Corallivory

Corallivory is the feeding on coral tissue by animals, rather than algae. Corallivores consume scleractinian corals and, in some cases, other cnidarians, often targeting polyps and mucous layers and occasionally removing tissue or skeleton. The behavior is found in a range of reef-dwelling taxa and can occur at varying intensities.

Prominent corallivores include the crown-of-thorns starfish (Acanthaster planci), which can strip large portions of coral colonies; coral-eating snails such as Coralliophila violacea; and reef fishes such as butterflyfishes (Chaetodon spp.) and some parrotfishes (Scaridae), which feed on coral polyps or the outer tissue. Feeding strategies range from selective polyp predation to broad, opportunistic tissue removal and coral skeleton erosion.

Ecologically, corallivory influences coral community structure by shaping competitive interactions among coral species and contributing to bioerosion. In some contexts, heavy corallivory can suppress coral growth and slow recovery after disturbances, while in others it helps maintain reef diversity by preventing dominance by a few species. Predation pressure can also create habitat for other organisms in frequently disturbed areas.

Research and management efforts include field observations, stomach content or fecal analyses, and stable isotope or DNA-based techniques to identify consumed corals. Outbreaks of corallivores, notably crown-of-thorns starfish, pose significant threats to reefs, prompting monitoring and control measures such as manual removal in affected areas and targeted management strategies to reduce outbreaks.