stippling instead of flecking. Liver was also removed from the paratype for DNA analysis. Measurements for the paratype are: SV = 8.5, TL = 3.8, HW = 3.2, HL = 2.7, IN = 0.9, EN = 0.6, SN = 1.1, EY = 1.3, TY = 0.5, 4th T = 0.44.

Etymology.

The species name “dekot” is the word for "very small" in Daga, the language spoken in the area from which this species was collected.

Range.

Known only from the western slope of Mt. Dayman in the saddle where it joins Mt. Suckling to the northwest, Milne Bay Province, Papua New Guinea (Fig. 3, square).

Ecological notes.

Paedophryne dekot inhabits leaf litter on the floor of steeply sloping primary foothill rainforest. Canopy at the type locality was approximately 35 m high; understory was dense, with some moss on trees and ground. This forest type terminates at approximately 1200 m elevation in this area, so Paedophryne dekot seems unlikely to occur higher than that.

This species was heard calling from the forest floor in mid- to late afternoon and at dusk but could not be recorded by me.

Both females contained two enlarged, well-yolked, cream-colored eggs and approximately a dozen small white oocytes.