The following four species (only females available) of the Philometridae (Nematoda: Dracunculoidea) were recorded from freshwater fishes of Lake Turkana, northwestern Kenya in 2007-2008: Philometra bagri (Khalil, 1965) from the subcutaneous tissue around the mouth, on gill covers and the fin base of the bayad Bagrus bajad (Forsskål) (Bagridae: Siluriformes), Philometra lati sp. n. from the abdominal cavity of the Nile perch Lates niloticus (Linnaeus) (Latidae: Perciformes), Philometra spiriformis sp. n. from capsules on the inner surface of gill covers of L. niloticus and Afrophilometra hydrocyoni (Fahmy, Mandour et El-Nafar, 1976) comb. n. from the fins of Hydrocynus forskahlii (Cuvier) (Alestidae: Characiformes). The new species P. lati is characterized mainly by the presence of distinct oesophageal teeth, absence of large cephalic lobes and caudal projections, and by a combination of other features. Philometra spiriformis differs from all congeners principally in the spirally coiled body and from individual species by a combination of other morphological features. The already known species P. bagri and A. hydrocyoni are redescribed based on light and scanning electron microscopy; findings of both these species in Kenya represent new geographical records.
A new species of philometrid nematode, Philometroides africanus sp. n., is described from female specimens found encapsulated in gill arches and inner surface of gill covers of the African pike, Hepsetus odoe (Bloch), an endemic freshwater fish in Africa, from the Okavango River and Delta in Botswana. This new nematode is characterised mainly by a markedly small and plump body of gravid females (body length 6-9 mm), a separate anterior oesophageal bulb, a conspicuously small oesophageal gland, presence of four pairs of very small submedian cephalic papillae, and absence of any caudal processes. The prevalence of P. africanus in African pike of the Okavango Delta was 29%, with the intensity 1-8 (mean 3) encapsulated nematodes per fish. The genus Margolisianum Blaylock et Overstreet, 1999 is considered a junior synonym of Philometroides Yamaguti, 1935 and, consequently, its type species is transferred to the latter as Philometroides bulbosus (Blaylock et Overstreet, 1999) comb. n.
Ascaridoid nematodes referable to Brevimulticaecum heterotis (Petter, Vassiliadès et Marchand, 1979) Khalil, 1984 were recorded from the intestine of the African bonytongue, Heterotis niloticus (Cuvier) (Arapaimidae, Osteoglossiformes), from the Mare Simenti in the Niokolo Koba National Park, East Senegal and from Kosti, Sudan. Their examination using light microscopy and for the first time both environmental scanning electron microscopy and scanning electron microscopy revealed some previously unreported morphological features and made possible a detailed redescription of this species. The most important finding is the presence of dentigerous ridges on the inner edges of the lips, which confirms the attribution of this species to Multicaecum Baylis, 1923, where it was originally placed, and not to Brevimulticaecum Mozgovoy in Skryabin, Shikhobalova et Mozgovoy, 1951 where it had subsequently been transferred. A key to Brevimulticaecum and Multicaecum species is provided. Multicaecum heterotis is the first species of the genus to be sequenced. Partial sequences of the small ribosomal subunit (18S) and internal transcribed spacer 2 region (ITS2) of nuclear ribosomal DNA (rDNA) have been analysed and compared with other nematode species.