Hemigaleidae facts for kids
Quick facts for kids Hemigaleidae |
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| Hooktooth shark, Chaenogaleus macrostoma | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Order: | Carcharhiniformes |
| Family: | Hemigaleidae Compagno, 1984 |
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The weasel sharks are a fascinating family of sharks, known scientifically as the Hemigaleidae. These sharks live in the warm, shallow waters of the ocean, from the eastern Atlantic Ocean all the way to the Indo-Pacific region. You can find them swimming close to the coast, usually in waters up to about 100 meters (330 feet) deep.
Contents
What are Weasel Sharks?
Most weasel sharks are quite small. They typically grow to about 1.4 meters (4.6 feet) long. However, one species, the snaggletooth shark, can be much larger. It reaches up to 2.4 meters (7.9 feet).
These sharks have some cool features:
- They have eyes that are shaped like horizontal ovals.
- They have tiny breathing holes called spiracles.
- They have special grooves near their tail called precaudal pits.
- They have two dorsal fins (the fins on their back).
- The first dorsal fin is placed quite far forward on their body. It is ahead of their pelvic fins.
- Their caudal fin (tail fin) has a strong lower part. It also has wavy edges on the upper part.
Weasel sharks are not known to attack people. They are generally considered harmless to humans.
Diet and Habitat: What Weasel Sharks Eat
Weasel sharks are carnivores. This means they eat other animals. They have a varied diet, munching on many kinds of small bony fishes. They also eat invertebrates like crabs and shrimp. Some species are even picky eaters. They specialize in hunting cephalopods, which include creatures like squids and octopuses!
They prefer to live in shallow coastal areas. This makes them easier to study for scientists. Their wide distribution across the Atlantic and Indo-Pacific shows they are well-adapted to different warm ocean environments.
Meet the Family: Different Kinds of Weasel Sharks
The weasel shark family includes eight known species. These are grouped into four main types, called genera. These genera are further divided into two subfamilies. Hemipristinae only includes Hemipristis. Hemigaleinae includes Chaenogaleus, Hemigaleus, and Paragaleus.
The Hooktooth Shark: Chaenogaleus
This group has only one species. It is the hooktooth shark (Chaenogaleus macrostoma). It's easy to spot because of its long, hooked teeth in its lower jaw. Unlike some other sharks, it doesn't have any toothless gaps in the middle of its jaws. Its gill slits are very long. Its snout is shaped like a wedge. Its fins are not curved or sickle-shaped.
The Hemigaleus Sharks
Sharks in the Hemigaleus genus have a rounded snout and shorter gill slits. Their mouth is short and wide, with a curved shape. Their teeth have very short points. Like the hooktooth shark, they don't have toothless spaces in the middle of their jaws. Their dorsal, pelvic, and lower tail fins are strongly curved, almost like a sickle.
The Snaggletooth Shark: Hemipristis
The Hemipristis genus also has just one living species. It is the famous snaggletooth shark (Hemipristis elongata). This shark has a rounded snout and very long gill slits. Its mouth is long, and it does have toothless spaces in the middle of its jaws. Its lower teeth are very long and strongly hooked. They stick out even when its mouth is closed! All its fins are strongly curved.
Scientists have found many fossil species of Hemipristis. Examples include H. curvatus and H. serra. Millions of years ago, during the Tertiary period, these sharks lived all over the world!
The Paragaleus Sharks
Sharks in the Paragaleus genus have snouts that can be rounded or slightly pointed. They have short gill slits and a wide, arched mouth. Their upper teeth have long points. They don't have toothless spaces in the middle of their jaws. Unlike some other weasel sharks, their dorsal, pelvic, and lower tail fins are not curved.
