Digestive System
Most sharks swallow their food whole or bite it into relatively large pieces. Sharks have U-shaped stomachs that use very strong acids and enzymes to dissolve most of what is eaten. The stomach produces an easily absorbed, soupy mush. Only this liquid mush enters the intestines because the pyloric valve (the valve between the stomach and the intestines) is small. Indigestible things, (like very large bones and non-nutritive items) are vomited.
Absorption of nutrients takes place in the intestines. Although the intestines are short, they have a large surface area due to infolding of the inner surface of the intestines. Some shark intestines are arranged in folds, some are in a spiral pattern, like a spiral staircase enclosed within a cylinder.
Absorption of nutrients takes place in the intestines. Although the intestines are short, they have a large surface area due to infolding of the inner surface of the intestines. Some shark intestines are arranged in folds, some are in a spiral pattern, like a spiral staircase enclosed within a cylinder.