Studies on some spirurids (Nematoda: Spirurida) from fishes of the Okavango River, Botswana.

Based on light and scanning electron microscopical studies, three adult spirurid nematode species, Camallanus (Zeylanema) ctenopomae Vassiliadès & Petter, 1972, Paracamallanus cyathopharynx (Baylis, 1923) (both Camallanidae) and Spinitectus polli Campana-Rouget, 1961 (Cystidicolidae), are redescribed from specimens collected in fishes of the Okavango River, Botswana: C. (Z.) ctenopomae from Ctenopoma sp. (Anabantidae), P. cyathopharynx from Clarias stappersi Boulenger, C. theodorae Weber (both new hosts, Clariidae) and C. gariepinus (Burchell), as well as S. polli from Synodontis nigromaculatus Boulenger (new host, Mochokidae). Moreover, spirurid larvae of an additional three species were found in fishes from the same locality: Rhabdochona paski Baylis, 1928 fourth-stage larva (Rhabdochonidae) in S. nigromaculatus (Mochokidae), Physalopteridae gen. sp. 1 third-stage larva in C. gariepinus (Clariidae) and Physalopteridae gen. sp. 2 third-stage larva in Serranochromis angusticeps (Boulenger) (Cichlidae), all representing new host and geographical records. Spinitectus zambezensis Boomker, 1993 is considered a junior synonym of S. polli.