Arthroleptis variabilis
It is found in the lowlands of eastern Nigeria , Cameroon , Equatorial Guinea ( including the island of Bioko ) , Gabon , the Central African Republic , the Republic of the Congo , and the Democratic Republic of the Congo . 
<triplet> Bioko <subj> Equatorial Guinea <obj> country <triplet> Central African Republic <subj> Democratic Republic of the Congo <obj> diplomatic relation