Despite being concentrated to a small surface area of the Earth’s oceans, coral reefs are home to roughly a quarter of all marine life. The two biggest reefs — the Great Barrier Reef in Australia and the Belize Barrier Reef in the Caribbean — are popular sites for divers and snorkelers who are looking to see the vibrant and colorful diversity of life underwater.
Coral reefs have a reputation for being home to colorful animals and some of the most beautiful coral and sea anemones in the world, but there’s a lot of wildlife to cover in these diverse aquatic landscapes. Our list looks to cover the true diversity of animals that call the coral reef home, and that includes mammals and birds as well as fish and more bizarre marine life. These 10 animals couldn’t exist in quite the same way without the coral reef, and the reef ecosystem wouldn’t be the same without them.
#10. Animals That Live in Coral Reefs: Whale Sharks — Mighty But Gentle Beasts
The whale shark has the distinction of being the largest fish in the world, and that means that it needs an environment that can support its ferocious appetite. As a result, whale sharks are known to migrate to coral reefs throughout the world. Despite that, the whale shark employs an incredibly efficient approach to digestion —essentially vacuuming up anything in its path and filtering out anything that doesn’t suit its appetite. Feeding with whale sharks is a popular attraction throughout Belize and other locations, an act that’s a lot less threatening when you realize that the whale shark’s 300 teeth are just used for filtering water.
#9. Animals That Live in Coral Reefs: Sea Turtles — The Gardeners of the Reef
Green sea turtles are one of a rare few species of large animals that graze on seabed grass, and that can have a dramatic effect on the ecosystem — especially in an environment like a coral reef. They manage, spread, and nurture these seabeds which serve as an integral component of the healthy environment that coral reefs foster. The Hawksbill sea turtle in particular serves a vital role in many coral communities by pruning sponges that could otherwise halt the growth of coral and the development of richer food and habitat sources for other sea life.
#8. Animals That Live in Coral Reefs: Crocodiles — Commuting Predators
Crocodiles are known for lurking in shallow and marshy waters, so it might come as something of a surprise to learn that they’re actually an integral part of some coral habitats. The Great Barrier Reef sees activity from nearby crocodiles that call the neighboring estuaries and islands home but still venture out to the reef in search of prey thanks to the bounty available there. And while crocodiles are a relative rarity in the Great Barrier Reef proper, some beaches have been closed thanks to crocodile sightings.
#7. Animals That Live in Coral Reefs: Dugongs — Descended From Elephants
The large and gentle dugong is evolutionarily related to the enormous land elephant, but the average person might have trouble telling it apart from the manatee. Dugongs share the duty with large turtles of grazing and pruning grass on the seafloor, and coral reefs make a natural place for them to settle down. But while the coral reef is mostly lacking in predators, humans have unfortunately driven this creature nearly to the brink of extinction. And given their slow breeding cycles and small litters, the path to recovery looks long and perilous.
#6. Animals That Live in Coral Reefs: Ospreys — Reefs’ Most Prevalent Seabird
The osprey is such a common seabird in coral reefs that a specific atoll in the Great Barrier Reef System was named Osprey Reef in honor of them. Ospreys flock around reefs in large numbers, and they’re so numerous that many of the bigger reefs actually have netting up to prevent them from devastating the habitat. That said, they play an important role above the surface of the water in terms of population control and fertilizing the environment. They spread biodiversity not just by carrying species from the coral to surrounding islands and vice versa but also by fertilizing the water with their defecation.
#5. Animals That Live in Coral Reefs: Manta Rays — Keeping the Whole Reef Fed
Crocodiles and seabirds tend to live on the outlying islands and venture into the coral reef to hunt for prey, but the manta ray ventures into the reef to get a good cleaning. Manta rays are regularly seen in spots where creatures regularly congregate, and they have the bacteria and grime cleaned off their surface by small and hungry fish. It’s just one sign of the uniquely symbiotic relationships that form on barrier reefs, and it’s such an established routine that many rays will return to the same places for grooming over and over again.
#4. Animals That Live in Coral Reefs: Dolphins — Recognizing the Medicinal Value of Coral
Dolphins are one of the smartest creatures in the water, so it comes as no surprise that they’d gravitate towards the abundant food and life that can be found in coral reefs. But while dolphins play a critical role in managing wildlife numbers and pollinating surrounding ecosystems, they also seem to have discovered the medicinal value that coral offers. Documentary filmmakers have found instances of injured dolphins rubbing their bodies against coral potentially for the anti-microbial and anti-bacterial properties that the mucous growing on them can provide. If true, it’s a sign that coral reefs could provide the future of medicine.
#3. Animals That Live in Coral Reefs: Caribbean Reef Octopus — The Reef’s Master of Disguise
Most fish and marine creatures manage to thrive especially well on coral reefs, but the Caribbean Reef Octopus is built exclusively for it. Found only in the Belize Barrier Reef — the second largest barrier reef in the world — and the surrounding areas, this cephalopod can camouflage itself even across the often wildly colored patterns that make up the coral reef system. Combine this with the prodigious intelligence of this tentacled creature, and you’re left with one of the most dangerous and ingenious of predators found in coral reefs.
#2. Animals That Live in Coral Reefs: Sea Dragon — Less Intimidating Than the Name Would Suggest
Thanks to the fact that it’s a notoriously poor swimmer that lives an exclusively aquatic life, the sea dragon is actually a member of the seahorse family that’s less effective than most of its brethren. But the fact that these creatures resemble seaweed that’s prevalent throughout coral reefs lends them a sort of perpetual camouflage that helps protect against predators. Only in an environment as vibrant as a coral reef would the brilliant colors of the sea dragon be considered camouflage rather than a liability.
#1. Animals That Live in Coral Reefs: Lionfish — A Colorful Warning to All Predators
While the bright colors and vibrant designs of the sea dragon actually allow them to conceal themselves among the reef, the uniquely colorful patterns of the lionfish are actually a sign for predators to stay away. The long and dangerous-looking spikes protruding from their bodies are actually poisonous bristles, and some of the venoms that some lionfish produce is enough to kill a grown man. They’re also aggressive predators in their own right that are known to feed on fish, crab, and shrimp for sustenance.
Next Up: Meet 9 Animals That Don’t Poop