Sawshark
The Bahamas sawsharks ("Pristiophorus schroeder") have very little information on them. Studies are being done daily to learn more about the deep sea dweller. They are located near Cuba, Florida, and the Bahamas (hence their name) where they dwell in the depths of 400–1000 m. As far as their appearance they can be identified by their snouts with teeth which appear as a saw, as well as their length, they are averaged at 80 cm in length.
Saw sharks and sawfish are cartilaginous fish possessing large saws. These are the only two fish that have a long blade-like snout. Although they are similar in appearances, saw sharks are distinct from sawfish. Sawfish are not sharks, but a type of ray. The gill slits of the sawfishes are positioned on the underside like a ray, but the gill slits of the saw shark are positioned on the side like a shark. Sawfish can have a much larger size, lack barbels, and have evenly sized teeth rather than alternating teeth of the saw shark. Clear difference is that a sawfish has no barbels and a saw shark has a prominent pair halfway along the saw. The saw shark uses these like other bottom fish, as a kind of antennae, feeling the way along the ocean bottom until it finds some prey of interest. Both the saw shark and the sawfish utilize the electroreceptors on the saw, ampullae of Lorenzini, to detect the electric field given off by buried prey.
Largetooth sawfish
The largetooth sawfish has been extirpated from many regions where formerly present. Among the 75 countries where recorded historically, it has disappeared from 28 and may have disappeared from another 27, leaving only 20 countries where certainly still present. In terms of area this means that it certainly survives in only 39% of its historical range. Only Australia still has a relatively healthy population of the species and this may be the last remaining population in the entire Indo-Pacific that is of sufficient size to be viable, but even it has experienced a decline. Other places in the Indo-Pacific where still present, even if in very low numbers, are off Eastern Africa, the Indian subcontinent and Papua New Guinea, and in the East Pacific it survives off Central America, Colombia and northern Peru. Whether it survives anywhere in Southeast Asia is generally unclear, but one was captured in the Philippines in 2014 (a country where otherwise considered extirpated). The species has disappeared from much of its Atlantic range and declined where still present. The likely largest remaining population in this region is in the Amazon estuary, but another important population is in the San Juan River system in Central America. It was once abundant in Lake Nicaragua (part of the San Juan River system), but this population rapidly crashed during the 1970s when tens of thousands were caught. It has been protected in Nicaragua since the early 1980s, but remains rare in the lake today, and is now threatened by the planned Nicaragua Canal. In West Africa, the Bissagos Archipelago has often been considered the last remaining stronghold, but interviews with locals indicate that sawfish now also are rare there.