Geographic distribution of Ophiothela brittle stars (Echinodermata: Ophiuroidea): substrate use plasticity and implications for the silent invasion of O. mirabilis in the Atlantic.
This study aimed to address the Ophiothela species distribution worldwide, report invasive populations, and investigate their association with benthic organisms through an extensive review of the scientific literature. All six Ophiothela species occur between latitudes 33° S and 38° N and, together, are dispersed across 75% of the marine realms. Spread throughout more than 6700 km of the Western Atlantic Ocean coastline, O. mirabilis is the only species recorded as invasive. Higher plasticity in substrate use was detected in invaded areas than in native ones, which indicates that substrate availability does not limit the invasive potential of O. mirabilis. The colonization affinity of Ophiothela species is high for Cnidaria species, irrespective of population origin. High densities (e.g., up to 2.8 brittle stars cm-2 per gorgonian surface) and opportunistic habitat colonization pattern found for O. mirabilis invasive populations suggest fast dispersion rates along the Atlantic coast. Therefore, the expansion of this species to nearby systems is likely, and the potential to damage native host species is high.