1. Education

Facts About Sawfish

Learn About the Fish With a Saw for a Snout

By

With their very distinctive, flattened snout, sawfish are intriguing animals.  What is their "saw?" How is it used? Where do sawfish live? Learn the answers to these questions and more below.

1. Sawfish have a unique snout.

A sawfish's snout is a long, flat blade that has about 20 teeth on either side. This snout may be used to catch fish, and also has electroreceptors to detect passing prey.

2. The teeth on a sawfish's snout are not true teeth.

The "teeth" on the sawfish's snout are not true teeth, but modified scales.  A sawfish's real teeth are located inside its mouth, which is on the fish's underside.

3. Sawfish are related to sharks, skates and rays.

Sawfish are elasmobranchs - fish that have a skeleton made of cartilage, and a group that contains sharks, skates and rays.  There are over 1,000 species of elasmobranchs. Sawfishes are in the family Pristidae, a word which comes from the Greek word for saw. The NOAA web site refers to them as "modified rays with a shark-like body."

4. Two sawfish species occur in the U.S.

There is some debate over the number of sawfish species, especially since sawfish are relatively understudied. According to the World Register of Marine Species, there are 4 species of sawfish.  The largetooth sawfish and the smalltooth sawfish occur in the U.S.

5. Sawfish can grow to over 20 feet long.

Sawfish can reach lengths over 20 feet.  The smalltooth sawfish might be small in teeth size, but not in length. According to NOAA, the maximum length of a smalltooth sawfish is 25 feet. The green sawfish, which lives off Africa, Asia and Australia, can reach lengths of at least 24 feet.

6. Sawfish are found in shallow waters.

Sawfish / lotopspin, Flickr
Courtesy lotopspin, Flickr

Watch your feet! Sawfish are found in shallow waters, often with muddy or sandy bottoms. They may also swim up rivers. 

7. Sawfish eat fish and crustaceans.

Sawfish eat fish and crustaceans, which they can find using the sensory capabilities of their saw, and which they can kill by slashing their saw back and forth. The saw may also be used to detect and dislodge prey on the ocean bottom.

8. Sawfish are ovoviviparous.

Reproduction occurs through internal fertilization.  Sawfish are ovoviviparous, meaning their young is in eggs, but eggs develop inside the mother's body. The young are nourished by a yolk sac. Depending on the species, gestation may last from several months to a year.  The pups are born with their saw fully developed, but it is sheathed and flexible to avoid injuring the mother at birth.

9. Sawfish populations have declined.

There appears to be a lack of reliable data on sawfish populations, but NOAA estimates that populations of smalltooth sawfish have declined by 95% or more and largetooth sawfish have declined dramatically. Threats to sawfish include fishing, bycatch in fishing gear, and habitat loss due to development, which particularly effects juveniles who seek shelter in vegetation in shallow water.

©2014 About.com. All rights reserved.