The crown-of-thorns seastar is feeding on the polyps of a brain coral
copyright 1975 by Shohei Shirai
copyright 1975 by Shohei Shirai
An Angelfish twists and turns, flashing its colors. It is sending a message to nearby sea creatures: "This is my territory and I'll fight to defend it." Seeing the Angelfish, an approaching fish swims away.
Living space is a problem for most reef animals. Like the angelfish, many animals are territorial and will not let other creatures come near.
These creatures must stay alert at all times to keep out invaders.
Young ocean creatures have a difficult time finding homes. Some take over living space by fighting for it. Others move immediately when another creature dies. As coral animals add new parts to the Great Barrier Reef, homeless creatures move into cracks and crevices. All sea animals are looking for living quarters, where they must find food and try to stay away from predators.
Camouflaged Creatures:
Some animals survive because they can blend in with their surroundings. Beautiful colors can camouflage fish among the brightly colored corals. Sometimes a fish's outline is broken up by bands, patches and spots. This is another kind of camouflage. Some creatures change colors to match their surroundings.
Since in the lagoons there is no place to hide, camouflage is very important. It is better not to have bright colors because predators could easily spot you. Usually fish that live in the reef have very bright colors. They also use their colors for blending in with their surroundings to try to catch food.
The Octopuses is one of the few creatures that can change colors instantly. It can change from brown to white to green to red.
Finding Food:
The ribbon-shaped remora (sucker fish) survives in a strange way. It has this little suction cup on the top of its head. It uses the suction cup to hook on to a manta ray or a shark. It's good for the remora because it gets a free ride and it won't get eaten by predators. It's good for the shark/manta ray because there are these little water flee things that makes the shark/manta ray itchy, and the remora eats the flees. So the animals work together to survive.
Trumpet fish hide behind bigger fish so they can catch shrimp and other small creatures.
Sea wasps use poison to catch their prey. They also use it to defend themselves from predators.
Protection from Predators:
A sea slug has poisonous tentacles that are spikes. Some fish use sea urchins to protect themselves. A female crab is about the size of your smallest fingernail. The crab chooses a piece of coral and stays on it until it builds around her. She can now lay her eggs in a safe place. The current brings her food.
The Reef's Sea Teams:
Two animals sometimes join up and become a team. This relationship is called symbiosis. The clown fish and the sea anemone is one of the best teams on the reef. The clown fish has this free stinging, slimy coat over its scales so that when it touches the sea anemone it won't sting itself. If another fish swims over to try to grab the clown fish the sea anemone will sting the approaching fish and then that fish will die. Sometimes a clown fish will leave the sea anemone and go looking around for food. But it never goes too far away. The sea anemone will eat the clown fish's scraps.
Snapping shrimp and gooby fish are another great team that lives on the reef. The shrimp can not see very well, but they are great diggers. Gooby fish can see extremely well. The gooby fish warns the shrimp when danger is coming, and then they both climb into the hole that the shrimp built. Usually the teams are always nearby each other. All along the cracks and crevices and caves, animals have found a way to protect themselves and other animals. These skills are needed every single day in order to survive!
