Coral Associations, Biocorrosion, and Space Competition in Pedum spondyloideum (Gmelin) (Pectinacea, Bivalvia)

In the northern Red Sea several genera of sclcractinian corals arc used as hosts by Pedum spondyloideum. High population densities lead to space competition. The bivalves use chemical means to interact with each other and with their host corals. Due to dorsal attachment and predominantly ventral growth - to keep pace with coral growth - biocorrosion is less obvious, than in Lilhophuga.