Freshwater Gold Clam
The freshwater clams offered by AquariumFishSale.com are not an invasive species and will not survive cold water. These clams will filter water and are a black and gold color so they are somewhat attractive. These critters actually move around at night looking for the best place to dig in the sand and filter.
Asian gold clams are about three inches and will put their head in the sand and stick their ends up about two inches.