Paradoxophyla palmata (Guibe, 1974)

Grosjean, Stéphane, Glos, Julian, Teschke, Meike, Glaw, Frank & Vences, Miguel, 2007, Comparative larval morphology of Madagascan toadlets of the genus Scaphiophryne: phylogenetic and taxonomic inferences, Zoological Journal of the Linnean Society 151 (3), pp. 555-576 : 569

PARADOXOPHYLA PALMATA ( GUIBÉ, 1974)

Tadpoles used for the description were collected at a large pond in a dense, unprotected forest near Fierenana. The pond had a muddy bottom and many dead leaves as well as whole trees covered the ground. Most of the collected tadpoles already lacked the tip of their tails when they were collected. An additional series used for comparison (ZSM 656/2004) was collected in a small stream (about 50–100 cm wide) that included quiet pools as well as rapids. The external morphological description is based on a specimen at stage 37, ZSM 647/2004 (TL and BL are 27.7 and 10.0 mm, respectively). Buccopharyngeal features are described on the basis of a tadpole at stage 37 (ZSM 645/2004).

External morphology: In dorsal view ( Fig. 3C ), body oval, widest in the posterior part of gills; snout semicircular. In profile ( Fig. 3D ), body depressed with a rounded ventral side, BW 112% of BH, snout flat and oblique. Eyes moderately sized, ED 12% of BL, bulging, visible in ventral view, positioned dorsolaterally and directed laterally. Nares not open, positioned dorsally, closer to snout than to pupils, RN 77% of NP, very close to each other, NN 14% of PP. Spiracle ventral, a large fold of skin free at the rear of spiracle composed of two fringed flaps divided by a medial notch, each part bearing four lobes, not attached to body wall, orientated posteriorly, very close to the ventral tube, SS 97% of BL. Tail musculature weak, TMH 28% of BH and 47% of MTH, gradually tapering, reaching tail tip. Upper fin moderately sized, UF 35% of MTH, slightly convex, extending very slightly onto body, lower fin moderately sized, LF 38% of MTH, convex; point of maximum height of tail located at the proximal third of the tail length, MTH 81% of BH, tail tip being a flagellum. Ventral tube moderately small, fine and relatively long, tubular, medial but directed to the right, directed almost ventrally, its anterior part linked to body wall, its posterior part linked to ventral tail fin, opening lateral. Neither lateral line organs nor glands visible.

Oral disc ( Fig. 3H ) moderately sized, in position and orientation terminal, not emarginated, ODW 18% of BL and 22% of BW. Upper labium a large flap of skin flattened circumflex accent-shaped hanging down the lower labium; lower labium flat with a large U-shaped extension medially covered in great part by the upper labium, only the extremity of the U going beyond it. No papillae, no denticulate papillae. No keratodonts. No jaw sheaths.

Coloration in preservative: Tadpole transparent. Upper side entirely punctuated by dark brown spots of different size; upper labium, nares, brain pan and upper side of intestine coil lighter brown. Flanks punctuated by small dark brown spots. Ventral side immaculate. Caudal muscle beige coloured by the same spots as the body, larger in the proximal quarter. Fins punctuated with these spots close to the caudal muscle in the proximal half, on the whole surface halfway. Upper side of hindlimbs densely punctuated by very small dark brown spots.

Variation: The ratios taken on nine tadpoles at stages 34–37 (ZSM 645/2004, ZSM 646/2004, ZSM 648/2004- ZSM 654/2004) vary in the following proportions: BW 109–118% of BH; RN 67–100% of NP; NN 13–21% of PP; SS 88–129% of BL; TMH 39–45% of BH; TMH 50– 64% of MTH; UF 15–35% of MTH; LF 36–40% of MTH; MTH 70–81% of BH; ODW 18–26% of BL; ODW 24– 33% of BW.

Buccal floor ( Fig. 3I ): Buccal floor as wide as long, its maximum width at the level of the buccal pockets. Prelingual arena very short and narrow; bearing a medial knob. Posteriorly to this knob, a large trapezoid area lacking ornamentation. Tongue anlage absent, a single medial papilla in the bottom of the depression present that may be homologous to papilla of tongue anlage. Buccal floor arena roughly triangular, delimited by about 15 stout and short papillae; interior of arena in a longitudinal depression, with no obvious pustulations; few secondary buccal floor arena papillae. Buccal pockets very long, extending from the prelingual arena to the middle of the buccal floor arena, deep, almost longitudinally orientated, seemingly perforated; some pustulations on the edge of the anterior wall of the buccal pocket; 2–5 small postpocket papillae. Glottis far ahead from the end of the ventral velum, orientated anteriorly. Ventral velum with spicular support, straight laterally, medial part damaged in dissection; secretory pits not visible. Branchial baskets almost round with a concavity posteromedially, three filter cavities, filter plates curved externally, long; filter mesh very dense with tertiary folds.

Buccal roof ( Fig. 3J ): Prenarial arena short and semicircular, with one short median pustule. Choanae large, round; anterior wall absent; narial valve greatly enlarged into a large and ventrally concave structure, anteriorly directed, covering entirely the choana. Postnarial arena absent. Median ridge and lateral ridge papillae absent. Buccal roof arena non-existent, interior of arena smooth, one pair of very small buccal roof arena papillae posteromedially to the buccal roof. Posterolateral ridges not visible. Glandular zone present at least medially; secretory pits visible on this band and on the ventral side of the dorsal velum. Dorsal velum continuous, its lateral parts extending anteriorly. Two small pressure cushions on each side.

Figures

Figure 3. Dorsal and lateral views of tadpoles of Dyscophus insularis (A, B) (stage 34, ZSM 402/2004) and Paradoxophyla palmata (C, D) (stage 37, ZSM 647/2004). Oral disc of D. insularis (E) (stage 36, specimen from batch ZSM 402/2004) and P. palmata (H) (stage 35, ZSM 645/2004). Buccal floor (BF) and buccal roof (BR) of tadpoles of D. insularis (F, G) (stage 38, specimen from batch ZSM 402/2004) and P. palmata (I, J) (stage 37, ZSM 645/2004). Scale bars in A–D represent 5 mm, scale bars for E–J are indicated on the images.