Derasa Clam (Tridacna derasa)
The derasa clam is desired by hobbyists for its beauty and fascinating behavior. This animal relies on two very different sources of nourishment. Like many other bivalve mollusks, it filter-feeds on phytoplankton through its gills. However, most of its daily sustenance comes from a symbiotic algae. At a maximum length of about 60 cm, T. derasa is one of the largest of the giant clams. However, it arguably stands out most for its elegant appearance. This species builds a relatively smooth shell and is richly colored with bright gold pigments.
See below for more information.
Size and Care Requirements
- Purchase Size: Approximately 2″+ 0.5″ (length)
- Purchase Size: Approximately 5″+ 1″ (length)
- Max Size: 20 cm (7.9″)
- Water Parameters: 72-78° F, dKH 8-12, pH 8.2-8.4, sg 1.023-1.025
- Color: Golden brown (mantle) with darker markings
- Reef-Safe: Yes
- Diet: Omnivore. In addition to consuming products released from its symbiont, this clam is a phytoplanktivore. Thus, it benefits greatly from the regular addition of live phytoplankton.
Derasa Clam Species Information
The derasa clam (Tridacna derasa) occurs from Australia and Fiji to Indonesia, Palau, Solomon Islands, Tonga, Papua New Guinea, the Philippines and Vietnam. Populations have also been reintroduced (after local extinctions) to the Federated States of Micronesia, Guam and the Northern Mariana Islands. Whether living on reef rock, over sand or nestled between corals, T. derasa prefers brightly sunlit habitats. It’s dependence on intense light arises from it’s dependence on an endosymbiotic dinoflagellate. This photosynthetic algae needs strong, full-spectrum light to survive.
The derasa clam is totally reef-safe. Beautiful and interesting, Tridacna derasa adds an exotic touch to any mature, well-maintained reef tank. It can’t be kept safely with certain predatory fishes such as triggerfish, puffers, certain wrasses, etc. A sustainable alternative to wild-caught derasa clams, these aquacultured specimens have a comparatively higher survivability.
Benefits of Aquacultured Aquarium Livestock
Captive-bred derasa clams provide a huge advantage over wild-caught specimens. Because they are cultured under captive conditions, they are better adapted to living in an aquarium and tend to be more resistant to disease. They are also better capable of handling shipping stress. By purchasing captive-bred organisms, you are supporting the aquaculture of marine organisms and helping make our hobby sustainable!
AlgaeBarn keeps these derasa clams in an invertebrate-specific system to minimize the transfer of fish parasites and other unwanted hitchhikers.
100% Alive on Arrival (AoA) Guarantee
We guarantee that every derasa clam we sell will be Alive On Arrival and in good health. Should any arrive in any other state, we will either replace them free of charge (including shipping). If the total livestock loss is less than $40, we will issue store credit. For more information, please also visit our 100% Alive On Arrival Guarantee page.