Their are about 1,000 Opae`ula's in the tank. These Opae`ula's came from the Island of Hawaii. They sent us 4 bigger shrimps that have claws and swim faster than the Opae`ula's. Some of them in the tank fight a lot. They eat a kind of algae that is called Spirulina. When they are stressed they lose color and turn white. When you bend down they look like seahorses because of their tale.