Ptychadena arnei Perret, 1997

Schiøtz’s Grass Frog

Material: Male, NGK-Nimba 0053 (Fig. 13C).

Comments: Ptychadena arnei is a poorly studied frog occurring in humid savannahs, secondary forests, and gallery forests, from southern Senegal to central Ivory Coast (Channing and Rödel 2019). Only two females (43.5 and 45.5 mm) and two males (39.5 and 40.5 mm) were recorded at night in the Yéalé village, sitting at the edge of a road puddle that intersected a heavily degraded forest. The basic color of their back was brown to grey with a light triangle on the snout. Ptychadena oxyrhynchus, which often have a pale snout as well, have much longer legs (see e.g., Fig. 13F). The P. arnei specimens had short dorsolateral folds and possessed distinct sacral folds. They had dark to pale crossbars on the legs and lacked external metatarsal tubercles. A female (Fig. 13B) exhibited a fine yellow vertebral line. A reddish to yellow longitudinal line on the tibia was broad towards the heel, but narrow towards the knee. The upper part of flanks was reddish, while the lower part was grey with black spots. The ventral surface ranged from whitish through beige to yellow. The species is known by its unique advertisement calls, which consist of a long succession of short double calls (Channing and Rödel 2019). In paddy fields around Daloa, western-central Ivory Coast, frogs that were morphologically identical emitted such calls (Kouamé et al., unpub. data).