Why do some fish live in the deepest ocean trenches?

The deepest parts of the ocean, including trenches below 6,000 meters, are cold, dark, and under immense pressure. Fish that live there have evolved bodies that can withstand crushing pressure, often with reduced air-filled spaces and specialized proteins. Many also have slow metabolisms because food is scarce, and they rely on falling organic matter or rare prey. Some species are poorly studied because these habitats are so hard to reach. Their adaptations show how life can persist in one of Earth’s most extreme environments.