Here's a clear and complete answer based on what’s typically found in coral reef ecosystems:One abiotic factor:Sunlight – Coral reefs need sunlight for photosynthesis, especially by the symbiotic algae (zooxanthellae) that live in corals.One biotic factor:Fish – Many species of fish live in and depend on coral reefs for food, shelter, and breeding grounds.You could write it like this:Abiotic factor: Sunlight, which helps support the growth of algae and corals.Biotic factor: Fish, which interact with corals and other marine organisms within the reef.