Pressure is the same inside an organism as outside.
Organisms at great depths must be able to withstand great internal pressures.
Many species of fish have gas-filled bladders in order to maintain buoyancy.
Sperm whales hold the deep diving record for cetaceans at 3050m (10,000 ft). They can dive for over one hour in search of their main prey—squid and some fish.
Humans get the bends if they rise to the surface too quickly (causing nitrogen to boil out of the blood). The same happens to deep water fish when they are brought to the surface.
|Figure 14.15. Sperm whales can dive to great depths in search of food.||Figure 14.16. Nautilus controls pressure in it shell and changes its buoyancy.|