A sawshark or saw shark is a member of a shark order bearing a unique long, saw-like rostrum edged with sharp teeth, which they use to slash and disable their prey. There are eight species within the Pristiophoriformes, including the longnose or common sawshark, shortnose sawshark, Japanese sawshark, Bahamas sawshark, sixgill sawshark, African dwarf sawshark, Lana's sawshark and the tropical sawshark.
Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish with some species reaching lengths of about 7–7.6 m (23–25 ft). They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, as well as freshwater rivers and lakes. They are also endangered.
The broadnose sevengill shark is the only extant member of the genus Notorynchus, in the family Hexanchidae. It is recognizable because of its seven gill slits, while most shark species have five gill slits, with the exception of the members of the order Hexanchiformes and the sixgill sawshark. This shark has a large, thick body, with a broad head and blunt snout. The top jaw has jagged, cusped teeth and the bottom jaw has comb-shaped teeth. Its single dorsal fin is set far back along the spine towards the caudal fin, and is behind the pelvic fins. In this shark the upper caudal fin is much longer than the lower, and is slightly notched near the tip. Like many sharks, this sevengill is counter-shaded. Its dorsal surface is silver-gray to brown in order to blend with the dark water and substrate when viewed from above. In counter to this, its ventral surface is very pale, blending with the sunlit water when viewed from below. The body and fins are covered in a scattering of small black & white spots. In juveniles, their fins often have white margins.
The bluntnose sixgill shark, often simply called the cow shark, is the largest hexanchoid shark, growing to 20 ft (6.1 m) in length. It is found in tropical and temperate waters worldwide and its diet is widely varied by region. The bluntnose sixgill is a species of sixgill sharks, of genus Hexanchus, a genus that also consists of two other species: the bigeye sixgill shark and the Atlantic sixgill shark. Through their base pairs of mitochondrial genes COI and ND2, these three species of sixgills widely differ from one another.
The Bahamas sawshark, Pristiophorus schroederi, is a sawshark of the family Pristiophoridae, found in the western Central Atlantic Ocean from the Bahamas and Cuba at depths of between 400 and 1,000 m. These sharks are at least 80 cm long.
The bigeyed sixgill shark is a cow shark of the family Hexanchidae. Its dorsal surface has a brownish-gray color, and is sharply separated from the light coloring of its ventral surface. The eyes are a fluorescent green while the shark is alive. The body of this shark is small, slim, and fusiform in shape. As the name suggests, this shark has six gill slits, unusual among most shark species. The head is narrow and somewhat flattened, and the mouth contains 5 rows of large, comb-shaped teeth. This shark's single dorsal fin is pushed back towards the caudal fin, and is behind the pelvic fins. The upper caudal fin is much longer than the lower, with a deep notch near the tip. All fins have thin white margins on the edge. In juveniles, the upper caudal fin has a black tip.
The sixgill stingray is a species of stingray and the only extant member of the family Hexatrygonidae. Although several species of sixgill stingrays have been described historically, they may represent variations in a single, widespread species. This flabby, heavy-bodied fish, described only in 1980, is unique among rays in having six pairs of gill slits rather than five. Growing up to 1.7 m (5.6 ft) long, it has a rounded pectoral fin disc and a long, triangular, and flexible snout filled with a gelatinous substance. It is brownish above and white below, and lacks dermal denticles.
The gummy shark, also known as the Australian smooth hound, flake, sweet william or smooth dog-shark, is a shark in the family Triakidae. These small to medium-sized bottom-dwelling sharks are found mostly in, but are not limited to, the area around the southern seas of Australia and is commonly baited and fished for cuisine because of its taste and market prices. According to a 2021 paper by White, Arunrugstichai & Naylorn (2021), Mustelus walkeri is the same animal as M. antarcticus. One theory is that M. walkeri is a subpopulation of M. antarcticus.
The daggernose shark is a little-known species of requiem shark, in the family Carcharhinidae, and the only extant member of its genus. It inhabits shallow tropical waters off northeastern South America, from Trinidad to northern Brazil, favoring muddy habitats such as mangroves, estuaries, and river mouths, though it is intolerant of fresh water. A relatively small shark typically reaching 1.5 m (4.9 ft) in length, the daggernose shark is unmistakable for its elongated, flattened, and pointed snout, tiny eyes, and large paddle-shaped pectoral fins.
The shortnose sawshark, or southern sawshark, is a sawshark of the family Pristiophoridae. The body of this shark is slightly compressed, and its rostrum is narrow. The two dorsal fins are almost identical in size. In color, the dorsal side of this sawshark tends to be uniformly slate gray, with few or no markings. The ventral side is pale white or cream. Females reach around 124 cm (49 in) long, and males reach around 110 cm (43 in) long. These sharks can live up to 9 years.
The Japanese sawshark is a species of sawshark in the family Pristiophoridae. This shark has a long, narrow rostrum. Its first dorsal fin originates behind the tips of the pectoral fins, and its caudal fin is angled almost straight in line with the body. The Japanese sawshark reaches a maximum length of up to 1.36 m.
The longnose sawshark or common sawshark, is a sawshark of the family Pristiophoridae.
The lollipop catshark is a little-known species of deep sea catshark, belonging to the family Scyliorhinidae, and the only described member of its genus. A diminutive, bottom-dwelling shark of the outer continental shelf and upper continental slope, this species can be readily identified by its tadpole-like shape with a greatly expanded, rounded head and narrow body. The large head houses expanded gills, which are thought to be an adaptation for hypoxic conditions. This shark preys on crustaceans and fishes. Reproduction is aplacental viviparous, with females retaining egg cases internally two at a time until they hatch. There is no fishery interest in this species.
The white-spotted Izak or African spotted catshark is a catshark of the family Scyliorhinidae. It is found in the western Indian Ocean off the coasts of Natal, South Africa, southern Mozambique, Madagascar, Kenya, and Tanzania between latitudes 4° S and 37° S, at depths of between 220 and 440 m. It can grow up to 35 cm in length.
The whiskery shark is a species of houndshark in the family Triakidae, and the only member of its genus. This common shark inhabits the Australian continental shelf from Western Australia to the Bass Strait, to a depth of 220 m (720 ft). It is demersal in habits and prefers rocky and vegetated habitats. Stout-bodied and almost "humpbacked" in form, the whiskery shark can be distinguished from all other members of its family by the presence of long nasal barbels. Its two moderately large dorsal fins are roughly equal in size. It is brownish gray above and lighter below, with a pattern of darker saddles and blotches in younger sharks. This species reaches 1.6 m (5.2 ft) in length.
The sand devil or Atlantic angel shark is a species of angelshark, family Squatinidae, native to the northwestern Atlantic Ocean. It occurs off the eastern United States, in the northern Gulf of Mexico, and possibly in parts of the Caribbean Sea. This bottom-dwelling shark is found in shallow inshore waters in summer and fall, and deep offshore waters in winter and spring. The sand devil's flattened body and enlarged pectoral and pelvic fins give it a ray-like appearance. There is a band of enlarged thorns running along the middle of its back. It is gray or brown in color, with scattered small dark spots. This species reaches 1.2–1.5 m (3.9–4.9 ft) in length.
The speckled smooth-hound is a houndshark of the family Triakidae. It is found on the continental shelf of the eastern Pacific, between latitudes 0° and 54° S, at depths between 16 and 50 m. It can reach a length of 130 cm (51 in). Collectively with certain other species of shark, it is known as "tollo".
The Australian angelshark is a species of angelshark, family Squatinidae, found in the subtropical waters of southern Australia from Western Australia to New South Wales between latitudes 18°S and 41°S, at depths down to 255 m (840 ft). Its length is up to 1.52 m (5 ft). Reproduction is ovoviviparous, with up to 20 pups in a litter.
Pristiophorus is a genus of sawsharks found in the Pacific, Atlantic and Indian oceans. Members of this genus differ from the Sixgill Sawshark (Pliotrema warreni) in having five gill slits. Their rostral sawteeth lack prominent transverse ridges on the basal ledges, and the large teeth are not posteriorly serrated.
The tropical sawshark, Pristiophorus delicatus, is a recently described species of sawshark, family Pristiophoridae, formerly known in literature as Pristiophorus sp. B. It is endemic to northeastern Australia, found on the upper continental slope off Queensland from south of the Samaurez Reef, at a depth of 246–405 meters (807–1,329 ft). Its specific epithet delicatus is Latin for "delicate", referring to the fine teeth on its saw-like rostrum.
