Animals

Facts about hammerhead sharks

22 facts about hammerhead sharks

Most distinctive of all sharks

These peculiar fish are common worldwide. Although, like most sharks, they have bad press; they do not include humans in their diet, attacking only while provoked. Despite, or maybe in fact because of, their peculiar look, their numbers systematically deteriorate.
1
Hammerhead sharks from the family Sphyrnidae.
There are two genera in the family Sphyrnidae, Sphyrna, and Eusphyra, with most hammerhead species belonging to the genus Sphyrna, and only one—the Winghead shark—to the genus Eusphyra.
2
Sphyrna derives from Greek and means “hammer.”
Eusphyra means “good” in conjunction with “hammer.”
3
There are a total of ten species of hammerhead sharks.
There are:

Winghead shark (Eusphyra blochii), Scalloped bonnethead (Sphyrna corona), Carolina hammerhead (Sphyrna gilberti), Scalloped hammerhead (Sphyrna lewini), Scoophead (Sphyrna media), Great hammerhead (Sphyrna mokarran), Whitefin hammerhead (Sphyrna couardi), Bonnethead (Sphyrna tiburo), Smalleye hammerhead (Sphyrna tudes), and Smooth hammerhead (Sphyrna zygaena).
4
Hammerheads are common in warmer waters along coastlines worldwide.
5
Their length ranges from 0.9 to 6.1 meters, and their weight ranges from 3 up to 580 kilograms.
The biggest of the genus is the great hammerhead. The record holder is a female caught in 2006 who weighed almost 581 kilograms. The reason for her unusual weight, however, was pregnancy.
6
The distinctive structure—a hammer-like head—is called a cephalofoil.
It allows sharks an increased binocular vision and depth perception.
7
The quaint structure of their hammer-like heads may have been an evolutionary way to enhance their vision.
Their eyes are located on the sides of their flattened heads, allowing them a 360-degree vision, apart from a blind spot in front of the shark.
8
Hammerhead species tend to swim in schools.
It is uncommon for sharks, however. During the day, hammerheads prefer company, but they hunt solitarily at night.
9
Their average lifespan ranges from 20 to 30 years.
10
Mostly carnivorous, some hammerhead species are omnivorous.
They feed on stingrays, small fish, and octopuses, however, 90% of bonnethead sharks’ diet consists of seagrass.