The digital picture you see here is an Emerald crab that I added to my coral reef aquarium to combat the green bubble algae which this crab loves to feast upon. I took this photo using macro settings. The body of this crab, minus the legs, is about the size of a U.S. nickle to put things into perspective. You can also see a couple of various mushroom corals in the background as well as some of the bubble algae which I was trying to eliminate by adding this Emerald crab to my aquarium. I took me several tries thru the aquarium glass to get this shot. Thank heavens for digital cameras or a lot of film would have been wasted trying to get this picture!