Best Saltwater Clams To Add to Your Reef Tank

When given the right conditions in your aquarium, clams are a great option for a reef tank. They are beautiful and they bring biological benefits as well.

Below we list 5 species of saltwater clams that you can add to your aquarium.

Giga clam – Tridacna gigas

  • Scientific name: Giga clam
  • Common Names: Tridacna gigas
  • Lighting: Strong
  • Aggressiveness: Peaceful. If disturbed, the brightly colored mantle tissue (containing zooxanthellae) is retracted and the shell valves are closed.
  • Current: medium to strong
  • Water parameters: High at all time! 24º C to 26º C
  • Hardiness: Easy

Color: Golden brown, yellow or green, although it may contain so many blue or purple spots that the overwhelming impression is of a beautiful iridescent colour. A number of pale or clear spots on the mantle, which are known as ‘windows’ function to allow sunlight to filter in through the mantle.

Feeding: Tridacna gigas can filter particulate food, including microscopic marine plants (phytoplankton) and animals (zooplankton), from seawater using its ctenidia (“gills”). However, it obtains the bulk of its nutrition from photosymbionts living within its tissues.

Origin: Found throughout the Tropical Indo-Pacific oceanic region, from the south China seas in the north to the northern coasts of Australia and from the Nicobar Islands in the west to Fiji in the east.

Propagation: Giant clams reproduce sexually via broadcast spawning. They expel sperm and eggs into the sea. Fertilization takes place in open water and is followed by a planktonic larval stage. The larvae (veligers) must swim and feed in the water column until they are sufficiently developed to settle on a suitable substrate, usually sand or coral rubble, and begin their adult life as a sessile clam.

Additional information
Can grow to over 4 feet in length and weigh 440 pounds. Giant clams occupy coral reef habitats, typically within 20 meters of the surface. They are most common found in shallow lagoons and reef flats, and are typically embedded in sandy substrates or those composed of coral rubble.


Spotted Clam – Hippopus hippopus

  • Scientific name: Hippopus hippopus
  • Common Names: Bear Paw, The Horse’s Hoof, Strawberry Clam, Horseshoe or Spotted Clam
  • Lighting: High lighting, preferably metal halide.
  • Aggressiveness: peaceful
  • Current: Medium to strong
  • Hardiness: They are very hardy and easy to keep.
  • Color: Various
  • Feeding: Mostly light. Need trace elements
  • Water parameters: Calcium must be around 400ppm to 450ppm.

Origin: This species is found in American Samoa, Australia, Fiji, Guam, possibly India, Indonesia, Japan, Kiribati, Malaysia, Marshall Islands, Micronesia, Myanmar, New Caledonia, Northern Mariana Islands, Palau, Papua New Guinea, the Philippines, Samoa, Singapore, the Solomon Islands, Taiwan, Tonga, Tuvalu, Vanuatu, and possibly Thailand.

Additional information
This is the Horse Hoof Clam, that has a zig-zag opening between the shells. Will grow up to 16″ long. Generalized bleaching may be caused by lack of nutrients to zooxanthellae algae, lack of light and heavy metal poisoning. Toxins or excessive metals, excessive Iodine levels (over NSW .06 mg/l) or high phosphate levels may affect clam health.

Possible fish predators of clams may be : some wrasses, angels, butterflies, triggers, neon gobies and blennies. Possible snail predators of clams are “rice” snails (Pyramidellidae) and Muricidae snails.

Tridacna derasa

  • Common Names: Sand clam, Derasa Clam, Southern Giant Clam or Smooth Giant Clam
  • Lighting: Has strong lighting needs.Symbiotic algae zooxanthellae are hosted within this organism.
  • Aggressiveness: peaceful
  • Current: Requires intermediate water flow.
  • Hardiness: This is a very easy clam to keep in aquariums
  • Color: They are usually colored with orange and black stripes. Can also be Blue, Green, Yellowish to Brown
  • Feeding: It likes to eat Phytoplankton.
  • Water parameters: Calcium must be around 400ppm to 450ppm.
  • Origin: Indo-Pacific

Additional information: 
It is one of the largest clams, growing to Up to 1′ 8″ in length. Does not appreciate high current. Can be nipped and harassed by clown gobies, blennies, shrimp, and most Angelfish and Butterfly fish. 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 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.


Crocea clam – Tridacna crocea

  • Common Names: Boring clam
  • Lighting: High lighting, preferably metal halide.
  • Aggressiveness: peacefull
  • Current: Medium
  • Hardiness: They are very hardy and easy to keep.
  • Color: Various
  • Origin: Indo-Pacific

Feeding: T. crocea creates most of the food it requires through photosynthetic processes accomplished by symbiotic algae called zooxanthellae living in the tissues of the clam.

Water parameters: Temperatures between 22-25C/72-78F, with a pH of 8.3-8.4 and a specific gravity of 1.024. Crocea clams require calcium levels of at least 280 mg/l, preferably 400-480 mg/l to grow. Natural levels of strontium and iodine are also needed.

T. crocea is the smallest and one of the most colorful of the Tridacnid family. They prefer a rock substrate where they will attach. Crocea don’t get very large, max about 15 cm.

Just about all shrimps and crabs (exception, skunk cleaners and scarlet hermits, my observations) will love to nip the mantle. Many, many fish that won’t touch a coral WILL try to nip the mantle of these clams.

Best kept with plankton or algae eaters in a reef tank. Any angel, and any butterfly will quickly consume this wonderful animal, as will arrow crabs, large hermits, Copperband butterflies, Chelmon rostratus or Cleaner wrasse, Labroides dimidiatus and most starfish. G

Good calcium and alkinity levels are a must for this species, as well as with most giant clams.


Tridacna squamosa

  • Scientific name: Tridacna squamosa
  • Common Names: Fluted giant clam, Scaled Clam
  • Lighting: Medium to strong
  • Aggressiveness: peaceful
  • Current: High
  • Hardiness: Exceptionally easy to keep in aquariums.
  • Water parameters: 72-78¼F, sg 1.020-1.025, pH 8.1-8.4
  • Color: Green, Blue, Brown, Yellow, Orange

Feeding: The Squamosa Clam relies heavily on the photosynthesis of the algae growing in its mantle. However, it should be fed daily with a yeast-based suspension unless the tank is populated with fish and corals which are fed regularly. It also requires nitrogen for proper growth, and if the nitrate level is too low, additional nitrate should be added, but the level should not be higher than 2 mg/L.

Origin: Indo-Pacific, Red Sea, The Great Barrier Reef

They prefer a sand bottom instead of rocky surfaces. Tridacna Squamosa grows to 16 inches across (12 inches in aquarium).

The Squamosa Clam requires calcium levels of 400-480 mg/L, and a carbon hardness of 7 to 12 degrees. Proper levels of strontium and iodine are also needed.


Do you have experience with clams? Share your thoughts below!

My name is James, and I’m in love with aquariums and fish since I was 12 years old. Back then my dad gave me a goldfish, and it’s been 35 years learning about this fascinating hobby. I’ve had some freshwater aquariums, tried my hand with marine tanks for 10 years, and kept some reefs for a while too. Here in the website I try to share some of my knowledge and experiences on fish keeping.


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