They can grow up to 4.5 feet long and weigh over 700 pounds. It is unclear how T. gigas can reach such a massive size.
The clams are also engaged in a mutually beneficial relationship with algae. They provide shelter for the algae, while the algae produce extra nutrients to feed the clams.
The last time an assessment of the T. gigas population took place was in 1996. That was when the IUCN listed the species as “vulnerable.” Many other giant clam species were overlooked back then because of a lack of research.
“This is a major issue in the conservation world. People, even scientists, tend to pay more attention to mammals and birds because they are big, cute, and familiar. So there’s a good chance you can find these animals on the Red List. But marine invertebrates are very neglected,” said Li.
The team of researchers collected data on the 12 giant clam species to do a reassessment. They found that T. gigas had already become locally extinct in regions near Taiwan. Its overall population has decreased by 84 percent over the past 100 years.
In many parts of the world, giant clams are harvested for food, and their shells are used for decoration.
They come in a range of beautiful colors, from turquoise with yellow spots to emerald green with black specks. As a result, they are highly sought-after by fishers.
Climate change is also a major threat to giant clams. They will spew out the algae living inside them when the water becomes too warm. They could starve without the algae.
The National Oceanic and Atmospheric Administration (NOAA) has proposed listing 10 giant species, including T. gigags, under the Endangered Species Act in an effort to save them from extinction.
If approved, the giant clams will be legally protected in the U.S., and the harvesting and trade of wild clams will be prohibited.
