Neotropical sisterhood: new species ofvon Nordmann, 1832 (Platyhelminthes: Monogenea) infectingand(Siluriformes: Heptapteridae) in Mexico.

Abstract

We describe two new species of monogenean parasites of the genusvon Nordmann, 1832 infecting Neotropical catfishes (Siluriformes) in southern Mexico:n. sp. from 'chulín',collected in Oaxaca; andn. sp. from 'juil',from Veracruz. Morphologically, both new taxa are similar tospp. infecting catfishes (Siluriformes) in South America. Sequences of the internal transcribed spacers (ITS1-5.8S-ITS2 rDNA), the D2+D3 domains of the large ribosomal subunit (28S rDNA) and the cytochrome oxidase II (COII) gene were obtained from multiple parasite specimens and analysed using Bayesian inference. Phylogenetic hypotheses using ITS rDNA and COII genes, recovered two newspecies fromspp.:n. sp.; andn. sp., which are sister species to, a parasite ofin Brazil, and show strong affinity to other gyrodactytlids infecting Neotropical catfishes. This suggests that these new taxa, the first gyrodactylids described fromspp. in Mexico, co-migrated to Tropical Middle America with their Neotropical catfish hosts, after the emergence of the Isthmus of Panama.