Bottlenose skate facts for kids
Quick facts for kids Bottlenose skate |
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| Conservation status | |
| Scientific classification | |
| Genus: |
Rostroraja
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| Species: |
alba
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| Synonyms | |
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Raja alba Lacepède, 1803 |
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The bottlenose skate is also known as the spearnose skate or white skate (Rostroraja alba). It is a type of skate, which are flat fish related to sharks. This fish lives on the bottom of the ocean, mainly in the eastern Atlantic Ocean.
Sadly, the bottlenose skate is now endangered. This is mostly because too many of them have been caught by fishing boats. In many areas where they used to live, like parts of the northeastern Atlantic and the Mediterranean Sea, they have become very rare or have disappeared completely.
Contents
Where They Live and What They Like
The bottlenose skate can be found along the coasts of the eastern Atlantic Ocean. Their range stretches from the southern British Isles all the way down to South Africa. They also live in the southwestern Indian Ocean near Mozambique. You can also find them in the western and northeastern parts of the Mediterranean Sea.
These skates are "benthic" animals. This means they live on the ocean floor. They prefer sandy or muddy areas. You can find them in waters from about 40 to 400 meters deep. Sometimes, they are found even deeper, up to 500 meters. Some scientists have also seen them in rocky places.
What They Look Like
Most bottlenose skates are about 60 to 150 centimeters long. That's like the length of a small person! The biggest males can reach up to 230 cm, and females up to 202 cm. Their body is flat and somewhat angular.
Their snout (nose) is wide at the base and then quickly narrows to a sharp, pointy tip. This snout is covered with small, sharp thorns. They have many rows of teeth in their upper jaw, usually around 40 to 45 rows.
Young skates have a few thorns around their eyes and three rows of thorns on their tail. As they grow older, adult skates have more thorns around their eyes and more thorns on their tail. Adult skates have rough skin, except for a smooth patch in the middle of their body. Their underside is prickly, but their snout is smooth. Young skates are mostly smooth, except for their snout.
When they are older, bottlenose skates are grey or bluish on top. They might have many small white spots. Their underside is white, with brown or black edges around their body. Baby skates are reddish-brown on top, often with blue spots. Their underside is white with dark edges.
How They Live and What They Eat
The bottlenose skate is a predator that lives on the ocean floor. They hunt and eat other animals. Their diet includes bony fishes, other types of sharks and skates, and even leftover fish parts. They also enjoy eating crabs, shrimps, octopus, and cuttlefish. Younger, smaller skates usually live in shallower water.
Like other skates, this species lays eggs. This is called being "oviparous." Female skates can produce between 55 and 156 eggs each year. It takes about 15 months for the babies to develop inside the egg cases.
The egg cases are oblong, which means they are longer than they are wide. They have stiff, pointy horns at each corner. The larger horns are flat. Females lay these egg cases in sandy or muddy areas during the spring. Each egg case is about 12.5 to 18.3 cm long and 10.0 to 13.9 cm wide. Males usually become adults when they are about 130 cm long, and females when they are about 120 cm long.
Why They Need Our Help
In the 1600s, people in France really liked to eat bottlenose skates. But because these skates are very large and don't have many babies often, they are easily affected by fishing. When too many are caught, their numbers drop quickly.
Scientists have noticed a big decrease in how many bottlenose skates there are and where they live. This is especially true in the north Atlantic and Mediterranean Sea. For example, in the Bay of Biscay and the Irish Sea, their populations have almost disappeared. Because of this, people no longer specifically fish for them in these areas. There are also no recent records of this species near the United Kingdom, where they used to be common.
In the Mediterranean Sea, bottlenose skates of all sizes, even their egg cases, are often caught by accident in fishing nets. This is called "by-catch." In the 1950s to 1970s, they were quite common. However, surveys since 1985 show that the bottlenose skate is now very rare in the Mediterranean. It only lives in a tiny part of its old home range.
Because of these big drops in numbers, the bottlenose skate is listed as "Endangered" on the IUCN Red List. This list helps us know which animals are at risk. In the northeast Atlantic, they are even considered "Critically Endangered," which means they are in extreme danger of disappearing. In 2010, Greenpeace added the bottlenose skate to its "Seafood Red List." This list includes seafood that is caught in ways that are not good for the environment and the fish populations.
