Astylosternus ranoides Amiet, 1978

Griesbaum, Frederic, Hirschfeld, Mareike, F. Barej, Michael, Schmitz, Andreas, Rohrmoser, Mariam, Dahmen, Matthias, Muehlberger, Fabian, Christoph Liedtke, H., L. Gonwouo, Nono, Doumbia, Joseph & Roedel, Mark-Oliver, 2019, Tadpoles of three western African frog genera: Astylosternus Werner, 1898, Nyctibates Boulenger, 1904, and Scotobleps Boulenger, 1900 (Amphibia, Anura, Arthroleptidae), Zoosystematics and Evolution 95 (1), pp. 133-160 : 144-145

Astylosternus ranoides Amiet, 1978

Material examined.

ZMB 82823 (GenBank MK318873), Gosner stage 25, Cameroon, Mt Manengouba, near summit, 2135 m, 5°0'35.4"N, 9°51'24.8"E, 7 August 2011, leg. M. Hirschfeld.

The tadpole was caught in a medium-sized river within a heavily degraded forest fragment. The tail tip had been taken as tissue sample; the continuation of the tail tip was thus reconstructed based on the generalized tail shape of the genus, and total length estimated (compare Fig. 14a).

The tadpole’s sequence has been compared with an adult from Kodmin, Cameroon (ZFMK 67364; GenBank MK318874). The two sequences were identical.

Description.

Long slender tadpole with narrow, muscular tail (Fig. 14); body longish oval in dorsal view, more flattened in lateral view; snout broadly rounded in dorsal view, almost truncate in lateral view; body length 34.1% of total length; body height 45.2% of body length; body width 58.1% of body length; eyes positioned dorsolaterally, eye diameter 9.6% of body length; nostrils positioned dorsolaterally, closer to snout tip than to eyes; inter-nostril distance 83.3% of interorbital distance; tail fins narrow; dorsal and ventral fin originating at tail base; ventral fin height 81.8% of dorsal fin height; highest part of tail approximately in the last third of the tail; body height 82.4% of maximum tail height; tail axis width 33.3% of body width; tail axis height 61.8% of maximum tail height; exact form of tail tip unknown; vent tube dextral; body with lateral sacs, extending from spiracle to end of body; short spiracle, sinistral; mouth ventral, near snout tip, narrower than interorbital distance; no keratodonts; anterior lip with large rostral gap, only two papillae on each side, close to angles of jaw; posterior lip with about 15 short roundish papillae (Fig. 14c); massive black, serrated jaws, both more or less U-shaped.

Total length of this tadpole was estimated to be about 18 mm (Fig. 14a). The absence of keratodonts implies that the tadpole is in a very early stage of development.

Coloration in preservation.

Body light brown to beige, slightly speckled; tail axis yellowish with large dark brown blotches; tail fins with dark patterning, but predominately transparent (in Fig. 14a the background was black).