New Caenis Species (Insecta: Ephemeroptera: Caenidae) from Angola, Okavango and Zambezi River Basins

Nine new species of Caenis from Angola are described herein: Caenis wegeneriana sp. n. (imago), Caenis angolensis sp. n. (imago and larva), Caenis branchiata sp. n. (larva), Caenis filappendicessp.n.(imago),Caenisulesisp.n.(larva),Caeniscubangosp.n.(larva),Caenisarmata sp. n. (imago), Caenis brevispinata sp. n. (imago), and Caenis gallocristata sp. n. (imago). The relationship between the newly described species and other known African species is discussed. The vicariant biogeographic affiliation of Caenis wegeneriana to a related species group in South America, separated by continental drift, is considered. A key to the male imagoes is provided, including Caenis antelucanaMalzacher, 1990, Caenis brevipes Kimmins, 1956, Caenis douglasiMalzacher, 1993 and Caenis jinjana Kimmins, 1956, which have previously been recorded in the Cunene River, along the shared border with Namibia.