This capability was found in the common Guiana dolphin
This dolphin most likely uses its sixth sense to find prey in the dark coastal waters it inhabits.
“Most of the animals which do this do this to find prey,” said study researcher Wolf Hanke, of Rostock University in Rostock, Germany. “All of the dolphins’ prey items, like crayfish, all of them generate electric fields to some degree.”
The researchers came to this conclusion after examining a Guiana dolphin that had died naturally at the Dolphinariumin Münster, Germany. They focused on specialized pores called vibrissal crypts, which in other animals are located in hair follicles at the bottoms of their whiskers, allowing the animals to sense movement using their whiskers.
They found that the specialized pores — which usually number from two to 10 along the dolphin’s snout — are surrounded by nerve endings, have simplified blood vessels and are filled with a special matrix of proteins and cells. The pores also produce a gel-like substance.
It’s possible other marine mammals also developed the ability, Hanke said. “I think it’s possible, it’s likely, because there are some dolphins, like the bottlenose, that have little pits on its snout, too. They are smaller, but it’s not unlikely that this one or other ones would develop it too,” he said.
The electroreception would be used in short-range scenarios, when the dolphins’ echolocation (ability to determine the environment around them using sounds and their echoes) becomes less sensitive. These waters are murky, so visibility is limited even at these short ranges, so being able to electrically sense their prey would help these dolphins feed.