Genetic and morphological discrimination of species within the nominal Brachidontes exustus (Mollusca: bivalvia) cryptic species complex from the Florida Keys:

The discovery of sibling and cryptic species complexes in the oceans has dramatically increased the estimated number of extant marine species. However, most cryptic species complexes remain taxonomically obscure, lacking descriptions of the morphological or ecological differences defining the species. The distributions and morphologies of species in the nominal Brachidontes exustus complex in the Florida Keys were investigated utilizing molecular and multivariate statistical techniques. DNA barcoding, a method of comparing newly generated sequences of the mitochondrial cytocrome c oxidase I gene (COI) from specimens of unknown species to a database of known sequences from voucher specimens, identified two cryptic species on Long Key, Florida Keys. Two differing habitats, which were