To the Mediterranean and beyond: An integrative approach to evaluate the spreading of Branchiomma luctuosum (Annelida: Sabellidae)

Abstract The non-indigenous sabellid polychaete Branchiomma luctuosum (Grube, 1870) has spread along the Mediterranean coast in a short time period. Well-established populations were recorded for 9 marinas and 3 natural habitats along the southern Iberian Peninsula, including the first record of the species in Portugal. The highest abundances (>60 ind./m2) were found in the Gulf of Cadiz (Atlantic coast of Spain). The ability to colonize artificial structures has also been tested experimentally; although the species showed high colonization rates, high water-flow rate and turbidity might adversely affect larval settlement. The tubes of B. luctusoum hosted a very diverse epibiota, comprising 79 taxa, many of which are considered to be introduced or cryptogenic species. The ability of this polychaete to facilitate the spread of these species when attached to vessel hulls is discussed. Our results suggest that this species is in a phase of active colonization by successfully colonizing both natural and artificial habitats.