For the first time, the nematode Rhabdochona kidderi kidderi Pearse, 1936 (Rhabdochonidae) was recorded from fishes of the Lacantún River (Usumacinta River basin) in the Lacandon rain forest, Chiapas State, southern Mexico. Amphilophus nourissati (Allgayer) and Theraps irregularis Günther (both Perciformes: Cichlidae) were found to be the only definitive hosts in the locality, whereas Eugerres mexicanus (Steindachner) (Perciformes: Gerreidae), Ariopsis sp., Cathorops aguadulce (Meek) and Potomarius nelsoni (Evermann & Goldsborough) (all Siluriformes: Ariidae), Ictalurus furcatus (Valenciennes) (Siluriformes: Ictaluridae) and Strongylura hubbsi Collette (Beloniformes: Belonidae) all harboured the nematode's fourth-stage larva and only served as paratenic hosts. All these fish species represent new host records for this parasite. The morphology of both adults and larvae was studied in detail by light and scanning electron microscopy, and some conspecific museum specimens from three other host species were also examined for comparison. Rhabdochona ictaluri Aguilar-Aguilar, Rosas-Valdez & Pérez-Ponce de León, 2010 is considered here to be a junior synonym of R. kidderi kidderi. A high degree of the variability of some morphological and biometrical features (deirid shape, left spicule length) and an unusually wide range of hosts suggest that R. kidderi may represent a species complex, but further studies are necessary in this respect. A key to Rhabdochona species and subspecies occurring in Mexico is provided.

• MeSH
• Species Specificity MeSH
• Nematoda classification   ultrastructure   MeSH
• Host-Parasite Interactions * MeSH
• Larva MeSH
• Microscopy, Electron, Scanning MeSH
• Nematode Infections parasitology   veterinary   MeSH
• Fish Diseases parasitology   MeSH
• Rivers * MeSH
• Fishes MeSH
• Trees * 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
• Mexico MeSH

Two species of Rhabdochona Railliet, 1916 (Nematoda: Rhabdochonidae) were recorded from cyprinid fishes in the basin of the River Tigris, northern Iraq: adults of R. (R.) tigridis Rahemo, 1978 (emend.) from Capoeta trutta (Heckel) and Cyprinion macrostomum Heckel and fourth-stage larvae of R. (Globochona) sp. from C. macrostomum, Barbus barbulus Heckel and Barbus kersin Heckel. Light and scanning electron microscopical studies of this material made possible a detailed redescription of R. tigridis, which is characterised by 14 anterior prostomal teeth and filamented eggs. It differs from the most similar species, R. fortunatowi Dinnik, 1933, mainly in the presence of large deirids close to the prostom. R. grandipapillata Rahemo & Kasim, 1979 is considered a junior synonym of R. tigridis. Fourth-stage larvae of Rhabdochona (G.) sp., characterised by eight anterior prostomal teeth and the presence of caudal processes on the tail tip, represent the first record of a Rhabdochona species of the subgenus Globochona Moravec, 1972 in Iraq.

• MeSH
• Cyprinidae parasitology   MeSH
• Spirurida Infections parasitology   veterinary   MeSH
• Microscopy, Electron, Scanning MeSH
• Microscopy MeSH
• Fish Diseases parasitology   MeSH
• Spiruroidea anatomy & histology   classification   isolation & purification   ultrastructure   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Iraq MeSH