The Littlest Giant (Clam)

For many years, home aquarium keepers were only able to procure one or two species of clams for their home saltwater displays, these two being Hippopus hippopus (with a wide variety of common names), and Tridacna derasa (generally called Derasa) Clams; both of these clams are good choices for the home aquarium, but lack the more distinctive colors and patters of Tridacna maxima and Tridacna crocea both of which were occasionally available as wild caught specimens. Some of this is attributed to both these clams being considered a delicacy in their native ranges. The last 15 years or so have seen huge advancements in mariculturing these species and Maxima and Crocea Clams have become the most readily available clams for the home hobbyist. Even hybrids of these two species aren't uncommon as of the commercial raising of them has resulted in more specific breeding. With very few exceptions (generally for academic research, or brood stock importation) 100% of the Tridacna Clams imported by us here at Quality Marine are aquacultured.

Crocea Clams are some of the most stunning clams you will see in a home aquarium, with patterns and colors in their mantle that are unbelievable. They are likely the smallest of the “Giant Clams” never getting much bigger than five or six inches long. Sometimes called Burrowing Clams for their wild behavior of “burrowing” into calcium carbonate substrate or even rock, this behavior doesn't seem to happen unless initiated when they are miniscule in size. This means this behavior is almost never seen in the home aquarium.

The general aquarium requirements for keeping Crocea Clams should be familiar if you have been studying about or keeping “reef aquaria”. Temperatures should be between 78 and 82, and in our opinion, the lower end of this range is preferable. The pH range should rest between 8.1 and 8.4, For all parameters, stability is incredibly important. Water flow should be turbulent and never laminar; the Mantle (pretty part) of Crocea Clams can be quickly, and irreversibly damaged by a powerhead pointed directly at it. Damaged clams close up, and can actually starve themselves to death by not being able to siphon food or soak up light.

Lighting is a topic of “intense” importance when it comes to keeping Crocea Clams. They do best in high PAR, broad spectrum light, as they come from (and are cultured in) shallower water, so shallow that some wild specimens are found exposed at high tide! Keeping Crocea is often done under Metal Halide lighting as the ability of these lights to produce a wide spectrum of intense light over a broad area is still difficult to match by all but the most intense LED setups; though many hobbyists report having long term success with highest power LED lights as well. Whatever lighting you choose, make sure the placement of your clam allows for it to rest under the brightest portion of the light as deep as possible in your aquarium, after all, clams only look pretty from above.

The biggest surprise / catch point for many aquarists is the water chemistry aspect of keeping clams. Even fairly small clams will drink calcium and alkalinty much faster than some of the most demanding coral. A few clams will go through these elements fast enough to require supplementation, unless water changes are nearly constant. Not ensuring enough calcium and alkalinity is available can be detrimental to health and growth of the clam and other aquarium inhabitants as well. Fear not however, as there are options for maintaining stability here; the easiest way to maintain adequate CA/Alk is likely 2 part supplements, though kalkwasser and calcium reactors are also options. Obviously a detailed testing regimen will be an important part of whatever dosing you choose to utilize.

Here at QM, we have a long history of aquaculturing and conditioning aquacultured clams. In our years of experience holding and raising these species, we've found that feeding and nutrition are vital to clam health, vibrancy and growth. While there are some people who advocate for allowing the clams to subsist on the lighting and secondary food sources in the aquarium, we've found this to be insufficient in most cases. It is true that a large portion of the nutrition needed by most Tridacna can be gained through their native zooxanthellae, however, they are all filter feeders and somewhat dependent on dissolved nutrients as well. In our experience a truly “happy clam” happens through target feeding with Nutramar's blend of Live Micro Algae Products. We utilize these products in house and have had great success with clams we house long term feeding a regular regimen. We see more vibrant coloration and faster growth rates. This line of food has our highest recommendation.

When keeping Crocea Clams (or pretty much any suitable marine clam), you want your clam to stay open and extend its mantle well. Vibrant coloration is a good indicator that the lighting and nutrition are adequate. Your Clams should also be firmly attached, a clam that lets go of its attachment point is likely very unhappy or damaged. As a side note on this point, clams should never be moved forcibly as the “feet” are easily damaged.

If you're looking for the most gorgeous single item you can put in an aquarium, and you're up for maintaining the details to keep it happy, then ask your LFS about an aquacultured Crocea Clam from Quality Marine today!