The ecological importance of a recently discovered intertidal sabellariid reef in St. Croix, US Virgin Islands

In Florida, the reef-building polychaete Phragmatopoma lapidosa is important in enhancing local biodiversity via the shelter it provides for various fish and invertebrate species. While the range of P. lapidosa extends south to Brazil, it is rare to find well-established populations in the Caribbean islands. In this study, we examined an intertidal worm reef recently discovered in St. Croix, U.S. Virgin Islands. The worm species was positively identified as P. lapidosa (also known as P. caudata). Analyses of measured worm lengths and mound photographs revealed multiple size cohorts that likely included recent recruits, and mature adults. An examination of the organisms living within small worm clumps collected from the reef, revealed a number of invertebrates including various mollusks, crabs, shrimp and echinoids. Combined, these data suggest that continuous recruitment is likely to maintain this worm reef which is similar to Florida worm reefs, and likely to enhance local biodiversity in St. Croix.