The copper shark (''Carcharhinus brachyurus''), bronze whaler, or narrowtooth shark, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

requiem shark Requiem sharks are sharks of the family Carcharhinidae in the order Carcharhiniformes. They are migratory, live-bearing sharks of warm seas (sometimes of brackish or fresh water) and include such species as the tiger shark, bull shark, le ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Carcharhinidae, and the only member of its genus found mostly at

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

latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...

s. It is distributed in a number of separate populations in the northeastern and southwestern

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

, off

southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...

, in the northwestern and eastern

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

, and around

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

, with scattered reports from

equator The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...

ial regions. This species can be found from

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

s and

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

, to shallow bays and harbors, to offshore waters deep or more. Females are found apart from males for most of the year, and conduct seasonal migrations. A large species reaching long, the copper shark is difficult to distinguish from other large requiem sharks. It is characterized by its narrow, hook-shaped upper teeth, lack of a prominent ridge between the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

s, and plain bronze coloration. Feeding mainly on

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

bony fish Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...

es, and other

cartilaginous fish Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue ...

es, the copper shark is a fast-swimming

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

that has been known to hunt in large groups, using their numbers to their advantage; however for most of the time they remain solitary. Off

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

, this species associates closely with the annual

sardine run The KwaZulu-Natal sardine run of southern Africa occurs from May through July when billions of sardines – or more specifically the Southern African pilchard ''Sardinops sagax'' – spawn in the cool waters of the Agulhas Bank and move northwar ...

, involving millions of

southern African pilchard ''Sardinops'' is a monotypic genus of sardines of the family Clupeidae. The only member of the genus is ''Sardinops sagax''. It is found in the Indo-Pacific and East Pacific oceans. Its length is up to . It has numerous common or vernacular name ...

(''Sardinops sagax''). Like other requiem sharks, it is

viviparous Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the m ...

, with the developing

embryo An embryo is an initial stage of development of 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 spe ...

s mainly nourished through a

placenta The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mater ...

l connection formed from the depleted

yolk sac The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is far ...

. Females bear litters of 7 to 24 pups every other year in coastal nursery areas, after a

gestation period In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus, and ends once it ...

of 12 or perhaps as long as 21 months. It is extremely slow-growing, with males and females not reaching maturity until 13–19 and 19–20 years of age respectively. This species is valued by

commercial Commercial may refer to: * a dose of advertising conveyed through media (such as - for example - radio or television) ** Radio advertisement ** Television advertisement * (adjective for:) commerce, a system of voluntary exchange of products and s ...

and recreational fisheries throughout its range, and utilized as food. The species population size is unknown, but the IUCN's Red List assesses the species as vulnerable because it is very susceptible to population depletion due to its low growth and reproductive rates and because its numbers are believed to have declined in some areas. Copper sharks only attack humans infrequently, but the species places tenth in the number of unprovoked attacks on people.

Taxonomy

Because of its very patchy range, the copper shark has been scientifically described several times from different locales. The earliest valid description is presently considered to be British

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

Albert Günther Albert Karl Ludwig Gotthilf Günther FRS, also Albert Charles Lewis Gotthilf Günther (3 October 1830 – 1 February 1914), was a German-born British zoologist, ichthyologist, and herpetologist. Günther is ranked the second-most productive re ...

's account of ''Carcharias brachyurus'' in the 1870 eighth volume of ''Catalogue of the fishes in the British Museum''. The earliest name was once thought to be

Auguste Duméril Auguste Henri André Duméril (30 November 1812 – 12 November 1870) was a French zoologist. His father, André Marie Constant Duméril (1774-1860), was also a zoologist. In 1869 he was elected as a member of the Académie des sciences. Duméril ...

's 1865 ''Carcharias remotus'', until it was found that the

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

associated with that name is actually a

blacknose shark The blacknose shark (''Carcharhinus acronotus'') is a species of requiem shark, belonging to the family Carcharhinidae, common in the tropical and subtropical waters of the western Atlantic Ocean. This species generally inhabits coastal seagrass, ...

(''C. acronotus''). Thus, this shark was often referred to as ''C. remotus'' in older literature. An even earlier name,

Richard Owen Sir Richard Owen (20 July 1804 – 18 December 1892) was an English biologist, comparative anatomist and paleontologist. Owen is generally considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils. Owe ...

's 1853 ''Galeolamna greyi'', is of questionable taxonomic status as it was based solely on a set of now-destroyed jaws that may or may not have belonged to a copper shark. Modern authors have assigned this species to the genus ''Carcharhinus''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''brachyurus'' is derived from the

Greek Greek may refer to: Greece 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 ...

''brachys'' ("short") and ''oura'' ("tail"). The name "whaler" originated in the 19th century, applied by the crews of whaling vessels in the Pacific who saw large sharks of various species congregating around harpooned whale carcasses. This species may also be referred to as black-tipped whaler, cocktail shark or cocktail whaler, or New Zealand whaler, as well as by the shortened "bronze", "bronzie", or "cocktail". Günther originally referred to four

syntype In biological nomenclature, a syntype is any one of two or more biological types that is listed in a description of a taxon where no holotype was designated. Precise definitions of this and related terms for types have been established as part of ...

s: a stuffed specimen from

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

and another from

, which have since been lost, and two

fetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal deve ...

es from

that were later discovered to be

bull shark The bull shark (''Carcharhinus leucas''), also known as the Zambezi shark (informally zambi) in Africa and Lake Nicaragua shark in Nicaragua, is a species of requiem shark commonly found worldwide in warm, shallow waters along coasts and in riv ...

s (''C. leucas''). In the interests of taxonomic stability, in 1982

Jack Garrick John Andrew Frank "Jack" Garrick (1928 – August 30, 2018) was a New Zealand ichthyologist. He specialized in elasmobranchs and published many books and articles about shark and ray biology. In 1982, he published a thorough taxonomy on sharks of ...

designated a long female caught off

Whanganui Whanganui (; ), also spelled Wanganui, is a city in the Manawatū-Whanganui region of New Zealand. The city is located on the west coast of the North Island at the mouth of the Whanganui River, New Zealand's longest navigable waterway. Whangan ...

, New Zealand as a new type specimen.

Phylogeny and evolution

The first efforts to determine the evolutionary relationships of the copper shark were based on

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

and returned inconclusive results: in 1982 Jack Garrick placed it by itself as a grouping within ''Carcharhinus'', while in 1988

Leonard Compagno Leonard Joseph Victor Compagno is an international authority on shark taxonomy and the author of many scientific papers and books on the subject, best known of which is his 1984 catalogue of shark species produced for the Food and Agriculture Organi ...

placed it in an informal "transitional group" that also contained the

(''C. acronotus''), the

blacktip reef shark The blacktip reef shark (''Carcharhinus melanopterus'') is a species of requiem shark, in the family Carcharhinidae, which can be easily identified by the prominent black tips on its fins (especially on the first dorsal fin and its caudal fin). ...

(''C. melanopterus''), the

nervous shark The nervous shark (''Carcharhinus cautus'') is a species of requiem shark, and part of the family Carcharhinidae, so named because of its timid behavior in regard to humans. It is common in shallow, coastal waters off northern Australia, Papua N ...

(''C. cautus''), the

silky shark The silky shark (''Carcharhinus falciformis''), also known by numerous names such as blackspot shark, gray whaler shark, olive shark, ridgeback shark, sickle shark, sickle-shaped shark and sickle silk shark, is a species of requiem shark, in the f ...

(''C. falciformis''), and the

night shark The night shark (''Carcharhinus signatus'') is a species of requiem shark, in the family Carcharhinidae, found in the temperate and tropical waters of the Atlantic Ocean. An inhabitant of the outer continental shelf and upper continental slope, ...

(''C. signatus''). Gavin Naylor's 1992

allozyme Alloenzymes (or also called allozymes) are variant forms of an enzyme which differ structurally but not functionally from other allozymes coded for by different alleles at the same locus. These are opposed to isozymes, which are enzymes that perfo ...

study concluded that the closest relative of the copper shark is the

spinner shark The spinner shark (''Carcharhinus brevipinna'') is a species of requiem shark, in the family Carcharhinidae, named for the spinning leaps it makes as a part of its feeding strategy. This species occurs in tropical and warm temperate waters worldw ...

(''C. brevipinna''), but could not resolve their wider relationships with the rest of the genus.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

ized teeth from the copper shark have been recovered from the

Pungo River The Pungo River is a river in eastern North Carolina, United States. It originally began in the Great Dismal Swamp in Washington County, North Carolina; the upper part of the river has since been supplanted by the Pungo River Canal, dug in the 19 ...

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

, dating to the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

(23–5.3 Ma), from

Tuscany Tuscany ( ; it, Toscana ) is a Regions of Italy, region in central Italy with an area of about and a population of about 3.8 million inhabitants. The regional capital is Florence (''Firenze''). Tuscany is known for its landscapes, history, art ...

, dating to the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 and from

Costa Mesa Costa may refer to: Biology * Rib (Latin: ''costa''), in vertebrate anatomy * Costa (botany), the central strand of a plant leaf or thallus * Costa (coral), a stony rib, part of the skeleton of a coral * Costa (entomology), the leading edge of t ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, dating to the

Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of ...

(126,000–12,000 years ago).

Distribution and habitat

The copper shark is the only member of its genus largely found in

rather than

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

waters, in temperatures above . It is widely distributed but as disjunct regional populations with little to no interchange between them. In the Atlantic, this shark occurs from 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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

and the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

, off

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, and off

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

and

(where there may be two separate populations), with infrequent records from

Mauritania Mauritania (; ar, موريتانيا, ', french: Mauritanie; Berber: ''Agawej'' or ''Cengit''; Pulaar: ''Moritani''; Wolof: ''Gànnaar''; Soninke:), officially the Islamic Republic of Mauritania ( ar, الجمهورية الإسلامية ...

, the

Gulf of Guinea The Gulf of Guinea is the northeasternmost part of the tropical Atlantic Ocean from Cape Lopez in Gabon, north and west to Cape Palmas in Liberia. The intersection of the Equator and Prime Meridian (zero degrees latitude and longitude) is in the ...

, and possibly the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

. 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 found from the

East China Sea The East China Sea is an arm of the Western Pacific Ocean, located directly offshore from East China. It covers an area of roughly . The sea’s northern extension between mainland China and the Korean Peninsula is the Yellow Sea, separated b ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

(excluding

Hokkaido is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel. The la ...

) and southern

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

, off southern

(mostly between

Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...

and

Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...

but occasionally further north), and around

but not as far as the

Kermadec Islands The Kermadec Islands ( mi, Rangitāhua) are a subtropical island arc in the South Pacific Ocean northeast of New Zealand's North Island, and a similar distance southwest of Tonga. The islands are part of New Zealand. They are in total are ...

; there are also unconfirmed reports from the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, V ...

and the

Gulf of Thailand The Gulf of Thailand, also known as the Gulf of Siam, is a shallow inlet in the southwestern South China Sea, bounded between the southwestern shores of the Indochinese Peninsula and the northern half of the Malay Peninsula. It is around in l ...

. In the eastern

, it occurs from northern

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, and from

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Point Conception Point Conception (Chumash: ''Humqaq'') is a headland along the Gaviota Coast in southwestern Santa Barbara County, California. It is the point where the Santa Barbara Channel meets the Pacific Ocean, and as the corner between the mostly north-s ...

, including the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja Ca ...

. The copper shark is common off parts of Argentina, South Africa, Australia, and New Zealand, and rare elsewhere; in many areas its range is ill-defined because of confusion with other species. Copper sharks can be found from the

surf zone As ocean surface waves approach shore, they get taller and break, forming the foamy, bubbly surface called ''surf''. The region of breaking waves defines the surf zone, or breaker zone. After breaking in the surf zone, the waves (now reduced in ...

to slightly beyond the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

in the

open ocean The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

, diving to depths of or more. This species commonly enters very shallow

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s, including

bay A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a Gulf (geography), gulf, sea, sound (geography), sound, or bight (geogra ...

shoal In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material and rises from the bed of a body of water to near the surface. It ...

s, and

harbor A harbor (American English), harbour (British English; see spelling differences), or haven is a sheltered body of water where ships, boats, and barges can be docked. The term ''harbor'' is often used interchangeably with ''port'', which is a ...

s, and also inhabits rocky areas and offshore islands. It is tolerant of low and changing

salinities Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

, and has been reported from

and the lower reaches of large

s. Juveniles inhabit inshore waters less than deep throughout the year, while adults tend to be found further offshore and regularly approach the coast only in spring and summer, when large aggregations can be readily observed in shallow water. Populations of copper sharks in both hemispheres perform seasonal migrations, in response to temperature changes, reproductive events, and/or prey availability; the movement patterns differ with sex and age. Adult females and juveniles spend winter in the subtropics and generally shift to higher latitudes as spring nears, with pregnant females also moving towards the coast to give birth in inshore nursery areas. Adult males remain in the

subtropics The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north and ...

for most of the year, except in late winter or spring when they also move into higher latitudes, in time to encounter and mate with post-partum females dispersing from the nurseries. During migrations, individual sharks have been recorded traveling up to . It is philopatric, returning to the same areas year after year.

Description

The copper shark has a slender, streamlined body with a slightly arched profile just behind the head. The snout is rather long and pointed, with the nostrils preceded by low flaps of skin. The round, moderately large eyes are equipped with

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. All ...

s (protective third eyelids). The mouth has short, subtle furrows at the corners and contains 29–35 upper tooth rows and 29–33 lower tooth rows. The teeth are serrated with single narrow cusps; the upper teeth have a distinctive hooked shape and become more angled towards the corners of the jaw, while the lower teeth are upright. The upper teeth of adult males are longer, narrower, more curved, and more finely serrated than those of adult females and juveniles. The 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 con ...

s are fairly long. The

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s are large, pointed, and falcate (sickle-shaped). The first

is tall, with a pointed apex and a concave trailing margin; its origin lies about even with the tips of the pectoral fins. The second dorsal fin is small and low, and positioned about opposite to the

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

. There is usually no ridge between the dorsal fins. The

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

has a well-developed lower lobe and a deep ventral notch near the tip of the upper lobe. This species is bronze to olive-gray above with a metallic sheen and sometimes a pink cast, darkening towards the fin tips and margins but not conspicuously so; the color fades quickly to a dull gray-brown after death. The underside is white, which extends onto the flanks as a prominent band. The copper shark is easily mistaken for other large ''Carcharhinus'' species, particularly the dusky shark (''C. obscurus''), but can be identified by its upper tooth shape, absent or weak interdorsal ridge, and lack of obvious fin markings. It reportedly reaches a maximum length of and weight of . Carcharhinus brachyurus phuket.JPG, The copper shark can be difficult to distinguish from other large ''Carcharhinus'' species Carcharhinus brachyurus jaws.jpg, Jaws Carcharhinus brachyurus upper teeth.jpg, Upper teeth Carcharhinus brachyurus lower teeth.jpg, Lower teeth

Biology and ecology

Fast but active, the copper shark may be encountered alone, in pairs, or in loosely organized

school A school is an educational institution designed to provide learning spaces and learning environments for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is sometimes compuls ...

s containing up to hundreds of individuals. Some aggregations seem to form for reproductive purposes, while others form to concentrations of food. This species may fall prey to larger sharks and killer whales. Known

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s of the copper shark include the

tapeworm Eucestoda, commonly referred to as tapeworms, is the larger of the two subclasses of flatworms in the class Cestoda (the other subclass is Cestodaria). Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cestodar ...

s ''Cathetocephalus australis'', ''Dasyrhynchus pacificus'' and ''D. talismani'', ''Floriceps minacanthus'', ''Phoreiobothrium robertsoni'', and ''Pseudogrillotia spratti'', the

leech Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodie ...

''Stibarobdella macrothela'', and the

fluke Fluke may refer to: Biology * Fluke (fish), a species of marine flatfish * Fluke (tail), the lobes of the tail of a cetacean, such as dolphins or whales, ichthyosaurs, mosasaurs Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ...

''Otodistomum veliporum''.

Feeding

The copper shark feeds more towards the bottom of the

water column A water column is a conceptual column of water from the surface of a sea, river or lake to the bottom sediment.Munson, B.H., Axler, R., Hagley C., Host G., Merrick G., Richards C. (2004).Glossary. ''Water on the Web''. University of Minnesota-D ...

than the top, consuming

s, including

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

(''

Loligo ''Loligo'' is a genus of squid and one of the most representative and widely distributed groups of myopsid squid. The genus was first described by Jean Baptiste Lamarck in 1798. However, the name had been used earlier than Lamarck ( Schneider, ...

'' spp.),

cuttlefish Cuttlefish or cuttles are marine molluscs of the order Sepiida. They belong to the class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone, which is used for control of ...

es, and

octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttle ...

;

es, including Sea robin, gurnards, flatfishes, Merluccidae, hakes, catfishes, Carangidae, jacks, Australian salmon, Mugilidae, mullets, sea breams, Smelt (fish), smelts, tunas, sardines, and anchovies; and

es, including Squalus, dogfish sharks (''Squalus'' spp.), stingrays, Rajidae, skates, electric rays, and sawfishes. Cephalopods and cartilaginous fishes become relatively more important food for sharks over long. Young sharks also consume Scyphozoa, scyphozoan jellyfish and crustaceans, including Thalassinidea, mud shrimps (''Callianassa (genus), Callianassa'') and penaeid prawns. It does not attack marine mammals, though has been known rarely to scavenge on dolphins that had succumbed to fishing nets. The predominant prey of this species off South Africa is the

(''Sardinops sagax''), which comprise 69–95% of its diet. Every winter, schools of copper sharks follow the sardine run, "run" of the pilchard from the Eastern Cape to KwaZulu-Natal. The gathering of millions of forage fish attract a multitude of predators, including several species of sharks, of which copper sharks are the most numerous. Large numbers of copper sharks have been observed hunting together in a seemingly cooperative fashion. Small schooling fish are "herded" into a tight ball, whereupon each shark swims through in turn with its mouth open to feed. For groups of tuna and larger prey, the pursuing sharks may adopt a "wing" formation to force their quarry closer together, with each shark targeting a particular fish and attacking in turn. In False Bay, South Africa, this species reportedly follows seine fishing, seine net fishing vessels. In New Zealand recent reports show that the copper shark is attracted towards swimming kids and especially pose a danger to those jumping off yachts.

Life history

Like other members of its family, the copper shark is

, in which the

of the developing

, once depleted, is converted into a

l connection through which the mother delivers nourishment. Adult females have one functional ovary, on the right, and two functional uteruses. The male bites the female as a prelude to mating. In the Southern Hemisphere, mating takes place from October to December (spring and early summer), when both sexes have migrated into offshore waters at higher latitudes. Birthing seems to occur from June to January, peaking in October and November. Female copper sharks make use of shallow inshore habitats, varying from stretches of open coast to more sheltered bays and inlets, as nurseries. These nurseries provide abundant food and reduce the likelihood of predation by larger members of the species. Known and suspected nursery areas occur off northern North Island from Waimea Inlet to Hawke Bay for New Zealand sharks, off Albany, Western Australia, Albany, in and around Gulf St Vincent, and in Port Phillip Bay for Australian sharks, off Niigata Prefecture, Niigata (Japan) for northwestern Pacific sharks, off the Eastern Cape for South Africa sharks, off Rhodes (Greece), Nice (France), and Al Hoceima (Morocco) for Mediterranean sharks, off Río de Oro (Western Sahara) for northwest African sharks, off Rio de Janeiro (Brazil) and Buenos Aires and Bahía Blanca (Argentina) for southwestern Atlantic sharks, and off Paita and Guanape Cove (Peru), in Sebastián Vizcaíno Bay (Mexico), and in and around San Diego Bay for eastern Pacific sharks. Most sources estimate a

of 12 months, though some data support the interpretation of a 15–21 month long gestation period instead. Females produce litters every other year, with the number of pups ranging from 7 to 24 and averaging 15 or 16. Females off California and the Baja Peninsula tend to bear fewer young relative to other parts of the world. The newborns measure long. The copper shark is among the slowest-growing ''Carcharhinus'' species: off South Africa, males reach sexual maturity at long and an age of 13–19 years, while females mature at long and an age of 19–20 years. Females off Australia mature at a comparable length of , while females off Argentina mature at a slightly smaller length of . The maximum lifespan is at least 30 years for males and 25 years for females.

Human interactions

Attacks on humans

Copper sharks attack humans infrequently, but the species places tenth in the number of unprovoked attacks on people. During the tracking period through 2013, the University of Florida attributed 20 attacks to the species. (In comparison, great white sharks topped the list, with 279 attacks.) Though large and powerful, the copper shark is not particularly aggressive towards humans unless in the presence of food. Copper Sharks have been known to harass and attack spearfishing, spear fishers in an attempt to steal catches. Copper sharks have bitten several swimmers in

and

, where the species is common. (The species is commonly called bronze whalers in this part of the world.) Fatal attacks attributed to the copper shark (bronze whaler) include the 2014 death of a swimmer in Tathra, New South Wales,

, and the 1976 death of a swimmer in Te Kaha,

. Three out of ten shark attacks in New Zealand are attributed to Copper sharks. Witnesses also attributed a fatal attack in September 2011 in Bunker Bay, Western Australia to a copper shark. One problem with counting attacks on humans is that the copper shark is so similar to other

s. Victims and witnesses are unlikely to correctly identify which type of genus Carcharhinus shark is responsible for the attack. Experts trying to confirm shark attacks by species warn that their statistics undercount the number of attacks by requiem sharks like the copper.

Captivity

Like many large, active sharks, this species adapts poorly to captivity; it tends to bump into the sides of its enclosure, and the resulting abrasions then become infected with often fatal consequences.

Fishing

Commercial fishing, Commercial fisheries for the copper shark exist off New Zealand, Australia (though the "bronze whaler fishery" of Western Australia actually takes mostly dusky sharks), South Africa, Brazil, Uruguay, Argentina, Mexico, and China; it also contributes to the bycatch of other commercial fisheries across its range. This species is caught in gillnets and on longline fishing, bottom longlines, and to a much lesser extent in bottom trawls and on pelagic longlines. The meat is sold for human consumption. The copper shark is also popular with recreational fishing, recreational fishers in Namibia, New Zealand, Australia, South Africa, Argentina, Mexico and California, predominantly by anglers but also by bowfishing, bowfishers and gillnetters. In New Zealand, it is the ''Carcharhinus'' species most frequently caught by sport fishers and sustains a small, summer recreational fishery in northern North Island, that mainly captures pregnant and post-partum females and for the most part practices tag and release. A tag and release program is also practiced in Namibia.

Conservation

The International Union for Conservation of Nature (IUCN) has assessed the copper shark as vulnerable worldwide. While the global population is unknown, the long maturation time and low reproductive rate of this species render it highly susceptible to overfishing. Regionally, the IUCN has listed this species under Least Concern off Australia, New Zealand, and South Africa, where fisheries are generally well-managed; the local copper shark population for each of those three countries is contained almost entirely within their respective Exclusive Economic Zones (EEZ). Reported catches by New Zealand have steadily declined from a peak of 40 tons in 1995/96 to 20 tons 2001/02, though it is uncertain whether this reflects a genuine decline or changing fishing habits. In the eastern Pacific, the copper shark is rare and little fishery information is available, leading to an assessment of Data Deficient. However, catch declines across all elasmobranchii, shark and ray species have been documented in the heavily-fished Gulf of California. Off East Asia, the copper shark has been assessed as Vulnerable species, Vulnerable; though species-specific data is unavailable, shark populations overall have been decimated in the region. The number of large adults have been too low to sustain targeted fisheries since the 1970s, and most of the current shark catch consists of small juveniles. Additional threats to this species include the habitat degradation, degradation and habitat destruction, destruction of its coastal nurseries from development, water pollution, pollution, and aquaculture, mortality from shark nets used to protect beaches in South Africa and Australia, and persecution by fish farmers in southern Australia. The New Zealand Department of Conservation (New Zealand), Department of Conservation has classified the copper shark as "Not Threatened" under the New Zealand Threat Classification System but with the qualifiers "Conservation Dependent", "Data Poor" and "Secure Overseas".

References

External links

''Carcharhinus brachyurus'', Copper shark
a
FishBase''Carcharhinus brachyurus'' (Bronze Whaler, Cocktail Shark, Copper Shark, Narrowtooth Shark, New Zealand Whaler)
a
IUCN Red List
a
Florida Museum of Natural History Ichthyology Department

Species Description of Carcharhinus brachyurus at www.shark-references.com
{{Good article Carcharhinus, copper shark Fish of the Mediterranean Sea Fish of New Zealand Fish of Peru Marine fauna of Southern Africa Marine fauna of East Asia Marine fish of Southern Australia Fauna of the Baja California Peninsula Southeastern South American coastal fauna Gulf of Guinea Vulnerable fish Fish described in 1870, copper shark Taxa named by Albert Günther Near threatened animals Near threatened biota of Oceania Near threatened biota of Asia