In vertebrates the gallbladder (also gall bladder, biliary vesicle or cholecyst), is a small organ where bile (a fluid produced by the liver) is stored and concentrated before it is released into the small intestine.Humans can live without a gallbladder.he bile that is secreted by the liver and stored in the gallbladder is not the same as the bile that is secreted by the gallbladder. During gallbladder storage of bile, it is concentrated by removal of some water and electrolytes.