Analysis of sediment and gut contents of the sand dollars mellita tenuis, encope michelini, and encope aberrans off the central Florida gulf coast

Abstract

Sand dollars are conspicuous macroinvertebrates on particulate substrates in intertidal and shallow water environments. Their locomotion and feeding can have major effects on the sediment and infauna. We investigated the sediment and gut contents of three species of sand dollars off the central Florida gulf coast. Sediment comprised quartz particles at two sites and mixed quartz particles and carbonate shell hash at the third site. At all sites, gut particles were smaller than those of the sediment. This could have been the result of the teeth of the Aristotle's lantern crushing the particles. However, particles in the food grooves of two species (Mellita tenuis and Encope michelini) were similar to theose in the gut contents, smaller than in the sediment. This indicates mat selection for small particles from the sediment occurred and that crushing of particles was not necessary to account for the small size of particles in the gut for those collections. The concentration of organic matter in the gut contents was much greater than that of the sediment, indicating that selection of organic matter not associated widi the inorganic sediment particles occurred. It is possible that the contribution of organic matter not associated with the inorganic sethment particles is of considerable importance to the nutrient requirements of the sand dollars. © 2009 by the Marine Environmental Sciences Consortium of Alabama.