Leptodactylodon ventrimarmoratus (Boulenger, 1904)

Mapouyat, Lissa, Hirschfeld, Mareike, Rödel, Mark-Oliver, Liedtke, H. Christoph, Loader, Simon P., Gonwouo, L. Nono, Dahmen, Matthias, Doherty-Bone, Thomas M. & Barej, Michael F., 2014, The tadpoles of nine Cameroonian Leptodactylodon species (Amphibia, Anura, Arthroleptidae), Zootaxa 3765 (1), pp. 29-53 : 43-45

Leptodactylodon ventrimarmoratus (Boulenger, 1904)

Fifteen tadpoles of L. ventrimarmoratus were found near Mount Kala: ZMB 78552–53 (one tadpole and seven tadpoles, respectively; all Gosner stage 25, 3°50’24,72”N, 11°21’6.66”E, 858 m); ZMB 78554 (seven tadpoles, Gosner stage 25, 3°50’23.46”N, 11°21’6.54”E, 901 m). All tadpoles were found on 8 November 2011 near Kala village in small, rocky rivers, mostly beneath leaf litter, at 858 and 901 m altitude.

The description is based on three genotyped individuals (ZMB 78552, 78553, 78554) at Gosner stage 25. Body length/total length ratio and description of tail tips was based on non-genotyped specimens of the same developmental stage.

Morphology. Long and slender tadpole with long, muscular tail; body elliptical to almost parallel in dorsal and depressed long ovoid in lateral view ( Fig. 13 a, b); body length 30.8 ± 2.5% (N= 12) of total length; body height 29.9–48.2% of body length (high value probably a preservation artifact; Amiet 1970 reports the body length to be 1.7 to 2 times the body widths); body width 48.2–56.1% of body length; snout truncate in dorsal view; nostrils oval and situated laterally; nostrils equidistant from eye and snout tip; eye diameter 10.5–12.3% of body length; interorbital distance equal to inter-nostril distance; tail fins narrow; dorsal fin originating (1.3–2.5 mm, N= 3) anterior to tail base, narrow, reaching deepest point at or posterior to mid-tail, slightly deeper or as deep as ventral fin; ventral fin originating at tail base, parallel to tail axis to about mid-tail, then broader ( Amiet 1970 reports the dorsal fin originating distinctly posterior to tail base and a more robust tail axis); tail tip rounded to slightly pointed; tail axis broad, continuously converging towards tail tip; body height 96.6% of total tail height; maximum height of tail axis 64.9% of total tail height; vent tube dextral; lateral sacs present, extending from spiracle to end of body, covering lower two thirds of flanks; short spiracle, sinistral, translucent, opening directed lateral, not visible in dorsal view, originating at mid-body; mouth opening frontal; labial tooth row formula 0/0; both jaw sheath completely keratinized, serrated, with a lateral pair of caniniform projections (fangs); upper jaw almost straight; lower jaw Ushaped, median part of lower jaw edge with six to seven needle-like cusps ( Fig. 13 d); two distinct serrations abaxial to fangs; posterior lip large and broadly bilobate, covered with 21 large papillae and numerous small papillae; large papillae arranged symmetrical and in two semicircular rows along vertical body axis; small papillae along edge of lower lip ( Fig. 13 c); depressed w-shaped skin fold on lower lip, just posterior to lower jaw sheath; oral disc width 34.7–57.9% of body length (lower value due to preservation artifact, lip not completely enfolded); mouth width 24.2–32.6% of oral disc width (see above).

The two largest known individuals (ZMB 78553 & 78554, Gosner stage 25) measured 41.6 and 42.8 mm total length, respectively (body length: 12.2 & 12.4 mm; tail length: 29.2 & 30.6 mm). Amiet (1970) reports that a total length of 60 mm may be reached. Metamorphs measure 17–21 mm ( Amiet 1980).

Coloration in preservation. Dorsal parts of body and tail light brown, densely and irregularly covered with dark dots; anterior half of tail axis with median, longitudinal dark line; pattern on tail changes towards tail tip, anterior part of tail axis and dorsal tail fin heavily covered with midsized dark dots; then dots get smaller but denser; overall posterior third of tail tip lighter but more densely dotted; anterior third of ventral fin translucent cream-white; venter lighter and with fewer dark patterns.

Coloration in life. Light brown with many minute dark brown dots; snout brown or yellowish ( Figs. 6 , 14 ); dark line from snout tip to anterior corner of eye; funnel light brown to almost yellow; density of dark dots on tail axis decreasing towards tail tip; anterior third of tail axis with dark longitudinal line; fins very light, almost white, dorsal part with dark patterning; venter lighter; intestines shining through skin ( Fig. 15 ). According to Amiet (1970) a greyish beige color with brown pattern on dorsal parts, the snout sometimes ochre, the lateral sacs are green in life (not differently colored in our specimens ( Figs. 6 , 14 , 15 ).

Tadpoles’ lateral line system of investigated Leptodactylodon species. As far as visible (depending on the preservation state of individuals) all examined Leptodactylodon tadpoles showed the following lateral lines (definitions sensu Lannoo 1987; compare also Fig. 11 in Amiet 1970 and Figs. in Cruz et al. 2013): Supraorbital, posteriororbital, dorsal, middle, ventral, longitudinal oral and angular lines present; angular line connected to posterior infraorbital line; second angular line running dorsal to spiracle, merging into middle line; middle line originating dorsal to lateral sacs, turns upward posteriorly and connects to dorsal line; supraorbital line s-shaped.

Figures

FIGURE 6. Life coloration of Leptodactylodon tadpoles, from top to bottom: L. cf. polyacanthus punctiventris (ZMB 78551, Fotabong), L. boulengeri (ZMB 78471, Fotabong), L. ventrimarmoratus (ZMB 78554, Mt. Kala); pictures not to scale.

FIGURE 11. Mouthpart (a) and jaw sheaths (b) of Leptodactylodon perreti, lacking caniniform projections.

FIGURE 13. Dorsal (a) and lateral view (b) of Leptodactylodon ventrimarmoratus with sketches of mouthpart in frontal view (c) and jaw sheaths with caniniform projections (d); scale bars: 1 mm.

FIGURE 14. Variation of dorsal coloration of Leptodactylodon ventrimarmoratus tadpoles (ZMB 78553).

FIGURE 15. Two Leptodactyodon ventrimarmoratus tadpoles (ZMB 78554, Mt. Kala) with unfolded funnel mouths, swimming vertically below the water surface (compare text), note fading of color pattern towards tail tip.