Blacktip Shark, Carcharhinus limbatus
The Blacktip Shark, Carcharhinus limbatus, whose common Spanish name is tiburón volador, is a member of the Requiem Shark or Carcharhinidae Family, known collectively as tiburónes gambuso in Mexico. Their common name is derived from the black color on the tip of their fins. Globally, there are 35 species in the genus Carcharhinus, 17 of which are found in Mexican waters, seven in the Atlantic, four in the Pacific, and six in both oceans.
The Blacktip Sharks are medium-sized and heavily built. They are dark gray-blue to brown dorsally and transition to white ventrally. Their anal fin is white. Their dorsal fins, the lower lobe of their caudal fin, and their pectoral fins have black tips. They have a small gray line running horizontally along their sides. Their caudal fin is strongly asymmetrical with a well-developed lower lobe and a notch under the tip of the upper lobe. Their first dorsal fin originates over the pectoral fins and is high on the body with a narrow pointed apex and a short free rear tip. Their second dorsal fin originates over the anal fin origin. They lack the prominent interdorsal ridge found in similar sharks. Their pectoral fins are large and pointed. Their head has a moderately long and pointed overhanging snout, small round eyes, prominent nasal flaps that are low and broad, and a broadly curved mouth that lacks obvious furrows at the corners. They are equipped with similarly-appearing, long, erect, and narrowly-pointed teeth with a broad base on their upper and lower jaws. Their upper teeth have coarse serrations and their lower teeth have fine serrations. Their upper jaw has 32 teeth in total set in three rows and their lower jaw has 31 teeth also set in three rows. They have five pairs of relatively short gill slits, the last two originating over the pectoral fin base. Their caudal fin has a large lower lobe with a strong ventral notch near the tip of the upper lobe.
The Blacktip Sharks are a widespread circumglobal species found in tropical and warm waters ranging from the edges of the continental shelf and insular slopes. They are found from the surface to depths of 1,410 feet and are often seen nearshore around river mouths, bays, mangrove swamps, and in estuaries normally at depths of less than 200 feet. They are found in small schools that are sexually segregated. They are not true pelagics as they do not inhabit open oceans. They are known to make seasonal migrations to cooler waters during the summer and to return in the fall. Male Blacktip Sharks are slightly larger than females reaching a maximum length of 2.55 meters (8 feet 4 inches) and weight of 37 kg (82 pounds). They feed on small schooling fish such as herrings, sardines, menhadens, mullets, and anchovies, and many other bony fish including numerous elasmobranchs. They are known to follow fishing trawlers consuming discarded by-catch. They also consume crustaceans and squids. Adults have no natural predators, however, juveniles fall prey to various larger sharks. In the Caribbean they are known to associate with the Caribbean Reef Shark, Carcharhinus perezi. Reproduction is viviparous and involves a two-year cycle with 11 to 12-month gestation periods and litter sizes of 4 to 11 pups. At birth, the pups measure between 53 cm (21 inches) and 65 cm (26 inches) in length and are immediately capable of caring for themselves. Juveniles inhabit shallow coastal waters away from adults for approximately 12 months. They are fast growers and mature sooner than their congeners. They have a lifespan of up to 12 years.
In Mexican waters the Blacktip Sharks are found in all waters of the Atlantic and the Pacific.
The Blacktip Sharks are most likely confused with the Bignose Shark, Carcharhinus altimus, the Copper Shark, Carcharhinus brachyurus, the Dusky Shark, Carcharhinus obscurus, the Galapagos Shark, Carcharhinus galapagensis, and the Spinner Shark, Carcharhinus brevipinna, but none of these have black tips on their dorsal, caudal, and pectoral fins.
The Blacktip Sharks are important recreational fish, known for their leaping abilities when feeding or hooked, and commercial fish in locations where they are abundant. They are the most abundant large coastal species in the northwest section of the Gulf of Mexico. Commercially they are caught primarily via longlines, fixed bottom nets, and as a by-catch of shrimp trawlers. They are second to the Sandbar Shark, Carcharhinus plumbeus as the most important shark catch in the Gulf of Mexico. They are also a sizeable portion of the artisanal fishery catch on the west coast of mainland Mexico. Their meat is considered to be excellent with meat from several other sharks being sold as “Blacktip Shark”. In general their meat is consumed locally and their fins are exported to Asia for use in shark fin soup. Their hides are used on a limited basis for manufacturing leather goods and their livers are used to extract oil. They are known to bite surfers while hunting but generate only minor bite wounds. From a conservation perspective they are classified as Near Threatened. Although widely distributed they are vulnerable to heavy fishing pressure and human-induced habitat destruction due to their inshore preferences. Only the Australian and United States governments currently manage this species.
Blacktip Shark, Carcharhinus limbatus, Fetus. Fish removed, along with 10 others, from a 2.6 meter (8 feet 6 inches) female provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, December 2009. Length 42 cm (17 inches).
Blacktip Shark, Carcharhinus limbatus. Fish caught at the mouth of the San José River, Baja California Sur, August 2005. Length: 1.05 meters (3 feet 5 inches). Weight: 7.9 kg (20 pounds).