March 19, 2015 — A New York University mathematician examined the fluid dynamics of a swimming rainbow trout and has found that a series of bumps called "the lateral line" along their flanks and snouts are positioned perfectly to sense the flow of the water around them, according to a recent New Yorker magazine article.
The article explains "each bump in the lateral line contains a gelatinous blob that is embedded with tiny hair cells.
"The hairs wobble in response to changes in water pressure, and their movement is translated into an electrical impulse in a nearby nerve. (This system is the aquatic analogue of the human inner ear, whose hair cells allow us both to hear and to maintain our balance.)"
Read the article summary from The Times-Picayune