Copper shark

Carcharhinus brachyurus is a large shark of the family Carcharhinidae, in the order Carcharhiniformes ^[1]. It is bronze to olive grey above and white below, and reaches about 292 cm ^[2]. It lives from the surf zone down to at least 100 m deep and its range includes Peru ^[2]. In Peru it is known as «cazón» and «tollo mantequero», and there is no fishery aimed at it: it is caught incidentally ^[3]. Its global category on the IUCN Red List is Vulnerable ^[4].

Günther described it in 1870 as Carcharias brachyurus; its type locality is New Zealand, and the neotype, a 2420 mm female held at the National Museum of New Zealand as NMNZ 2262, was caught at Wanganui and designated by Garrick in 1982 ^[2]. The original specimens in the British Museum appear to be lost, and two Australian foetuses that Günther assigned to the species are in fact Carcharhinus leucas ^[2]. The FAO catalogue lists 6 synonyms and gives tiburón cobrizo as the Spanish name; the name bronze whaler is used in Australia and narrowtooth shark in the United States ^[2].

It is a large, fairly slender shark with a moderately long snout, narrowly rounded or pointed, and circular eyes of moderate size ^[2]. The upper teeth are narrow, serrated and have a bent or hooked cusp, with no smaller cusplets at the base, in 15 or 16 rows on each side of the upper jaw ^[2]. There is usually no ridge between the two dorsal fins, the pectoral fins are long, the first dorsal is falcate and the second is small and low ^[2].

The colour is bronze to olive grey above and white below, with a fairly conspicuous white band on the flank; the fins have somewhat darker edges and inconspicuous dark tips ^[2]. It reaches 292 cm; males mature between 200 and 229 cm, females below 240 cm, and pups are 59 to 67 cm long at birth ^[2]. Checking its size at the landing sites is difficult: it is sometimes landed eviscerated or without its tail fin, which makes verifying its total length hard ^[3]. The FAO catalogue also warns that its biology is poorly known because of confusion with other species ^[2].

In Peru it is recorded in the updated checklist of chondrichthyans of the Peruvian sea ^[5]. The finding cites an IMARPE field guide for identifying sharks in the small-scale fishery, and shark landings are recorded at authorised points by means of a landing certificate ^[3].

Similar species

• Carcharhinus falciformis: Carcharhinus falciformis is a dark, slim oceanic shark with a ridge between the dorsal fins, upper teeth with small cusplets or very coarse serrations at the base, and a first dorsal that starts behind the tips of the pectorals; Carcharhinus brachyurus usually has no ridge and its first dorsal starts over those tips or slightly ahead of them ^[2].
• Carcharhinus galapagensis: Carcharhinus galapagensis has broad, triangular upper teeth, with about 14 rows on each side, and a low ridge between the dorsals; in Carcharhinus brachyurus the upper teeth are narrow and hook-cusped, with 15 or 16 rows ^[2].

It has an irregular distribution in temperate and tropical waters; in the eastern Pacific it is reported from southern California to the Gulf of California and Peru ^[2],[3]. In Peru it appears on the checklist of chondrichthyans of the Peruvian sea ^[5], and the Ministry of the Environment's 2025 finding places its presence along the whole coast of the country ^[3].

It is found from near the surf line to at least 100 m deep; in the northern parts of its range it seems to move north in spring and summer and south in autumn and winter ^[2]. The genetic studies cited in the finding indicate that southern hemisphere populations are isolated from one another, with a southeastern Pacific stock distinct from the southwestern Pacific one ^[3].

It is viviparous, with a yolk-sac placenta, and the sex ratio at birth is 1 to 1 ^[2]. The FAO catalogue gives litters of 13 to 20 pups ^[2] and the Ministry of the Environment's finding, 8 to 20 ^[3].

It matures late and lives long. For southern Africa the finding reports that males mature at 13 years and females at 20, and a maximum recorded age of 30 years in males and 25 in females ^[3]. The FAO catalogue gave a much earlier maturity, at about 5 years, and a maximum age of at least 12 ^[2]. This slow pace makes it biologically vulnerable to fishing ^[3].

It eats a wide variety of bony fishes, among them sardines, sea catfish, mullets, jacks, hakes and soles, as well as spiny dogfish of the genus Squalus, torpedo rays, sawfish, squid and cuttlefish ^[2]. Off South Africa, in winter, large numbers follow sardine shoals along the southern coast of Natal ^[2].

The diet studies gathered in the Peruvian finding come from New Zealand and South Africa, and give a mean trophic position of 4.5, that of a high-level predator ^[3].

Its global category on the IUCN Red List is Vulnerable ^[4]. The finding reports that, on a precautionary basis, a population reduction of between 30 and 49 % is presumed over the last three generations, which are 71 years, attributed to fishing pressure ^[3].

In Peru there is no regional or national stock assessment, and the 2025 finding notes that no national Red List assessment has been made either ^[3]. Shark landings are only allowed at authorised points, with a landing certificate, and Ministerial Resolution 209-2001-PE sets a minimum catch size of 150 cm total length for species of the genus Carcharhinus, with a tolerance of 15 % ^[3].

The species is subject to CITES controls, and the Peruvian Scientific Authority issued in 2025 a non-detriment finding for its fins, positive with conditions and valid for 1 year ^[3]. That finding rates fishing pressure as low between 2020 and 2022 and moderate in 2023 and 2024, when fishing mortality came close to natural mortality, and recommends, within 3 years, using interdorsal length as an alternative measure to monitor the minimum size ^[3].

Not medical advice. For a sting, a poisoning or an allergy, seek medical care.

The FAO catalogue considers it a dangerous species, to which a few provoked and unprovoked attacks on swimmers and divers are attributed; it is probably much less dangerous than the tiger shark and the bull shark, because of its slender teeth and feeding habits ^[2].

In Peru it is known as «cazón» and «tollo mantequero» ^[3]. There is no fishery aimed at it: it is caught incidentally in the dolphinfish fisheries, with longlines and gillnets, and the tuna fisheries, with longlines and purse seines, and longlines and gillnets are the main gears ^[3].

The meat is eaten fresh in the country and the dried fins are exported ^[3]. Exports of dried fins of this species peaked in 2022, at 419.63 kg, fell to 53.05 kg in 2023 and none were recorded in 2024 ^[3]. In 2023 and 2024 the main landing places were Tumbes, Piura, La Libertad, Áncash and Lima ^[3].

In the small-scale longline fishery of Ilo, in the south of the country, 145 trips were observed between 2005 and 2010: of the sharks identified to species, 1 % were species other than the blue shark and the mako, this one among them ^[6].

In Peru it is known mainly through fishing. According to the data for 2023 and 2024, it is landed in Tumbes, Piura, La Libertad, Áncash and Lima ^[3], and between 2005 and 2010 it was recorded in the small-scale longline fishery of Ilo ^[6]. The Ministry of the Environment's finding places it along the whole coast ^[3].