The bramble shark (''Echinorhinus brucus'') is one of the two

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Echinorhinidae ''Echinorhinus'' is the only extant genus in the family Echinorhinidae. Taxonomy Echinorhinidae are traditionally classified in the order Squaliformes, together with kitefin and gulper sharks.Compagno, 2005. "Sharks of the World". However, a ...

. Aside from the eastern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

, it is found in

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

and

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

waters worldwide. This rarely encountered shark swims close to the bottom of the seafloor, typically at depths of , though it may enter much shallower water. The bramble shark has a stout body with two small

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

s positioned far back and no

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

. It can be readily identified by the large, thornlike

dermal denticle A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scale (zoology), scales, which can also provide effective Underwater camouflage, camouflage through the us ...

s scattered over its body, some of which may be fused together. It is purplish brown or black in color and grows up to long. The diet of the bramble shark includes smaller sharks,

bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...

es, and

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

s, which this slow-moving species may capture via suction. It is

aplacental viviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that rema ...

, with females producing litters of 15–52 pups. Harmless to humans, it is an occasional

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

commercial Commercial may refer to: * (adjective for) commerce, a system of voluntary exchange of products and services ** (adjective for) trade, the trading of something of economic value such as goods, services, information or money * a dose of advertising ...

and recreational fishers, and may be used for

fishmeal Fish meal (sometimes spelled fishmeal) is a commercial product made from whole wild-caught fish, bycatch, and fish by-products to feed farm animals, such as pigs, poultry, and farmed fish.R. D. Miles and F. A. Chapman.FA122: The Benefits of Fish ...

and liver oil. Its population has declined substantially in the northeastern Atlantic since the 18th and 19th centuries, likely because of

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing Fish stocks, fish stock), resu ...

Taxonomy

The original description of the bramble shark was authored by French

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

Pierre Joseph Bonnaterre Abbé Pierre Joseph Bonnaterre (1752, Aveyron – 20 September 1804, Saint-Geniez-d'Olt) was a French zoology, zoologist who contributed sections on cetaceans, mammals, birds, reptiles, amphibians, fish, and insects to the ''Tableau encyclopéd ...

in the 1788 '' Tableau encyclopédique et méthodique des trois regnes de la nature''. He named it ''Squalus brucus'', from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''brux'' or ''bruchios'' meaning "from the depths of the sea". The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

has since been lost. In 1816,

Henri de Blainville Henri Marie Ducrotay de Blainville (; 12 September 1777 – 1 May 1850) was a French zoologist and anatomist. Life Blainville was born at Arques, near Dieppe. As a young man, he went to Paris to study art, but ultimately devoted himself to natur ...

created the genus ''Echinorhinus'' for this species. Until the 1960s, specimens of the

prickly shark The prickly shark (''Echinorhinus cookei'') is one of the two species of sharks in the family Echinorhinidae (the other one is the bramble shark), found in the Pacific Ocean over continental and insular shelves and slopes, and in submarine canyon ...

(''E. cookei'') caught in the Pacific Ocean were misidentified as bramble sharks. Other common names for this species are spinous shark and spiny shark.

Description

The bramble shark has a thick, cylindrical body and a somewhat flattened head. The snout is blunt and shorter than the width of the mouth, with widely spaced nostrils that are preceded by small flaps of skin. The eyes lack

nictitating membrane The nictitating membrane (from Latin '' nictare'', to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. Most ...

s; the tiny spiracles are located well behind them. The wide, curved mouth bears very short furrows at the corners. There are 20–26 upper and 22–26 lower tooth rows; each tooth is knife-like, with a single main cusp and up to three cusplets on either side. There are five pairs of

gill slit Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In c ...

s, with the fifth pair the longest. The

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s are short and angular, while the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s are long and relatively large. The

s are small, with the first dorsal fin origin lying behind the pelvic fin origins. There is no

. The

caudal peduncle Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

is robust and lacks notches at the

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

origins. The asymmetrical caudal fin has an indistinct lower lobe and an upper lobe without a notch in the trailing margin. The skin is covered by a layer of foul-smelling

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

several millimeters thick. The

s are scattered irregularly over the body and vary greatly in size, measuring up to across. Each denticle is thornlike in shape, with ridges radiating out from the central point over the base. As many as ten denticles may be fused together to form multi-pointed plates. The underside of the snout and the area around the mouth is densely covered by small denticles in sharks under long; these denticles become larger and sparser in larger sharks. This species is brown to black above, with a metallic purplish hue, and paler below; some individuals have red or black blotches. There is a report of one specimen that had a greenish glow when freshly caught. The bramble shark may reach in length. The maximum weight on record is for a long female.

Distribution and habitat

Records of the bramble shark are fairly rare and originate from widely scattered locations in

and

waters worldwide, save for the eastern

. Most have come from the eastern

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

and western

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

s, where its range extends from the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

and the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

to southern

Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...

, including the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

. In the western Atlantic, this species is represented by a handful of specimens from

Massachusetts Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode ...

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

Tobago Tobago, officially the Ward of Tobago, is an List of islands of Trinidad and Tobago, island and Regions and municipalities of Trinidad and Tobago, ward within the Republic of Trinidad and Tobago. It is located northeast of the larger islan ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, and

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. In the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, it is known from

Oman Oman, officially the Sultanate of Oman, is a country located on the southeastern coast of the Arabian Peninsula in West Asia and the Middle East. It shares land borders with Saudi Arabia, the United Arab Emirates, and Yemen. Oman’s coastline ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

, southern

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, southern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

, and possibly

Kiribati Kiribati, officially the Republic of Kiribati, is an island country in the Micronesia subregion of Oceania in the central Pacific Ocean. Its permanent population is over 119,000 as of the 2020 census, and more than half live on Tarawa. The st ...

. Found close to the

sea floor The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as seabeds. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

, the bramble shark most commonly inhabits continental and insular shelves and

slopes In mathematics, the slope or gradient of a Line (mathematics), line is a number that describes the direction (geometry), direction of the line on a plane (geometry), plane. Often denoted by the letter ''m'', slope is calculated as the ratio of t ...

at depths of . However, it has been reported from as shallow as , in areas with

upwelling Upwelling is an physical oceanography, oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted sur ...

s of cold water, and from as deep as . At least in European waters, this species may

migrate Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

into shallower depths of during the summer.

Biology and ecology

Sluggish in nature, the bramble shark feeds on smaller sharks (including the

spiny dogfish The spiny dogfish (''Squalus acanthias''), spurdog, mud shark, or piked dogfish is one of the best known species of the Squalidae (dogfish) family of sharks, which is part of the Squaliformes order. While these common names may apply to several ...

, ''Squalus acanthias''),

es (including ling,

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

es, and

lizardfish The Synodontidae or lizardfishes(or typical lizardfish to distinguish them from the Bathysauridae and Pseudotrichonotidae) are benthic (bottom-dwelling) marine and estuarine bony fishes that belong to the aulopiform fish order, a diverse grou ...

es), and

s. The large size of its

pharynx The pharynx (: pharynges) is the part of the throat behind the human mouth, mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates ...

, relative to its mouth, suggests that it may capture prey by suction. This species is

; females have two functional

ovaries The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are endocr ...

and two

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

es. Recorded litter sizes have ranged from 15 to 52, and newly born pups have been estimated to measure long. The dermal denticles in near-term

embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...

s are underdeveloped, appearing as minute spines located within open pits in the skin. The size at

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. ''Puberty'' is the biological process of sexual maturation, while ''adulthood'', the condition of being socially recognized ...

is uncertain; the smallest known mature males and females are and long respectively.

Human interactions

The bramble shark is not known to pose a danger to humans. It is caught incidentally by

commercial fisheries Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often p ...

bottom trawl Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and Demersal zone, demersal trawling. Benthic tra ...

s and on fishing line, as well as by sport anglers. In the eastern Atlantic, this species is processed into

but has little commercial significance. The Bramble Shark's liver oil was found to be rich in squalene, fatty acids, and vitamins A, D, and K actively making it a dietary supplement. Its liver oil is highly valued in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

medicine Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...

, whereas in India the oil is considered poor and is used to coat

canoe A canoe is a lightweight, narrow watercraft, water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using paddles. In British English, the term ' ...

s to discourage

woodboring beetle The term woodboring beetle encompasses many species and families of beetles whose larval or adult forms eat and destroy wood (i.e., are xylophagous). In the woodworking industry, larval stages of some are sometimes referred to as woodworms. The ...

s. Historical accounts suggest that bramble shark numbers in the northeastern Atlantic have fallen markedly since the 18th and 19th centuries, such as that it is now extremely rare off northern Europe and in the Mediterranean. This decline has been attributed to fishing pressure, to which this species may be highly vulnerable as large, deep-sea sharks generally have slow growth rates and long lifespans. Regarding the species as a whole, the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

(IUCN) assesses it as Endangered. In June 2018 the New Zealand

Department of Conservation Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

classified the bramble shark as "At Risk – Naturally Uncommon" with the qualifiers "Data Poor" and "Secure Overseas" under the

New Zealand Threat Classification System The New Zealand Threat Classification System is used by the Department of Conservation to assess conservation priorities of species in New Zealand. The system was developed because the IUCN Red List, a similar conservation status system, had s ...

References

External links

"''Echinorhinus brucus'' Bramble shark" at FishBase

{{Taxonbar, from=Q1297550

bramble shark The bramble shark (''Echinorhinus brucus'') is one of the two species of sharks in the family Echinorhinidae. Aside from the eastern Pacific Ocean, it is found in tropical and temperate waters worldwide. This rarely encountered shark swims close ...

Fish of Japan Fauna of Kiribati Fish of the Atlantic Ocean Fish of the Mediterranean Sea Fish of Europe Marine fish of New Zealand Fauna of South India Gulf of Oman Marine fish of Southern Africa Marine fish of Southern Australia Taxa named by Pierre Joseph Bonnaterre