Brown catshark

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Brown catshark
Brown catshark, Apristurus brunneus.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Superorder: Selachimorpha
Order: Carcharhiniformes
Family: Scyliorhinidae
Genus: Apristurus
Species:
A. brunneus
Binomial name
Apristurus brunneus
Apristurus brunneus distmap.png

The brown catshark (Apristurus brunneus) 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. [2]

Contents

Description

Brown catsharks have long, slender bodies with broad, bell-shaped snouts. They are dark brown with light-colored markings on the posterior margins of their fins. Their bodies are soft and flabby, with a weak skin that can easily be harmed. Brown catsharks' two dorsal fins are the same size and do not have spines. The first dorsal fin originates to the front of the pelvic fin and the second dorsal fin is located in front of the anal fin's insertion. They typically reach a maximum size of 68 cm in total length, but they average between 30 and 60 cm.

Behavior

Very little is known about the behavior of brown catsharks; they are believed to be solitary, nocturnal creatures. They are thought to be migratory, but most of the year near the edge of the continental shelf.

Communication specific to brown catsharks is unknown. However, as with most other sharks, including other members of the family Scyliorhinidae, they are believed to have a well-developed sense of smell, and are electroreceptive, which allows them to detect electricity emitted by other animals, and may also allow them to detect magnetic fields, which aides in navigation.

Food habits and predation

Brown catsharks feed on many bottom-dwelling species, including small shrimp, euphausiids, squid, and small fish. It is unknown whether brown catsharks are important predators within their ecosystem.

Reproduction

Reproduction in brown catsharks is oviparous, with a single egg at a time per oviduct. Egg cases are usually about 5 cm long and 2.5 cm wide. The egg cases are transparent and have long tendrils that are probably used to attach them to hard structures. The incubation period is possibly a year. In Canadian waters, females carry egg cases from February to August; however, the carrying time for warmer waters is unknown. [1]

Conservation status and economic impact

Brown catsharks are not listed as endangered on the IUCN Red List or the CITES list. They are not known to be a vulnerable or threatened species. They are, however, listed on the IUCN list as needing to be reclassified. The only known negative impact that brown catsharks have on humans is the frequent bycatch of deep-water fishing trawlers, which while not economically significant, can cause damage to nets, as well as time lost in removing the bycatch from the viable catch. [1]

Related Research Articles

Catshark Family of fishes

Catsharks are ground sharks of the family Scyliorhinidae. They are one of the largest families of sharks with around 160 species placed in 17 genera. 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.

Redspotted catshark Species of shark

The redspotted catshark, also known as the Chilean catshark, is a species of catshark commonly found in the coastal waters of the southeastern Pacific, from central Peru to southern Chile. They are typically found in the rocky sublittoral areas at the edge of the continental shelf, in waters down to 100 m in depth. They spend the spring, summer, and fall in rocky subtidal areas, but winter in deeper offshore waters due to the strong currents at that time of year.

<i>Galeus</i> Genus of sharks

Galeus is a genus of catshark, belonging to the family Scyliorhinidae, commonly known as sawtail catsharks in reference to a distinctive saw-toothed crest of enlarged dermal denticles, found along the upper edges of their caudal fins. They are found in the Atlantic, the western and central Pacific, and the Gulf of California, inhabiting deep waters at or close to the sea floor. Members of this genus are rather small, slim sharks with firm bodies and thick, rough skin. Their heads are usually fairly long and pointed, and have large mouths with well-developed furrows at the corners. They have large pectoral and anal fins, and two similar dorsal fins placed well back. Many species are ornately patterned with dark saddles and/or blotches. Sawtail catsharks feed on various invertebrates and fishes, and may be either egg-laying or live-bearing. These harmless sharks are sometimes caught as bycatch but are of minimal commercial value.

Lollipop catshark Species of shark

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.

Australian swellshark Species of shark

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.

Izak catshark Species of catshark, of the family Scyliorhinidae

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.

Quagga catshark Species of fish

The quagga catshark is a species of catshark, belonging to the family Scyliorhinidae. A small, slim-bodied shark reaching 37 cm (15 in) in length, it has a distinctive color pattern of narrow, dark brown vertical bars, which resemble those of the quagga. Its head is short and flattened, with a pointed snout tip that is not upturned.

Tiger catshark Species of shark

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.

Blackspotted catshark Species of shark

The blackspotted catshark is a catshark of the family Scyliorhinidae. It is found in the waters off the coasts of Japan, Korea, China, and Taiwan between latitudes 39° N and 20° N, at the depths of between 80 and 100 m. It can grow up to 49 cm in length.

Speckled catshark Species of shark

The speckled catshark is a catshark of the family Scyliorhinidae. It is found in the Gulf of Aden and off the coast of Somalia. It occurs at depths of between 37 and 250 m. Its length is up to 48 cm.

West African catshark Species of shark

The West African catshark is a catshark of the family Scyliorhinidae. It is found in the eastern Atlantic between latitudes 20° N and 17° S, at depths between 45 and 500 m. It can grow up to a length of 80 centimetres (31 in). At one time, the West African catshark was considered to be a subspecies of the nursehound, Scyliorhinus stellaris, but is now considered to be a separate species. The reproduction of this catshark is oviparous.

Freckled catshark Species of shark

The freckled catshark is a catshark of the family Scyliorhinidae. It is found on the continental shelf and upper slope from the western Atlantic from western Venezuela, Suriname, Brazil, and Uruguay, between latitudes 11° N and 32° S. However, specimens from the northern part of this range probably refer to other species.

Blackmouth catshark Species of shark

The blackmouth catshark is a species of catshark, and part of the family Scyliorhinidae, common in the northeastern Atlantic Ocean from Iceland to Senegal, including the Mediterranean Sea. It is typically found over the continental slope at depths of 150–1,400 m (490–4,590 ft), on or near muddy bottoms. The youngest sharks generally inhabit shallower water than the older juveniles and adults. This slim-bodied species is characterized by the black interior of its mouth, a marbled pattern of pale-edged brownish saddles or blotches along its back and tail, and a prominent saw-toothed crest of enlarged dermal denticles along the upper edge of its caudal fin. It reaches lengths of 50–79 cm (20–31 in), with sharks in the Atlantic growing larger than those in the Mediterranean.

Australian sawtail catshark Species of shark

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).

Mouse catshark Species of shark

The mouse catshark is a species of catshark and part of the family Scyliorhinidae. It is common in the northeastern Atlantic Ocean from Iceland to Western Sahara. There is much taxonomic confusion regarding this species in Icelandic waters, where it may be confounded with another species of Galeus or Apristurus. Probably not exceeding 49 cm (19 in) long, the mouse catshark has a uniformly brown body and is characterized by large, rounded pelvic fins and crests of enlarged dermal denticles along both the dorsal and ventral caudal fin margins. In addition, in adult males the inner margins of the pelvic fins are merged into an "apron".

African sawtail catshark Species of shark

The African sawtail catshark is a species of catshark, part of the family Scyliorhinidae. Demersal in nature, it is found at depths of 160–720 m (520–2,360 ft) off the western African coast from Morocco to South Africa. This slender species has a rather long, pointed snout, a series of dark saddles along the back and tail, and a prominent crest of enlarged dermal denticles along the upper edge of the caudal fin. Its maximum known length is 46 cm (18 in).

Blacktip sawtail catshark Species of shark

The blacktip sawtail catshark is a species of catshark, and part of the family Scyliorhinidae, found off the coasts of Taiwan and the Philippines. It is demersal in nature and occurs deeper than 60 m (200 ft). Growing up to 46 cm (18 in) long, this slim-bodied species is characterized by its plain brownish dorsal coloration with dark tips on the dorsal and caudal fins, and a prominent crest of enlarged dermal denticles on the upper edge of the caudal fin. It is oviparous, with females producing encapsulated eggs two at a time year-round. The blacktip sawtail catshark is caught incidentally in bottom trawls and used for fishmeal in Taiwan.

White ghost catshark Species of shark

The white ghost catshark is a shark of the catshark family Scyliorhinidae found in deep water in the northeast Atlantic between latitudes 57°N and 58°N. A deep-water catshark known from the eastern North Atlantic from depths of 1,014 to 1,800 m, it is known from only a limited number of specimens. It reaches a maximum of 54 cm or 1.7 ft total length which is a medium size for the Apristurus genus.

Spongehead catshark Species of shark

The spongehead catshark is a rare species of deep-sea catshark, family Scyliorhinidae. This species was only known from two specimens taken in the Pacific Ocean: an adult from near Bird Island, Hawaii, and a juvenile from the Banda Sea off Sulawesi. They are found on or near the bottoms of insular continental slopes, at depths of 570 to 1,480 meters. In 2002, the spongehead catshark was seen alive in its natural habitat for the first time, from the submersible Pisces IV at a depth of about a kilometer, on the Northampton Seamount off the northwestern Hawaiian Islands.

Longhead catshark Species of shark

The longhead catshark or smoothbelly catshark is a species of catshark, family Scyliorhinidae, with a patchy distribution in the Indo-Pacific from Mozambique to southern Japan to northern Australia. It is found in water between 500 and 1,140 m deep. This species grows to 59 cm (23 in) long and is characterized by its extremely long and narrow snout, short abdomen, and long anal and caudal fins. In addition, a large area of the anterior ventral portion of its body lacks dermal denticles. The longhead catshark is oviparous and the only known cartilaginous fish that is normally hermaphroditic, with the majority of individuals having both the functional reproductive organs of one sex and the undeveloped reproductive organs of the opposite sex.

References

  1. 1 2 3 Huveneers, C., Duffy, C.A.J., Cordova, J. & Ebert, D.A. (2015). Apristurus brunneus. The IUCN Red List of Threatened Species doi:10.2305/IUCN.UK.2015-4.RLTS.T44209A80671448.en
  2. Castro, Jose; Peebles, Diane (2011-08-11). The Sharks of North America. ISBN   9780195392944.

Sources