Based on light and scanning electron microscopical studies, two new species of nematode parasites are described from freshwater fishes in Thailand: Orientatractis mekongensis n. sp. (Atractidae) from the intestine of Pangasius bocourti Sauvage (type-host) and Helicophagus leptorhynchus Ng & Kottelat (both Pangasiidae, Siluriformes), and Neosynodontisia suratthaniensis n. sp. (Pharyngodonidae) from the intestine of Labiobarbus siamensis (Sauvage) (Cyprinidae, Cypriniformes), for which a new genus Neosynodontisia n. g. is established. Orientatractis mekongensis is mainly characterised by the number and distribution of caudal papillae (2 preanal, 1 adanal and 5 postanal pairs), the length of the left spicule (306-384 µm) and large body sizes (length of males and gravid females 5.4-6.7 mm and 7.8-9.0 mm, respectively). Neosynodontisia differs from other pharyngodonid genera with representatives parasitic in fishes not only by some morphological features (mouth withdrawn into the cephalic end with inflated cuticle, structure of the male caudal end, filamented eggs), but mainly by the occurrence of males inside the body of females. A key to the genera of the Pharyngodonidae with representatives parasitising fishes is provided.

• MeSH
• Species Specificity MeSH
• Nematoda anatomy & histology   classification   ultrastructure   MeSH
• Microscopy, Electron, Scanning MeSH
• Fresh Water MeSH
• Catfishes parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Thailand MeSH

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.

• MeSH
• Species Specificity MeSH
• Larva ultrastructure   MeSH
• Rivers MeSH
• Fishes parasitology   MeSH
• Spirurida classification   ultrastructure   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Botswana MeSH

Three species of Procamallanus (Spirocamallanus) Baylis, 1923 (Camallanidae) (Nematoda: Camallanidae) were found in the digestive tract of freshwater fishes from the Okavango River, Botswana, i.e. P. (S.) daleneae (Boomker, 1993) from Synodontis vanderwaali Skelton & White (Mochokidae), P. (S.) spiralis Baylis, 1923 from Clarias stappersi Boulenger, C. theodorae Weber (both Clariidae) and Hepsetus odoe (Bloch) (Hepsetidae), and P. (S.) serranochromis n. sp. from Serranochromis macrocephalus (Boulenger) (type-host), S. angusticeps (Boulenger) and S. robustus (Günther) (all Cichlidae). All findings of the two previously known species represent new host records. The specimens were studied using both light and scanning electron microscopy. Spirocamallanus mazabukae Yeh, 1957 is considered a junior synonym of P. (S.) spiralis. A key to the species of Procamallanus (Spirocamallanus) parasitising fishes of continental Africa is provided.

• MeSH
• Cichlids parasitology   MeSH
• Nematoda classification   physiology   ultrastructure   MeSH
• Microscopy, Electron, Scanning MeSH
• Rivers parasitology   MeSH
• Fishes parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Botswana MeSH

Parasitological dissections of fishes from the Okavango River, Botswana, revealed the presence of nematodes of the subgenus Procamallanus (Procamallanus) Baylis, 1923 in five fish species belonging to three different families. Based on light and scanning electron microscopical examinations, they proved to represent one previously known and one new species, i.e. P. (P.) laeviconchus (Wedl, 1861) from Synodontis nigromaculatus Boulenger, S. thamalakanensis Fowler (new host) (both Mochokidae) and Schilbe intermedius Rüppel (new host) (Schilbeidae), and P. (P.) pseudolaeviconchus n. sp. from Clarias stappersi Boulenger and C. theodorae Weber (both Clariidae). Specimens of the new species previously collected from Clarias gariepinus (Burchell) (type-host) in Egypt were also examined. Both of these nematode species are very similar, differing from each other mainly in the shape of the circumoral flange, which is conspicuously lobed in P. laeviconchus and unlobed in P. pseudolaeviconchus. Previously, these two species have been confused in the literature under the name P. laeviconchus. A key to Procamallanus (Procamallanus) spp. parasitising freshwater fishes in Africa, including Madagascar, is provided.

• MeSH
• Species Specificity MeSH
• Nematoda classification   physiology   ultrastructure   MeSH
• Microscopy, Electron, Scanning MeSH
• Rivers parasitology   MeSH
• Fishes parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Botswana MeSH
• Egypt MeSH

Numerous nematodes were found in the rectum of three fish species Synodontis ocellifer, S. nigrita, and S. schall (Mochokidae, Siluriformes) from the Gambia River and Mare Simenti, National Park Niokolo Koba, Senegal. A nematode species Raillietnema synodontisi Vassiliadès, 1973 (host S. ocellifer), is redescribed using morphometric (including scanning electron microscopy) and molecular characteristics and transferred into the genus Labeonema Puylaert, 1970. It is morphologically and metrically similar to Labeonema intermedium Puylaert, 1970, the other congeneric species (L. bainae Baker, 1982; L. bakeri Van Waerebeke, Chabaud, Bain et Georges, 1988; and L. africanum Moravec et Van As, 2004) differ from them either by the spicule and gubernaculum lengths, distribution and number of pre-cloacal papillae, position of the vulva, as well as hosts and geographical distribution. The partial sequences of small ribosomal subunit rDNA of L. synodontisi were analyzed and compared with other nematode sequences. Molecular analyses seem to support the position of this nematode species based on the morphological observation.

• MeSH
• DNA, Helminth analysis   MeSH
• Rhabditida Infections parasitology   veterinary   MeSH
• Microscopy, Electron, Scanning MeSH
• Molecular Sequence Data MeSH
• Fish Diseases parasitology   MeSH
• Rivers MeSH
• Rhabditida * anatomy & histology   classification   genetics   ultrastructure   MeSH
• RNA, Ribosomal, 18S genetics   MeSH
• Sequence Analysis, DNA MeSH
• Catfishes parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Africa, Western MeSH
• Names of Substances
• DNA, Helminth MeSH
• RNA, Ribosomal, 18S MeSH