Growing up, fish meant lunch, or dinner, or both. Typically, swimming in mustard oil, accompanied by fresh green chillies  that stung. The only exceptions were inhabitants of a cloudy green tank the size of eight shoeboxes at a dimly lit Chinese restaurant&mdashone that also served first-rate chilli fish. So, standing next to an aquarium the size of a private pool, swarming with giant fish that could have me for dinner instead, is mostly disconcerting. But such apocalyptic thoughts&mdashincluding the improbable event of the water from the world&rsquos ninth most voluminous aquarium gushing out in a tsunami&mdashare held at bay, once I scan the faces of other surprisingly calm spectators at Hong Kong&rsquos Aqua City.