Mitochondrial DNA sequence evidence supporting the recognition of two subspecies or species of the Florida spiny lobster Panulirus argus

Samples of the spiny lobster Panulirus argus from populations in the western Atlantic and Caribbean were compared with spiny lobsters from Brazil for DNA sequence variation for 2 mitochondrial genes. Phylogenetic analyses of 16S sequence data reveal 2 distinct clades of P. argus, a clade consisting of Caribbean populations and a second clade of samples from Brazil. Mean sequence divergence estimates between Brazilian and western Atlantic/Caribbean populations were 8.32% for the mitochondrial large subunit ribosomal RNA (16S) and 19.82% for the cytochrome oxidase I subunit (COI). Levels of sequence divergence among sister species of Panulirus in the japonicus-group were similar to that observed between Brazilian and Caribbean/western Atlantic P. argus. In addition to large mitochondrial DNA sequence differences between western Atlantic/Caribbean and Brazilian P. argus, characteristic color patterns also distinguish Brazilian P. argus. Based on the results presented here, Brazilian P. argus is distinct from populations in the Caribbean and western Atlantic and may represent a complex of 2 species or subspecies. The degree of differentiation between the Caribbean and Brazilian clades indicates that formal recognition is warranted.