The Japanese sawshark is a sawshark of the family Pristiophoridae, found in the northwest Pacific Ocean around Japan, Korea, and northern China. It has a flat snout, studded with teeth, which resembles a serrated saw. Protruding from the middle of the saw-like snout are two long, sensitive, whisker-like barbels. The sawshark uses these barbels, along with electro-receptors located on the underside of its saw (Ampullae of Lorenzini) to help it find prey buried in the sand as it cruises along the bottom of the ocean. [x]
…a species of sawshark (Pristiophoridae) which occurs in the northwest Pacific Ocean around Japan, Korea, and northern China, where it inhabits the sandy or muddy bottoms of the continental shelves (at depths of 50-800 m). Japanese sawsharks are primarily “benthic” and will feed on a wide range of small bottom dwelling invertebrates and fish.
Sawfish (Family Pristidae) and Sawsharks (Family Pristiophoridae) are commonly mistaken for each other. It’s pretty easy to do that, since they’re both really unique predators built for a gnarly kill with their intense saws for teeth. They’re both elasmobranchs, making them distantly related. The sawshark is, you guessed it, a shark! The sawfish, on the other hand, is a ray. Sawsharks also have two barbels that stick out in the middle of their saws, resembling whiskers, and happen to work like that of a catfish. They feel along the ocean floor for any potential prey, which is something saw fish can’t do. Also, sawfish have gill slits on their undersides like a typical ray, whereas sawsharks have gill slits on their side like a shark. Makes sense, eh? Saw sharks have alternating teeth sizes, making them look a bit more unkempt, whereas sawfish have a nice polished look with evenly sized teeth all around. This sucks for the tidy sawfish though, since unlike that unorganized sawshark, his teeth don’t grow back. It’s cool though, since they’re bigger than sawsharks. Measuring in from 1.4 m (4.6 ft) to 7 m (23 ft), sawsharks can barely compare at up to 1.7 m (5.6 ft) long.
The African dwarf sawshark (Pristiophorus
nancyae) is one of the least known species of the genus and is the only
species of the genus known from the western Indian Ocean.
species was described in 2011 based on type specimens in
rather poor condition and with a very restricted distribution off
southern Mozambique. Since nine further specimens in mostly
excellent condition became available to reinvestigated the species.
Most sawsharks communicate using sight, touch, and electric signals. They perceive their environment with mediocre eyesight, use their barbels to touch the ocean floor, and use their ampullae to sense electrical fields. They communicate with other animals visually and use their barbels and ampullae when searching for prey
Photographs: Adult female, fresh, in dorsal view;
in (a) dorsal and (b) ventral views (Scale bar: 5 cm); and
nout tip in
ventral view (Scale bar: 1 cm)
“There are seven known species of sawsharks (Pristiophoriformes) that have long snouts with teeth, but they are not related to sawfish (although sawsharks are fish). They swim along the floor of the ocean and use their snouts exactly as you would imagine: they smack their prey sideways to disable them. Sawsharks eat squid, crustaceans, and small fish. They look much more dangerous than they are.” -
The African dwarf sawshark (Pristiophorus nancyae) was accidentally captured in a 1,600-foot-deep (490-meter-deep) trawl off Mozambique. The animal is only the seventh species of sawshark known to science, according to David Ebert, a research associate at the Academy.
The predator has a long, tooth-studded snout that it uses like a sword, whipping the appendage through schools of fish and then returning to eat any casualties.
Along with the sawshark, a new species of angel shark, Squatina caillieti, was named from a single specimen collected in 1,200-foot-deep (370-meter-deep) water off the Philippine island of Luzon, Ebert said.
Bottom-dwelling angel sharks, whose large pectoral fins resemble wings, lie partially buried in sediment and ambush passing prey.
In addition, two species of lanternshark in the Etmopterus genus were also discovered in Taiwan and South Africa, respectively.
The discoveries are part of a recent boom in new shark and ray finds. Over the past decade, about 200 new species have been described, compared with fewer than 200 in the previous three decades, Ebert said.
Despite these advances in describing new sharks, scientists know very little about the predators’ behaviors or their populations, he added.