Two new species of Gyrodactylus von Nordmann, 1832 parasitizing Cnesterodon decemmaculatus (Poeciliidae) from the southern limit of the family in the Neotropical region

TAGLIORETTI VERÓNICA; GARCÍA VÁSQUEZ ADRIANA; ROSSIN M. A.; PINACHO PINACHO CARLOS DANIEL; RUBIO-GODOY MIGUEL; TIMI JUAN T.

PARASITOLOGY RESEARCH

SPRINGER

Lugar: Berlin; Año: 2020 vol. 119 p. 1713 - 1728

0932-0113

In this study, we followed an integrative taxonomy approach to describe two new species of Gyrodactylus von Nordmann, 1832,and to identify specimens of G. breviradix Vega, Razzolini, Arbetman, and Viozzi, 2019, all three collected from ten spotted livebearer Cnesterodon decemmaculatus (Jenyns, 1842), an endemic and widespread poeciliid from the Pampean region, which isthe southernmost occurring species of the Poeciliidae in the Americas. Gyrodactylids were first characterized morphologicallyand mophometrically, and when possible, sequences of the Internal Transcribed Spacers (ITS1-5.8S-ITS2) and the cytochromeoxidase II (COII) were used to delimit species. Gyrodactylus breviradix, Gyrodactylus marplatensis n. sp., and Gyrodactyluspampeanus n. sp. were found on the fins and body surface of C. decemmaculatus in La Tapera Creek, Mar del Plata, BuenosAires province, Argentina. A phylogenetic analysis combining newly generated sequences of one of the new species,G. marplatensis n. sp., and of G. breviradix, along with those available in GenBank for a further 36 species of Gyrodactylus,revealed that G. marplatensis n. sp. is a sister taxon of Gyrodactylus decemmaculati Vega, Razzolini, Arbetman, and Viozzi,2019. Genetic distances for the ITS and COII gene were estimated among Gyrodactylus spp. and further supported the validity ofthe new species. Overall, morphometric and molecular data coincided in delimiting the new taxa, thus demonstrating the value ofintegrative taxonomy for the erection of new species of Gyrodactylus and species identification