Particularly for aquarium animals, the giant clams Tridacna and Hippopus spp. They are, in fact, among the largest of all invertebrate animals. The group claims the most massive living marine bivalve mollusk species. Some giant clams really are gigantic; THE giant clam, T. These strange and beautiful creatures do not become hulks overnight.
Still, their growth rates are pretty high, especially considering where they live. They undoubtedly owe their rapid growth to their broad, and somewhat opportunistic, feeding strategy. Coral reefs are typically very nutrient-poor environments. Many animals there adapt by specializing on a particular food source whereas a few others such as giant clams become highly inclusive.
Tridacnids are somewhat unusual among their bivalve brethren in that they form mutualistic relationships with endosymbiotic dinoflagellates zooxanthellae. During the daylight hours, the clam opens its shell widely and exposes its mantle to the sun.
Some experts insist that along with nutrients taken up directly from the surrounding waters via special epithelial tissues it is possible for tridacnids to survive indefinitely off of the fuel produced by their zooxanthellae. Even so, it appears that giant clams prefer a rather varied diet. One might even consider them to be omnivorous. Though even heavily fed tridacnid clams cannot survive solely by filter feeding, the foods they capture seem to contribute significantly to their growth and development.
A whole lot of things can be found in a giant clam gut. These items are all miniscule in size mostly within microns ; they are, however, highly varied in composition. Gut contents range from detritus to tiny zooplankton and bacterioplankton. Tridacnids even consume unneeded zooxanthellae.
But a substantial portion of the suspended material that giant clams capture and eat consists of assorted phytoplankton. Thankfully, giant clam aquaculture is successfully replacing wild harvesting, while giant clams in the wild are under strict protection by the Endangered Species Act.
Giant clams grow to their enormous size by eating the sugars and proteins created by the billions of symbiotic algae that live inside their tissues. Thanks to their intimate relationship with plant-like algae, giant clams can live up to years and beyond. The giant clam provides a safe home and regular exposure to sunlight for the algae. The omnivorous giant clam uses its siphons pipes to expel bodily fluids and draw water to filter and eat plankton and other small prey that swim nearby.
Like coral, algae is the food of choice for giant clams. Below depths of about 66 feet 20 m , the sunlight is too weak to support the algae these mollusks depend on to survive. Thankfully, there is no real account of a human being consumed or killed by a giant clam. Even the largest of clams would retreat into the safety of its shell instead of tasting human prey.
Save my name, email, and website in this browser for the next time I comment. Unfortunately, this hunting has put the species at risk, and conservationists now consider it to be vulnerable to extinction.
Recent large-scale aquaculture operations have reduced the pressure on wild populations while allowing for continued human use of this vital protein source particularly on remote islands in the Pacific and Indian oceans. This species is also a favorite in public and private aquaria. Most individuals currently on display were likely raised in captivity rather than collected from the wild.
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