Based on light microscopical and scanning electron microscopical (SEM) examinations, two North American species of Spinitectus Fourment, 1884, S. acipenseri Choudhury & Dick, 1992 and S. micracanthus Christian, 1972 (Nematoda, Cystidicolidae) are redescribed from museum voucher specimens (S. acipenseri) and those newly collected from centrarchid and some other fishes in the Upper San Marcos River in Texas and the Santee River in South Carolina, USA. The first use of SEM to study S. acipenseri, a parasite of lake sturgeon Acipenser fulvescens Rafinesque (Acipenseridae) in Canada, made it possible to describe dorsal and ventral lips, amphids and sublabia, and the presence of a dorsal barb on the right spicule, which was confirmed to be the most characteristic feature of this species. The SEM study of S. micracanthus, a parasite mainly of centrarchids, enabled us to correctly determine the location of the excretory pore in relation to rings of cuticular spines in the male, and to describe the exact structure of the tip of the male tail, sublabia, phasmids and the presence of a median ventral protuberance on the male tail. Some taxonomic problems of North American species of Spinitectus are discussed. Filaria serrata Linton, 1901 is considered a junior synonym of S. oviflagellis Fourment, 1884. To date, there are 13 valid species of Spinitectus parasitising fishes in North America. Keys to species of Spinitectus-like nematodes from fishes in North American waters are provided.

TITLE: Redescriptions de Spinitectus acipenseri et S. micracanthus (Nematoda, Cystidicolidae), et notes sur la taxonomie des nématodes de type Spinitectus parasitant les poissons nord-américains. ABSTRACT: Deux espèces nord-américaines de Spinitectus Fourment, 1884, S. acipenseri Choudhury & Dick, 1992 et S. micracanthus Christian, 1972 (Nematoda, Cystidicolidae) sont redécrites à partir de spécimens de musée et d’autres nouvellement collectés aux USA dans les rivières Upper San Marcos (Texas) and Santee (Caroline du Sud), avec l’aide de la microscopie optique et électronique à balayage (MEB). L’utilisation pour la première fois du MEB pour étudier S. acipenseri, un parasite de l’esturgeon Acipenser fulvescens Rafinesque (Acipenseridae) au Canada, a permis de décrire les lèvres dorsales and ventrales, les amphides et sublabia, ainsi que la barbe dorsale sur le spicule droit que nous confirmons être le critère le plus caractéristique de cette espèce. L’étude au MEB de S. micracanthus, un parasite principalement de centrarchides, nous a permis de déterminer correctement la place du pore excréteur en relation avec les couronnes d’épines cuticulaires chez le mâle, ainsi que de décrire la structure exacte de l’extrémité caudale du mâle, des sublabia, des phasmides et la présence d’une protubérance médiane et ventrale sur la queue du mâle. Des problèmes taxonomiques sur les espèces nord-américaines de Spinitectus sont discutés. Filaria serrata Linton, 1901 est considéré synonyme plus récent de S. oviflagellis Fourment, 1884. À ce jour, il y a 13 espèces valides de Spinitectus parasites de poissons en Amérique du Nord. Des clés des espèces des nématodes de type Spinitectus provenant des poissons des eaux nord-américaines sont fournies.

• Klíčová slova
• Canada, Ctenascarophis, Morphology, Parasitic nematode, Prospinitectus, South Carolina, Texas, USA,
• MeSH
• mikroskopie elektronová rastrovací MeSH
• plži * MeSH
• ryby MeSH
• Spiruroidea * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Severní Amerika MeSH

Nematodes belonging to Spinitectus Fourment, 1883 (Nematoda: Cystidicolidae) were found in the intestine of Pimelodella avanhandavae Eigenmann (Siluriformes: Heptapteridae) from the Aguapeí River, Brazil. They represent a new species, Spinitectus aguapeiensis n. sp., which differs morphologically from its congeners in the body length, the number of spinose rings, the location of the excretory pore, the number of precloacal papillae and the length of the spicules. The new species is the first South American species within the genus with a remarkably spirally coiled posterior extremity in males and the largest spicules. It is also the second species with the highest number of precloacal papillae and has unique shape of the small spicule. Spinitectus aguapeiensis n. sp. is the first helminth species found in P. avanhandavae, the fourth species of this genus recorded in the River Paraná Basin and the sixth species of Spinitectus in South America.

• MeSH
• druhová specificita MeSH
• hlístice anatomie a histologie   klasifikace   MeSH
• řeky MeSH
• střeva parazitologie   MeSH
• sumci parazitologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Brazílie MeSH

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
• druhová specificita MeSH
• hlístice klasifikace   ultrastruktura   MeSH
• interakce hostitele a parazita * MeSH
• larva MeSH
• mikroskopie elektronová rastrovací MeSH
• nematodózy parazitologie   veterinární   MeSH
• nemoci ryb parazitologie   MeSH
• řeky * MeSH
• ryby MeSH
• stromy * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Mexiko MeSH