Polydora uncinata (polychaeta : spionidae) in chile: an accidental transportation across the pacific

Abstract

A Polydora species was found boring in shells of the abalone Haliotis discus hannai cultivated in land-based tanks in Coquimbo, Chile. Spionid polychaetes of Polydora and related genera have been reported from Chile but no worms similar to those found in abalone have been described. The abalone pest corresponds in morphology to Polydora uncinata Sato-Okoshi, 1998, a shell-boring species which was originally described from Japan and never reported from outside the country. It is suggested that occurrence of the species in Chile resulted from its accidental transportation from Japan. Adult worms were most likely transported to Coquimbo with imported abalone brood stock. Prevalence of abalone infestation by worms in Coquimbo varied substantially among cultivation tanks, reaching values as high as 98.8%. Up to 42 worms were found in one shell. The worms often caused formation of nacreous blisters which covered up to 50% of the inner shell surface. Egg capsules with developing larvae were present in female burrows. Larval development was entirely lecithotrophic, with larvae feeding on numerous nurse eggs, staying inside egg capsules until 16-17-segment stage and hatching shortly before metamorphosis. Polydora uncinata is redescribed based on individuals from Coquimbo to alert zoologists in case of accidental release of worms into Chilean coastal waters. Regardless of how the species was transported to Chile, its release to the natural ecosystem may have negative unforeseen impacts on the native fauna.