The Giant Clam is a pretty animal because of its beautiful color patterns on its mantles. The giant clams are the members of the clam genus Tridacna that are the largest living bivalve mollusks. There are actually several species of "giant clams" in the genus Tridacna, which are often misidentified for Tridacna gigas, the most commonly intended species referred to as “the giant clam”.
The giant clams mostly found in shallow coral reefs of the Indian and Pacific Oceans, especially around Indonesia, the giant clam can grow up to about 1.2 m, weigh can be more than 200 kg and live can be more than 100 years, being the largest living bivalve mollusk.
One interesting aspect of the giant clam and its close relatives is that they live in a symbiotic association with some dinoflagellates (the so-called zoxanthellae, also found in corals), having even a special structure, the zooxanthellal tubular system, to house them. During the day, the giant clam exposes its mantle to the light in order to allow the algae to photosynthesize. Part of the nutrients produced by the algae are given to the clam. This allows the giant clam to survive in otherwise nutrient-poor environments, where its standard bivalvian feeding stile, by filtering partiles from the water, would not be enought to allow it to grow properly.
The giant clam lives in flat coral sand or broken coral and can be found at depths of as much as 20 m, and it become extinct in many areas where it was once common. The Tridacna Maxima clam has the largest geographical distribution among giant clam species; it can be found off high or low elevation islands, in lagoons or fringing reefs that offer enough sunlight.
Giant clams play various ecological roles within coral reef ecosystems, they are suppliers of food and shelters, contributors to reef productivity, and builders and shapers of reefs.
Moreover, giant clams counteract eutrophication, the nutrient enrichment of water that typically leads to excessive algal growth, by filtering the water and sequestering nutrients. Giant clams also contribute to the topographic relief of reefs, which in itself modifies or creates habitat and affects local water flow and their presence is indicative of reef health. Unfortunately, overfishing has put giant clams under great pressure, and their local extinction could be detrimental to coral reefs
The giant clam populations are in decline in much of their native range and they have numerous life characteristics that act against their long term survival. They are slow growing, reaching full sexual maturity between 9-10 years old.
The suite of challenges facing these creatures include overfishing, habitat degradation and destruction, overharvesting for the ornamental trade, and impacts from climate change. These threats have led to local extinctions of multiple species, especially the larger ones.
Tridacna gigas is one of the most endangered clam species, because it is used as food in many countries, especially in Asia. Some Asian delicacies include the meat from the muscles of clams. Additionally, the giant shell is considered a valuable decorative item and can be sold for large amounts of money.
Oceans occupy the largest part of Earth, and are the powerful sourse of energy and life for the humankind.
Countless issues that the oceans are currently experiencing, the extinction of plant and animal species is endangering the functioning of ecosystems and Our concern is needed to help the species that are on the edge of extinction!.
