FAO Species Identification Guide for Fishery Purposes Western

1362 Sharks
2a. Anterior margin of head nearly
straight in adults, moderately
convex in young; prenarial
grooves hardly developed; teeth
strongly serrated at all sizes; first
dorsal fin markedly falcate; second
dorsal fin about 1/3 as high
as first, with a short inner margin;
posterior margins of second dorsal
and pelvic fins deeply concave
(Fig. 2) . . . . . . . . Sphyrna mokarran
2b. Anterior margin of head moderately
convex in adults, strongly so
in young; prenarial grooves well
developed; teeth generally
smooth, but may be finely ser-
rated in adults; first dorsal fin erect or slightly falcate; second dorsal fin less than 1/3 the
height of first, with a long inner margin; posterior margins of second dorsal and pelvic
fins slightly concave to nearly straight (Figs 3 and 4) . . . . . . . . . . . . . . . . . . . . . . . → 3
3a. Median indentation present on anterior margin of head; free rear tip of second dorsal
fin nearly reaching upper caudal-fin origin; anal-fin base noticeably larger than that of
second dorsal fin (Fig. 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sphyrna lewini
3b. Median indentation absent from anterior margin of head; free rear tip of second dorsal
fin well ahead of upper caudal-fin origin; anal-fin base about as large as that of second
dorsal fin (Fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sphyrna zygaena
median indentation
prenarial groove
List of species occurring in the area
The symbol is given when species accounts are included.
Eusphyra blochii (Cuvier, 1817)
Sphyrna lewini (Griffith and Smith, 1834)
Sphyrna mokarran (Rüppell, 1837)
Sphyrna zygaena (Linnaeus, 1758)
ventral view
of head
Fig. 3 Sphyrna lewini
median indentation
ventral view
of head
ventral view
of head
prenarial groove weak
Fig. 2 Sphyrna mokarran
Fig. 4 Sphyrna zygaena
References
Compagno, L.J.V. 1988. Sharks of the order Carcharhiniformes. Princeton, New Jersey, Princeton University Press,
572 p.
Gilbert, C.R. 1967. A revision of the hammerhead sharks (family Sphyrnidae). Proc. U.S. Natl. Mus., 119:88 p.
Gilbert, C.R. 1967. A taxonomic synopsis of the hammerhead sharks (family Sphyrnidae). In Sharks, skates and rays,
edited by P.W. Gilbert, R.F. Mathewson, and D.P. Rall. Baltimore, Johns Hopkins Press, pp. 69-76.
nostril
nostril