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Great Hammerhead Shark
The Great Hammerhead Shark is also known
as the squat-headed hammerhead shark.
- GREAT HAMMERHEAD SHARK
Scientific Name.... Sphyrna Mokarran
Family Name...... Sphyrnidae
- General Information: The great hammerheads
most striking feature is its wide thick head . The head is indented
at the center of the "hammer", which is almost rectangular
in shape. One of its impressive characteristics is its large,
orca-like dorsal fin. It is the only hammerhead with falcate pelvic
fins. The free tip of the dorsal fin is in front of the pelvic
fin origin and there are no markings on the pelvic fins ( as with
the scalloped hammerhead. )
- Size: The great hammerhead is the largest of
all other hammerheads. The average size of a great hammerhead
is approx.11.6 feet, but can grow up to 20 feet. These sharks average
over 500 pounds but can weigh as much as 1,000 pounds.
Like most sharks the females are larger than the males.
- Teeth and Jaws: Their teeth are triangular
with extremely serrated edges. They have several rows of teeth
that have 24 to 37 teeth per row.
- Color: These sharks are a gray-brown above,
grading to a paler color below.
- Feeding Habits: The Great hammerhead has a
very keen sense of smell, that helps find its prey and is an impressive
predator. It feeds on other sharks and bony fishes such as sardines,
herring, sea cats, groupers, squid and crustaceans. But this shark
is best known for its fondness of stingrays, butterfly rays, guitar fishes.
In its voracious and unique predatory behaviour toward stingrays, even
though the rays are armed with one or more venomous spined, or
" stingers " on their tails. Hammerheads do not seen
to mind being stung. The great hammerhead uses the side of its
head to pin a fleeing ray to the bottom. It then rotates its head
to the side and cleanly bites off a large chunk of the ray's wing.
- Senses: Great hammerheads swing their heads
from side to side as they swim along, which gives them an excellent
all-around view, since their eyes are right at the tips of their
hammers. Their broad heads bear many ampullae of Lorenzini, which
sense tiny electric currents generated by their prey.
- Social Behaviour: Unlike the smoothead this
is a solitary species. Some populations display migratior behaviour,
moving into warmer waters in the winter. This shark has been reported
to be avoided by other shark species, possibly because of its
taste for elasmobranch flesh and its superior maneuverability.
- Habitat | Migration | Distribution: Great hammerheads
are found in temperate and tropical oceans around the world. It
occurs in coastal areas above continental and island shelves,
and adjacent offshore waters to depths of about 260 feet. Divers
are likely to see it in shallow waters close to shore, especially
near coral reef drop-offs and adjacent sand habits. It makes long
migrations to cooler waters during the summer months.
- Life Span: The Great Hammerhead Shark usually lives
between the ages of 20-30 years.
- Reproduction: The great hammerheads are viviparous,
giving birth to live young. The females reach sexual maturity
when about 10 feet long. They usually produce 20-40 pups per litter,
and the pups are about 2 1/4 feet long at birth. Gestation period
is about 11 months.
- Great Hammerhead Shark Attacks: The great hammerheads
do not attack humans unless bait attracts them to an area where
- Population Report: Common.