Sphyrna zygaena

Author: (Linnaeus, 1758)

Sphyrna zygaena (Linnaeus, 1758)

Status in World Register of Marine Species:
Accepted name: Sphyrna zygaena (Linnaeus, 1758) (updated 2009-06-25)

Diagnosis: head with front contour slightly convex, without median indentation, but scalloped opposite each nostril; head widely expanded laterally (hammer); corners of mouth anterior to outer posterior corners of head; eyes close to nostrils, being separated by a distance of about half the horizontal diameter of eye; prenarial grooves developed; teeth smooth-edged in young, tending to become weakly serrate with growth; fifth gill opening about as long or shorter than first gill opening, both somewhat shorter than three middle slits, the fifth being situated behind pectoral fin origin. Posterior lobe of first dorsal fin anterior to origin of pelvic fins; free posterior tip of second dorsal longer than its anterior margin, but well ahead of pre-caudal pit; pelvic fins low and not falcate. Colour: deep olive to brownish-grey above, shading to white below; pectoral fin tips sometimes faintly grey-black ventrally. Size: to about 4 m, usually to 3.4 m.

Habitat: epipelagic and inshore antitropical in coastal waters of temperate regions from coast to about 20 m. Food: pelagic fishes and squids. Reproduction: viviparous; number of embryos to 37; size at birth 50-60 cm.

Distribution: Atlantic coasts northward to British Isles, also Mediterranean. Elsewhere, southward to Senegal, also South Atlantic, western Indian Ocean and temperate Pacific.

Complementary iconography. Herald, 1961, left fig. on p. 30.
Eggs, larvae and young stages. Bigelow and Schroeder, 1948: 441 | Tortonese, 1950: 54, fig. 4. (embryos) | Capapé, 1974a: 339.