Aquarium Livestock Pet Care Guides

Derasa Clams

Natural Habitat

Indo-West Pacific

Tank Temperature




Specific Gravity


Tank Requirements

Requires very low Nitrates, pristine water quality.


Photosynthetic, filter-feeder; regular feedings of phytoplankton and zooplankton and high direct lighting.


Can be placed on the substrate, on rubble piles, or on a hard surface like rockwork. Color, pattern and shell shape can vary greatly.


Reef and Invert Safe. Should not be kept with fish or invertebrates that will pick at their sensitive mantle.

Species Overview

Clams are wonderful additions to any reef aquaria, but they do have some requirements that make them more difficult than other inverts to keep. Some research is recommended before purchasing clams to find out what species will work the best in your reef aquarium.

Derasa Clams (Tridacna derasa) can grow quite large in the home aquarium. They typically have a yellow or gold-striped mantle edged in brilliant blue or purple. Mantle pattern and colors varies between individual specimens. Unlike most other species of clams, the Derasa Clam has a mostly smooth shell without prominent scutes. They generally have six or seven vertical folds, but may have up to twelve. The shell itself is white and fan-shaped when small, becoming slightly more elongated as the clam grows. These clams are more narrow than other species. The byssal opening (where the foot and byssal threads are extended from on the bottom of the clam) is very small - more slot-like in shape rather than the elliptical or circular opening found on other clams. Some Derasa Clams may have no visible byssal opening at all. The top edge of this clam is symmetrical and the clam can close up very tightly.

Derasa clams are found on a variety of surfaces. They can grow within colonies of corals (especially Acropora corals) or on sandy flats, rubble piles or rock faces. They are usually found in fairly shallow waters, but some thrive in deeper where the water is very clear.

Derasa's are one of the hardiest Tridacna species. They require strong, direct light. Smaller clams rely heavily on planktonic foods filtered from the water for their nutrition. They should be fed regularly with various types of invert foods like phytoplankton, zooplankton, oyster eggs, rotifers and similar items. Avoid keeping with potential predators

We always suggest that you do further research before adding a new pet to your tank. What we have provided for you are guidelines and suggestions. If you have any further questions or concerns, please contact our fish room at 717-299-5691 ext. 1213 or

Recommended Items

Wave Maker
LED Lighting
Coral & Invertebrate Food
Aragonite Sand
Calcium & Reef Building Supplements