Pincushion ray facts for kids
Quick facts for kids Pincushion ray |
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| Conservation status | |
| Scientific classification | |
| Genus: |
Fontitrygon
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| Species: |
ukpam
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The pincushion ray (Fontitrygon ukpam) is a unique type of stingray. It is also known as the thorny freshwater stingray. This ray lives in the rivers and lakes of West and Middle Africa.
It is a heavy-bodied ray that can grow up to 1.2 meters (about 4 feet) wide. What makes it special are its rounded body, a tail that might not have a long stinging spine, and many strong thorns covering its back and tail when it's an adult. Instead of a long spine, the pincushion ray uses these thorns to protect itself. This species is rarely seen and is considered Critically Endangered by the International Union for Conservation of Nature (IUCN).
Contents
Discovering the Pincushion Ray
How it Got its Name
A scientist named John Alexander Smith first described the pincushion ray in 1863. He wrote about it in a science paper. He named it ukpam because that's what local people called freshwater stingrays.
Smith thought this ray was special because its tail spine was smaller than other stingrays. He created a new group, or genus, called Hemitrygon for it. Hemi means "half" in Greek. Later, other scientists placed it in different groups like Dasyatis or Urogymnus.
Where Pincushion Rays Live
African Freshwater Homes
The pincushion ray is one of only two freshwater stingrays found in Africa. The other is the Niger stingray. Pincushion rays have been seen in several rivers and lakes. These include the Old Calabar River in Nigeria and the Sanaga River in Cameroon. They also live in Lake Ezanga and the Ogooué River in Gabon. You can also find them in the Congo River in the Democratic Republic of the Congo.
When it was first described, it was also found in slightly salty water near the mouth of the Old Calabar River. We don't know if it can still live in salty water today. If it can, it might be able to travel between different river systems along the coast.
What Pincushion Rays Look Like
Body Features
The pincushion ray has a slightly pointed snout. Its body, called a disk, is oval-shaped and very thick. It's a bit longer than it is wide. It has large eyes with a small bump on the upper eyelid. Behind the eyes are two openings called spiracles.
Its mouth is slightly curved. It has many small, round teeth. There are about 38 to 40 rows of teeth in the upper jaw. The lower jaw has 38 to 48 rows. Inside its mouth, there are five small bumps called papillae. The fins on its belly, called pelvic fins, are rounded. Their inner edges are joined together.
Tail and Thorns
The tail is thin and whip-like. It has a small fin fold underneath. In young rays, the tail can be three times longer than the body. As the ray gets older, its tail becomes shorter compared to its body. Some pincushion rays have a small spine on the top of their tail near the base. This spine is about 5.6 cm (2.2 inches) long in males. In females, it's about 4.6 cm (1.8 inches) long. Young rays have smooth spines covered by skin. Adult rays have exposed spines with about 46 jagged edges.
Newborn pincushion rays have smooth skin. But as they get older, many large, thorny bumps grow on their back and tail. The top of the ray is dark brown or gray-brown. The tail is almost black past its base. The underside of the ray is white with a wide dark edge around its body. These rays can grow very large. Some old records mention rays that were 1.2 meters (4 feet) wide and 3 meters (10 feet) long. They were so big that four men were needed to lift them!
Biology and Life Cycle
Defense and Diet
According to early reports, the pincushion ray defends itself by striking with its thorn-covered tail. This can cause "severe and even dangerous wounds." Its main food source is said to be small eels.
Reproduction
Like other stingrays, the pincushion ray gives birth to live young. This is called aplacental viviparous reproduction. This means the babies grow inside the mother without a placenta. One female ray was found carrying two babies. A female ray that was 45.2 cm (17.8 inches) wide was found in the Sanaga River. She was not yet old enough to have babies.
Pincushion Rays and People
Threats to Survival
In the 1800s, the pincushion ray was very common in the Old Calabar River. But today, it is very rare. There are fewer than 10 museum specimens of this ray. Only a few more have been caught recently in Gabon.
This ray lives in an area with many people. It might have been over-fished by local fishermen. People used to think it was a "great delicacy" to eat. They hunted it with barbed spears. The pincushion ray may also be harmed by habitat degradation. This means its home is being damaged or polluted. Because it is so rare and faces many threats, the International Union for Conservation of Nature (IUCN) has listed it as Critically Endangered. This means it is at a very high risk of disappearing forever.
