Taxonomy
The sand tiger shark was originally named Carcharias taurus by Rafinesque in 1810.
Since then it has also been referred to literature as Odontaspis taurus Rafinesque 1810,
Eugomphodus taurus Rafinesque 1810, Odontaspis americanus Mitchill 1815, Squalus
americanus Mitchill 1815, Carcharias griseus Ayres 1843, Odontaspis arenarius Ogilby 1911,
Carcharias arenarius Ogilby 1911, Odontaspis platensis Lahille 1928, and Carcharius
platensis Lahille 1928.
Common Names
English language common names include sand tiger shark, grey nurse shark, ground shark,
spotted raggedtooth shark, slender-tooth shark, spotted sandtiger shark and ground shark.
Other common names are bacota (Spanish), pintado (Spanish), sarda (Spanish), cação-da-areia
(Portuguese), mangona (Portuguese), tavrocarcharias (Greek), chien de mer (French), kalb,
(Arabic), grauer sandhai (German), hietahai (Finnish), karish khol pari (Hebrew), oxhaj
(Swedish), zandtijgerhaai (Dutch), peshkaqen i eger (Albanian), shirowani (Japanese) and
spikkel-skeurtandhaai (Afrikaans).
Geographical Distribution
The sand tiger shark can be found in most warm seas throughout the world except for the eastern
Pacific. In the western Atlantic Ocean it ranges from the Gulf of Maine (U.S.) to Argentina and is
commonly found in Cape Cod (U.S.) and Delaware Bay (U.S.) during the summer months. In the eastern Atlantic
it can be found from the coast of Europe to North Africa and within the Mediterranean Sea. Its
range also extends from Australia to Japan and in the waters off South Africa.
World distribution map for the
sand tiger shark
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Habitat
Commonly found inshore ranging in depths from 6 to 626 feet (1.8 to 191 m), the
sand tiger shark’s range extends to a variety of areas including the surf zone, shallow bays, coral
and rocky reefs and deeper areas around the outer continental shelves. C. taurus is
often found on the bottom but can also be seen throughout the water column. The sandtiger is migratory within its region, moving poleward during the summer while making equatorial
movements during the fall and winter months.
Biology
Sand tiger shark © Doug Perrine
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- · Distinctive Features
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The sand tiger shark is a large, bulky shark with a flattened conical snout and a
long mouth that extends behind the eyes. The first dorsal fin is set back and is
much closer to the pelvic fins than the pectoral fins. The anal and dorsal fins are
large and broad-based and the second dorsal fin is almost the same size as the first
dorsal. Gill slits are anterior to the origin of the pectoral fins in this species.
The caudal fin of the sand tiger shark is asymmetrically shaped with a strongly pronounced
upper lobe.
Sandtiger shark showing near
equally sized dorsal fins and reddish-brown spots © Doug
Perrine
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- · Coloration
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Coloration of the sand tiger shark is generally light brown or light greenish – gray above and
grayish white below. Many individuals have darker reddish or brown spots scattered on the
body.
Sand tiger shark dentition source Bigelow and Schroeder (1948) FNWA
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- · Dentition
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The teeth of the sand tiger shark have prominent narrow cusps with lateral cusplets. The upper
anterior teeth are separated by small intermediate teeth. The upper teeth number 44 to 48
and the lower teeth number 41 to 46. The teeth in the corners of the mouth are very small
and numerous. The ragged looking teeth give the sand tiger shark a distinct menacing look.
Sandtiger shark denticles, A.
Dermal denticles, B. Apical view of dermal denticle source
Bigelow and Schroeder (1948) FNWA
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- · Denticles
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Dermal denticles are loosely spaced and ovoid lanceolate shaped with three ridges.
The axial ridge is prominent and sharp-edged anteriorly but usually is subdivided and
flat-topped posteriorly. In individuals around 3.3 feet (100cm) long denticle sizes are about
0.016 inches (0.4mm) broad by 0.018 inches (0.45mm) long.
Sand tiger shark © Doug Perrine
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- ·Size, Age, and Growth
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Average size ranges from four to nine feet with maximum length believed to be around
10.5 feet (320 cm) in females and 9.9 feet (301 cm) in males. Male maturity is reached at
6.3 feet (190-195 cm) at four to five years of age. Female maturity is reached at six years
or over 7.2 feet (220 cm) in total length. Individuals in aquariums have lived to be
16 years old.
Mutton Snapper
(Calamus penna) are prey for the sand tiger shark
© David Snyder
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- · Food Habits
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The diet of this ravenous feeder mainly consists of a wide variety of small bony fish
including herrings, bluefishes, flatfishes, eels, mullets, snappers, hakes, porgies,
croakers, bonito, remoras, sea robins and sea basses. Other prey items of the sandtiger
are rays, squids, crabs, lobsters and other smaller sharks. Cooperative feeding has been
observed by schools of sharks surrounding and bunching schooling prey in order to feed
on them.
Juvenile sand tiger shark © George Burgess
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- · Reproduction
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Embryonic development is ovoviviparous with ovophagy and embryophagy occurring in the uteri.
Usually only one pup survives in each uteri since the largest embryo ends up eating all of its
smaller siblings during gestation. This generally limits litter sizes to two individuals.
At 6.7 inches (17 cm) embryos have functional teeth and are feeding and at 10.2 inches (26 cm)
they are able to move in utero. Gestation periods are believed to be around eight to nine months
long and pups generally measure 39 inches (99 cm) at birth.
A pair of sand tiger sharks
© Doug Perrine
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- Predators
- Juveniles are susceptible to predation by larger sharks.
Mature individuals have no major predators.
Distinctive Behavior
Since the sand tiger shark is denser than water and lacks a swim bladder like bony fish, it
has adopted a behavior that allows it to become neutrally buoyant in the water column.
The shark comes to the surface and gulps air, which it holds in its stomach. This allows
the shark to hover motionless in the water.
Sandtiger sharks are occasionally caught by recreational
fishers © T. Abraham and J. Strahm
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Importance to Humans
In the North Pacific, northern Indian Ocean and off the tropical west coast of Africa,
the sandtiger is commercially fished for food. The meat is utilized, fresh frozen and
dried-salted, fins are sold in oriental markets for sharkfin soup and jaws and teeth are
used for trophies and orniments. The sand tiger shark is not a commercially targeted species in
North American waters, partially due to its protected status. In some instances in
Australian waters the sand tiger had been killed by divers using underwater weapons since
it is slow moving and approachable. This practice was banned in Australia in 1984.
Sandtigers survive very well in aquariums and are a favorite because of their large size
and fierce look. This shark also inhabits coastal waters and popular dive sites,
such as shipwrecks, where they can be observed by recreational divers.
Danger to Humans
Underwater observations of this shark reveal that it is not aggressive unless provoked.
Its size and jagged teeth demand respect and have given it an undeserved reputation as a
maneater in Australia, where it is often confused with other species, mainly requiem sharks.
It has been known to attack people when provoked, especially when they are spearfishing.
There have been accounts of sandtigers stealing fish off stringers and spears underwater.
In total there have been relatively few documented attacks on humans. ISAF records account
for only 29 unprovoked attacks with two resulting in fatalities.
Sandtiger shark near a
shipwreck © Doug Perrine
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Conservation
Currently sand tiger sharks are regulated in the commercial longline shark fishery on the
east coast of the United States by the National Marine Fisheries Service where it is
identified as a prohibited species. Any sand tiger caught must be immediately released
with minimal harm to the shark. The World Conservation Union classifies the sandtiger
as "Vulnerable", which means it faces a high risk of extinction in the wild in the medium
term future. This is due to an observed, estimated, inferred or suspected reduction in
the population of at least 20% over the last 10 years or three generations. Since the
sand tiger’s reproductive rate is very low, only one or two pups per mature female every
one or two years, the population needs to be closely monitored. Catch rates of
populations in Australia and South Africa have shown declines due to
commercial fishing, spearfishing and beach meshing. Even with status as a protected species, the recovery of the sandtiger shark off the coast of Australia has been very slow.
Prepared by:
Peter Cooper
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