Scalloped hammerhead

Photo: Nicholas Hess · CC BY-NC

Iconic for their laterally-extended cephalofoil — the hammer-shaped head that improves electroreception and manoeuvrability — scalloped hammerheads are pelagic schooling sharks most often encountered at seamounts and offshore pinnacles. Schools of dozens to hundreds form at depth during the day, dispersing at night to hunt. The hammer provides a 360-degree vertical field of vision, making them acutely aware of divers. Critically endangered; fins are among the most traded shark products globally, and populations have collapsed at many historical aggregation sites.