Not only is it fascinating, relaxing and absorbing, but it's also the ideal thing for people who either don't have the time or can't be bothered to look after other creatures. Available in a range of shapes and sizes, the EcoSphere Closed Aquatic Ecosystem holds a mini submarine world of algae, shrimps and micro-organisms, all totally cocooned and all totally self-sustaining. Just make sure they get some light and warmth, easy.