By Dr. Erich K. Ritter
The tiger shark (Galeocerdo cuvier). The name stems from the typical
stripes found on the backs of young animals which probably serve as camouflage.
© Doug Perrine / Shark Foundation
Tiger sharks (Galeocerdo cuvier) belong to the large-sized species of sharks. Their size is
comparable to that of the white sharks (Carcharodon carcharias), but they look somewhat less
massive. Although they have been proven to be involved in some accidents involving humans,
they are still less well-known among the average population. This is due partly to the fact that
science has not concerned itself so much with this species. Outside of Hawaii there are few
projects specifically involving tiger sharks. This is somewhat surprising since the tiger shark is
one of the largest and perhaps most common predator in the Bahamas, and the second most
caught shark species in the Western Atlantic, the Gulf of Mexico and Cuba (see the special
report "U.S. Government Shark Research Project" in this edition.) So a lot of
mythologies revolve around tiger sharks, especially with members of the local island populations.
They are one of the few shark species who not only change their body forms but also their skin
pattern during growth. Another unique feature of tiger sharks are their astonishingly formed
teeth, allowing them to rip apart almost any prey.
The exterior appearance of a tiger shark is relatively atypical for the family of gray sharks
(Carcharhinidae) for its body is longer and the snout is not pointed but noticeably flat and edgy.
Tiger sharks are the only species of gray sharks with suction holes (Spiraculi). They were given
the name because of the tiger-like pattern on their body during their youth, a pattern which slowly
disappears with age and which eventually may only be faintly or no longer visible. This coloring
probably serves as camouflage because the young usually stay close to the coast, directly
below the water surface, and with their stripes they very much resemble the shadows of
waves in the water.
Tiger sharks usually grow to a length of 5.5 meters, however, assumably they may sometimes
even grow to a size of more than 7 meters (Fourmanoir 1961). Their maximum age can only be
estimated, but they can definitely reach a minimum age of 12 years. Adult tiger sharks do not
really have any more enemies for their size prevents them from being chased by other shark
species. Only the young are exposed to this kind of pressure.
Tiger sharks are noted for having the widest food spectrum of all sharks. They can eat almost
anything, from turtles to birds, as well as other sharks and fish. Besides normal prey they even
eat garbage like tires, nails or car license plates, as sometimes documented by examinations of
their stomach contents. For this reason they acquired the reputation of being "garbage eaters"
and were considered primitive. In reality, it is exactly their diverse food palette and unique
chewing mechanism which today puts them into a different light, for their apparent lack of
specialization indicates a much higher development. Tiger sharks are special because they feed
on a broad spectrum of prey rather than being specialized on specific prey. A shark species
which can grow to a length of 5 meters thus has a selective advantage when its prey is not
restricted (in the sense of their evolution). Sharks of this size need a lot of energy and any
decrease in the numbers of one prey could well pose a threat to such highly specialized forms of
Typical teeth of the tiger shark (Galeocerdo cuvier). The tooth
region which protects the saw from the enormous
biting pressure is marked with an arrow.
© Shark Info
The tiger shark's teeth and jaws is what differentiates this species from other gray sharks and
generally from most other shark species. While the teeth of other sharks which hunt swimming
prey as a rule are designed to cut in the upper jaw region and to grab and hold onto possible
prey in the lower jaw, tiger sharks have rows of almost 24 identical teeth both in the upper and
lower jaws. These teeth have both a cutting as well as sawing region. The flatter, rear tooth
component protects the large saw from the tooth pressure which amounts to three tons per
square centimeters (see photo).
Also in contrast to other sharks, their jaws have a square rather
than round form. The jaw cartilage meets almost at a right angle in the middle of the snout, which
gives this shark its typical appearance.
Pregnancy with tiger sharks lasts between 15 and 16 months. Normally, the young are born with
a length of 50 to 70 centimeters, but depending on where they are born, the young may also be
much larger. For example, in the region around Hawaii their size at birth reaches 80 to 90
centimeters. The average number of pups per litter is 41 (Crow, 1995), whereby the spectrum
fluctuates between 10 all the way up to 80 (Compagno, 1984). Females appear to bear young
only every three years. It is not known if males have a similar cycle, but generally they are
presumed to have more of an annual cycle. Tiger sharks are the only species of gray shark who
do not bear their young live with a placenta (placentally viviparous), but reproduce
aplencentally viviparous. It is unclear if this should be considered a more primitive method of
Tiger sharks are found almost worldwide in tropical and moderate coastal regions, preferring
murky waters and estuaries. In addition to these areas they are found near island groups such
as the Marshall Islands, Hawaii, Tahiti or the Galapagos.
Very little is known about the behavior of tiger sharks. They tend to be active at dusk or at night,
demonstrating different behavioral patterns in various regions, depending on the time of day.
Usually they stay in very flat regions in the evening and at night, preferring to retreat to lower
depths during the day. Youngsters appear to be more active during the day than in the evening
and demonstrate less hesitation to appear directly underneath the water surface. Although
several animals may appear at the scene of food simultaneously, most larger animals tend to go
their own way.
People who are not used to these animals should avoid them whenever possible. They are very
curious and may be rather persistent when encountering skin divers who chase and harpoon
fish. Even though the accident rate should not be overemphasized, it cannot be denied that most
accidents in the tropics are ascribed to tiger sharks. Nevertheless, the danger of being bitten by
a tiger shark is still relatively small - as is the case for all other shark species. In Hawaiian
waters, a region frequented by numerous tiger sharks, the accident rate does not exceed one
It is somewhat astonishing that the old Hawaiians gave the same name to both the tiger shark and
white shark: "Niuhi". Many shark species found in Hawaiian waters were honored as being
sacred and were even considered reincarnations of dead family members.
The "Niuhi" were, however, more feared than adored. Still, both species played a role in local
mythology. Legends suggest that many kings living in the historical Hawaiian environment
acquired their premonition of future events by consuming the eyes of the "Niuhi". It is said that
even the mother of the most famous king of Hawaii, King Kamehameha (born around 1753 and
having died on May 8, 1819) asked for "Niuhi" eyes during her pregnancy because they
supposedly would enhance the leadership qualities of the future king she was carrying. Tiger
sharks were always considered a very special shark species not only in the Pacific but also in
the Maldives, where they were called "Femunu".
Compagno, L. (1984). FAO Species Catalogue. Vol. 4. Part 2. Sharks of the world: 503-506.
Crow. G. L. (1995). The reproductive biology of the tiger shark Galeocerdo cuvierin Hawaii:
A compilation of historical and contemporary data. Abstract, AES-Meeting, Alberta, Canada.<
Fourmanoir, P. (1961). Requins de la côte ouest de Madagascar. Mem. Inst. Sci.
Madagascar (Ser. F). 4: 1-81.
Taylor, L. (1993). Sharks of Hawai´i. Their biology and cultural significance. University
of Hawaii Press.
May be published only by indicating the source: Shark Info / Dr. Erich K. Ritter