Synodontis dhonti facts for kids
Quick facts for kids Synodontis dhonti |
|
|---|---|
| Conservation status | |
| Scientific classification |
Synodontis dhonti is a special kind of upside-down catfish. It lives only in Lake Tanganyika in the Democratic Republic of the Congo. This means it is endemic to that lake. The fish was first described by a scientist named George Albert Boulenger in 1917. He found it in Kilewa Bay in Lake Tanganyika. The species was named after M.G. Dhont-De Bie, who helped with the expedition. For a while, another fish called Synodontis irsacae was thought to be the same as S. dhonti. But now, scientists know they are two different species.
Contents
What Synodontis dhonti Looks Like
Like all fish in the Synodontis group, S. dhonti has a strong, bony head. This head bone goes all the way back to its first fin spine. The head is about one-third of the fish's total length.
Head Features
The fish's head has a special bony part called a humeral process. This part helps scientists tell different species apart. In S. dhonti, this process is narrow, long, and feels rough. Its top edge curves inward, and the end is blunt. It is about half as long as the fish's head. The eye of the fish is quite small, about one-ninth the length of its head.
Whiskers (Barbels)
S. dhonti has three pairs of whiskers, called barbels. One pair is on its upper jaw, and two pairs are on its lower jaw.
- The upper jaw whiskers are straight and long. They reach almost to the pectoral fins.
- The outer pair of lower jaw whiskers is shorter. They have four or five small branches.
- The inner pair of lower jaw whiskers is even shorter. They have two pairs of branches.
Skin and Texture
The skin of S. dhonti has many tiny vertical folds. Scientists are not sure why these folds are there. But they are common in Synodontis species that live in Lake Tanganyika. The skin also has small, grainy bumps called papilla.
Fins and Spines
The front edges of the dorsal (top) and pectoral (side) fins are stiff spines.
- The dorsal fin spine is long and mostly straight. It is smooth on the front and rough on the back. It ends with short, dark threads. The rest of the dorsal fin has seven dark, branching rays.
- The pectoral fin spine is slightly curved. It is about as long as the dorsal fin spine. It has large rough edges on its back side. This spine also ends in short, dark threads. The rest of the pectoral fins have eight branching rays.
- The adipose fin is a small, fleshy fin without rays. It has a rounded shape.
- The pelvic fins (bottom fins) have one unbranched and six branched rays. They line up with the back of the dorsal fin.
- The anal fin (near the tail) has 5 unbranched and 8 branched rays. It lines up with the adipose fin.
- The tail fin is forked, like a "V" shape. It has pointed ends. The upper part has eight rays, and the lower part has nine rays.
Mouth and Teeth
The mouth of S. dhonti faces downward and has wide lips. These lips also have small bumps. All Synodontis fish have a special pad of teeth on their upper jaw. This pad has several rows of short, chisel-shaped teeth. In S. dhonti, this tooth pad is one continuous piece. On the lower jaw, the teeth are "s-shaped" or "hooked." They are attached to flexible stalks. S. dhonti has 22 teeth on its lower jaw, arranged in a single row.
Special Pores
Some Synodontis species have an opening called an axillary pore. It is found on the side of the body, near the pectoral fin. Scientists do not fully know what this pore does. Some fish use similar pores to release a slimy, possibly toxic, substance. S. dhonti has a large axillary pore.
Coloration
The only known specimen of this fish has been kept in alcohol for a very long time. Because of this, most of its original colors are gone. However, many Synodontis fish from Lake Tanganyika have dark triangles at the base of their fins. S. dhonti also has these markings. They may also have dark spots on their bodies. The whiskers are usually white, but might have some dark spots near their base. The rays of the fins are dark.
Size
The known specimen of S. dhonti is about 32.5 centimeters (12.8 inches) long. Its total length, including the tail, is about 39.5 centimeters (15.6 inches). In general, female Synodontis fish are a bit larger than males of the same age.
Habitat and Life Cycle
S. dhonti lives in Lake Tanganyika. The water temperature in the lake is usually between 23 to 26 degrees Celsius (73 to 79 degrees Fahrenheit). The water is slightly alkaline, with a pH of about 8.5 to 9.
Where They Live
Synodontis fish in Lake Tanganyika often live near rocky shorelines. They also like sandy areas and places with shells on the bottom.
Reproduction and Diet
Scientists do not know much about how most Synodontis species reproduce. They have found eggs in some female fish. Spawning, or laying eggs, likely happens during the rainy season, from July to October. During spawning, pairs of fish probably swim together.
Synodontis fish are omnivores, meaning they eat both plants and animals. They eat things like insect larvae, algae, snails, clams, sponges, and small crustaceans. They also eat the eggs of other fish. These fish grow quickly in their first year, then their growth slows down as they get older.
