Crocea Clam

The crocea clam is the smallest species of the genus Tridacna; its shell rarely exceeds 12–15 cm. In the wild it bores into coral rock and embeds itself, leaving only its mantle outside; this is why it is also called the "boring clam" in English. Its mantle is extremely bright in electric blue, orange, gold or a mix of these colors. Because it gets most of its food from the symbiotic algae in its mantle, it needs very strong light. Legal note: All Tridacna species are listed in CITES Appendix II; only documented, preferably farm-raised individuals should be bought.

• 100 liters or more, a mature reef at least 6–12 months old.
• Salinity 1.024–1.026 specific gravity, pH 8.1–8.4, temperature 24–27°C; calcium 400–450 mg/L, alkalinity 7–9 dKH, magnesium 1250–1350 mg/L, all stable.
• It should be placed on a solid rock in the brightest part of the aquarium. Reef-safe.
• It should be acclimated by the drip method for at least 1 hour and not exposed to air; copper-based medications are lethal.

It feeds on light; small individuals also filter phytoplankton. Giving phytoplankton a few times a week is recommended for juveniles under 5 cm.

It does not move; it quickly closes its mantle when a shadow falls on it or the water is disturbed. White parasitic snails (pyramidellids) that feed at night on the edge and underside of its shell should be checked for regularly.

Good companions: clownfish, gobies, cardinalfish, six line wrasse; shrimp, snails.

Avoid: dwarf angelfish, butterflyfish, triggerfish and pufferfish that pick at the mantle; chocolate chip starfish.