When purchasing a Tridacnid clam and placing it in your aquarium, be mindful of how large the clam can get and how big the opening of the aquarium is. Many times, we’ve heard stories of people buying T. gigas clams, placing them in a tank for several years, only to find that the clam was almost too big to remove. The hobbyist would have to basically tear down the entire tank just to remove the clam, causing a huge disruption to all of the other livestock. Nowadays, T. gigas clams are extremely hard to come by, and therefore not a problem anymore. That said, T. derasa and T. squamosa clams can still get quite large, and both readily available. They could present issues for certain tanks as well.