Scyliorhinidae is a family of sharks, one of a few families whose members share the common name catsharks, belonging to the order Carcharhiniformes, the ground sharks. Although they are generally known as catsharks, some species can also be called dogfish due to previous naming. However, a dogfish may generally be distinguished from a catshark as catsharks lay eggs while dogfish have live young. Like most bottom feeders, catsharks feed on benthic invertebrates and smaller fish. They are not harmful to humans. The family is paraphyletic, containing several distinct lineages that do not form a monophyletic group.
The Squaliformes are an order of sharks that includes about 126 species in seven families.
The Centrophoridae are a family of squaliform sharks. The family contains just two genera and about 15 species. They are sometimes called gulper sharks, but this is also the name of a specific species in the family, Centrophorus granulosus. These are generally deepwater fish. While some, such as the gulper shark C. granulosus, are found worldwide and fished commercially, others are uncommon and little-known. Their usual prey is other fish; some are known to feed on squid, octopus, and shrimp. Some species live on the bottom (benthic), while others are pelagic. They are ovoviviparous, with the female retaining the egg-cases in her body until they hatch.
Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making it the second largest order of sharks, numbering 119 species across 7 families. Having earned their name after a group of fishermen reportedly observed the species chasing down smaller fish in dog-like packs, dogfish have slender, streamlined bodies, usually more compact in comparison to other species, and a pointed snout. Dogfish likewise have two dorsal fins, each with smooth spines, but no anal fin, and their skin is generally rough to the touch. As the species reaches adulthood, males usually measure a maximum of 100 cm, while females typically measure 125 cm long. The species therefore exhibits female-dominant sexual dimorphism.
The prickly shark is one of the two species of sharks in the family Echinorhinidae, found in the Pacific Ocean over continental and insular shelves and slopes, and in submarine canyons. Bottom-dwelling in nature, it generally inhabits cool waters 100–650 m (330–2,130 ft) deep, but it also frequently enters shallower water in areas such as Monterey Bay off California. This stocky, dark-colored shark grows up to 4.0 m (13.1 ft) long, with two small dorsal fins positioned far back on its body and no anal fin. It is characterized by a dense covering of thorn-like dermal denticles, hence its common name.
Echinorhinus is the only extant genus in the family Echinorhinidae.
Deania is a genus of long-snouted, deepwater dogfish sharks in the family Centrophoridae.
The prickly dogfish is a poorly known species of dogfish shark in the family Oxynotidae, inhabiting temperate Australian and New Zealand waters. Reaching a length of 75 cm (30 in), this brown to gray shark has a very thick body with a prominent "humpback" and extremely rough skin. It is further characterized by two enormous, sail-like dorsal fins placed relatively close together. Both dorsal fins have a spine embedded mostly within the fleshy leading portion of the fin; the first dorsal spine is tilted forward.
The viper dogfish or viper shark is a rare species of dogfish shark in the family Etmopteridae, and the only extant member of its genus. It has been found in the Pacific Ocean off southern Japan, the Bonin Islands, Pacific Ocean off northern Taitung County and the Northwestern Hawaiian Islands. This species inhabits upper continental slopes and seamounts. It may migrate vertically, shifting between bottom waters 270–360 m (890–1,180 ft) deep during the day and upper waters less than 150 m (490 ft) deep at night. A slender, black shark reaching 54 cm (21 in) in length, the viper dogfish can be recognized by its narrow, triangular jaws and well-spaced, fang-like teeth. It also has two spined dorsal fins, dermal denticles with faceted crowns, and numerous light-emitting photophores concentrated on its ventral surface.
The Japanese roughshark is a rare species of shark in the family Oxynotidae, known only from a handful of specimens recovered from Suruga Bay and the Enshunada Sea off Japan. It is a benthic species that occurs at a depth of 150–350 m (490–1,150 ft). This shark is caught as bycatch by bottom trawlers throughout its entire limited range, and may be threatened given the declines in other bottom deep sea species in Suruga Bay.
The Caribbean roughshark is a rough shark of the family Oxynotidae, found on the upper continental slopes of the Caribbean Sea, at depths between 400 and 450 m. It reaches a length around 50 cm (20 in).
The angular roughshark is a rough shark of the family Oxynotidae.
The sailfin roughshark is a species of dogfish shark in the family Oxynotidae, found in the eastern North Atlantic from Scotland to Senegal between latitudes 61°N and 11°N, at depths of between 265 and 720 m. Its length is up to 1.2 m (3.9 ft).
Squalomorphi is a superorder of cartilaginous fishes, generally characterized by lacking traits such as an anal fin, nictitating membrane, or suborbital shelves in the cranium. Squalomorphii sharks are also called squalea, or squalean sharks. There are about 163 living species in 11 families. Squalean sharks are divided into four orders: the Hexanchiformes, Squaliformes, Squatiniformes, and Pristiophoriformes.
The Pacific spiny dogfish is a common species of the Squalidae (dogfish) family of sharks and are among the most abundant species of sharks in the world. This species is closely related to Squalus acanthias and for many years they were treated as a single species. Recent research, using meristic, morphological and molecular data led to the resurrection of the Pacific spiny dogfish as a separate species. The American Fisheries Society recommends the common name "Pacific spiny dogfish" for Squalus suckleyi over alternatives such as "spotted spiny dogfish" and "North Pacific spiny dogfish" and "spiny dogfish" for Squalus acanthias.
