The genus Mytilopsis includes some of the most invasive estuarine bivalves in the world, and M. leucophaeata (native to the Gulf of Mexico) and M. sallei (indigenous in the Caribbean Sea) are the most often reported species. Molecular investigations of the COI gene in invasive populations of M. leucophaeata in Europe found only one haplotype, whereas the invasive M. sallei in Asia had high haplotype diversity. The present study investigated COI variability of invasive populations previously identified as M. leucophaeata in Brazil, located at the cities of Recife and Rio de Janeiro. Our genetic analysis revealed that the record of M. leucophaeata from Recife appears erroneous; this population forms a clade adjacent to but genetically separated from the Asian M. cf. sallei. Similarly, samples from Rio de Janeiro clustered close to but not within European/North American sequences of M. leucophaeata. The Automatic Barcode Gap Discovery test suggested the existence of three species: M. leucophaeata, M. cf. sallei (Asia), and M. cf. sallei (Recife), which merit confirmation with nuclear DNA sequences. The discovery of two lineages of Mytilopsis in Brazil augments concerns about their expansion. |
