Summary Description

Amphibalanus eburneus is a native species of North America and the Caribbean through to northern South America. It is a medium to large-sized sessile barnacle that attaches itself to hard substrates and is commonly found on rocks in the intertidal region (DeFelice et al. 2001). Large adults approach 20 mm in diameter. The surface of its test plates are generally smooth or have shallow horizontal grooves. Unlike the closely related species Amphibalanus amphitrite and Amphibalanus reticulatus, Amphibalanus eburneus lacks longtiudinal stripes on its outer shell and its tergum has a short broad spur with a rounded tip (DeFelice et al. 2001). Amphibalanus eburneus has a thick conical shell attaching itself by its wide base on the dorsal end with an opening at the top used for feeding. The opening is equipped with two free moving plates (or 'tergum') that can be completely closed (Costlow and Bookhout 1959).

Amphibalanus eburneus are filter feeders with adult barnacles having specialised paired appendages, called 'cirri ', that are used as a scoop net for reaching out into the water and extracting food particles. The barnacle feeds by drawing the cirri back into its body and scraping off the food into its mouth (DeFelice et al., 2001). As a juvenile the nauplis-stage larvae use a bristle-like part called a setae to feed on zooplankton and surrounding algae (Costlow and Bookhout 1959).

Geographic Extent Description

USA: Atlantic coast of North America.
USA: Gulf of Mexico.
Caribbean to northern South America.