Incorrect identification of invasive Indo-Pacific member of the bivalve genus Mytilopsis can affect construction of molecular phylogenies

An invasive bivalve of the genus Mytilopsis has been present in the Indo-Pacific region since at least 1870, although most of the literature on this species states that it invaded the Pacific from the Caribbean through the Panama Canal after 1914. Although species of Mytilopsis are difficult to identify using morphological characters, difficult does not mean impossible. Comparisons of recently collected specimens as well as museum holdings suggest that the invasive Indo-Pacific bivalve is Mytilopsis adamsi, although further research including genetic analyses can help to answer this question. Review of literature and historical records support the interpretation that the invasive species of Mytilopsis in the Indo-Pacific probably originated in the eastern Pacific and not the Caribbean. If phylogenetic constructions within the family Dreissenidae have used genetic sequences from a misidentified species they must be revised.