Common skate facts for kids
Quick facts for kids Common skate |
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The common skate (Dipturus batis) is also known as the blue skate. It is the biggest skate in the world. It can grow up to 2.85 meters (about 9 feet, 4 inches) long!
Long ago, common skates were very common. They lived in the northeast Atlantic Ocean and the Mediterranean Sea. But today, they are hard to find in many of these areas. Fishing boats used to catch many of them. Now, they are often caught by accident.
Because of this, the common skate is now listed as critically endangered. This means it is at very high risk of disappearing forever. It is now protected in the EU. Scientists have also found that the common skate might actually be two different species. These are the smaller blue skate and the larger flapper skate.
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What Does the Common Skate Look Like?
The common skate is the largest skate in the world. It can grow to be about 2.85 meters (9 feet, 4 inches) long. It can also be 2 meters (6 feet, 7 inches) wide. The heaviest ones can weigh up to 113 kilograms (249 pounds).
This skate has a pointed snout. Its body is shaped like a diamond. It also has a line of spines or thorns along its tail. The top of the skate is usually olive-grey or brown. It often has a pattern of spots. The underside is a lighter blue-grey color.
Where Do Common Skates Live?
Common skates live in the northeast Atlantic Ocean. They are bottom-dwelling fish. This means they live on the ocean floor. They are usually found at depths of 100 to 200 meters (330 to 660 feet). But they can live in water as shallow as 30 meters (98 feet). They can also be found as deep as 1000 meters (3,300 feet).
Sadly, their numbers and living areas have shrunk a lot. They have disappeared from many places. You can find them from Norway and Iceland down to Senegal. It is not clear if they still live in the Mediterranean Sea. Earlier sightings might have been of the flapper skate.
How Do Common Skates Grow and Reproduce?
Common skates can live a very long time. Some might live for 50 to 100 years! They become adults when they are about 11 years old. The size they reach adulthood depends on if they are male or female. It also depends on where they live.
- The blue skate (D. cf. flossada) males become adults at about 1.15 meters (3 feet, 9 inches) long. Females become adults at about 1.23 meters (4 feet) long.
- The flapper skate (D. cf. intermedius) males become adults at about 1.86 meters (6 feet, 1 inch) long. Females become adults at about 1.98 meters (6 feet, 6 inches) long.
They usually reproduce every other year. They mate in the spring. In the summer, females lay about 40 egg cases. They lay these eggs in sandy or muddy areas. The eggs take 2 to 5 months to hatch. When they hatch, the young skates are about 22.3 centimeters (8.8 inches) long.
Egg Cases
The egg cases of the common skate are quite large. They can be up to 25 centimeters (9.8 inches) long. This does not include their "horns." They are about 15 centimeters (5.9 inches) wide. These egg cases are covered in thick, felt-like fibers. They often wash up on beaches.
In the past, many egg cases were found all along the British coastline. Now, they are only found in a few areas. These include northern Scotland and the north of Ireland.
What Do Common Skates Eat?
Like other skates, the common skate eats food from the ocean bottom. Their diet includes:
- Crustaceans (like crabs)
- Clams and oysters
- Snails and bristle worms
- Cephalopods (like squid)
- Small to medium-sized fish (like sand eels and flatfish)
Bigger skates eat bigger prey, especially fish. They need more food to support their large bodies. How active a skate is also affects how much it eats. More active skates eat more.
Common skates do not only eat from the bottom. They can also swim up quickly from the seabed. They do this to catch fish like mackerel and herring.
Why Are Common Skates Endangered?
The common skate is listed as critically endangered by the IUCN. This means it is very close to disappearing. Its population has dropped a lot because of overfishing. This happens when too many fish are caught.
Skates are often caught by accident. This is called bycatch. Trawl fishing is very profitable. So, bycatch will likely remain a big problem for the common skate. The species has already disappeared from the Baltic Sea.
Some areas still have common skates. These include western Scotland and the Celtic Sea. It was thought they were common off Norway. But recent studies show they are rare there. Many past sightings were likely other types of skates.
Common skates live a long time and grow slowly. This means they might take a long time to recover. However, a similar skate, the barndoor skate, has recovered. This gives hope that the common skate can also recover.
The common skate is strictly protected in the EU. It is against the law for fishing boats to catch them on purpose. If they are caught by accident, they must be released. Scientists believe they have a good chance of surviving if they are released.
Common Skate Species
Scientists have found differences within the common skate group. These differences are in their genes and how they look. This has led to the idea of splitting them into two species:
- The smaller southern D. cf. flossada (blue skate)
- The larger northern D. cf. intermedius (flapper skate)
The blue skate is up to about 1.45 meters (4 feet, 9 inches) long. The flapper skate is larger and grows more slowly.
Scientists are still deciding on the official names for these two species. One idea is to keep the name D. batis for the blue skate. The name D. intermedius would be used for the flapper skate.
The flapper skate (D. cf. intermedius) has dark olive-green eyes. It has a group of pale spots on each wing. The blue skate (D. cf. flossada) has pale yellow eyes. It has a large, round, dark spot with a pale ring on each wing. There are also other differences in their tails and body shapes.
Both species are found around the British Isles. Their living areas overlap a lot there. But the flapper skate is more common in the north. This includes off Scotland and Northern Ireland. The blue skate is more common in the southwest. This includes the Celtic Sea.
