Is this biconditional true or false. An animal is a fish if and only if it lives in water?

The biconditional statement "An animal is a fish if and only if it lives in water" is false. While many fish live in water, there are exceptions, such as certain species of fish that can survive out of water for extended periods. Additionally, some animals that live in water, like dolphins and whales, are not fish but mammals. Thus, the conditions do not hold true for all cases.