Bioerosion on brachiopod shells of a thanatocoenosis of Alboràn Sea (Spain)

Bioerosion on shells of a brachiopod-bearing thanatocoenosis dredged on red-coral sea-bottom (depth 100 m, 12 miles off the southwestern coast of Alborán Island, Spain) was analyzed. Although low, the intensity of predation was noticeable. Predation drill holes belonging to the ichnogenera Oichnus simplex, O. paraboloides and O. ovalis were recognized. They were probably produced by Muricidae and Marginellidae (gastropods) and octopod cephalopods, respectively. Oichnus ovalis was more common on Terebratulina retusa. A strong selectivity with respect to species, valve, and size was noted. Terebratulina retusa, especially small individuals, was preyed upon more often than any other species. The central portion of both valves was attacked more frequently than expected by chance.