Derasa Clam

The Derasa Clam is also referred to as the Southern Giant Clam or Smooth Giant Clam. The latter name refers to the relative lack of ribbing and scales on the shell. The smoothness of its thick shell, and the 6-7 vertical folds helps to differentiate its species from T. gigas, its larger relative which is not as smooth and has 4-5 folds. In an aquarium, however, scutes may develop on the Deresa Clam. Its mantle is a mixture of orange, yellow, blue, and black and white, and usually has a wavy striped or spotted pattern, usually with vivid blues and greens. It has a narrow byssal opening and the incurrent siphon has tentacles. This species is one of the largest of the "giant" clams, and grows rapidly, reaching a maximum size of approximately 20 inches. Under the proper conditions, smaller Derasa Clams can double or triple their size in less than a year. Those in the aquarium trade are usually cultured.
The Derasa Clam is the most widely available and hardy of the Tridacna clams. It needs bright lighting supplied by intense flourescent or metal halide lamps to live, grow, and keep its bright colors. The type of lamp will depend on the depth of the tank and the position of the clam. A daylight fluorescent tube is also recommended. The Deresa Clam requires calcium levels of 400-480 mg/L, and an alkalinity of 7 to 12 degrees. Proper levels of strontium and iodine are also needed.

The Deresa Clam relies heavily on the photosynthesis of the zooxanthellae cells growing in its mantle. However, all clams also require micro foods designed for filter feeders, especially when small. Offer phytoplankton and other micro-foods, such as Marine Snow.

Quick Stats:
Care Level: Moderate
Temperament: Peaceful
Lighting: Moderate
Waterflow: Medium
Water Conditions: 72-78° F, sg 1.020-1.025, pH 8.1-8.4, dKH 8-12
Max. Size: 1' 8"
Color Form: Blue, Green, Yellow
Supplements: Calcium, Trace Elements
Origin: Aquacultured, Cook Islands
Family: Tridacnidae

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