Manta rays are large eagle rays belonging to the genus Manta. The larger species, M. birostris, reaches 7 m (23 ft) in width while the smaller, M. alfredi, reaches 5.5 m (18 ft). Both have triangular pectoral fins, horn-shaped cephalic fins and large, forward-facing mouths. They are classified among the Elasmobranchii (sharks and rays) and are placed in the eagle ray family Myliobatidae.
Mantas can be found in temperate, subtropical and tropical waters. Both species are pelagic; M. birostris migrates across open oceans, singly or in groups, while M. alfredi tends to be resident and coastal. They are filter feeders and eat large quantities of zooplankton, which they swallow with their open mouths as they swim. Gestation lasts over a year, producing live pups. Mantas may visit cleaning stations for the removal of parasites. Like whales, they breach, for unknown reasons.
Both species are listed as Vulnerable by the International Union for Conservation of Nature. Anthropogenic threats include pollution, entanglement in fishing nets, and direct harvesting for their gill rakers for use in Chinese medicine. Their slow reproductive rate exacerbates these threats. They are protected in international waters by the Convention on Migratory Species of Wild Animals, but are more vulnerable closer to shore. Areas where mantas congregate are popular with tourists. Only a few aquariums are large enough to house them. In general, these large fish are seldom seen and difficult to study.
1. Except during mating season, mantas are not known to be social; however, the great fish regularly congregate in areas with plentiful food.
2. Like most reef fishes, mantas regularly attend cleaning stations where certain species of fishes pick parasites from their hovering bodies.
3. Mantas give birth every other year to a single pup, or a pair of four-foot pups that arrive rolled up like burritos.
4. It is not known why mantas leap from the water. Theories abound: to impress females, to help control parasites, to escape predators, or as a means of intraspecific communication.
5. Mantas can grow to nearly 25 feet from wingtip to wingtip, live for a quarter century, and will consume about 60 pounds of plankton and small fish each day by filter feeding.
6. Mantas and their smaller kin, mobulas, were once tagged with the unflattering name “devilfish” because the cephalic lobes attached to each side of their mouths resemble horns. When extended, the flattened lobes help direct food into their mouths.
7. Currently only two species of mantas have been scientifically described, although a third, similar-appearing species inhabiting the Caribbean and Atlantic is suspected.
8. Although useless and nonfunctioning, a manta has approximately 300 rows of skin-covered teeth in its lower jaw.