mtDNA analysis of Mytilopsis (Bivalvia, Dreissenidae) invasion in Brazil reveals the existence of two species

The spreading of the invasive bivalve Mytilopsis leucophaeata (Dreissenidae) into estuaries of Rio de Janeiro, Brazil

“…Additional sequences of M. leucophaeata and other dreissenids were retrieved from GenBank, resulting in a final alignment of 570 bp (Table II). A maximum-likelihood tree was computed in PhyML 3.0 (Guindon et al 2010), following parameters used by Fernandes et al (2018). The same alignment of 570 bp was used to compare the haplotype and nucleotide diversity between the former invasion in Rio de Janeiro (Rodrigo de Freitas Lagoon) and the new one, which was estimated with Arlequin 3.5 (Excoffier & Lischer 2010).…”

“…Medium or small-scale dispersion of M. leucophaeata may occur through the incrustation of specimens on the hull of boats or other vectors. In the metropolitan region of Rio de Janeiro, several estuaries are found near Rodrigo de Freitas Lagoon, increasing the propagation risks of this biological invasion through man-made vectors or even larval dispersal (Rizzo et al 2014, Fernandes et al 2018. The present study aimed to ascertain whether or not M. leucophaeata reached other estuaries in the metropolitan region of Rio de Janeiro, after an extensive field survey.…”

“…Mytilopsis leucophaeata (Conrad, 1831) is an estuarine bivalve native from the Gulf of Mexico and possibly part of the eastern U.S.A., although invasive in many regions around the globe, especially in Europe, causing a series of negative economic and ecological effects (Verween et al 2010, Kennedy 2011. In Brazil, this species is only known from the city of Rio de Janeiro (southeastern Brazil), regarding the recent fi nding that the record from the city of Recife (northeastern Brazil) is related to another species (Fernandes et al 2018), probably Mytilopsis sallei (Récluz, 1849).…”

“…Based on published data, the invasion of M. leucophaeata in Rio de Janeiro is restricted to the Rodrigo de Freitas coastal lagoon (Rizzo et al 2014, Fernandes et al 2018, where it forms large clusters in rocky/woody substrata and others, such as styrofoam, plastic packaging, tires and buoys (Rizzo et al 2014). Mytilopsis leucophaeata is believed to not colonize mangrove roots in Rodrigo de Freitas Lagoon (Rizzo et al 2014), contrary to some native sites, where it may form dense aggregates in roots of Rhizophora mangle L. (Odum & Heald 1972, Pérez-Sarabia et al 2012, Ruiz & López-Portillo 2014, Hernández et al 2015.…”

Preface

“…Molecular tools allow detection of cryptic species. Fernandes et al (2018) analyzed mtDNA COI gene sequences, together with phylogenetic analyses, to determine genetic distances among estuarine populations from the Brazilian coast of the dreissenid mussel Mytilopsis. Interpreting their data with a barcode program suggested discovery of three species, rather than the single species previously reported.…”