Afrixalus osorioi (Ferreira, 1906)

Badjedjea, Gabriel, Masudi, Franck M., Akaibe, Benjamin Dudu & Gvoždík, Václav, 2022, Amphibians of Kokolopori: an introduction to the amphibian fauna of the Central Congolian Lowland Forests, Democratic Republic of the Congo, Amphibian & Reptile Conservation (e 301) 16 (1), pp. 35-70 : 49-51

Afrixalus osorioi (Ferreira, 1906)

Fig. 7C .

Area: Yalokole, Yetee, Yotemankele.

Season/survey: Wet (May 2018), dry (Aug 2019).

Material: CSB:Herp: RNBK 093, 098, 135, 136, 150, 151, 153, 162, 165, 167, 174, 200, 338, 354, 381, 388, 398, 408, 435, 438, 454, 467, 508, 517, 593, 672, 674.

Comments: This species was described from westcentral Angola and is known to occur throughout much of the Congo Basin, in Uganda, and in western Kenya. The subspecies A. osorioi congicus ( Laurent 1941) was described from northern DRC, with the presumed distribution in northern and eastern DRC ( Laurent 1972). Later, Laurent (1982) noted that specimens of A. osorioi from central Congo (Sankuru) were found to be intermediate between the nominotypical subspecies

and ssp. congicus and explained this pattern as a clinal variation. Laurent agreed with other earlier authors (e.g., Perret 1976b) to synonymize ssp. congicus with the nominotypical subspecies. However, a detailed investigation of the geographic morphological variation and molecular phylogeography of the species may reveal a more complex pattern in the future and possibly resurrect the congicus taxon. This name could also be applicable for the central Congolian population. In Kokolopori, A. osorioi was found in ponds or along streams usually in open habitats, but it was also recorded in disturbed flooded forest together with A. cf. quadrivittatus . Most males were found calling, hidden in higher herbaceous vegetation, and some were found in amplexus. Based on a comparison of three similar Congolian forest species ( A. equatorialis , A. leucostictus Laurent, 1950 , and A. osorioi ), Laurent (1982) mentioned that A. leucostictus can turn its coloration into dark brown, almost without pattern, a condition which rarely happens in A. osorioi . However, some of the Kokolopori specimens of A. osorioi were dark brown, with their dorsal pattern barely visible.

Figures

Fig. 7. Hyperoliids, Afrixalus, Congolius, and Cryptothylax. (A) Afrixalus equatorialis (male, nocturnal coloration). (B) A. equatorialis (female, nocturnal coloration). (C) A. osorioi (male). (D) A. cf. quadrivittatus (amplectant pair). (E) Congolius robustus (male). (F) C. robustus (female). (G) Cryptothylax greshoffii (male). (H) C. greshoffii (female).