Smalltooth sandtiger (Odontaspis ferox)

(Risso, 1810).
Fr |
Requin feroce |
Sp |
Solrayo; Salroig (Catalunya); Salraig
(Llevant) |
It |
Cagnaccio; Smidiru (Messina); Piscicani
(Palermo); Cagnassun de fundo (Liguria) |
Ma |
Silfjun; Kelb
salvagg | Other Scientific Names
Recently Used: Carcharias ferox of authors
Diagnosis
A large, stocky shark with anal fin and second dorsal fin
conspicuously smaller than the first dorsal fin; 1st dorsal
mid-placed on back and closer to pectoral fins than pelvic fins;
pectoral fins short, broad and paddle-like. Origin of second dorsal
over posterior ends of pelvic fin bases, Snout dorsally depressed,
conical and rather long; eyes fairly large, mainly black in colour,
non-feline in appearance and without nictitating eyelids. Mouth
extending posterior to eyes; protruding, fang-like unserrated teeth
with two or more pairs of very prominent lateral cusps; 3 to 5 rows
of smaller intermediate teeth between the anterior ad lateral teeth
of the upper-jaw. Caudal fin strongly asymmetric, without lateral
keels but upper precaudal pit present. Dorsal colour mid-grey or
grey-brown, sometimes with ochre spots on the dorsum and flanks;
ventral surfaces paler grey or white with dusky blotching on ventral
surfaces of pectoral and pelvic fins; some fin apices dusky in
juveniles but indistinct.
Size
To at least 360cm but generally to 300cm; size at birth over
105cm TL.
Status and Distribution
N.E. Atlantic: Infrequent or rare, but probably
wider-ranging in warm-temperate and tropical deep water than current
records suggest. Occurrences mostly confined to coastal zones
adjacent to Mediterranean interface, between 30N and 37N, and
include southern Spain and Portugal; Madeira and Morrocco; nominal
from Gulf of Gascony (northern Spain), suggesting the potential for
occasional captures anywhere along the Portuguese coast. A recent
(1995) record from Natal, N.E. Brazil, represents a substantial
global range extension and supports the inference that these sharks
are actually wide-ranging in warmer parts of the North Atlantic.
Mediterranean Sea Infrequent but more commonly
encountered here than within the N.E. Atlantic. Mainly Western and
Central Mediterranean, deeper waters (coastal) from Gibraltar to
Sicily; Alboran and Catalon Seas off Valencia region and Balearics;
also Cote d'Azur and Ligurian Seas (not frequent); Sardinia;
Tyrrhennian Sea, particularly at islands (e.g., Ponza, Lipari);
Algeria and Tunisia, Sicilian Channel (Linosa, Lampedusa and Malta);
Straits of Messina and Ionian Sea along Italian coastline; also
Adriatic (now mostly restricted to the eastern side, from Split
southwards); Greek mainland coasts, Crete, Aegean Sea and Turkey (at
offshore islands); probably rare or absent to the southeast of
Rhodes but scant data.
Biology
A poorly-known shark of generally deepwater on continental and
insular shelves down to at least 420m, but also infrequently in
shallower littoral waters (less so in the Atlantic), particularly at
remote, rocky islands adjacent to deepwater; found mainly near to
the bottom based on Mediterranean captures. Zava and Montagna (1992)
describe a recent (1991) specimen (female, 230cmTL) taken at Linosa,
Isole Pelagie (Sicilian Chanel) at a depth between 10 and 40m. This
shark is also sporadically caught by setlines south-west of Malta,
at depths of 40 to 200m over rocky bottoms and mainly at night.
Regional feeding ecology is poorly-known, but available data on
stomach-contents demonstrates a primarily piscivorous diet of small
bony fishes, also squid and crustaceans (shrimp). Compagno (1984)
suggests that the less robust and weakly-differentiated tooth
structure of this shark implies a diet of smaller and less active
prey than that of the sandtiger Carcharias taurus. Assumedly
ovoviviparous, but no reproductive data. Females mature at 360cm and
males at 275cm. Note Recent vists by Ian K. Fergusson to
fisheries based in Malta and Sicily demonstrate a wide-ranging
confusion in colloquial names of those sharks including the word
"tiger" in their English names. This is manifested in the belief
that Odontaspis ferox is synonymous with the pan-tropical
carcharhinid tiger shark, Galeocerdo cuvier, not recorded to-date
from Mediterranean waters. English-speaking commercial fishermen
will typically refer to catching "tiger" sharks, when actually
referring to O. ferox . Moreover - to add further to this problem -
the shortfin mako, Isurus oxyrinchus, is also called the
"tiger" shark by many Maltese fishermen. Referral to either
photographs or preserved dentition is typically the only route to
clarify these post-dated misidentifications, yet even single teeth
from O. ferox and I. oxyrinchus are sometimes assumed as
coming from the same shark.
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