Leptolalax sp. 1

Dehling, Maximilian, 2012, Redescription of Leptolalax gracilis (Günther, 1872) from Borneo and taxonomic status of two populations of Leptolalax (Anura: Megophryidae) from Peninsular Malaysia, Zootaxa 3328, pp. 20-34 : 28-29

Leptolalax sp. 1

( Figure 5 )

Leptobrachium gracile — Grandison 1972 (partim), Berry 1975 (partim) Leptolalax gracilis — Chan et al. 2010

Referred material: BMNH 1967.2297 , adult female from Camp IV , 5000 ft. [ca. 1524 m], Gunung Benom, Pahang, Malaysia, collected by A. G. C. Grandison on 30.03.1967 ; BMNH 1967.2298 , adult male from Camp IV , 5000 ft. [ca. 1524 m], Gunung Benom, Pahang, Malaysia, collected by Lord Medway [now the Earl of Cranbrook] on 31.03.1967 ; BMNH 1967.2299 , juvenile from below Camp III , 3430 ft. [ca. 1045 m], Gunung Benom, Pahang, Malaysia, collected by A. G. C. Grandison and F. V. Slade on 22.03.1967 ; BMNH 1967.2300–2308 , nine tadpoles, same data as 1967.2299.

Description of BMNH 1967.2297 ( Figure 5 ): Measurements are given in Table 1 . Habitus moderately stout; head broad (HW/SVL 0.38), wider than long (HW/HL 1.19) and wider than trunk; snout rounded in ventral view, truncate in lateral view, slightly protruding, its length half the head length (SL/HL 0.49) and greater than eye diameter (SL/ED 1.34); canthus rostralis distinct, almost straight-lined in both dorsal and lateral view; loreal region oblique, slightly concave; nostrils rounded, directed dorsolaterally, situated in low protuberance, closer to tip of snout than to eye (EN/NS 1.09); distance between eye and nostril subequal to internarial distance (EN/NN 0.96) and smaller than eye diameter (EN/ED 0.83); pupil vertical; tympanum distinct, rounded, its diameter half the eye diameter (TD/ED 0.49); interorbital distance greater than eyelid width (IO/EW 1.27); pineal ocellus absent; symphysial knob on anteriormost part of mandible; vomerine ridge and teeth absent; tongue large, broad, bifid, free for about half its length; median lingual process absent.

Fore limbs slender, moderately long (ELB/SVL 0.72, ARM/SVL 0.56); hand longer than forearm (HND/ARM 0.54); fingers long and slender, without webbing or lateral fringes of skin; relative length of fingers II<I<IV<III; finger tips rounded and thickened; subarticular tubercles indistinct; large rounded tubercle in thenar and metacarpal region of fingers I and II, separated by a distinct groove from smaller, subtriangular tubercle in metacarpal region of fingers III and IV.

Hind limbs moderately long (LEG/SVL 1.65); tibiofibula long (TFL/SVL 0.54), longer than foot (TFL/FOT 1.17) and longer than thigh (TFL/THL 1.14); heels overlapping each other considerably when knees are flexed and thighs are held laterally at right angle to body; toe tips rounded and thickened, smaller than finger tips; toe webbing rudimentary; very narrow fringes of skin on lateral sides of toes, hardly discernible; relative length of toes I<II<V<III<IV; subarticular tubercles indistinct; longitudinal ridges of thickened skin on plantar side of phalanges of toes II–V, except distal ones; inner metatarsal tubercle large, oval, about one-third the length of first toe; outer metatarsal tubercle absent.

Skin on dorsum and dorsal side of head shagreened with tiny tubercles, weakly wrinkled on dorsal surfaces of the extremities; wrinkles forming indistinct, reticulated, predominantly longitudinal, low ridges; several enlarged tubercles on lateral surfaces; ventral side smooth; supratympanic fold thick and conspicuous, curved, running from posterior margin of eye to just behind corner of mouth; pectoral glands large, at the insertion of the forelimbs; supraaxillary glands and ventrolateral glandular ridges absent.

Colouration in preservative: Dorsum mottled light and dark, yellowish and reddish brown; indistinct triangular dark blotch between the eyes, its anterior two corners reaching to median parts of upper eyelid where the colour is almost black; anterior corner of eye and skin below tympanum including posterior corner of the eye and posterodorsal half of tympanum dark brown; several dark brown blotches on upper lip; two short, longitudinal bands on tip of snout, running anteriorly from nostril to edge of jaw on both sides, slightly converging; row of dark brown, light-centred spots on dorsolateral side of trunk; upper arm cream-coloured with irregularly distributed small darker, brown blotches; dorsal side of lower arm, thigh, tibia, and tarsus, and foot with brown cross-bands which are light-centred at their widest parts; ventral side light-coloured and unpatterned except edge of lower jaw which is dark-mottled. Probably due to the preservative in which the specimens were initially stored during the 1967 expedition, the specimens have a greenish dye, which is most obvious in the light ventral areas but also in the light areas of the dorsal side. The same greenish dye was observed in specimens of other species collected during the same expedition and deposited in the BMNH (pers. observ.).

Colouration in life (after Grandison [1972] and information on collector tags deposited with the specimens): Dorsum mottled brown and dull claret red; upper arm dull coral red; canthal edge, rim of eyelid, supratympanic fold, and pectoral glands near axillae orange-red; tubercles on dorsal surfaces of body and limbs bright orange red with those on flanks and hind limbs being wholly or partly encircled with dark brown; iris orange-red ( Grandison 1972) or reddish brown (voucher tag).

Variation: With an SVL of 35.1 mm, the adult male is considerably smaller than the female (SVL 46.0 mm). Measurements are given in Table 1 . Otherwise, the male is very similar to the female in body proportions, skin texture, and colouration and colour pattern. It has an external median, subgular vocal sac.

The juvenile (SVL 24.4 mm) is at a late metamorphic stage with its tail only partly resorbed. It is assigned to the species because it is similar to the adults in many characteristics, including dorsal and ventral colouration, toe webbing, snout shape, skin texture, large interorbital distance, and size and shape of palmar and metatarsal tubercles and of the pectoral gland. Several basic measurements like tibia length (0.58) and head width (0.31) in relation to SVL differ markedly from those of the adults which might be due to an ontogenetic shift in these characters.

Comparisons: The specimens from Gunung Benom differ from topotypic L. gracilis in a number of morphological characters, including head size, interorbital and internarial distance, eye size, distance between the eye and the nostril, snout shape, size of pectoral gland, size of palmar tubercle, ventral and dorsal colouration, and the presence of a skin flap above the vent. Furthermore, they differ from all other described species of the genus and represent an undescribed species. The formal description of this species will be published elsewhere.

Figures

FIGURE 5. Dorsal view (left) and ventral view (right) of the female specimen of Leptolalax sp. 1 from Gunung Benom (BMNH 1967.2297). Scale bar represents 10 mm.