Blacknose shark

About the Blacknose shark

Carcharhinus acronotus, or the Blacknose Shark, gets its name from the dark blotch on the tip of its snout, which often fades as it matures.

It is a tropical and warm-temperate shark found in the western Atlantic Ocean from North Carolina to southern Brazil. It lives on continental and insular shelves, mainly over sandy, shell, and coral bottoms, at depths of 18 to 64 m (59–210 ft).

Biology and Behaviour

The Blacknose Shark is born at 31 to 50 cm (12–20 in)  in total length, but can reach up to 137 cm (4.5 ft) in length and 18.9 kg (41.7 lb) in weight. Its diet consists mainly of small fishes, including pinfish, croakers, porgies, anchovies, spiny boxfishes, and porcupine fish. It may also feed on octopus and can be preyed upon by larger sharks.

Blacknose Sharks are fast-swimming predators. They may form schools and sometimes associate with schooling fish such as mullet or anchovies. They perform a “hunch” display, with the back arched, the caudal fin lowered, and the head raised, possibly as a threat display.

Reproduction and Lifespan

The Blacknose Shark is viviparous, meaning embryos develop inside the mother’s uterus and are nourished through a placental connection. It has a biennial reproductive cycle in United States South Atlantic waters, but an annual reproductive cycle has been reported in the Gulf of Mexico and off northern Brazil. Females give birth to about 3 to 6 pups, although litters of up to 8 pups have been reported. Mating usually occurs in early summer and gestation lasts 10 to 11 months.

Maturity in this species varies by region, age, size, and sex of the shark. Females reach sexual maturity at approximately 101–120 cm (3.3–3.9 ft) in length, while males mature at about 97–110 cm (3.2–3.6 ft). Age at maturity also varies between regions. In Atlantic waters, females mature at approximately 4.5 years and males at about 4.3 years. In the Gulf of Mexico, females mature at about 6.6 years and males at approximately 5.4 years.

The Blacknose Shark has been reported to live for up to 20 years.

Conservation and Tourism

The Blacknose Shark is classified as Endangered on the IUCN Red List. It is caught as bycatch in coastal fisheries and targeted in some areas, mainly for its meat. Bycatch from shrimp trawl fisheries is a major threat, particularly during the juvenile life stage.

In US waters, the Blacknose Shark is managed by the National Marine Fisheries Service under the Fishery Management Plan for Atlantic Tunas, Swordfish, and Sharks. Its decreasing population trend should continue to be monitored.

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Blacknose shark Gallery