Limnonectes laticeps ( Boulenger, 1882 )

Ming, Leong Tzi, 2004, Larval Descriptions Of Some Poorly Known Tadpoles From Peninsular Malaysia (Amphibia: Anura), Raffles Bulletin of Zoology 52 (2), pp. 609-620 : 612-613

Limnonectes laticeps ( Boulenger, 1882)

( Figs. 3 , 4 , Table 3)

Larval microhabitat. – A total of five larvae were encountered in a small, shallow creek (ca. 20cm wide, 2cm deep, sandy substrate) flowing slowly down hill slopes of the Canopy Trail within FRIM (3 14’N, 101 38’E) ( ZRC.1.10808-10812; coll. T. M. Leong & Gary H. S. Lim, 29 May.2003). Adult, sub-adult and recent emergent vouchers found within this exact microhabitat were collected Larval diagnosis. – A small, sedentary tadpole (maximum TL ca. 18mm); nostrils located at upper edge of snout tip, opening towards anterior; mouthparts consisting only of a pair of papillae on upper rim of oral aperture; prominent yolk sac (visible from dorsal perspective) up to advanced stages; nutritional mode endotrophic (non-feeding); vent median; tail fins low, dorsal fin originating after proximal 1 / 4 of tail .

Larval morphology. – ( Figs. 3 , 4 ) Body elliptical, BL 1.45- 1.53 of BW, slightly depressed dorsoventrally, cross-section almost cylindrical, BH 0.85-0.94 of BW; snout rounded from dorsal perspective, truncate from lateral perspective, nostrils located at upper edge of snout tip, directed anteriorly; eyes lateral, IOD 2.48-2.61 of IND; spiracle sinistral, not projecting as a free tube, tapered towards the opening, opening directed backwards, spiracle visible from above and below, snout-spiracle 0.41-0.46 of BL; vent median, tapering towards narrow opening directed posteriorly, exceeds margin of ventral fin. Tail almost straight for entire length, except for abrupt tapering towards a round tip, dorsal fin originating after proximal 1 / 4 of tail, tail muscle deeper than either fins for proximal 3 / 4. TAL 3.18-3.27 of BL, MTH 0.18-0.19 of TAL. No observable lateral line pores or glandules.

Colour/Markings. – In life, dorsum and flanks light beige to buff, lightly speckled with orange brown and whitish pigments; yolk sac creamy yellow; tail muscle translucent, tail fins clear, entire tail with scattered pigments.

Mouth. – ( Fig. 4 ) Entirely lacking any fleshy anterior/ posterior labia and associated labial teeth/jaw sheaths; a miniscule oral aperture (width ca. 1/10 th of BW) flanked only by a pair of elongate papillae originating from upper rim of mouth, possibly serving the function of preventing particulate matter from entering buccal cavity while breathing.

Developmental changes. – Although attempts to rear the larvae to complete metamorphosis were unsuccessful, the single most advanced larva (Stage 41, died 14 days after initial collection) was already beginning to exhibit characteristics of its parental species. These include slightly expanded toe tips, incomplete webbing of hindfeet and a dark, inverted chevron, scapular marking. Despite the advanced stage of this particular larva, the amount of yolk sac remaining still occupied just under half the volume of the entire body cavity. This larva was observed to swim to the water surface for gulps of air with increasing frequency as it matured. However, like the other larvae, it remained motionless at the bottom unless disturbed. The measurements of this small, but crucial, series are given in Table 3.

Figures

Fig. 3. Lateral (A) and dorsal (B) aspects of Limnonectes laticeps larva (Stage 37). Note persistence of pronounced yolk sac, despite well developed hind limb buds.

Fig. 4. Ventral aspect of larval Limnonectes laticeps (Stage 37). Note single pair of elongate papillae (P) trailing from upper rim of mouth; complete absence of anterior or posterior labia (and associated marginal/infra-marginal papillae), labial tooth rows, or jaw sheaths. Nostrils (N) visible at upper edge of snout; yolk sac (YS) extensive; H = heart; SO = spiracular opening. Scale bar = 1mm.