Acclimation: invertebrates cope badly with even small changes in water chemistry, and clams are sensitive to salinity changes. Acclimate it slowly, by floating and then drip, and never rush the process. It must then get used to the light: a clam under 5 cm has a thinner mantle and is more sensitive to very intense lighting. Start it on the bottom, on a small rock or in a dish of coarse substrate, then move it up gradually, as you would a newly added coral.
Setup: it needs a large, well-established reef tank, powerful lighting and strong, intermittent flow (powerheads, wavemaker). In culture it grows about 12 cm a year: an adult far outgrows any hobby aquarium. Set it on sand or rubble, as in the wild. Keep nitrate and phosphate as close to zero as possible, with high pH, alkalinity and calcium; LiveAquaria advises adding calcium, strontium, iodine, magnesium and trace elements. Never pull it off once it has attached: the foot and tissues would be fatally damaged. As a last resort, cut the byssal threads one by one with a razor blade, close to the surface, without touching the tissue.
Tankmates: it is a peaceful animal that harms nothing, but in an aquarium anemones, triggerfish and puffers may attack it, and a wandering anemone may sting it. Inspect it before adding it, and quarantine it if you can, to spot parasitic Pyramidellidae snails: they are white, conical, a few millimetres long, and feed on the clam on its shell and foot until it weakens or dies. Remove them by hand (a toothpick will do), checking day after day; the wrasses Halichoeres melanurus and Halichoeres chrysus eat them.
Health signs and sensitivities: the mantle edge carries hundreds of simple eyes; the clam partly closes when the light dims, a shadow passes or an object moves, which is a normal reflex. A mantle that no longer opens fully for several days, on the other hand, should make you look for parasites. Like all invertebrates, it does not tolerate copper treatments. It builds its shell from calcium carbonate, so it draws on the tank's calcium and alkalinity.
Water: aim for 22 to 25.5 °C, a specific gravity of 1.023 to 1.025, pH 8.1 to 8.4 and an alkalinity of 8 to 12 dKH.
