Opegaster Ozaki, 1928 is one of the most species-rich genera of the trematode family Opecoelidae, commonly found in marine teleost fishes. This study describes a new species of Opegaster of the intertidal fish species Labrisomus xanti Gill (Labrisomidae) (type host) and Tomicodon zebra (Jordan et Gilbert) (Gobiesocidae) from the coast of Oaxaca, Mexican Pacific. Opegaster mezcal sp. n. is characterised by the absence of papillae on the ventral sucker and the size and shape of the testes. Sequences of the D1-D3 domains from large subunit from nuclear DNA (28S) were generated for the new species and for another opecoelid species, Opecoelus adsphaericus Manter et Van Cleave, 1951. The new sequences of Opegaster mezcal sp. n. formed a clade, which is sister to O. adsphaericus. However, the phylogenetic relationships among genera of Opecoelinae remain unresolved because few species have been analysed; the addition of further taxa is necessary to better understand the evolution of the subfamily.

• Klíčová slova
• Digenea, Mexico, Oaxaca, Plagiorchiida, marine fish, taxonomy,
• MeSH
• DNA helmintů genetika   MeSH
• fylogeneze MeSH
• infekce červy třídy Trematoda * veterinární   parazitologie   epidemiologie   MeSH
• nemoci ryb * parazitologie   epidemiologie   MeSH
• Perciformes * parazitologie   MeSH
• RNA ribozomální 28S genetika   MeSH
• Trematoda * klasifikace   genetika   anatomie a histologie   izolace a purifikace   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Mexiko epidemiologie   MeSH
• Tichý oceán MeSH
• Názvy látek
• DNA helmintů MeSH
• RNA ribozomální 28S MeSH

Molecular and morphological data were gathered for specimens of species of Macvicaria Gibson & Bray, 1982 and Pseudopycnadena Saad-Fares & Maillard, 1986 (Digenea: Opecoelidae) collected from two sparid fishes, Diplodus vulgaris (Geoffroy Saint-Hilaire) and Sparus aurata L., off the Algerian coast of the Western Mediterranean. Phylogenetic analyses based on ITS1-5.8S-ITS2 and partial 28S rDNA sequences provided evidence for the distinct species status of eight Mediterranean species of Macvicaria. Novel molecular data are provided for four species, M. gibsoni n. sp. and M. crassigula (Linton, 1910) (sensu stricto) based on specimens from D. vulgaris, and M. mormyri (Stossich, 1885) and M. maamouriae Antar, Georgieva, Gargouri & Kostadinova, 2015 based on specimens from S. aurata; descriptions of the molecular voucher material of the former three species are provided. Two species were delineated within the "crassigula" species complex of Macvicaria, M. gibsoni n. sp. and M. crassigula (s. str.), the distinctive differentiating features being the distribution of the dorsal vitelline fields in the forebody, confluent in M. gibsoni n. sp. and non-confluent in M. crassigula (s. str.), and the molecular data for both markers. Sequences associated with morphological description are also provided for the type-species of Pseudopycnadena, P. fischthali Saad-Fares & Maillard, 1986, based on material from D. vulgaris.

• MeSH
• druhová specificita MeSH
• fylogeneze * MeSH
• mezerníky ribozomální DNA genetika   MeSH
• Perciformes parazitologie   MeSH
• ribozomální DNA genetika   MeSH
• RNA ribozomální 28S genetika   MeSH
• Trematoda anatomie a histologie   klasifikace   genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• mezerníky ribozomální DNA MeSH
• ribozomální DNA MeSH
• RNA ribozomální 28S MeSH