Sphyrna

Sphyrna is a genus of hammerhead sharks in the family Sphyrnidae. Members are characterized by a wide, hammer-shaped head called a cephalofoil, with elongated lateral lobes that may aid sensory perception and maneuverability. The genus includes several well-known species, such as the scalloped hammerhead (Sphyrna lewini), the great hammerhead (Sphyrna mokarran), the smooth hammerhead (Sphyrna zygaena), and the bonnethead (Sphyrna tiburo).

Anatomy and senses: The cephalofoil provides a broad surface for the ampullae of Lorenzini, enhancing electroreception, and offers a wider field of view. The bodies are typically robust, with a broad head and a powerful tail that supports fast swimming.

Distribution and habitat: Sphyrna species occur in tropical and temperate oceans around the world. They are most common along continental shelves, in coastal waters, coral reefs, and estuaries, but some species travel long distances and may be found in deeper offshore waters.

Biology and reproduction: Sphyrna species are ovoviviparous, with embryos developing inside eggs contained within the mother and born live. Gestation varies by species, generally several months, and litter sizes range from a few to several dozen pups. They feed on fish, cephalopods, and crustaceans and are important mid-level predators in many ecosystems.

Taxonomy and conservation: The genus comprises several notable species. Taxonomic treatment sometimes places winghead sharks in a separate genus, Eusphyra, rather than Sphyrna. Many Sphyrna species are threatened by overexploitation and bycatch; some are listed with elevated IUCN threat statuses, and regional protections and management plans exist in various regions.