Marine Wildlife Encyclopedia
Trottoir coralline Lithophyllum lichenoides
Trottoir coralline is one of many types of hard, encrusting coralline seaweeds that actively build chalky reefs in regions with warmer waters. The seaweed grows best at the outer edge of the reef, where waves keep the crusts wet even during low tide. The crusts are riddled with animals that bore holes in it and live beneath it, including worms that live in hard tubes, which in turn become part of the reef structure.