When you think of coral, you probably think of its bright colors. You may even think about how they are home to so many marine creatures. But did you know that a coral is an animal?
Coral cannot move from their place in the ocean, but they do hunt. These sea creatures are vital to the ocean’s ecosystem, living in a complex symbiosis with many fish and other marine animals. Let’s examine what makes a coral an animal and how these beautiful creatures survive in the wild.
What Is a Coral?
A coral is a sessile animal, meaning that it is stationary and firmly takes root in the seafloor. Although it is often mistaken for a plant, it is not. Corals do not create their food using photosynthesis as plants do. Instead, they use their tentacles to hunt and bring in food from the sea around them.
They are invertebrates belonging to the phylum Cnidaria. The coral structures you see when you dive into the ocean or view a picture are a whole colony of hundreds or thousands of individual animals. Each one is called a polyp.
How Do Corals Live?
Each polyp is made up of a soft body that has a stomach that opens at one end. These polyps are usually no bigger than a nickel. They secrete limestone that creates a hard outer skeleton that they use to attach to rocks or the dead skeletons of other polyps.
These groups of polyps form the large coral reefs we see today. These colonies can live for a very long time.
Many corals also have microscopic algae living in their tissues. Corals are the masters of symbiosis, which is a relationship where two creatures benefit mutually.
The algae benefit from the coral’s waste and are better able to achieve photosynthesis. The coral enjoys the oxygen and waste removal that algae provide. The algae’s photosynthesis also provides nourishment for the polyps.
However, if the algae aren’t producing enough nutrients, these coral polyps have tentacles that they use for bringing in food. These tentacles sting small marine animals such as shrimp.
Do Corals reproduce?
Corals can reproduce in two ways. First, clonal polyps can bud off a parent polyp. This asexual reproduction occurs when the parent reaches a certain size.
However, they can also reproduce sexually. Many species of corals produce male and female gametes. They release a massive amount of eggs and sperm into the water. All the coral of a certain species in a single area will release their eggs and sperm at the same time.
Since corals can live far away from each other, this is the only way they can reproduce sexually. Once the egg and sperm meet, they form small plankton; a larva called planulae, that are transported across the water currents. There is a high mortality rate in planulae.
Once the conditions are just right for the planulae, they settle on the seabed and metamorphose into polyps.
Why Are Corals Important?
Coral reefs protect coastlines from powerful waves. They also house thousands of species of fish, mollusks, and sea turtles.
They are important to the fishing and tourist industries, as well. They provide food for people around the world. They also protect areas with mangrove forests and seagrass beds. Animals and plants living in coral also provide essential extracts that are turned into medical treatments for serious illnesses like cancer and asthma.
They are more than just beautiful creatures; they are essential to both humans and other animals on the planet.
Where Do Most Corals Live?
Corals colonies are called coral reefs, and these extensive ecosystems become home to a variety of small fish and other sea creatures. They provide food and protection to many other marine animals.
The coral reefs are most frequently located in shallow water all along the equator. However, corals are found throughout the world’s oceans in tropical and subtropical waters.
There are even deep-sea corals that live in depths of up to 20,000 feet. Many of these types of corals are found in underwater seamounts.
Are Corals Endangered?
Corals are an important part of the world’s ecosystem. However, they are in danger due to the rising temperatures of Earth’s waters. The rise of CO2 in the atmosphere dissolves in seawater, making the water more acidic and less hospitable to coral. This makes it hard for the coral to form their limestone skeletons.
It is important to work hard to combat global warming to preserve these beautiful ecosystems. Additionally, pollution and excessive fishing pose a danger to our coral reefs. If we are not careful, humans could destroy this important part of our world’s oceans.
That’s why scientists are working tirelessly to save Earth’s coral reefs and preserve these beautiful animals.
Although they look more like a plant or a rock, corals are animals that feed and live harmoniously with other animals. Their symbiotic relationship with algae benefits not only them but many sea creatures who feed and call these large coral reefs home. It is important, if you dive at coral reefs, to leave these reefs intact and not take any samples home for a souvenir. Corals are fascinating animals and important creatures in Earth’s ecosystem.