Sawfish

No. Sawfish are rays, part of the group that also contains stingrays, skates, and guitarfish, and the tell is anatomy rather than appearance. Like all rays, a sawfish has its five pairs of gill slits on the flat underside of the body and its pectoral fins fused broadly to the head, whereas a shark has gill slits on the sides. The confusion is understandable because a sawfish has a fairly shark-like tail and dorsal fins and is sometimes called a carpenter shark. There is a separate group of genuine sharks called sawsharks that also have a toothed snout, but they are smaller, have a pair of long barbels partway along the saw, and live in deeper water, and they are not closely related to sawfish.

Two main things, and not for digging as was once assumed. First, it is a hunting weapon. The sawfish swims into or alongside a school of fish and slashes the rostrum rapidly from side to side, and the tooth-like denticles injure, stun, or impale several fish, which the sawfish then picks off the bottom. Second, it is a sensing array. The rostrum is covered in thousands of tiny electroreceptor pores that pick up the faint electrical signals given off by living animals, so a sawfish sweeping its saw slowly over the sea floor can locate prey buried in the sediment. The saw is also occasionally used to rake through mud for crustaceans, but the fish does not use it as a shovel.

The same feature that makes the saw useful, its toothy projecting shape, makes a sawfish exceptionally vulnerable to fishing nets. A sawfish that encounters a gillnet, trawl, or seine gets its rostrum tangled in the mesh within seconds and usually cannot free itself, so sawfish are caught as bycatch at very high rates wherever these gears are used in their shallow, coastal, muddy-water habitat. On top of that, sawfish have been deliberately targeted for their fins, which are highly valued in the shark-fin trade, for their meat, and for the saw itself, which is sold as a curio and used in some cultural practices. They also mature slowly and produce few young, so populations cannot rebound quickly. The combination has driven declines of 90 percent or more and local extinction across much of the world.

The best remaining populations by far are in northern Australia, especially the rivers and coasts of Queensland, the Northern Territory, and Western Australia, which are considered a global stronghold for the largetooth, green, dwarf, and narrow sawfishes. The other significant population is the smalltooth sawfish in the southeastern United States, centred on southwest Florida and the Everglades, where decades of complete legal protection, a ban on catching or harming them, and conservation of the mangrove and estuary nurseries have produced signs of a slow recovery. Elsewhere, sawfish are rare or gone, and most encounters are of single animals.