Unrolled, these distinctive fins are said to be used to guide masses of plankton into its mouth, which is in front of its body rather than underneath it. Mantas have a highly developed branchial sieve which retains any small organisms taken in with the water through the mouth. Mantas are probably circumtropical but their actual range and number is poorly understood, even today. In the West Atlantic, mantas have been recorded from New England and Bermuda to Brazil, including the Gulf of Mexico.
Mantas are dark brown to black on top with paler margins and are primarily white underneath.
Individuals may have whitish patches of various sorts and patterns on top and may have irregular and variable gray or black botches underneath. Mantas are pelagic, that is they live in the open ocean, but, luckily for divers, they do frequent coastal waters as well. Mantas are known to leap from the water, sometimes even somersaulting, and then fall back with a large splash. This has been thought to be either a way to remove irritating parasites or simply playful occupation, perhaps both. It is thought that these remora feed on parasites from the manta's body and perhaps even on the plankton as well.