The Giant Clam

The giant clam is known as a reef dwelling
mollusk. The domestication factor has

become of large importance to the
Indo-Pacific peoples. Mainly in the area of their diet.

These huge clams
are huge targets for fishermen and can be found easily. With the crystal

water
complection of the reef waters they live in makes them even easier to be spotted
by

the fishermen an by poachers. The people of this region eat every part
of the flesh of the

animal. They either dry, cook, or eat them raw.

In
Taiwan there has been a large illeagal industry of selling these huge clams.
With

a demand of somewhere around 100 tons of the meat a year that is
worth around $7.50-

$21.25 a kilogram at the dockside of Taiwan. It is
being severely poached by foreigners

and the population of the giant clam
is decreasing. The reefs that they live on are also

being severely damaged
and destroyed in large amounts. The giant clam has been

eliminated from
the areas of Indonesia and the Phillippines. The species Tridacnid gigas

and
the Tridacnid derasa are the most heavily hunted species.

Tridacnid gigas
are the largest of the giant clams. They grow to around a meter in

length
and weigh around 300 kilograms. These particular clams are hermaphrodites
which

reach sexual maturity at around five years of age. They spray out
large numbers of their

eggs and sperm into the seawater which then meet
to form a free floating larvae. A large

Tridacnid gigas has the ability
to release hundreds of millions of microscopic eggs in a

single day, which
makes it one of the most fertile marine invertebrates. However most of

the
free floating larvae do not survive during their one week planktonic period.
The ones

that survive settle on a patch of hard reef by means of a sticky
byssal threads and orient

their fleshy mantles towards the sun. They
continue to grow their at a rate of around five

to ten centimeters a year.
But they are not safe from other reef predators until they are

around
2.5 years old, which makes this large species hard to find. About 100 of the


original eggs will eventually become a full grown clam, but that number
is much lower in

dense and exploited areas of a reef. Usually they will
continue to grow in that spot for

several decades. There is also never
any paternal care and the clam will probably move

anywhere but deeper in
the sand.

In the Asia Pacific area there are many groups of scientists
artificially cultivating

these large clams in an effort to learn more about
this rare and extremely over hunted and

captured creature.


Category: Science