Some interesting research into feeding behaviour in Guiana dolphin.
Dolphins are famous for their ability to hunt prey via echolocation. Now, scientists have discovered that at least one dolphin species, the Guiana dolphin, can also detect fish by tuning into their electrical fields. It is the first time this sense has been reported in a marine mammal—or in any placental mammal. The researchers expect that electroreception, as this sense is called, will be found in other cetacean species. Until this discovery, it was known only in fish, amphibians, and two egg-laying mammals, or monotremes, the platypus and echidna.
All animals generate weak electric fields from the activity of their muscles and nerves. Species with electroreceptors can sense this bioelectric field and use it to spot prey that they can't see. And visibility is a real problem for Guiana dolphins, which live off the western Atlantic coast of Central and South America and hunt fish in turbid water and muddy sediments.