Atlantic Spotted DolphinsFLICKR, SHEILAPIC76
Guiana dolphins (Sotalia guianensis), which inhabit the Caribbean and waters along Atlantic coasts of Central and South America, can sense electrical activity in the water using hairless follicles on their rostrums, where a land mammal’s whiskers would be. Once thought to be nonfunctional remnants of their land-dwelling ancestors, these so-called vibrissal crypts contain dense populations of nerves (about 300 axons per crypt), as well as intraepithelial nerve fibers, suggesting the structures may serve a sensory purpose, according to a paper published yesterday (July 26) in Proceedings of the Royal Society B. The study's authors confirmed this hypothesis by exposing a captive Guiana dolphin to electrical fields of various strengths. The animal could sense and respond to low electrical signals, but did not react to even ...
