Marine Species Identification Portal : Great hammerhead

Author: (Ruppell, 1837)

Sphyrna mokarran (Ruppell, 1837)

Diagnosis: head broad with anterior contour moderately convex, scalloped in the midline and opposite each nostril; head widely expanded laterally (hammer); corners of mouth opposite or posterior to outer posterior corners of head; eyes large, far from nostrils; centre of eyes anterior to front of mouth; prenarial grooves absent or hardly developed; teeth strongly serrated in young and old specimens; fifth gill opening shorter than other four and situated behind origin of pelvic fins; second dorsal fin very high, with short inner margin and deeply concave hind margin; pelvic fins high and falcate; anal fin base short. Colour: grey or greyishbrown above, shading to paler below; pectoral fins without marks. Size: to more than 6.1 m, usually to 4 m.

Habitat: coastal pelagic and semi-oceanic over continental and island shelves from coast to 30 m. Food: see family. Reproduction: viviparous; number of embryos 14-42; size at birth 50-70 cm.

Distribution: eastern Atlantic in warmer waters, also Mediterranean (Gulf of Genoa); elsewhere circumtropical (Atlantic, Pacific, northern Indian Ocean).

Great hammerhead (Sphyrna mokarran)