Knifetooth sawfish facts for kids
Quick facts for kids Narrow sawfish |
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The narrow sawfish (Anoxypristis cuspidata) is a special type of sawfish. People also call it the pointed sawfish or knifetooth sawfish. It belongs to a group of fish called Batoidea. This group includes rays and skates. These fish have skeletons made of cartilage, not bone.
Sawfish live all over the world in warm ocean waters and fresh water. There are only five types of sawfish left today. Sawfish are easy to spot because of their long, flat snout. This snout looks like a saw. It has sharp teeth on the sides. They use this "saw" to catch and kill their food.
The narrow sawfish lives in shallow coastal waters. It is found in places like the Persian Gulf, southern Japan, Papua New Guinea, and northern Australia. It is the only living member of its genus called Anoxypristis. It can grow up to about 3.5 meters (11.5 feet) long.
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What the Narrow Sawfish Looks Like
The narrow sawfish can grow to about 3.5 meters (11.5 feet) long. Some people have claimed to see much bigger ones, but this is not confirmed. Its body looks a lot like a shark. But its most unique part is its flat head. This head extends into a long, blade-like snout.
This snout has 18 to 22 pairs of teeth on its sides in Australia. In other places, it can have up to 25 pairs. These teeth are short, flat, and shaped like triangles. The "saw" part does not get narrower towards the tip. In adult sawfish, the first quarter of the saw has no teeth. Younger sawfish have about one-sixth of the base without teeth.
Young sawfish have smooth skin. Older ones have a few small, rough bumps called dermal denticles. The top of the fish is grey. Its belly and fins are a light grey. The saw is grey with white teeth. Sometimes, the base of the saw is brown.
Where the Narrow Sawfish Lives
The narrow sawfish used to live in many parts of the Indo-Pacific Ocean. This included places like Iran, India, and Australia. It was also found as far north as China and Japan. Today, it is only known to live in a few areas. These include parts of the Arabian Sea, South Asia, Australia, and Papua New Guinea.
This sawfish lives near the bottom of the ocean. It can be found at depths of about 100 meters (328 feet). It likes soft bottoms, like sand, mud, or seagrass beds. It does not like rocky areas. It can also live in water that is not very salty. This means it can be found in bays and river mouths.
The narrow sawfish can move between salty ocean water and less salty river water. Younger sawfish usually stay closer to shore. Older and larger sawfish, especially females, are found further out in the ocean.
Sadly, the narrow sawfish might be gone from the coast of Vietnam. This is due to too much fishing and building along the coast.
Narrow Sawfish Behavior
Reproduction and Life Cycle
Scientists have not studied the narrow sawfish's breeding habits very much. The babies grow inside the mother. Each baby gets food from a yolk sac. The time of year they mate changes depending on where they live. Babies are born after about five months.
A mother sawfish can have 6 to 23 babies at a time. The average is 12 babies. When they are born, the babies are usually 43 to 61 centimeters (17 to 24 inches) long. Their saw teeth are covered by a soft layer. This keeps them from hurting the mother during birth.
Only two studies have looked at how old narrow sawfish get. The oldest one found was nine years old. But scientists think they could live up to 27 years. Females start to become adults when they are about 2.4 meters (8 feet) long. They are fully grown at about 4.7 meters (15.5 feet). Males are fully grown at about 2.4 meters (8 feet) long.
Temperament
The narrow sawfish is usually calm around people. It is not big enough to see humans as food. If you leave it alone, it will not hurt you. However, if it feels very scared, like when it is caught in a net, it will thrash its head. This can cause serious injury to anyone too close.
Diet
The narrow sawfish eats small fish, squid, and other small sea creatures. These include crabs and shrimp. It uses its saw to stir up the sand or mud. This helps it find hidden prey. It can also swing its saw through groups of fish. This stuns or hurts them, making them easier to catch.
The sawfish's head and saw have thousands of special organs. These are called ampullae of Lorenzini. They help the sawfish sense the tiny electric fields made by its prey. This helps it find food even in murky water.
The narrow sawfish can also be food for other animals. These include different types of sharks. For example, hammerhead sharks, bull sharks, and copper sharks. It is also prey for the saltwater crocodile.
Protecting the Narrow Sawfish
Threats to Sawfish
Humans are the main reason why narrow sawfish numbers are dropping. The biggest threat is too much fishing. Sawfish are often caught on purpose. Their fins are used for soup, and their saws are kept as trophies. Many countries have rules against catching them. But illegal fishing still happens.
Sawfish are also often caught by accident in fishing nets. Their toothed saw makes it easy for them to get tangled. It is very hard for them to get out of nets, especially nylon ones. Lost or broken fishing gear, called "ghost nets," are also a big danger. Pregnant females and young sawfish are most at risk from these nets. Many sawfish die after being caught and released.
Losing their homes and water pollution are also big problems. Building along the coast and mining can destroy their habitats. Pollution from these activities makes the water dirty. The IUCN says that by 2020, the narrow sawfish might be gone from 61% of where it used to live. These problems are expected to get worse as more people live near the coast.
Natural threats like sickness or other animals eating them do not harm the sawfish population much.
Conservation Status
The IUCN (International Union for Conservation of Nature) keeps a list of threatened species. In 2000, they listed the narrow sawfish as "Endangered". This was because of too much fishing and losing their homes. In 2006, its status changed to "Critically Endangered". This means it was in even greater danger. In 2013, it went back to "Endangered" because new information was found. But in 2023, it was again listed as "Critically Endangered". This is because its global population has dropped by more than 80% in the last 18 years.
Conservation Efforts
In Western Australia and Queensland, the narrow sawfish is a "no-take" species. This means you cannot catch it. India also has this rule, but it is often not followed. The international trade of narrow sawfish is banned. This is thanks to an agreement called CITES (Convention on International Trade in Endangered Species).
We do not know the exact number of narrow sawfish alive today.
See also
- Threatened rays
