It is not. You should not put anything into your aquarium that you have found in the ocean. There are different bacteria and parasites in the ocean than found in your tank. In addition, the differences in PH balance and salinity are far greater. You not only risk the clam dying, but potentially killing off everything in your tank. There are quite a few beautiful species of clams available at your local Saltwater Fish store. Many are quite affordable and the expert at these stores can give you directions on how to acclimate your new tank item.
If by "clam" you mean a bivalve mollusc then the answer is yes they will live and grow in an aquarium. They do however need to be counted when working out the fish holding capacity of the tank. The basic rules are "1 inch of fish needs a minimum of 1 gallon of water" and "all aquaria containing living things must have a cycled filter".
Fishing in an aquarium; aquarium fishing is when you scoop fish out of your tank with a net.
an aquarium
Inverts can be very beneficial to your aquarium if suitable with your existing livestock. Inverts are the cleaners of the tank and can help create a more balanced, clean and safe environment.
Aquarium as in fish-tank means "Aquarium"
Fish tank
No. Not in the traditional definition of the tropical tank. A tropical tank is a freshwater aquarium. Regal Tangs are saltwater fish and go in a saltwater tank (marine aquarium).
BLODDY HELL, ITS A DEAD CLAM, GET OVER IT! By Waterloo Gang
Aquarium is another name for a fish tank
The "brown stuff" should not be a disease, it's called algae. To get rid of this, move your aquarium away from sunlight and make sure those plants are safe for aquarium use. If you can't move the aquarium away from sunlight, use some medications for your fish tank at your local fish store.
An aquarium
Aquarium.