One more place to call home: the invasive bivalve Mytilopsis leucophaeata reaches the Maricá-Guarapina lagoon system (Rio de Janeiro, Brazil)

Abstract

Mytilopsis leucophaeata is an estuarine bivalve native from the Gulf of Mexico and Southeast USA, and it was introduced in Europe, Asia, Caribbean, South America and Northeast USA, showing massive colonization skills. In Brazil, the single invasion records of M. leucophaeata occur in the city of Rio de Janeiro, i.e., in the Rodrigo de Freitas Lagoon and in the Marapendi Lagoon. We conducted a new series of fieldworks in estuaries from the Rio de Janeiro state in order to evaluate the propagation of this invasive bivalve, aiming sites with proper salinities for the establishment of M. leucophaeata. A new record is given for the Maricá-Guarapina lagoon system, where M. leucophaeata mainly colonizes hard substrata (such as piers and rocks), reaching a mean density up to 43,375 specimens/m2; however, aggregates of M. leucophaeata were also observed in the soft substratum. Based on mitochondrial sequences, the taxonomic identification of the invasive bivalve was confirmed. The associated fauna to the agglomerates of M. leucophaeata in the lagoon system comprises amphipods, barnacles, tanaidaceans, isopods, crabs, polychaetes and snails. The expansion of M. leucophaeata requires a continuous investigation due to the great circulation of boats in the littoral of the Rio de Janeiro state and the increased chance of new introductions.