JawDropper

Hammerhead Shark

Shark in a Snapshot

Hammerhead sharks are remarkable creatures with distinctive features and behaviors. Their unique hammer-shaped heads, known as cephalofoils, provide them with a 360-degree vertical field of vision, allowing them to see both above and below simultaneously. This head structure also houses numerous sensory organs called ampullae of Lorenzini, which detect the electrical fields emitted by potential prey, giving hammerheads a significant advantage in hunting.

Fin-tastic Facts

Hammerhead sharks give birth to live young, a trait known as viviparity. The number of pups in a litter varies by species, ranging from 6 to 42, with a pregnancy lasting about 11 months. Of the nine recognised hammerhead species, the great hammerhead (Sphyrna mokarran) is the largest, growing up to 20 feet (6 meters) long and weighing nearly 1,000 pounds (450 kilograms).

Encounters of the Deep

Hammerhead sharks are not usually aggressive towards humans. According to the International Shark Attack File (ISAF), only 16 to 38 hammerhead shark attacks have been recorded since 1580.

One reason attacks are rare is that hammerheads have highly sensitive electromagnetic sensors, which help them differentiate between humans and their natural prey. Additionally, they do not typically feed on mammals, so humans do not resemble their usual food source.

These sharks are generally shy and tend to avoid human interaction. However, larger species, such as the great hammerhead, could pose a potential risk due to their size, though attacks remain extremely rare.

Endangered or Thriving?

Hammerhead sharks are critically endangered and experiencing significant population declines worldwide. Most species are listed as Critically Endangered or Endangered on the IUCN Red List. In particular, the great hammerhead shark has seen its global population drop by more than 50% over the past 70 years.

Like other shark species, hammerheads face major threats such as the shark fin trade, accidental capture in fishing operations (bycatch), high mortality rates during capture (over 90%), and illegal or unregulated fishing.

Sources from the Deep

• Alimo, T. (no date) Conservation of the Critically Endangered Hammerhead Sharks in Ghana, Conservation Leadership Programme. Available at: https://www.conservationleadershipprogramme.org/project/conservation-of-the-critically-endangered-hammerhead-sharks-in-ghana/ (Accessed: 4 February 2025).
• Allred, B. (2022) Discover Why Hammerhead Sharks Have Never Killed a Human, AZ Animals. Available at: https://a-z-animals.com/blog/discover-why-hammerhead-sharks-have-never-killed-a-human/ (Accessed: 4 February 2025).
• Hammerhead Sharks (2010) National Geographic. Available at: https://www.nationalgeographic.com/animals/fish/facts/hammerhead-sharks (Accessed: 4 February 2025).