Petrocephalus okavangensis sp. nov. SAIAB 030046, holotype, specimen R22, 6.1 cm SL, Botswana, Okavango, Thoage River, Nguma (Guma) Lagoon, 18 ◦ 56 ′ 60 ′′ S, 22 ◦ 22 ′ 59.99 ′′ E, 3 January 1987, coll. G. Merron, SAIAB 186062 (41), paratypes, 4.2–7.8 cm SL, Botswana, Okavango, Thoage River, Nguma (Guma) Lagoon, 18 ◦ 56 ′ 60 ′′ S, 22 ◦ 22 ′ 59.99 ′′ E, 3 January 1987, coll. G. Merron, Non-types: ZSM 38665(3), 8.0– 8.1 cm SL, Botswana, Okavango, Thoage River, Guma Lagoon, 18 ◦ 57 ′ 46.6 ′′ S, 22 ◦ 22 ′ 25.3 ′′ E, 10 August 2004, coll. F. H. Van der Bank and B. Kramer, one specimen for EOD only, Botswana, Okavango, Thoage River, 19 ◦ 03 ′ 45.3 ′′ S, 22 ◦ 23 ′ 24.3 ′′ E, 23 March 2002, 26 ◦ C water temperature, 50 µS / cm, EOD recorded 7 March 2003 Regensburg, one specimen for EOD only, Botswana, Okavango, Thoage River, Guma Lagoon, 18 ◦ 57 ′ 46.6 ′′ S, 22 ◦ 22 ′ 25.3 ′′ E, 17.1 ◦ C water temperature, 38 µS / cm, EOD recorded 12 August 2004, SAIAB 36841 (24), 3.7–6.6 cm SL, Namibia, Okavango River, Popa Rapids, 18 ◦ 06 ′ 00 ′′ S, 21 ◦ 36 ′ 00 ′′ E, 15 July 1986, coll. P. Skelton, SAIAB 36823 (12), 3.6–7.8 cm SL, same location, second island, 14 July 1986, coll. T. Andrew, G. Merron, P. Skelton, SAIAB 19769 (21), 4.5–8.3 cm SL, Botswana, Okavango Delta, Moanachira River, Gadikwe Lagoon, mid island 19 ◦ 10 ′ 00 ′′ S, 23 ◦ 14 ′ 00 ′′ E, 3 November 1983, coll. G. Merron, SAIAB 19705 (11), 5.6–9.5 cm SL, Botswana, Okavango Delta, Moremi Game Reserve, Xakanixa Channel, opposite Safari Lodge, upper swamp 19 ◦ 10 ′ 00 ′′ S, 23 ◦ 24 ′ 00 ′′ E, 2 November 1983, coll. G. Merron, SAIAB 21271 (38), 3.6–9.3 cm SL, Botswana, Okavango Delta, Moremi Game Reserve, Xakanixa River, 19 ◦ 15 ′ 00 ′′ S, 23 ◦ 15 ′ 00 ′′ E, 24 June 1984, coll. G. Merron and G. May.

Published as part of Kramer, Bernd, Bills, Roger, Skelton, Paul & Wink, Michael, 2012, A critical revision of the churchill snoutfish, genus Petrocephalus Marcusen, 1854 (Actinopterygii: Teleostei: Mormyridae), from southern and eastern Africa, with the recognition of Petrocephalus tanensis, and the description of five new species, pp. 2179-2258 in Journal of Natural History 46 (35 - 36) on page 2192, DOI: 10.1080/00222933.2012.708452, http://zenodo.org/record/4590828