Sleeping fish? From sharks to salmon, guppies to groupers, here's how they grab a snooze

pema href=""Curious Kids/a is a series for children of all ages. If you have a question you’d like an expert to answer, send it to a href="" hr blockquote pstrongCould you explain how fish sleep? Do they drift away on currents, or do they anchor themselves to a particular location when they sleep? – Laure and Neeraj, New York/strong /p /blockquote hr pFrom the goldfish in your aquarium to a bass in a lake to the sharks in the sea – a href=""35,000 species of fish are alive today/a, more than 3 trillion of them. /p pAll over the world, they swim in hot springs, rivers, ponds and puddles. They glide through freshwater and saltwater. They survive in the shallows and in the darkest depths of the ocean, more than five miles down./p