Care guide, husbandry, breeding, disease, sourcing, and tankmate intelligence on Derasa Clam - written by the Fast Aquatics editorial team and cross-verified against vendor records on the live marketplace.
Derasa Clam (Tridacna derasa) is a marine invertebrate kept by aquarists for reef-tank cleanup, biological control of pests, or aesthetic display. Hardy and forgiving of typical beginner mistakes when given proper water chemistry.
Where Derasa Clam comes from
Derasa Clam (Tridacna derasa) is native to Indo-Pacific reef ecosystems, with wild populations distributed across coral reefs, sandy lagoons, and rocky tide pools. Captive specimens are typically wild-collected; some species are starting to be aquacultured but most Derasa Clam sold today still comes from wild reef collection. Sustainable sourcing matters - look for vendors who can verify their collection practices, and consider aquacultured alternatives when available.
Derasa Clam tank size and setup
Derasa Clam requires a minimum of 75 gallons for healthy adults. The minimum is based on the species' adult size (24 inches), territorial range, and behavior pattern. Most Derasa Clam sold at small juvenile size will reach full adult size within 12-24 months and the system must be sized to the adult, not the juvenile.
For a Derasa Clam setup: mature reef tank with stable parameters, live rock for cover, sandbed substrate (1-2"), reef-grade lighting if photosynthetic, and a fully-cycled biological filter at least 6 weeks old. Newly-cycled tanks under 6 weeks crash the parameters that Derasa Clam depends on.
Derasa Clam requires standard reef parameters held tightly stable: Temperature: 76-80°F (24-27°C) Specific gravity: 1.025 (refractometer-measured) pH: 8.1-8.4 Alkalinity: 8-9 dKH Calcium: 420-450 ppm Magnesium: 1300-1400 ppm Ammonia + nitrite: Both 0 ppm Nitrate: Under 10 ppm Copper: 0 (lethal to invertebrates)
Derasa Clam is sensitive to copper - never medicate the display tank with copper if Derasa Clam is present. Stable parameters beat perfect parameters.
What Derasa Clam eats
Derasa Clam is a photosynthetic + filter feeder. Powered primarily by photosynthesis through symbiotic zooxanthellae living in the tissue. Supplemental feeding of reef foods supports faster growth but is optional once light + parameters are dialed in. Feed Derasa Clam appropriately for its size + activity level. Overfeeding is the #1 cause of water-quality crashes in tanks of all sizes.
Derasa Clam tankmates and compatibility
Derasa Clam is generally peaceful and compatible with most reef community species. Avoid keeping with predatory fish that view inverts as food: large wrasses (especially halichoeres + thalassoma), triggerfish, pufferfish, and certain large angelfish. Multiple Derasa Clam can share a tank but compete for food.
Browse care guides for tankmate-compatibility tables for Derasa Clam and similar species.
Derasa Clam adult size and lifespan
Derasa Clam reaches 24 inches at adulthood with a captive lifespan of 15-30 years with proper care. Many marine inverts molt periodically; provide adequate calcium and a stable parameter regime to support healthy molts.
Can you breed Derasa Clam?
Derasa Clam breeding in captivity ranges from straightforward (some shrimp, snails) to nearly impossible (most starfish, urchins) due to pelagic larval requirements. Captive-bred specimens are increasingly available from sustainable aquaculture facilities; check with vendors before assuming wild-caught origin.
Common Derasa Clam diseases and problems
Derasa Clam is sensitive to copper, ammonia spikes, low oxygen, and rapid parameter swings. NEVER use copper medications in a tank with Derasa Clam. Symptoms of stress: reclusive behavior, color loss, refusal to feed, abnormal molting (incomplete or stuck molts). Most Derasa Clam deaths trace back to acclimation shock or parameter mismatch - drip-acclimate over 45-60 minutes when adding to a new tank.
Where to buy Derasa Clam online
Derasa Clam is sold at LFS (local fish stores), online retailers, and direct from breeders/wholesalers. Pricing varies widely by source, size, and quality:
Browse live Derasa Clam from vetted Fast Aquatics vendors with carrier-tracked overnight shipping (FedEx Priority + UPS Next Day), climate-aware hold logic, and a 4-hour DOA window with photo-evidence claims. Captive-bred or aquacultured specimens cost more upfront but arrive healthier and integrate faster.
Derasa Clam FAQ
How big does Derasa Clam get?
24 inches at adulthood within 12-24 months.
How long does Derasa Clam live?
15-30 years with proper care.
What is the minimum tank/pond size?
75 gallons, with larger systems strongly recommended.
Is Derasa Clam hard to keep?
Derasa Clam is rated beginner difficulty.
What does Derasa Clam eat?
Derasa Clam is a photosynthetic + filter feeder; appropriate diet matches its natural feeding pattern.