The Manta Ray
The manta ray (Manta birostris), is the largest of the rays, with the largest known specimen having been more than 7.6 m (about 25 ft) across, with a weight of about 2,300 kg (about 5,000 lb). It ranges throughout tropical waters of the world, typically around coral reefs.
Mantas have been given a variety of common names, including Atlantic manta, Pacific manta, devilfish, and just manta. Recent studies have discovered that what is called manta ray are at least two different species, one smaller local and one much larger and migratory.
Evolution and taxonomy
Manta rays may have evolved from bottom-feeders, and then adapted to become filter feeders in the open ocean. This allowed them to grow larger than other ray species. Due to being plankton feeders, some of the ancestral characteristics have degenerated. For example, all that is left of their oral teeth is a small band of vestigial teeth on the lower jaw, almost hidden by the skin. Their dermal denticles are also greatly reduced in number and size but are still present. They have a much thicker body mucus coating than other rays. Their spiracles have become small and non-functional, as all water is taken in through their mouth instead.
Taxonomically, mantas are under investigation. Three species are identified: Manta birostris, Manta ehrenbergii, and Manta raya. They are quite similar, and the latter two may just be isolated populations. The genus Manta is sometimes placed in its own family, Mobulidae, but this article follows FishBase taxonomy and places it in the family Myliobatidae, along with eagle rays and their relatives.
Mantas are filter feeders: they feed on plankton, fish larvae and the like, passively filtered from the water passing through their gills as they swim. Small prey organisms are caught on flat horizontal plates of russet-coloured spongy tissue spanning spaces between the manta’s gill bars.
Mantas frequent reef-side cleaning stations where small fish such as wrasses and angelfish swim in the manta’s gills and over its skin to feed, in the process cleaning it of parasites and removing dead skin.
Mantas are extremely curious around humans, and are fond of swimming with scuba divers. Although they may approach humans, if touched, their mucus membrane is removed, causing lesions and infections on their skin. They often surface to investigate boats without engines running. They have the largest brain-to-body ratio of the sharks and rays.
Mantas are known to breach the water into the air.
The Moche people of ancient Peru worshipped the sea and its animals. They often depicted Manta rays in their art.  Not knowing about their gentle nature, two movies of the 1930s played on the manta’s “fearsome” appearance: 1930′s The Sea Bat, starring a pre-Frankenstein Boris Karloff, and 1936′s The Sea Fiend, later re-issued as the 1946 Devil Monster.
In modern times, the manta ray continues to serve as a source of inspiration. For example, the manta ray is the namesake of the Tampa Bay Rays Major League Baseball team, and the team’s original name was the Devil Rays, one of the manta’s alternate names. In 2009, SeaWorld Orlando will debut Manta, a flying roller coaster themed to resemble the manta ray, along with an exhibit featuring other ray species.
Manta rays are very rarely kept in captivity, primarily due to their size. Only four aquariums in the world have manta rays on display. One notable example is “Nandi”, a manta ray that was accidentally caught in shark nets off Durban, South Africa in 2007. Rehabilitated, and outgrowing her aquarium, uShaka Marine World, Nandi was transferred to the larger Georgia Aquarium in August 2008, where she resides in its 6.2-million-gallon “Ocean Voyager” exhibit.