These marine invertebrates inhabit sandy beaches along coasts in the Bahamas. They measure about 10 to 25 mm (0.4 to 1 inch) in length. Its shell is wedge-shaped and varies widely in color from white, yellow,pink,red, blue and many more, making them an awesome choice for aquariums. Rainbow dwarf clams are very active; they migrate up and down wave-washed beaches in the wild with the tide and can re-burrow between each wave. They have short siphons and feed on suspended plant material and detritus. In the home aquarium they provide a crucial role being a filter feeder (bivalve) and will filter out algae, debris, viruses and bacteria from your water. If you're just looking to add them to your aquarium for show then we recommend any size. However if you are looking to utilize them for their tank stability aspect, then we recommend 100 per 25 gallons.