Mekong freshwater stingray facts for kids
Quick facts for kids Mekong freshwater stingray |
|
|---|---|
 |
|
| Conservation status | |
| Scientific classification | |
| Genus: |
Hemitrygon
|
| Species: |
laosensis
|
The Mekong freshwater stingray is a special type of stingray. Its scientific name is Hemitrygon laosensis. This ray lives only in freshwater rivers. You can find it in the Mekong River and the Chao Phraya River. These rivers are in Laos and Thailand. The stingrays in the Chao Phraya River likely got there because of humans.
This stingray can grow quite large. Its body, called a disc, can be up to 62 cm (24 in) wide. It has an oval shape. Its tail has folds on both the top and bottom. A line of spine-like bumps runs down its back. A cool fact about this stingray is its bright orange belly!
Mekong freshwater stingrays eat small creatures without backbones. They give birth to live young. Sadly, this stingray is in danger. The International Union for Conservation of Nature (IUCN) says it is an Endangered species. This is because too many are caught by fishing. Also, their homes are being damaged.
Contents
Discovering the Mekong Freshwater Stingray
Scientists first noticed this stingray in 1968. A scientist named Yasuhiko Taki listed it as a new type of Dasyatis stingray. He found it in the Mekong River in Laos. But his samples of the stingray later went missing.
The stingray was officially described in 1987. This was done by Tyson Roberts and Jaranthada Karnasuta. They wrote about it in a science magazine. The first official sample was a young male. It was 23 cm (9.1 in) wide. It was caught in the Mekong River in Chiang Rai Province, Thailand.
Where They Live
The Mekong freshwater stingray lives only in large, freshwater rivers. They like sandy areas. They have been found in the Mekong River along the border of Laos and Thailand. They also live in the Chao Phraya River in central Thailand. The groups of stingrays in these two rivers probably do not mix.
What They Look Like
The Mekong freshwater stingray has an oval-shaped body. This body part is called a pectoral fin disc. It is a bit longer than it is wide. The tip of its snout sticks out a little past the disc. Its eyes are small. Behind the eyes are slightly larger holes called spiracles.
This stingray has many teeth. It has 28 to 38 rows of teeth on top. It has 33 to 41 rows of teeth on the bottom. Young stingrays and females have blunt teeth. Adult males have pointed teeth. The jaws of adult males also become very curved. Inside their mouth, they have five small bumps called papillae. The outer two bumps are smaller. They also have five pairs of short gill slits.
Their pelvic fins are triangular with rounded corners. They are longer than they are wide. The tail is like a whip. It is not more than twice the width of the body disc. It usually has one stinging spine on top. Sometimes it has two. Behind the spine, the tail has folds on both the top and bottom. The bottom fold is much longer than the top one.
A single row of thorn-like bumps runs down the middle of its back and tail. These bumps are called dermal denticles. The biggest ones are at the base of the tail. As the stingray gets older, it gets more of these larger bumps. There are also tiny, grainy bumps on its back.
The top of the stingray's body and tail are plain brown. The tail folds are much darker. The underside is pale. It has large, orange-yellow patches. There is also a wide orange-red band around the edge of its body. Another stingray, the red stingray, also has a bright orange belly. But the two species look different in other ways. The Mekong freshwater stingray can grow up to 62 cm (24 in) wide. It can weigh up to 30 kg (66 lb).
Diet and Reproduction
The Mekong freshwater stingray eats invertebrates. These are small creatures without backbones. It finds them on the river bed. Like other stingrays, it gives birth to live young. This means the babies grow inside the mother. They may have as few as one baby at a time.
How Humans Affect Them
People fish a lot in the Mekong River. They often try to catch large bony fishes. The Mekong freshwater stingray is often caught by accident. This is called bycatch. They are usually caught in nets or with hooks and lines. Fishermen often break off the tail spine before selling them. The stingrays are sold fresh for people to eat.
However, a bigger problem for these stingrays is their shrinking home. Their habitat is being damaged. This happens because of dams being built. Also, water pollution from farms and factories hurts the rivers. Young stingrays are sometimes caught for the aquarium trade.
Because of all these problems, the International Union for Conservation of Nature (IUCN) has listed this species as Endangered. The Thai government started a program in the 1990s. It aimed to breed this and other freshwater stingrays in captivity. This program was in Chai Nat. But it has since been paused.
