Keeping Tridacna Clams in a Saltwater Aquarium

We'd like to start with something of a rather personal nature. NO ONE should attempt keeping a CROCEA in a home aquarium. Everyone here has been in the industry at least 20 years. Crocea clams are one of the only reef creatures, in our opinion, that should be left in the wild. Over the last 2 decades we've had hundreds of people try to counter this claim, but we have never seen a picture of a Crocea after 3-5 years in captivity that still had vibrant color, ever.

Clams need several types of food. Clams have almost every organ humans have including a stomach. “Food” is such a broad range of things when it comes to clams. Because “food” to a clams means both proper lighting and plankton….

Every clam has a symbiotic relationship with Zooxanthellae. Symbiotic is where two organisms reside together in the same area and usually at least one benefits from the relationship they have. Zooxanthellae is a type of unicellular algae. Zooxanthellae are responsible for the coloration of the clam, and reside within a small maze of tubes located on the outside of the clams’ mantle (soft fleshy colorful part of the clam). These tubes extend from the stomach of the clam into the mantle. If the zooxanthellae die, the clam will lose its unique color and pigmentation and turn white. This is known as "bleaching". Zooxanthellae are photosynthetic organisms. They harness light and transform the light into energy-rich compounds, which are then transferred to the coral polyp.

One rather important factor about zooxanthellae is they need certain nutrients, such as nitrogen and phosphate, to survive and continue photosynthesis. Zooxanthellae can acquire these nutrients from the clam itself. BUT, the clam can only obtain these nutrients that are so essential to the Zooxanthellae through the capturing and digestions of plankton and other food it eats. One cannot survive without the other, Zooxanthelae and clam, and in the long term both will perish without the other performing the tasks that it needs to.

The Zooxanthellae, by means of photosynthesis, provide clams with the same nutrients that corals receive from their host. The Zooxanthelae within a clam transforms broken down nitrogen and carbon dioxide into carbs for the clam. As with corals, glucose is the primary carbohydrate that Zooxanthelae produce for their host. This symbiotic relationship is just another amazing example of how the organisms in our marine tanks co-exist.

One reason this is an important factor is because the little Zooxentallae power plant basically shuts down at night while the lights are off. As most people can derive from looking in their tank this is usually when the coral polyp or clam is closed. This requires a large amount of energy to stay closed. Think of it as making a fist. This is why the majority of people will feed their corals at night when the tentacles are fully extended in search of particles floating around the tank. That is why plankton, both Zooplankton and Phytoplankton, are such an important factor to both corals and clams surviving. It IS best to feed corals at night; and usually clams aren't too finicky about when they eat during the day. The plankton that your corals and clams take in after the lights have gone out will go a long way to keeping them happy and stress free.

Lighting is an extremely important factor when it comes to clams surviving; just as important as plankton.  And not just regular light, but the right type of light. Good strong lights with the ability to produce a full spectrum of lighting, including UV lighting, is extremely important to either reef member thriving in your tank. The Zooxanthelae within both organisms require a very good light source in order to transform the nutrients they consume into a viable source of food for the clam itself. Without an adequate light source, meant for helping a reef tank flourish, the Zooxenthalae will not be able to continue feeding the coral or clam. Just something to keep in mind before making a light purchase. Do your best to ensure your corals and clams are kept as happy as possible, so your tank offered years of viewing pleasure.

If there are any other questions about corals please contact us.

Reef2Land LLC