The bullhead sharks are a small order of modern sharks (Neoselachii). The nine living species are placed in a single genus, Heterodontus, in the family Heterodontidae. All are relatively small, with the largest species reaching just 1.65 metres (5.5 ft) in maximum length. They are bottom feeders in tropical and subtropical waters.
The brown catshark is commonly found in the Pacific Ocean, ranging from the northern Pacific waters off the coast of British Columbia and south to the Baja California peninsula in Mexico. They may live as far south as Ecuador and Peru. Brown catsharks are deep-water sharks that live on the outer continental shelf and the upper slope. They have been known to live at depths ranging from 30 to 650 m and live on the bottom, usually in muddy or sandy areas. The brown catshark, when originally described, was called Catulus brunneus.
The horn shark is a species of bullhead shark, in the family Heterodontidae. It is endemic to the coastal waters off the western coast of North America, from California to the Gulf of California. Young sharks are segregated spatially from the adults, with the former preferring deeper sandy flats and the latter preferring shallower rocky reefs or algal beds. A small species typically measuring 1 m (3.3 ft) in length, the horn shark can be recognized by a short, blunt head with ridges over its eyes, two high dorsal fins with large spines, and a brown or gray coloration with many small dark spots.
The Port Jackson shark is a nocturnal, oviparous type of bullhead shark of the family Heterodontidae, found in the coastal region of southern Australia, including the waters off Port Jackson. It has a large, blunt head with prominent forehead ridges and dark brown harness-like markings on a lighter grey-brown body, and can grow up to 1.65 metres (5.5 ft) long. They are the largest in the genus Heterodontus.
The smalltail shark is a species of requiem shark, and part of the family Carcharhinidae. It is found in the western Atlantic Ocean, from the northern Gulf of Mexico to southern Brazil. It inhabits shallow waters close to shore, particularly over muddy bottoms around estuaries. It tends to swim low in the water column and forms large aggregations segregated by sex. A slim species generally not exceeding 1.1 m (3.6 ft) in length, the smalltail shark has a rather long, pointed snout, a broad, triangular first dorsal fin, and a second dorsal fin that originates over the midpoint of the anal fin base. It is plain gray in color, without prominent markings on its fins.
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 crested bullhead shark is an uncommon species of bullhead shark, in the family Heterodontidae. It lives off the coast of eastern Australia from the coast to a depth of 93 m (305 ft). This shark can be distinguished from other members of its family by the large size of the ridges above its eyes and by its color pattern of large dark blotches. It typically attains a length of 1.2 m (3.9 ft).
The Japanese bullhead shark is a species of bullhead shark in the family Heterodontidae found in the northwestern Pacific Ocean off the coasts of Japan, Korea, and China. This benthic shark occurs at depths of 6–37 m (20–121 ft) over rocky bottoms or kelp beds. Measuring up to 1.2 m (3.9 ft) long, it can be identified by its short, blunt head, two high dorsal fins with anterior spines, and pattern of irregularly shaped, vertical brown bands and stripes. The Japanese bullhead shark is a docile, slow-swimming species that feeds mainly on shelled invertebrates and small bony fishes. Reproduction is oviparous, with females laying spiral-flanged eggs in communal "nests". This species is of little interest to fisheries.
The Australian swellshark or draughtboard shark, is a species of catshark, and part of the family Scyliorhinidae, endemic to southern Australia. This bottom-dwelling species can be found on the continental shelf down to a depth of 220 m (720 ft). Usually measuring 1 m long, it is a stout-bodied, broad-headed shark with a short tail and a first dorsal fin much larger than the second. It can be identified by its variegated dorsal coloration of brown or grey patches and numerous spots.
The pyjama shark or striped catshark is a species of catshark, and part of the family Scyliorhinidae, endemic to the coastal waters of South Africa. This abundant, bottom-dwelling species can be found from the intertidal zone to a depth of around 100 m (330 ft), particularly over rocky reefs and kelp beds. With a series of thick, parallel, dark stripes running along its stout body, the pyjama shark has an unmistakable appearance. It is additionally characterized by a short head and snout with a pair of slender barbels that do not reach the mouth, and two dorsal fins that are placed far back on the body. It can grow up to a length of 1.1 m (3.6 ft) long.
The Izak catshark or simply Izak is a species of catshark, belonging to the family Scyliorhinidae, common off the coasts of South Africa and southern Namibia. It typically inhabits the outer continental shelf at depths of 100–300 m (330–980 ft), with the males found deeper than the females and juveniles. The Izak catshark has a short, wide, flattened head and a robust body tapering to a long, slender tail. It can be identified by its ornate color pattern of dark brown spots or reticulations and blotches on a light yellowish background, as well as by the enlarged dermal denticles over its pectoral fins and along its dorsal midline from the snout to the second dorsal fin. This species reaches 69 cm (27 in) in length, with the males larger than females.
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 smooth lanternshark or slender lanternshark is a species of dogfish shark in the family Etmopteridae, found widely in the Atlantic and Pacific Oceans. It inhabits benthic environments at a depth of 274–1,000 m (899–3,281 ft), and pelagic environments at a depth of 0–708 m (0–2,323 ft). The smooth lanternshark forms a species group with the larger blurred lanternshark, both of which are distinguished from other members of their family by small, irregularly arranged dermal denticles with a truncated shape. This species has a slender, dark brown body with an indistinct black band on the sides over the pelvic fins, and reaches 50 cm (20 in) in length. This slow-growing, ovoviviparous shark feeds on smaller squid, fishes, and fish eggs. Smooth lanternsharks are often caught as bycatch in eastern Atlantic and Japanese commercial fisheries. The International Union for Conservation of Nature (IUCN) has evaluated this species as of Least Concern because of its wide distribution and limited threats.
The brown shyshark or plain happy is a species of catshark, part of the family Scyliorhinidae. It is endemic to the shallow, coastal waters of South Africa from west of Cape Agulhas to KwaZulu-Natal. This benthic species is usually found over sandy or rocky bottoms. Measuring up to 73 cm (29 in) long, the brown shyshark is stoutly built, with a broad, flattened head and rounded snout. Unlike other shysharks, the brown shyshark has a plain brown color, though some individuals have faint "saddle" markings or light or dark spots. When threatened, this shark curls into a circle with its tail over its eyes, which is the origin of the name "shyshark". It feeds on bony fishes and lobsters, and is oviparous with females laying pairs of egg capsules. The International Union for Conservation of Nature (IUCN) has assessed this harmless species as Vulnerable. It is of no commercial or recreational interest, but its limited distribution makes its entire population vulnerable to increases in fishing pressure or habitat degradation.
The tiger catshark is a species of catshark, belonging to the family Scyliorhinidae. It is found over sandy areas and near reef peripheries off South Africa and perhaps Mozambique, from close to shore to usually no deeper than 100 m (330 ft). Reaching a length of 50 cm (20 in), this small, slim shark has a broad, flattened head with an upturned snout tip. It can additionally be identified by its dorsal colour pattern of ten dark brown saddles on a yellowish brown background.
The cloudy catshark is a common species of catshark, belonging to the family Scyliorhinidae. It is a bottom-dweller that inhabits rocky reefs in the northwestern Pacific Ocean, from the shore to a depth of 320 m (1,050 ft). Growing up to 50 cm (20 in) long, this small, slim shark has a narrow head with a short blunt snout, no grooves between the nostrils and mouth, and furrows on the lower but not the upper jaw. It is also characterized by extremely rough skin and coloration consisting of a series of dark brown saddles along its back and tail, along with various darker and lighter spots in larger individuals.
The Australian sawtail catshark is a common species of catshark, and part of the family Scyliorhinidae, endemic to southern Australian waters. It is found on or near the bottom of the outer continental shelf and upper continental slope, at depths of 85 to 823 m. This slim-bodied species is characterized by crests of enlarged dermal denticles along both the dorsal and ventral edges of its caudal fin and caudal peduncle, along with a color pattern of broad, dark saddles outlined in white. It can grow to 61 cm (24 in) in length. The Australian sawtail catshark feeds mainly on fishes, crustaceans, and cephalopods. Females are oviparous and lay eggs enclosed by capsules. This species is often caught incidentally by commercial bottom trawl fisheries, but is not significantly threatened by fishing activity. Thus, it has been assessed as of Least Concern by the International Union for Conservation of Nature (IUCN).
The green lanternshark is a species of dogfish shark in the family Etmopteridae, found in the western central Atlantic Ocean. This species usually occurs on the upper continental slope below a depth of 350 m (1,150 ft). Reaching 26 cm (10 in) in length, the green lanternshark has a slender body with a long, thin tail and low, conical dermal denticles on its flanks. It is dark brown or gray with ventral black coloration, which contain light-emitting photophores that may serve a cryptic and/or social function. Green lanternsharks are thought to be gregarious and may attack their prey, squid and octopus often larger than themselves, in packs. Reproduction is aplacental viviparous, with females giving birth to litters of one to three young. This relatively common shark is an occasional, valueless bycatch of commercial fisheries; currently it does not appear to be significantly threatened by human activities.
The Arabian carpetshark is a species of carpet shark in the family Hemiscylliidae, inhabiting coral reefs and other shallow coastal habitats from the Persian Gulf to India. Reaching 78 cm (31 in) long, this shark is characterized by a slender, plain brown body, and by two dorsal fins with straight trailing margins and the second smaller but longer-based than the first. The Arabian carpetshark feeds on bony fishes and invertebrates. Reproduction is oviparous with an annual cycle; females deposit egg capsules four at a time and the young hatch after 70–80 days. This small shark is often captured as bycatch but rarely used by humans. It has been assessed as Near Threatened by the International Union for Conservation of Nature (IUCN), as there is increasing fishing pressure and habitat degradation within its range. It does well in aquariums and has been bred in captivity.
The inshore lizardfish is a member of the family Synodontidae found in the western Atlantic.
