How do deep-sea organisms survive crushing pressure?

The answer

Deep-sea organisms have evolved remarkable biochemical adaptations to withstand immense hydrostatic pressure. Their cell membranes contain higher proportions of unsaturated fatty acids, keeping them fluid under pressure that would solidify normal membranes. They produce specialized molecules called piezolytes, particularly trimethylamine N-oxide (TMAO), which stabilize proteins and prevent them from being crushed into nonfunctional shapes. Many deep-sea fish lack swim bladders entirely, and their bodies are largely composed of water at ambient pressure, meaning there are no air-filled cavities to compress. These adaptations have evolved independently in many lineages, reflecting the power of convergent evolution under extreme conditions.