Mantidactylus curtus (Boulenger)

Schmidt, Heike, Glaw, Frank, Teschke, Meike & Vences, Miguel, 2009, Description of tadpoles of five frog species in the subgenus Brygoomantis from Madagascar (Mantellidae: Mantidactylus), Zootaxa 1988, pp. 48-60 : 53-54

Mantidactylus curtus (Boulenger)

Series examined. ZSM 943/2004 (1 specimen). The single specimen was collected near Antoetra by M. Vences in the period of 18–22 January 2003 in a stream flowing through largely deforested highland grassland, with some bushes and isolated trees. The stream had a width of 1.5–3 m and included some small and shallow tributaries. Parts of the stream were of clear and fast-flowing water and rocky bottom whereas other parts, and especially the tributaries, were slow-moving, with the water largely covered by high grass tufts.

Taxonomic note. Tadpoles described by Arnoult & Razarihelisoa (1967) and Blommers-Schlösser (1979) as Mantidactylus curtus most likely belong at least partly to a different species (see section on Mantidactylus sp. aff. curtus "Ankaratra" below). The tadpole described here originates instead from a site in the general region corresponding to the type locality of M. curtus ("East Betsileo"), and its DNA sequence is close to specimens that we assign to this species (see Glaw & Vences 2007: page 237, figs. 1a and 1b).

Description. Based on the single voucher specimen (ZSM 0943/2004; field number FG/MV 2003.1757; Genbank accession number EU717879 ; Figure 3 ) in developmental stage 26, and in good state of preservation (a huge section from the dorsal tail has been excised for DNA analysis). BL 14.8 mm, TL 42.3 mm, for further measurements see Table 1 . Colouration in preservative yellowish, transparent. A dark mid-dorsal yellowish line slightly visible through skin. Dark yellowish pigments concentrated dorsally besides eyes and at middle of body. Caudal fin dorsally covered to the tip with some irregular light brown patches and spots. Belly, caudal muscle and ventral fin almost uniformly transparent. In dorsal view, body shape ovoid to nearly rounded, snout elongated and flattened to tip. In lateral view, body depressed, BW 1.32 of BH, snout rounded. Nostrils elliptical and pointed to tip of snout, rimmed with a mediodorsal projection giving them a bean shape, not protuberant, positioned dorsolaterally. IND 0.38 of IOD. Nostrils, closer to tip of snout than to eyes. Eyes positioned dorsally, directed dorsolaterally, and moderately sized, ED 0.07 of BL, not protuberant. Spiracle sinistral, not visible in dorsal view, attached to body wall but its inner wall lifting up from body wall, closer to snout than to end of body, ESD 0.26 of BL. Spiracular opening oval, laterally positioned, oriented posteriorly. Intestinal spiral not visible in dorsal view, well visible in ventral and lateral views. Medial vent tube with lateral displacement, dextral. Caudal musculature rather strongly developed, upper origin well visible in dorsal view, TMH 0.76 of BH and 0.72 of MTH, fast tapering from approximately three-fourths of tail, almost reaching the tip. Dorsal fin originating at the end of first-quarter of caudal muscle, point of maximum height located after mid-tail, MTH 1.06 of BH. Margins of ventral and dextral fin slightly convex to finely rounded tail tip. Oral disc of moderate size, generalized, laterally emarginated, ODW 0.32 of BL and 0.56 of BW, transversely ovoid to nearly rounded, anteroventrally positioned, with robust dark coloured beaks, which slightly lost keratinisation. Oral disc margins not visible in dorsal view, but visible in lateral view. LTRF 5(2–5)/3(1), with additional gaps in rows A1 and P3, here interpreted as oral deformities. About 30 teeth per mm and a total of 115 teeth in A2. A5 very small, consisting of only 5 teeth on right side and 3 teeth on left of oral disc. Three small gaps in first anterior tooth row and large medial gap in second anterior tooth row. First and third posterior tooth rows with small medial gap.

Upper labium with large dorsal gap in marginal papillae, upper and lower labium with two rows of papillae. Papillae with a rounded tip (some pigmented), sporadically with pointed tip (total number of papillae: 82). Upper jaw sheath M-shaped, lower jaw sheath V-shaped, both with almost equal-sized serrations.

Figures

FIGURE 3. Drawings of the preserved DNA voucher tadpole of Mantidactylus curtus (stage 26), series ZSM 943 / 2004; (a) oral disc, (b) lateral view, (c) dorsal view. Scale bars represent 1 mm.