Common Name: Knifetooth Sawfish

Scientific Name: Anoxypristis cuspidata

Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Order: Pristifomes

Family: Pristidae

Genus: Anoxyoristis

Species: A. cuspidata

1.jpg

The knifetooth sawfish is a shark like ray and likes to live in warmer waters. There is not a lot known about the size of the knifetooth sawfish. In Australia, the maximum length is 11.5 feet. In India, they grow up to 19.7 feet long. This amazing fish has unconfirmed reports of reaching lengths of 26.2 feet and over 1200 lb. in weight. These fish have a unique grayish coloration. Its upper surface is dark to blend in with the muddy seafloor. The color on their underside is whitish to blend in with the water. They have a flattened body, and with their tooth snout, they are “Sharks with Swords”.

 

An adaptation that the knifetooth sawfish has is that it can live in both the ocean and rivers. There are many identifying characteristics to this fish. First, you should notice the saw like snout. Then you might notice that they have 18 to 22 pairs of teeth on each side of their snout. These are not really teeth but are actually modified scales. Thousands of tiny dome-shaped teeth line their jaws. The knifetooth sawfish likes to live in shallow rivers or on inshore places. They prefer dark, murky water and sandy or muddy bottoms. These fish have sensors in their snouts so they can detect the heartbeats of buried prey. They can also use their snout to rake out the buried prey.

 

The knifetooth sawfish lives by Australia, India and Thailand. There are about 4 to 10 different species of this fish. Its population has stayed constant or the same over the years. These humongous fish feed on bottom-dwelling invertebrates like, squid, crab, shrimp and schools of small fish. They crush and swallow their food whole with their mouth. They are great competitors for food; they capture their prey by slashing them with their sharp pointed saws. The shark, its main competitor also eats the same things but in addition, the shark eats the knifetooth sawfish. The knifetooth sawfish has the worst predator of all, the shark! This fish attracts the hammerhead, bull and copper sharks. It also attracts saltwater crocodiles. This might be a reason why these magnificent fish live in warm water rivers. The interesting fact that stood out to me while I was reading was that at birth the fish is born with a soft saw that has a protective layer or a sheath of tissue covering it, so that it does not injure the mother in the birthing process. They shed it off soon after birth. I learned that some knifetooth sawfish live not only in oceans but in rivers too.

 

Author: Paden H

Published: 02/2007

 

Sources: http://www.flmnh.ufl.edu/fish/gallery/descript/ktsawfish/ktsawfish.html http://en.wikipedia.org/wiki/Knifetooth_sawfish http://www.fishbase.us/Summary/SpeciesSummary.php?id=8211

 

Photo Credit: http://www.flmnh.ufl.edu/fish/gallery/descript/ktsawfish/ktsawfish.html