While sawfish may look like sharks, they are a family of rays. Sawfish belong to a group of fish called chondrichthyans, and like other members of this group, sawfishes have cartilaginous skeletons. They are closely related to sharks and other rays, in a group called elasmobranchs.
The most notable feature on a sawfish is their rostrum, otherwise known as their saw or snout. The rostrum is made up of cartilage and is long and flat, with rostral “teeth”—which are actually modified scales—sticking out on either side. The teeth are used for feeding and for defense; sawfishes can slash their rostrum from side to side to defend themselves from predators and catch prey.
The rostrum can also be used as a tracker or sensory device. They’re studded with small pores that allow the sawfish to sense the electrical fields produced by living things and anything moving through the Earth’s magnetic field. The rostrum also has a system to detect motion and vibration—even in murky water, their prey cannot hide.
The sawfish’s eyes are located near the top of its head, which allows them to see even when partially buried. Although they have good eyesight, the waters where sawfish reside are often murky. Therefore, they rely on the rostrum as well as other sensory structures—such as their nares, or nostrils, and lateral line—to help locate prey.
Sawfishes have four types of fins. The pectoral fins are used for lift and steering while swimming. The dorsal and pelvic fins are used for stabilization. The caudal fin, or tail, is used to propel the sawfish forward while swimming.
Sawfish can grow to more than 20 feet in length and can weigh well over 700 pounds, depending upon species. Despite their fierce appearance, sawfishes are generally docile when unprovoked.
There are five species of sawfish, and all are threatened; two species—the knifetooth and dwarf—are considered Endangered, and three species—the smalltooth, green and largetooth—are considered Critically Endangered by the International Union for the Conservation of Nature (IUCN). They are susceptible to entanglement in many types of fishing gear, and have suffered from habitat destruction, in addition to having been exploited for their fins and rostra. They do not mature until later in life and bear few young.
You can help protect sawfish! The conservation of mangroves and other coastal habitats can help protect the environment they need to thrive. Additionally, supporting laws focused on reducing bycatch and other regulations can help protect this species.
To learn more about sawfish and what you can do to help protect them, check out this infographic from the IUCN!
The Sawfish Conservation Society worked in tandem with Dallas World Aquarium, Ripley’s Aquarium, IUCN, The Deep, the National Aquarium and other institutions to organize this year's inaugural International Sawfish Day.