Atelomycteridae - (Coloured catsharks)
Carcharhinidae - (Requiem sharks)
Distribution: global. Gill openings 5, the fifth behind origin of pectoral fin. Small to large sharks with round eyes, internal nictitating eyelids, no nasoral grooves or barbels, usually no spiracles. Teeth usually bladelike with one cusp. Development usually viviparous with young born fully developed. Includes several dangerous species, but most prefer to avoid divers.
Galeocerdonidae - (Tiger sharks)
Hemigaleidae - (Weasel sharks)
Common coastal tropical sharks from shallow water down to 100 m, limited to the eastern Atlantic and continental Indo-West Pacific but not extending far into the central Pacific. Horizontally oval eyes, small spiracles, two moderate-sized spineless dorsal fins and an anal fin, the first dorsal base well ahead of pelvic bases. Precaudal pits present. Caudal fin with a strong ventral lobe and lateral undulations on its dorsal margin. They feed on small bony fish, small elasmobranchs, cephalopods, crustaceans, and echinoderms.
Leptochariidae - (Barbeled houndsharks)
Small, common, inshore tropical shark of the West African continental shelf, found near the bottom at depths of 10 to 75 m. Light grey or grey-brown shark with horizontally oval eyes and internal nictitating eyelids. Nostrils with slender barbels. Two small, spineless, equal-sized dorsal fins and an anal fin, the first dorsal fin on the back between pectoral and pelvic fins. Viviparous, with a unique spherical or globular placenta. Feeds on small bottom and littoral organisms with a preference for crustaceans. Other food items: sardines, anchovies, snake eels, blennies, gobies, flatfish, crabs, shrimps, lobsters, octopi and sponges.
Pentanchidae - (Deepwater catsharks)
Previously in Scyliorhinidae. Identification Mostly small (less than 80cm long; some may mature at about 30cm, a few reach about 90cm); elongated body; two small, spineless dorsal fins (first dorsal base over or behind pelvic bases), and an anal fin. Externally, they are similar to the catsharks (Scyliorhinidae) but are separated from them by the structure of the cranium (skull, or brain case). The deepsea catsharks (Pentanchidae) do not have an internal ‘crest’ over the orbits of their eyes, whereas the catsharks (Scyliorhinidae) do. The crest, if present, can usually be felt by running your fingers over the eye orbits. Unfortunately, the members of some genera of deepsea catsharks (including the largest genus, demon catsharks, Apristurus) are very difficult to tell apart, even for experts. See below. Biology Mostly oviparous (egg-laying) species, but a few are viviparous and give birth to live young. Eggcases are thick and may or may not have corner tendrils, which are used to attach to the seafloor or invertebrate structures, such as gorgonian corals. Hatching may take up to two or three years, depending on the species. Although no deepsea catsharks are known to make long-distance migrations, several species move vertically hundreds of metres off the bottom into midwater to feed. The newborns of some species inhabit midwater early in life. The deepsea catsharks feed on small bony fishes, cephalopods, crustaceans, and other invertebrates (Ref. 125614)
Proscylliidae - (Finback catsharks)
Small (< 1.2 m) deepwater sharks (50-713 m) with a disjunct distribution in tropical to warm temperate waters of the western North Atlantic and Indo-West Pacific. Elongate, catlike eyes with nictitating eyelids. Small cuspidate teeth. Two small, spineless dorsal fins and anal fin. The first dorsal base well ahead of pelvic bases. Most species are ovoviviparous. The food of these harmless sharks consists of small fishes and invertebrates.
Pseudotriakidae - (False catsharks)
Big deep-water bottom-dwelling shark of the continental and insular slopes from 200 to 1500 m. Found in all oceans from Madagascar to Taiwan and Hawaii, and to Iceland. A large, bulky, dark-brown, soft-bodied shark with elongated, catlike eyes and nictitating eyelids, large spiracles, a huge, wide, angular mouth that reaches behind eyes, very short labial furrows, numerous small cuspidate teeth in 200 or more rows in each jaw. Two large spineless dorsal fins and an anal fin, the first dorsal fin being low, long and keel-like. Caudal fin with a strong ventral lobe. Ovoviviparous, with litters of 2 to possibly 4 young. Probably feeds on a variety of deepwater bony fishes, elasmobranchs and invertebrates.
Distribution: temperate and tropical seas, temperate and tropical latitudes of the Indian, Atlantic and Pacific oceans Habitat: shallow and deep water on continental and insular shelves and slopes (Ref. 119368); between depths of 0 to 2200 m (Ref. 106604). Usually elongated, catlike eyes with nictitating eyelids. Lower eyelid usually with longitudinal fold. Gill openings 5, the fifth over origin of pectoral fin. Two small, spineless dorsal fins. One of the largest family of sharks, occurring from the intertidal zone to the edges of the continental and insular shelves and down the slopes to depths greater than 2000 m. Spawns large eggs in tough egg-cases with tendrils. Some species are ovoviviparous. Feed mainly on invertebrates and small fishes. Maximum size: 24 to 162 cm TL (Ref. 119368)
Sphyrnidae - (Hammerhead, bonnethead, or scoophead sharks)
Marine, coastal; occasionally in brackish water. Distribution: global (chiefly warm waters). Head laterally expanded, with eyes and nasal openings much wider set than in other sharks. The blades presumably server to increase the sharks' sensory capabilities. No spiracle. A maximum length of 4.5 m was reported for Sphyrna tudes. They feed on a wide variety of bony fish, elasmobranchs, cephalopods, crustaceans, and other prey. Young born fully developed. Potentially dangerous.
Small to moderate-sized sharks with horizontally oval eyes, nictitating eyelids, anterior nasal flaps, two large-sized, spineless dorsal fins and an anal fin, the first dorsal base well ahead of pelvic bases. Species found in all warm and temperate coastal seas. They feed primarily on bottom and midwater invertebrates and bony fishes.
Note: Families with unknown counts of dorsal or anal spines are also included