Opisthothylax immaculatus (Boulenger, 1903)

Class: Amphibia > Order: Anura > Family: Hyperoliidae > Subfamily: Hyperoliinae > Genus: Opisthothylax > Species: Opisthothylax immaculatus

Megalixalus immaculatus Boulenger, 1903, Mem. R. Soc. Esp. Hist. Nat., 1: 63. Syntypes: BMNH (2 specimens), by original designation, although only one specimen (BMNH 1947.2.9.85, formerly numbered 1903.6.20.22) is currently known to exist, by museum records. Type locality: "Escalera au Cap Saint-Jean", Equatorial Guinea.

Megalixalus immaculatusNoble, 1924, Bull. Am. Mus. Nat. Hist., 49: 270.

"Heterixalus" immaculatusPerret, 1960, Rev. Zool. Bot. Afr., 61: 372.

"Megalixalus" immaculatusSchiøtz, 1963, Vidensk. Medd. Dansk Naturhist. Foren., 125: 61.

Opisthothylax immaculatusPerret, 1966, Zool. Jahrb., Jena, Abt. Syst., 93: 445.

English Names

Gray-eyed Frog (Frank and Ramus, 1995, Compl. Guide Scient. Common Names Amph. Rept. World: 69).

Orange Frog (Channing and Rödel, 2019, Field Guide Frogs & Other Amph. Afr.: 152).   


Southeastern Nigeria through southern Cameroon and Equatorial Guinea (including Bioko I.) to Gabon and southwestern Dem. Rep. Congo; expected in western Rep. Congo, southwestern Central African Republic, and Cabinda enclave of Angola.

Geographic Occurrence

Natural Resident: Cameroon, Congo, Democratic Republic of the, Equatorial Guinea, Gabon, Nigeria

Likely/Controversially Present: Angola, Central African Republic, Congo, Republic of the


See account for Cameroon by Amiet, 2012, Rainettes Cameroun: 413–422. Schiøtz, 1999, Treefrogs Afr.: 312–313, provided a brief account and map. Channing, Rödel, and Channing, 2012, Tadpoles of Africa: 242, provided information on comparative larval morphology. Jongsma, Tobi, Dixon-MacCallum, Bamba-Kaya, Yoga, Mbega, Mve Beh, Emrich, and Blackburn, 2017, Amph. Rept. Conserv., 11 (1: e144): 14, provided a record for southeastern Gabon and briefly discussed habitat and range. Dewynter and Frétey, 2019, Cah. Fondation Biotope, 27: 29, summarized the literature for Gabon. Channing and Rödel, 2019, Field Guide Frogs & Other Amph. Afr.: 152–153, provided a brief account, photograph, and range map. See brief account, range map, and photographs for Equatorial Guinea in Sánchez-Vialas, Calvo-Revuelta, Castroviejo-Fisher, and De la Riva, 2020, Proc. California Acad. Sci., Ser. 4, 66: 137–230.  

External links:

Please note: these links will take you to external websites not affiliated with the American Museum of Natural History. We are not responsible for their content.