Atlantic halibut facts for kids
Quick facts for kids Atlantic halibut |
|
|---|---|
 |
|
| Conservation status | |
| Scientific classification | |
| Genus: |
Hippoglossus
|
| Species: |
hippoglossus
|
| Synonyms | |
|
|
The Atlantic halibut (Hippoglossus hippoglossus) is a very large flatfish. It belongs to the Pleuronectidae family. These fish live on or near the sandy, gravelly, or muddy bottom of the ocean. They can be found at depths from 50 to 2,000 m (160 to 6,560 ft).
The halibut is one of the biggest bony fish in the world. Sadly, it is an endangered species. This is because it grows slowly and has been overfished. Halibut are strong swimmers and can travel long distances. Their size often depends on how much food is available.
Atlantic halibut live in the cool and cold waters of the northern Atlantic Ocean. You can find them from Labrador and Greenland to Iceland. They also live in the Barents Sea and as far south as the Bay of Biscay and Virginia. It is the largest flatfish, growing up to 4.7 m (15 ft) long. They can weigh as much as 320 kg (710 lb). These amazing fish can live for up to 50 years.
Scientists can guess a halibut's age by counting rings inside its otolith. An otolith is a small bone in the fish's inner ear.
Contents
What Does an Atlantic Halibut Look Like?
The Atlantic halibut is a "right-eyed" flounder. This means its body is flat from side to side. It usually lies on its left side. During its growth, both of its eyes move to the right side of its head.
When halibut larvae are born, they swim upright like most fish. They have one eye on each side of their head. But once they are about one inch long, their left eye moves. It travels over their nose to the right side of their head. At the same time, the left side of their body turns white. The top side of the fish is a dark color. It can be chocolate brown, olive, or even almost black. The end of their tail fin is shaped like a crescent.
Young halibut are lighter in color and have more spots. Adult males usually weigh about 25 to 30 pounds. They can sometimes reach over 60 pounds, but rarely 100 pounds. Females can grow much larger, sometimes up to 600 pounds! The biggest halibut ever caught in Alaska weighed 459 pounds in 1996. Most halibut caught are between 5 and 15 years old.
Life Cycle and Reproduction
Atlantic halibut grow slowly. They also become ready to have babies later in life. Males are mature at seven to eight years old. Females are ready at 10 to 11 years old. Most halibut live for about 25 to 30 years. The oldest one ever caught was 50 years old.
Female halibut lay many eggs, from a few thousand to four million. Older females tend to lay about two million eggs in one spawning period. Spawning happens between December and April. It takes place near the ocean bottom where the water is 5-7 degrees Celsius. The eggs are about 3.0-3.8mm big. When they hatch, the larvae are about 6.5mm long.
Halibut growth depends on how many other fish are around. It also depends on how much food is available. Halibut use external fertilization. This means the female and male release their eggs and sperm into the water. The eggs are fertilized outside their bodies. The fertilized eggs float freely in the water. They hatch about 16 days later. Adult halibut usually live on the ocean floor.
Where Do Atlantic Halibut Live?
These ocean fish usually live on the ocean floor. They are found at depths between 50 and 2,000 m (160 and 6,560 ft). But sometimes, they swim closer to the surface. Young halibut larvae float freely in the water. When they are about 4 cm long, they move to the ocean bottom. Young fish, aged two to four years, live near the shore. As they get older, they move into deeper waters.
You can find Atlantic halibut in both the eastern and western parts of the North Atlantic Ocean. In the western Atlantic, they live from southwestern Greenland and Labrador, Canada, down to Virginia in the USA. In the eastern Atlantic, they are found around Iceland, the United Kingdom, and northern Europe, all the way to Russia.
What Do Atlantic Halibut Eat?
Atlantic halibut are high up in the food chain. This means they eat many other animals. Their diet mainly includes other fish. Some examples are cod, haddock, herring, pogge, sand eels, and capelin. They also eat cephalopods (like squid), large crustaceans (like crabs), and other animals living on the ocean floor.
When they are very young, halibut mostly eat tiny ocean creatures called plankton. After their first year, they start eating small shrimp-like creatures and small fish. This continues until they are about three years old. As halibut grow bigger, their diet mostly changes to other fish. They even eat smaller halibut!
Who Eats Atlantic Halibut?
Atlantic halibut have several natural predators. Seals eat them. They are also a main food source for the Greenland shark. Killer whales are also natural predators of the halibut. Of course, humans also catch and eat halibut.
Fishing for Atlantic Halibut
The wild Atlantic halibut used to be a very important fish for food. However, because it grows slowly, its population cannot recover quickly from too much fishing. This has caused the number of wild halibut to drop a lot. Because of this, when you see "halibut" for sale, it is often another large flatfish. A common one is the Pacific halibut.
A popular way to catch halibut is using circle hooks. These hooks are baited with herring or similar fish. They are fished from the bottom of the ocean. Halibut that are caught and then released have a very high chance of surviving. This is because they do not have a swim bladder. This means they are not badly affected by changes in water pressure.
Farming Atlantic Halibut
Because Atlantic halibut is a popular food fish, people have started farming them. As of 2006, countries like Canada, Norway, the UK, Iceland, and Chile were raising Atlantic halibut in aquaculture farms.
Protecting Atlantic Halibut
In 1996, the IUCN listed the Atlantic halibut as an Endangered species. It was placed on their IUCN Red List.
The Atlantic halibut is also a "Species of Concern" in the U.S. This means the U.S. Government is worried about its status. But they don't have enough information to list it under the U.S. Endangered Species Act. The American Fisheries Society calls the species "Vulnerable." In 2010, Greenpeace International added the Atlantic halibut to its "seafood red list." This list includes fish commonly sold in stores that are at high risk from unsustainable fishing.
The Atlantic halibut has been on the endangered species list since 1996. This is mainly due to too much fishing since the 1800s. People wanted its meat, and it was easy to catch because it is one of the largest flatfish.
See also
In Spanish: Fletán del atlántico para niños
