Habitat: Grow in association with a variety of living hard coral species, protecting the coral from bioerosion by boring sponges. Occasionally in mangroves where it can grow to record size. Distribution: Caribbean Depth: 20 - 100 ft. Characteristics: Thick cushions (5 cm) sometimes with branches (1-10 cm wide, up to 50 cm tall). Orange-yellow externally, lighter internally. Rough surface with oscula with white strands on membranes (up to 4 cm wide). Compressible.