Abstract

Digestive gases, which naturally occur inside marine animals, affect their buoyancy. Following Boyle’s law, any change in hydrodynamic pressure leads to a change in the volume of such gases. Therefore during an ascent from deep to shallow waters, decompressing gases can lead to a positive effect on buoyancy. It may be necessary to release these gases into the surrounding water for an animal to control its depth effectively. Here, two videos are presented on how sharks can get rid of excessive digestive gases and it is discussed how these observations fit with the general understanding of digestive gas production and buoyancy control.

Keywords: Boyle’s law; Compression; Decompression; Digestive gas; Shark