FAO Species Identification Guide for Fishery Purposes Western

Carcharhinidae 1335
Carcharhinus falciformis (Bibron in Müller and Henle, 1839)
Frequent synonyms / misidentifications: None / None.
FAO names: En - Silky shark; Fr - Requin soyeux (= Réquiem soie, Area 31); Sp - Tiburón jaquetón.
Diagnostic characters: A large shark, with an
elongate and slender body. Snout narrowly
rounded, moderately long, equal to or slightly
shorter than mouth width, but longer than internasal
space; labial furrows very short; anterior nasal flaps
low, rudimentary; spiracles absent; upper teeth
with relatively narrow cusps well delimited from
the heavy, serrated bases, their outer edges
notched; teeth in lower jaw erect, their edges only
slightly serrated. First dorsal fin moderately high, its
apex rounded, its origin behind the free rear tips
of pectoral fins; second dorsal fin very low, its
ventral view
of head
upper and lower
tooth near centre
posterior lobe noticeably long and slender, its inner margin twice the height of fin, its origin about over that
of anal fin; pectoral fins long and falcate, more so in adults than in young; interdorsal ridge present. Colour:
back dark grey, greyish brown or bluish black (in life); belly greyish or white.
Size: Maximum total length 3.5 m; commonly to 2.5 m; size at birth 57 to 87 cm.
Habitat, biology, and fisheries: Inhabits oceanic waters near and beyond the continental slopes, but also found
in coastal waters. Lives usually near the surface, but occurs sometimes at considerable depths (to 500 m).
Viviparous, number of young 2 to 14 per litter. Feeds chiefly on fishes, including tunas, squids, and pelagic
octopuses. Very quick in its movements, it often causes damage to the catch and gear in tuna fisheries. Reported
to be dangerous to humans. This species is very commonly taken by pelagic longline fisheries, but is also taken
in fixed bottom nets and probably also drifting gill nets. Its meat is used fresh or dried-salted for human
consumption, its hide for leather, its fins for shark-fin soup, and its liver is extracted for oil, which has a high
Vitamin A content.
Distribution: Circumglobal in
tropical and subtropical seas;
in the western Atlantic from
Massachusetts to southern
Brazil, in the eastern Atlantic
from Madeira to northern
Angola, in the Indian Ocean
off East Africa, Red Sea, Gulf
of Oman and South India,
widespread in the western
Pacific (including Japan and
New Zealand), and in the
eastern Central Pacific from
southern Baja California to
Peru.