Blacktip Shark 

The blacktip shark (Carcharhinus limbatus) belongs to the requiem shark family Carcharhinidae. You can find blacktip sharks in subtropical and tropical waters throughout the world. Unlike some other requiem sharks, blacktip sharks are rather timid, although they can become aggressive in the presence of food. Female blacktips give birth to live young, which develop in shallow waters. When females cannot find suitable males to mate with, they can also reproduce asexually. 

5 Quick Facts

• At full size, Carcharhinus limbatus can measure up to 9.2 feet long and weigh around 271 pounds. 
• Female blacktip sharks endure a long gestation period lasting anywhere from 11 to 12 months. 
• On average, most blacktip sharks live around 10 years, but they can live up to 15.5 years under some circumstances. 
• Blacktip sharks rank as one of the most commonly sighted sharks by humans due to their “docile” nature and habit of staying close to coastlines. 
• Sometimes, blacktip sharks will leap out of the water and spin several times about their axis before landing. 

Classification and Scientific Name

Blacktip sharks belong to the requiem shark family Carcharhinidae. The word Carcharhinidae derives from the Greek word karcharos, meaning “jagged” or “sharp,” and rhine, meaning ‘rasp.” Both of these words refer to the jagged skin of requiem sharks. Meanwhile, the history of the common name “requiem” remains up for debate. Some believe it could stem from the French words requin, meaning “shark,” or reschignier, meaning “to grimace while baring teeth.” 

Blacktips belong to the genus Carcharhinus, the largest genus in the Carcharhinidae family. Its specific name, limbatus, stems from the Latin words limbus, meaning “hem,” “edge,” or “fringe,” and the ending –atus, meaning “-ed.” The name references the black tips or edges on its fins. These markings are also where the shark gets its common name.   

Appearance

According to some, blacktip sharks look like the “sharkiest” of sharks. While vague, this description suits the blacktip shark due to its stereotypical “sharklike” appearance. Like other requiem sharks, Carcharhinus limbatus have round eyes and one or two of the gill slits lie over the pectoral fin base. The body is fusiform and robust, allowing the blacktip to swim seamlessly through the water. Each jaw contains 15 tooth rows on either side, with two teeth at the middle of the upper jaw and one at the middle of the lower jaw. The teeth have a broad base and sharp, serrated edges. 

You can identify a blacktip based on the shape and markings on its fins. The first dorsal fin appears sickle-shaped, and no ridge runs between the first and second, smaller dorsal fin. The pectoral fins are thinner and less curved than the dorsal fin and terminate at a narrow point. Most feature black tips on the pectoral fins, the second dorsal fin, and the lower lobe of the caudal fin. Meanwhile, the first dorsal fin and upper lobe of the caudal fin have black edges. However, some individuals lack markings or have no markings on the fins. The upper half of the body appears grayish-brown, while the belly looks white. 

On average, most blacktip sharks measure around 4.9 feet long. That said, they can grow up to 9.2 feet and weigh a maximum of 271 pounds. 

Distribution, Population, and Habitat

You can find blacktip sharks all around the world in subtropical and tropical waters. In the Atlantic, their range extends as far north as Massachusetts and as far south as Brazil. They range along the edges of the Indian Ocean from South Africa to Southeast Asia. In the western Pacific, they range from Japan’s coasts to northern Australia’s waters. In the eastern Pacific, they range from southern California to Peru. 

Blacktips normally inhabit relatively shallow waters. They typically inhabit waters less than 100 feet below the surface but sometimes travel to depths up to 210 feet. These sharks rarely stray far from shore. Their preferred habitats include coral reefs, bays, and lagoons. On some occasions, they may travel into brackish waters such as estuaries and mangrove swamps. Blacktips migrate long distances to their breeding grounds but do not travel through the open ocean. 

Predators and Prey

Upon reaching maturity, adult blacktip sharks have no known predators. However, juveniles face a risk of predation, particularly from other sharks. 

Blacktip sharks are carnivores that prey on fish, rays, skates, crustaceans, and cephalopods. That said, fish make up around 90% of their diet. Common prey include sardines, anchovies, herring, mackerel, and flatfish. They feed most often at dusk and dawn and often feed in large groups. While normally docile, they grow increasingly aggressive in the presence of food. Blacktip sharks often follow fishing vessels and go into feeding frenzies when the ships toss refuse overboard. 

Blacktip sharks are fast, powerful swimmers. They can launch themselves into the air and spin when feeding on schools of small fish. During these leaps, they can reach speeds of up to 21 feet per second.

Reproduction and Lifespan

Mating season typically occurs in spring or early summer. Females possess two working uteri, each of which houses compartments for a separate embryo. Although blacktip sharks normally mate to reproduce, females can also reproduce asexually. The gestation period lasts between 11 and 12 months. Once they are ready to give birth, pregnant females travel to shallow “nurseries” to give birth. Like other requiem sharks, blacktip sharks give birth to live young. Females give birth to 1 and 10 young every other year, with the average litter containing 4 to 7 pups. Upon giving birth, females leave the nurseries and allow the young to develop. 

Male blacktip sharks reach sexual maturity at around 4 or 5 years old, while females reach maturity between 6 and 7 years old. On average, blacktip sharks live around 10 years. However, some specimens can live up to 15 years under the right conditions. 

Blacktip Sharks in Food and Cooking

Due to their density in coastal waters, blacktip sharks are caught in large numbers by recreational and commercial fisheries. As a matter of fact, they rank as one of the most important species in the commercial shark fishing industry. Many people consider blacktip shark meat superior to the flesh of other sharks. You can eat its meat fresh, frozen, or dried, and some cultures use its fins to make shark fin soup. Although its meat contains high levels of mercury, you can eat it in small quantities. That said, many conservationists question the wisdom of eating sharks. Sharks serve an important role in maintaining a healthy ecosystem. The more we feed on sharks like blacktips, the more environmental harm we may cause. 

Population

Blacktip reef sharks rank among the most common sharks in coastal waters. Their presence near coasts means people and anglers often encounter them while fishing or recreationally swimming. Moreover, their proximity to people means they are responsible for a large number of shark attacks. 

In recent years, blacktip shark numbers have been on the decline worldwide. There are several reasons behind this decline. The main reason for the decline stems from the overharvesting by commercial fisheries and recreational anglers. In fact, recreational angling takes more blacktip sharks each year than commercial fisheries in the United States. Due to their low reproductive rate, blacktip sharks cannot breed their way out of this problem. 

Another threat comes from habitat loss and climate change. The death of coral reefs and coastal ecosystems has reduced the supply of fish and other ocean life around reefs. This decline in food makes it harder for blacktip sharks to find enough food to eat. 

Due to these declines, the IUCN currently lists the blacktip shark as a Vulnerable species.