Ptychadena mascareniensis (Duméril & Bibron, 1841)

Segniagbeto, Gabriel Hoinsoudé, Ohler, Annemarie, Rödel, Mark-Oliver, Luiselli, Luca & Dubois, Alain, 2024, Amphibians of Togo: taxonomy, distribution and conservation status, Zoosystema 46 (25), pp. 631-670 : 658

Ptychadena mascareniensis (Duméril & Bibron, 1841)

( Fig. 12E )

MATERIALS EXAMINED. — Togo • 4 ♂, 24 ♀; Agoé ; MNHN-RA-2006.2108-2112, MNHN-RA-2006.2118-2123, MNHN-RA-2006.2140-2155 • 1 ♂, 6 ♀; Djagblé ; MNHN-RA-2006.2105, MNHN-RA-2006.2101-2104, MNHN-RA-2006.2106, MNHN-RA-2006.2107 • 5 ♂, 24 ♀; Kovié ; MNHN-RA-1995.1999, MNHN-RA-1995.2000, MNHN-RA-1995.2018, MNHN-RA-1995.2024, MNHN-RA-1995.2027, MNHN-RA-1995.1233-1235, MNHN-RA-1995.1940, MNHN-RA-1995.1985, MNHN-RA-1995.1987, MNHN-RA-1995.1989-1996, MNHN-RA-1995.2019-2023, MNHN-RA-1995.2026, MNHN-RA-1995.2033, MNHN-RA-1995.2034, MNHN-RA-1995.2039, MNHN-RA-1995.2044 • 1 ♂, 24 ♀; Togblékopé ; MNHN-RA-2006.2113-2118, MNHN-RA-2006.2125-2139 .

DESCRIPTION. — Frog of moderate size (SVL 30-43 mm ♂, 28- 53 mm ♀), usually slender and elongated body. Snout pointed, protruding beyond mouth slit. Head longer than broad HW 25-33% SVL; HL 34-44% SVL). Tympanum distinct (TYD 6-9% SVL). Hind legs long (TL 51-68% SVL). Webbing small, leaving three phalanges free; webbing formula: I 1 ½ – 2 ½ II 1 ½ – (2 ½ or 3) III (1 ½ or 2) – 3 IV 3 – 1 ½ V. Back with four pairs of continuous glandular folds, the innermost pair bordering the medio-dorsal line from the palpebral region to the vent, the fourth outermost pair of folds constituting the dorsolateral folds; finely granular skin on the back; some glandular granules on the flanks; belly smooth.

COLOURATION. — The dorsal colouration is essentially brown, sometimes gray, the glandular folds are darker. The vertebral line is whitish for most specimens, sometimes green in some living specimens. The ventral side is white and the posterior side of the thighs has large dark transverse spots.

SEXUAL DIMORPHISM. — The males have a pair of laterally opening vocal sacks, with the external opening parallel to the lower jaw, and nuptial pads on first to third fingers.

HABITATS AND DISTRIBUTION. — Ptychadena mascareniensis is present throughout the country. In the suburbs of Lomé, individuals sometimes enter houses during the rainy season. The species is very abundant in the wetlands around Lomé (Zio, Haho, Lake Togo and the small ponds around these rivers). We observed specimens in ecological zones I, II, III and IV of the country. The species was reported by Bourgat (1979) from Lomé, Kovié and Kloto, and by Segniagbeto et al. (2022) from Tetetou to Nagbeto dam along the Mono River.

TAXONOMIC NOTE. — This nominal taxon consists of a species complex. Lamotte (1967b) distinguished two forms on the size of the individuals. He considered the West African form described as Rana (Ptychadena) hylaea Schmidt & Inger, 1959 as a larger form (♂ 49-56 mm, ♀ 59-72 mm), specifically related to forest ecosystems in Côte d’Ivoire, Guinea, Liberia, Sierra Leone, and the smaller species Ptychadena pumilio (Boulenger, 1920) (♂ 29-36 mm, ♀ 36-40 mm) related to savannah ecosystems in central Côte d’Ivoire and Burkina Faso. The name Ptychadena pumilio applies to small frogs, and may comprise several species, living in degraded rainforest and savannah areas of West Africa, respectively ( Rödel 2000 and M.-O. Rödel unpubl. data). Ptychadena mascareniensis is larger and also occurs in both ecosystems, but is usually best observed in rice paddies. Several morphological and colour morphs have been observed (see e.g. Rödel & Glos 2019; M.-O. Rödel unpubl. data). In Togo we observed specimens that do not resemble the hylaea form of Lamotte (1967b) with regard to size. Some examined specimens that are adult males and females have an intermediate size (SVL) ranging from 40 to 52 mm. It has been shown that Ptychadena mascareniensis as currently understood is a complex of species ( Vences et al. 2004; Zimkus et al. 2017). The latter publication revealed a high level of genetic differentiation, i.e., 10 distinct lineages or operational taxonomic units. Further morphological and molecular work is needed to clarify the taxonomy of West African populations.

Figures

FIG. 12. — Representatives of anuran species from Togo in life: A, Phrynomantis microps Peters, 1875 (Tsévié); B, Xenopus fischbergi Evans, Carter, Greenbaum, Gvoždík,Kelley,McLaughlin, Pauwels,Portik, Stanley, Tinsley,Tobias & Blackburn, 2015 (Siou);C, Xenopus tropicalis (Gray, 1864) (Agoté); D, Ptychadena bibroni (Hallowell, 1845) (Kovié); E, Ptychadena mascareniensis (Duméril & Bibron, 1841) (Kovié); F, Ptychadena oxyrhynchus (Smith, 1849) (Tchamba),