Blue shark is a large shark with a dark blue back. It has metallic-blue sides and a white belly. These colors help the shark blend in with its surroundings.
The blue shark is long and thin. It has large pectoral (side) fins and a long, pointy snout. Adults may grow as long as 13 feet (4 meters), though most are smaller. They typically weigh 300 to 400 pounds (135 to 180 kilograms).
The blue shark is found in all but the coldest oceans. It generally prefers the open sea. However, it does come close to shore. The blue shark is probably the widest-ranging shark. It is the most abundant large shark in most waters. The shark migrates frequently. For example, blue sharks often travel across the Atlantic Ocean from North America to Europe. They may then travel to Africa and return to North America. Blue sharks also migrate to different depths, usually to find food.
The blue shark mainly eats octopuses, squids, and fish. But it may eat whatever food is available. It sometimes feeds on dead animals and even garbage. Blue sharks rarely bite people.
Females give birth to an average of 25 to 50 live young per litter, but the size of a litter varies widely. Litters have been reported with as few as 4 and as many as 135 babies. Blue sharks can live for more than 20 years.
Fishing boats frequently catch the blue shark, usually by accident. In some countries, people eat the meat of the blue shark fresh, smoked, or salted. They may use the fins for shark fin soup. The hide is used for leather. The blue shark also provides liver oil and fish meal. The blue shark is not considered an endangered species, but the number of blue sharks is decreasing. Over several decades, fishing has reduced the population.
