The invasive worm Hydroides elegans (Polychaeta – Serpulidae) in southeastern Brazil and its potential to dominate hard substrata

Abstract

ABSTRACTThe serpulid Hydroides elegans is recognized as an invasive species in many harbour areas of the world, growing mainly on man-made structures such as pier pilings, where native diversity is low. In addition, because they build large aggregations of calcareous tubes, this increases the maintenance and fuel costs of vessels. While H. elegans is well known for the North Atlantic, Europe, Caribbean and Pacific Ocean, detailed information of the species for the South Atlantic is missing. In the last decade, owners of boats moored at the Clube Naval Charitas (CNC), in the Guanabara Bay, southeastern Brazil noticed an increase in the occurrence of an encrusting organism that we identified as H. elegans. In this study we characterize H. elegans specimens from CNC and Itaguaí Harbor, both in southeastern Brazil, and discuss its distribution in the world. In addition, we deployed PVC panels at two different depths to quantify how H. elegans affects community assembling over two months. We observed that H. elegans could dominate hard substrata in the intertidal zone, occupying more than 50% of the available substrata. Considering the damage caused by H. elegans elsewhere and the ability of the species to monopolize space in the intertidal zone demonstrated here, accurate taxonomic information is essential for future monitoring and management of the species in Brazil and the South Atlantic.