An important commercial fish in the western Atlantic, the blacknose shark (Carcharhinus acronotus) is a small, slender shark that is heavily harvested for its fins and meat (1)(2)(3). A graceful, sleek species, the blacknose shark is characterised by the black or dusky spot under the tip of the rather long, rounded snout, which is most conspicuous on young individuals (2). It is an otherwise grey to greenish-grey shark, with black or dusky tips on the second dorsal fin and on the upper lobe of the tail fin (2). It has large eyes, a fairly short first dorsal fin and a relatively large second dorsal fin(2)(3).
A quick swimmer and a voracious predator, the blacknose shark feeds on a variety of small fishes including pinfish (Lagodon rhomboides) and porcupine fish (Diodontidae), but may itself fall prey to larger sharks such as the dusky shark (Carcharhinus obscurus) (2)(4). When threatened, it performs a defensive display by hunching the back, lowering the tail and raising the head, which possibly serves to warn off potential predators (4).
The blacknose shark mates in late May to early June and has a 10 to 11 month gestation period. In the U.S. South Atlantic waters it may only breed every second year, but in the Gulf of Mexico it is thought to breed each year (2). The offspring develop inside the female, meaning that live young are born, with three to six offspring produced per litter (2)(4). The blacknose shark is a relatively fast growing species and maturity is reached at only two years of age (2). In U.S. South Atlantic waters male blacknose sharks are reported to reach maturity at 4.3 years and females at 4.5 years of age (1).
An important commercial species, the blacknose shark is regularly captured in a large number of fisheries across its range due to its economic value (1). It is caught mainly off south-eastern Florida and north-eastern Venezuela and may be sold to food markets (2)(5). It is also targeted in a number of shark fisheries along the U.S. Atlantic coast, and these fisheries are often driven by the demand for shark fins in Southeast Asia, where they are considered a delicacy. But like most other shark species, the main threat to the blacknose shark is bycatch. Large numbers of juvenile sharks are caught in shrimp trawl fisheries, which are particularly intensive in the Gulf of Mexico where such fishing is causing the blacknose shark population to decline. Elsewhere there is little information on the status of the blacknose shark, although it is thought to still be fairly abundant off the northern and northeastern Brazilian coast (1).
The blacknose shark has not been the target of any known conservation measures, although it receives some protection in a small coastal shark reserve in the U.S. With such little information available on the impact of fisheries upon the species and the trends of its population, it is recommended that the blacknose shark is monitored as it may become threatened in the future (1). Furthermore, as there are no binding international treaties for the management of sharks yet in place, careful fisheries management and measures to protect marine habitats are required to ensure the blacknose shark continues thrive in our oceans (1)(6).
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