Meristogenys whiteheadi, (Boulenger, 1887)

Shimada, Tomohiko, Matsui, Masafumi, Yambun, Paul & Sudin, Ahmad, 2011, A taxonomic study of Whitehead’s torrent frog, Meristogenys whiteheadi, with descriptions of two new species (Amphibia: Ranidae), Zoological Journal of the Linnean Society 161 (1), pp. 157-183 : 175-177

MERISTOGENYS WHITEHEADI ( Boulenger, 1887)

Specimens examined: Seventy-four males and 19 females from Kiau , Melangkap , Monggis , Nalumad , Poring , Wario (western Sabah), and Bario (northern Sarawak; see Appendix 2) .

Colour in life (see Figs 2C, D , and 7E ): Dorsum light brown to greenish dark brown; lores with interrupted dark streaks below canthus; upper and lower lips dark grey to black; iris bicoloured, whitish brown above and below, with tips of reddish orange in between; a small light circle usually on the centre of a tympanum; a blackish brown band beginning behind eye bordering rear of the tympanum, diverging above the tympanum and nearly reaching the inguinal area; dorsal and ventral boundaries obscure; limbs marked dorsally with alternating light- and dark-brown crossbars; a short dark streak ventrally at insertion of arm; rear of thigh light brown with scattered light dots; throat and chest whitish, with dots of melanophores; abdomen whitish; ventral surfaces of legs whitish, with patches of pigmentation of melanophores.

Larvae ( Fig. 7F ): We examined 15 specimens of stage 26–29 from Gosner (1960), collected from Bario and Wario, with head–body length 8.2–11.8 mm in stages 26–29, 12.5 mm in stage 30, and 15.2 mm in stage 35 ( Table 7).

Head–body oval, broadly rounded at snout, flat below, eyes dorsolateral, not visible from below, pointing outward; nostril open, rim not raised, closer to eye than to tip of snout.

Oral disk ventral; upper lip separated from snout by a groove; upper lip with short marginal papillae in lateral third, inframarginal papillae near corner; lower lip with uninterrupted row of short marginal papillae; LTRF 7 (4–7)/6(1) in all five specimens from Wario and one specimen from Bario, and 7(4–7)/7(1) in nine specimens from Bario; upper jaw sheaths M-shaped, lower jaw sheaths V-shaped; upper jaw sheaths divided; lower jaw sheaths undivided; jaw sheaths heavy and completely black, except for outer margins covered by thin film; upper sheath film thicker than lower sheath film; outer surface of lower jaw sheaths with several weak ribs; margin finely serrate, between five and seven serrae on half of upper jaw sheath, and five or six serrae on half of lower jaw sheath; a large suctorial abdominal disk following oral disk; peripheral part of disk darkened and keratinized .

Spiracle sinistral; tube moderately long, length subequal to length of eyeball, pointing upwards and backwards, free of body wall for half its length; anal tube median, free of tail; tail heavily muscled, dorsal margin strongly convex, deepest before middle, tapering to slightly pointed tip; caudal muscle deeper than fins in basal half; dorsal fin origin behind body, fin deeper than ventral fin, except in final fourth; ventral fin origin at end of proximal third of tail; head–body with four pairs of glandular clusters; a postorbital cluster about an eye length behind eye, with between one and three glands; an infraorbital at the base of snout, with between one and five glands; a prespiracular cluster just anterior to spiracle, with between one and nine glands; a midlateral at the posterior end of body, with between one and nine glands; no ventral and dorsal fin glands; up to ten ventral fin glands; head–body scattered dorsally, with minute protuberances in developed larvae; lateral line pores indistinct.

Head–body light brown dorsally and laterally, sometimes posterior half of lateral surface dark brown; caudal muscle light brown; fins translucent with scattered pigmentations.

Range: In Sabah, this species has been collected around Mt. Kinabalu: Kiau (900 m a.s.l.), Melangkap (310 m a.s.l.), Monggis (300 m a.s.l.), Nalumad (450 m a.s.l.), Poring (500 m a.s.l.), and Wario (950 m a.s.l.). The larvae collected from Mamut (larva E in Inger, 1966, 1985; Inger & Gritis, 1983) also seem to be this species (see comparison with known larvae). In Sarawak, M. whiteheadi was collected from Bario (1000 m a.s.l.), which is 250 km remote from Mt. Kinabalu. There seems to be a disjunction of distribution between these two areas.

COMPARISONS

Meristogenys stigmachilus sp. nov. and M. stenocephalus sp. nov. have relatively large SVLs (45–50 and 50–60 mm, respectively, in males, and> 70 mm in females of both species), and are easily distinguished from some congeners with small SVLs: M. amoropalamus , M. jerboa , M. macrophthalmus , M. maryatiae , M. orphnocnemis , and M. phaeomerus (<41 mm in males and <66 mm in females; Matsui, 1986). Meristogenys kinabaluensis , M. poecilus , and M. whiteheadi are similar to M. stigmachilus sp. nov. and M. stenocephalus sp. nov. in having large SVLs (> 41 mm in males and> 66 mm in females). Of these, M. kinabaluensis usually lacks outer metatarsal tubercles, and has a yellowish-green to moss-green pattern on at least part of the dorsal surface; Meristogenys stenocephalus sp. nov. and M. stigmachilus sp. nov. usually have outer metatarsal tubercles, and lack a green pattern on the back. Additionally, males of M. kinabaluensis (> 65 mm) are larger than males of M. stenocephalus sp. nov. and M. stigmachilus sp. nov. Meristogenys poecilus is differentiated from M. stenocephalus sp. nov. and M. stigmachilus sp. nov. by its blotched pattern on the rear of the thigh (which is a dotted pattern in the latter two species). Meristogenys whiteheadi differs from M. stigmachilus sp. nov. in the absence of both dark spots on the upper lip and dots on the back ( M. stigmachilus sp. nov. is characterized by the presence of these markings). Meristogenys whiteheadi differs from M. stenocephalus sp. nov. in the relatively small male SVL (40–50 mm) and broader head (HW/SVL usually more than 0.35 in M. whiteheadi , and less than that in M. stenocephalus sp. nov.). Meristogenys stigmachilus sp. nov. and M. stenocephalus sp. nov. differ in male body size and colour pattern. The dark spots on the upper lip and dark dots on the back seen in M. stigmachilus sp. nov. are absent in M. stenocephalus sp. nov.

The larvae of M. stigmachilus sp. nov. and M. stenocephalus sp. nov. share morphological characteristics with those of M. whiteheadi , in having surface projections, undivided lower jaw sheaths, four divided labial tooth rows on the upper jaw, and no glands on their dorsal fin or ventral surface. The larvae of M. stenocephalus sp. nov., however, have larger body size, more serrations in the upper jaw sheaths, and fewer glands on the ventral fin than larval M. stigmachilus sp. nov. and M. whiteheadi (see above). Larval M. stenocephalus sp. nov. is one of the largest among Meristogenys species , judging from previous studies (e.g. Inger, 1966, 1985; Inger & Gritis, 1983; Shimada et al., 2007). Head–body lengths in larval stages 26–29 of M. stigmachilus sp. nov. and M. whiteheadi are less than 12 mm, whereas those of M. stenocephalus sp. nov. are more than 12 mm. No morphological characters exist to distinguish between larval M. whiteheadi and M. stigmachilus sp. nov.

COMPARISON WITH KNOWN LARVAE

Amolops larva D in Inger & Gritis (1983) (= ‘ Amolops kinabaluensis ’ of Inger, 1985) may include several species, but at least one series among them (FMNH 109492, collected from the Kaingeran River near Tambunan) shares morphological characters with M. stenocephalus sp. nov., such as labial tooth row formula, serrations of jaw sheaths, sharp surface projections on the head and body, and a large body size. This assignment is geographically reasonable because the Kaingeran River is close to Kimanis, where we collected M. stenocephalus sp. nov.

Shimada et al. (2007) reported that Amolops larva E of Inger & Gritis (1983) (= Amolops sp. E in Inger, 1985) shares morphological characters with larval morphotype 2 of Shimada et al. (2007), which is described here as M. stigmachilus sp. nov. However, as we cannot distinguish M. stigmachilus sp. nov. and M. whiteheadi through larval morphology, we are uncertain as to which name should be assigned to larva E. Yet, considering the collection locality, M. whiteheadi is more plausible because larva E was collected from Sg. Mamut on the southern slope of Mt. Kinabalu. This river is close to Poring, where we collected M. whiteheadi .

Figures

Figure 2. Profiles of M. cf. whiteheadi. Patterns of upper lip were separated into five types: (A) pattern 1-a, several large black spots similar to those of lower lip; (B) pattern 1-b, irregular black blotches smaller than lower lip spots; (C) pattern 2, uniformly black; (D) pattern 3, uniformly grey; (E) pattern 4, uniformly white. Specimen vouchers: (A) BORNEENSIS 12560 from Mahua; (B) BORNEENSIS 12512 from Mahua; (C) BORNEENSIS 23302 from Wario; (D) BORNEENSIS 23340 from Wario; BORNEENSIS 12810 from Ulu Senagang.

Figure 7. Adults and larvae of three Meristogenys species treated in this study. A, B, Meristogenys stigmachilus sp. nov. (BORNEENSIS 12512 and 03B1 from Mahua). C, D, Meristogenys stenocephalus sp. nov. (B12808 and 05B217 from Ulu Senagang). E, F, Meristogenys whiteheadi (B22971 and 05B209 from Wario). Scale bars: 10 mm.