Examining the Octopus joubini species complex (Cephalopoda: Octopodidae) in the northeastern Gulf of Mexico

Morphological and molecular comparisons were made in an attempt to resolve the confusion associated with the proposed Octopus joubini species complex in the Gulf of Mexico. We utilized COI and 16S rRNA markers to determine if O. joubini represents a species complex in the northeastern Gulf of Mexico and if cryptic species were identified, to determine if they have overlapping geographical ranges. Traditional systematics and molecular evidence confirmed that O. joubini represents a complex in the northeastern GoM. We propose that O. mercatoris and O. joubini continue to be considered a species complex due to a small sample size and subtle morphological differences observed in the present study. It is still uncertain if Forsythe and Toll’s (1991) “large egg” species represents a third species in the complex or is conspecific with O. mercatoris . The two species appear to have broad distributions with overlapping geographical ranges. Future research would benefit from a larger sample size that would include organisms from the northern GoM where Forsythe and Toll (1991) collected their “small” and large egg species.