Реферат: The Giant Clam Essay Research Paper The

Название: The Giant Clam Essay Research Paper The
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The Giant Clam Essay, Research Paper

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.