Thursday, November 20, 2014

Let's save the Giant Clam (Tridacna gigas)

Dr Abe V Rotor

Tridacna in its natural habitat - lighted seafloor

Tridacna graveyard.

Tridacna shell for holy water, Mount Carmel Church, QC

Facts about the giant clam, Tridacna gigas.

1. In the Philippines it is called taklobo. It is the largest living bivalve mollusk and one of the most endangered clams.

2. It lives on shallow coral reefs of the South Pacific and Indian oceans, up to 20 meters deep.

3. It weighs more than 200 kilograms (440 pounds), and measures as much as 1.2 m (4 feet) across. It has an average lifespan in the wild of 100 years or more.

4. Although larval clams are planktonic, they become sessile in adulthood. Growth is enhanced by the clam's ability to grow algae in symbiosis. The creature's mantle tissues act as a habitat for the symbiotic single-celled dinoflagellate algae (zooxanthellae) from which it gets its nutrition. By day, the clam opens its shell and extends its mantle tissue so that the algae receive the sunlight they need to photosynthesize.

5. T. gigas reproduce sexually. They are hermaphrodites (producing both eggs and sperm), but self fertilization is not possible. Since giant clams can't move across the ocean floor, the solution is broadcast spawning. This entails the release of sperm and eggs into the water where fertilization takes place.

Let's protect the giant clams. It's better to be assured they are alive on the seafloor than to have their fossils in our home.~

References: Marine Biology: An Ecological Approach by JW Nybakken; Wikipedia.

1 comment: 
Mammoth said...

It is a 'rare' balance achieved when any resource or endangered species is labeled for protection. 'Endangerment' is attached to many marine species as to be all encompassing in scope. There are just hundreds of thousands fossil 'Giant Clam' shells of various species that need not be 'protected.' It is the agenda of the American government to restrict fossil collecting and 'personal' research is controlled. The collecting of ancient fossils in the case of the 'Tridacna' Giant Clam is made illegal for transport internationally as the modern species is under protection." "Because of this unfair imbalance I cannot support the current bi-lateral agreement provisions."August 27, 2010 at 5:08 PM

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