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The cephalofoil — that distinctive flattened head — is one of evolution's most elegant engineering solutions. We look at what it actually does and why hammerheads are some of the ocean's most capable predators.
Nine species of hammerhead shark exist, ranging from the 1.5m bonnethead to the great hammerhead (Sphyrna mokarran) at over 6m. The defining feature — a laterally expanded head called a cephalofoil — is not an evolutionary accident. It solves several hunting problems at once.
Sharks detect the weak bioelectric fields produced by prey muscle movements via sensory organs called ampullae of Lorenzini. In most shark species, these organs are concentrated around the rostrum and jaw. In hammerheads, they are distributed across the entire leading edge of the cephalofoil — dramatically expanding the detection area.
A great hammerhead sweeping its head across sand can map the electrical signature of a stingray buried beneath the surface with centimeter precision. This explains the unusual diet of hammerheads relative to other large sharks — stingrays and skates make up a disproportionate share of their prey.
Most sharks have eyes positioned laterally, creating a panoramic field of view but minimal binocular overlap directly ahead. The hammerhead's wide head places the eyes far apart, but — crucially — angled forward enough to create significant binocular overlap. Studies using behavioral tests confirm that hammerheads have substantially better depth perception than related carcharhinid species.
The cephalofoil also functions as a forward hydrofoil. Combined with an unusually large pectoral fin, it gives hammerheads exceptional maneuverability in the vertical plane — allowing rapid pivots and tight turns when pursuing agile prey.
All three large hammerhead species (great, scalloped, and smooth) are listed as Critically Endangered or Endangered on the IUCN Red List, driven primarily by targeted and bycatch fishing pressure. Their distinctive fins command premium prices in the shark fin trade.
Shark Data Lab