Squaretail coral grouper facts for kids
Quick facts for kids Squaretail coral grouper |
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| Conservation status | |
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| Genus: |
Plectropomus
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| Species: |
areolatus
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| Synonyms | |
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The squaretail coral grouper (Plectropomus areolatus) is a type of ray-finned fish that lives in the ocean. It belongs to a group of fish called groupers. This family also includes fish like anthias and sea basses. People also call this fish the spotted coral trout or the squaretail coral trout. It grows quickly and doesn't live very long, but it starts having babies early. Sadly, its numbers are going down. Because of this, it is now listed as a vulnerable species. This means it needs protection from human activities.
Contents
What Does It Look Like?
The squaretail coral grouper has a long body. When it first becomes old enough to have babies, it is about 36.65 centimeters (about 14 inches) long. It weighs around 771.2 grams (about 1.7 pounds). This fish can grow up to 80 centimeters (about 31 inches) long. Female fish are usually longer than males.
This fish has 7 to 8 spines on its back fin. It also has 10 to 12 soft rays. Its anal fin (bottom fin near the tail) has 3 spines and 8 soft rays. It has 1 to 4 sharp teeth, called canines, on its upper jaw. The tail fin is flat at the end, like it was cut straight. This is why it's called "squaretail."
Squaretail coral groupers can be many different colors. They can be whitish-gray with dark spots. Some are greenish-gray or have red and brown patterns. Their fins are usually dark brown.
Where Does It Live?
The squaretail coral grouper is often found in the western Pacific. This includes the waters around Japan, southeastern China, the Philippines, Indonesia, and Australia. You can also find it in the Indian Ocean, near East Africa.
These groupers live in shallow areas of the ocean. They like places with lots of coral, like lagoons and reef fronts. They are common in coral reefs or rocky reefs in warm, tropical waters. They usually live in water from 1 to 70 meters (about 3 to 230 feet) deep. This is in the neritic zone, which is the part of the ocean near the coast.
Squaretail coral groupers do not travel far from their homes. Many stay close to where they gather with other fish. Their baby fish, called larvae, spread out within about 14.4 kilometers (about 9 miles). The places where these groupers gather are often close to each other.
Scientists studied 32 grouper gathering spots. They found that 59% of the squaretail coral groupers gathered where other types of groupers also met. The other 41% gathered only with their own kind. Squaretail coral groupers often gather with camouflage groupers and brown-marbled groupers. But they also have their own special spots. At these single-species spots, they gather on flatter reef areas. These areas might not be good enough for other grouper species to gather.
Reproduction
Squaretail coral groupers usually lay their eggs from January to April. This is their main breeding season, lasting 2 to 3 months. They often lay eggs during new and full moons. This might be because the tides are stronger then, which helps spread their eggs or keep them in one place.
Groupers gather every month throughout the year to lay eggs. You can tell they are ready to spawn because their color changes. They also fight, quiver, and many females will be full of eggs. When it's time to lay eggs, the male fish usually arrive first. They come alone or in small groups to claim their space. The female fish often arrive in large schools.
What Does It Eat?
The squaretail coral grouper mainly eats other fish. This means it is a piscivore. It hunts like other groupers. It creates a strong suction that pulls fish into its mouth. It usually hunts alone.
Life Cycle
The squaretail coral grouper becomes old enough to have babies at about 2.8 years old. It lives for about 10 years. After it hatches from an egg, it starts as a tiny larva floating in the water. Then it grows into a full-sized fish.
How Humans Affect It
Humans are the biggest threat to the squaretail coral grouper. This fish is very popular for food, especially in southern China. Squaretail coral groupers grow slowly and live a long time. This means they cannot easily make more babies to replace their numbers when too many are caught.
Catching too many fish, called overfishing, is the main reason these groupers are vulnerable. This is especially true when fishermen target the places where the fish gather to lay eggs. Squaretail coral groupers are one of the most common types of Plectropomus fish sold in restaurants.
Squaretail coral groupers are important for local fishermen. They are one of the most wanted and valuable fish in the fish trade in Hong Kong. They are sold for a high price. Most fishermen catch them at night using spearfishing or hook and line fishing. This is because the fish stay in shallow reef areas that are easy to reach. Squaretail coral groupers are bigger and more common than other fish in their gathering spots. This makes them easier to hunt. Also, they are often not active at night, so they are easy to spear.
When human populations grew or other reef fish became harder to find, people started targeting squaretail coral groupers more. This led to fewer groupers in certain areas. At one gathering spot, night spearfishing caught so many groupers that it was no longer profitable to fish there.
To help protect squaretail coral groupers, there are limits on how many can be sold. There are also bans on catching them during their breeding seasons. Fishing decreased from 1999 to 2000, but still too many fish were brought in from other places. Even fish in protected areas are affected by changes in the climate.
Other Information
Sometimes, people get sick from eating squaretail coral grouper. This illness is called ciguatera. It is caused by a toxin from a tiny algae called Gambierdiscus toxicus. From 1997 to 2006, two cases were reported in Okinawa, Japan.
The squaretail coral grouper can also carry a type of worm called Anisakis typica. This worm can live inside fish. If you eat undercooked or raw fish with this worm, you could get a sickness called anisakiasis. This can cause stomach pain and fevers.
