A New Record of the Polychaete Boccardia proboscidea (Family Spionidae), Imported to Hawai'i with Oysters

Abstract

The spionid polychaete Boccardia proboscidea Hartman, 1940 was introduced to an oyster culture farm at Keahole, Hawai'i, with a shipment of Ostrea edulis from Maine. Oysters were heavily infested with adult worms, and burrows contained egg capsules with late-stage larvae. Diagnostic morphological features match the species description based on California material, except that the Hawai'i specimens are smaller. This genus differs from other oyster-associated spionids, Polydora nuchalis and P. websteri, in having blunt, bristle-tip setae on the fifth setiger. Boccardia proboscidea forms shallow, burrows nestled under shell lamina and so differs from P. websteri, a true carbonate borer, and P. nuchalis, which builds tubes of sediment in ponds and ditches used for penaeid shrimp culture. Boccardia proboscidea has a pan-Pacific distribution including the west coast of North America, Japan, and southeastern Australia. This distribution is attributed in part to the production of early and late larval stages that are widely dispersed by ocean currents.