Bioacoustics of Petropedetes palmipes

Description. Medium to large-sized Petropedetes with robust body; females growing slightly larger than males (SUL in males: 40.3–57.8 mm , in females: 37.5–54.7 mm ); mean head width in males about 41% of SUL, in females about 37%; snout more pointed than in other species; canthus rostralis distinct but rounded, loreal region concave; eye diameter about 1.7 times eye-narial distance; nose closer to snout tip than eye; tympanum very small and indistinct (tympanum / eye in males: 0.18–0.23, in females: 0.20–0.25); no tympanic papilla; supratympanic fold distinct; fingers slender, with typically T-shaped fingertips; relative length of fingers: III> IV> II> I; manual subarticular tubercles single; manual webbing absent; palmar tubercle and thenar tubercle present, palmar tubercle sometimes indistinct; forearm hypertrophy moderately developed in males; carpal spike present in males; spinosities on whole body; dorsal surfaces with heterogeneous skin structure, some larger warts on flank and back, otherwise skin texture on flanks and dorsum similar ( Fig. 8 d); ventral skin more granular than in other species; mean femur length in males 53% of SUL, in females 51%, mean tibia length in males 58% of SUL, in females 57%; mean foot length in males 73% of SUL, in females 72%; upper hind limbs of moderate size, lower hind limbs slender; femoral glands larger in males than in females (femoral gland / femur length in males: 0.26–0.38, in females: 0.22–0.31; Fig. 9 d); relative length of toes: IV> III> V> II> I; toes fully webbed, on 4th toe sometimes slightly less developed 4 (0.5-0.5). Coloration. Dorsum uniformly dark; green and black with very few minuscule pale spots; throat whitish or dark marbled; upper hind limbs with pale, thin cross bars; coloration in preservation as in life, but pale. According to Lamotte et al . (1959) adults are of a glossy black colour in life, and therefore hard to find between stones. Boulenger (1905) describes them as dark olive above, spotted or marbled dark and light. Limbs bear broad dark bands and narrow light cross-bars, the ventral side is dirty whitish ( Boulenger 1905 ). Tadpole. Lamotte et al . (1959) describe the tadpoles of P. palmipes . Tadpoles were found in high numbers in small rocky pools at the foot of rapids. The general coloration of the tadpoles is grey on dorsum and flanks, a duller colour around eyes and nostrils; venter translucent, intestinal tract being visible ( Fig. 3 d); overall body shape flat; large eyes situated in the first third of body; tail almost twice as long as body and tail tip pointed; jaw sheats small, narrow and serrated; keratodont formula in younger stages 4:3+3//1+1:5, in older ones 3+3//1+1:2 ( Fig. 3 d). More developed tadpoles are darker than younger stages. Tadpoles do not exceed a total length of 35 mm ( 25 mm being tail; Lamotte et al. 1959 ). Natural history. Very little data on the biology of this species has been published. Specimens were caught at night in primary forest among stones in a stream. Clutches were found glued to rocks ( Fig. 16 ). Gossmann et al . (2002) explains that both eggs and larvae occur on submerged rocks. Lamotte et al . (1959) find tadpoles of P. palmipes in stagnant parts of rivers beneath small rapids. Schiøtz (1966) describes similarities in the morphology of advanced larval stages of P. palmipes and P. cameronensis , possessing identical teeth formulae. Schiøtz (1966) interprets the different tadpole mouth development as a change in biology, younger larvae being rheophilous and older ones semiterrestrial, scraping algae off stones. The full webbing of adults points to a more aquatic life history, at least in post-metamorphs. The call of P. palmipes is not known ( Amiet 1989 ).