Manta ray

Manta rays are large rays belonging to the genus Mobula (formerly its own genus Manta). Three species are known: M. birostris, the largest at 7 m (23 ft) in width, M. yarae, which reaches 6 m (20 ft), and M. alfredi, the smallest at 5.5 m (18 ft). All three have triangular pectoral fins, horn-shaped cephalic fins and large, forward-facing mouths. They are classified among the Myliobatiformes (stingrays and relatives) and are placed in the family Myliobatidae (eagle rays). They have one of the highest brain-to-body ratio of all fish, advanced cognition, and may understand mirror contingencies. Mantas are found in warm temperate, subtropical and tropical waters. All three species are pelagic; M. birostris and M. yarae migrate 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 gather with their open mouths as they swim. However, research suggests that the majority of their diet comes from mesopelagic sources. Gestation lasts over a year and mantas give birth to live pups. Mantas may visit cleaning stations for the removal of parasites. Like whales, they breach for unknown reasons. M. birostris and M. alfredi are both listed as vulnerable by the International Union for Conservation of Nature. Anthropogenic threats include pollution, entanglement in fishing nets, and direct harvesting of their gill rakers for use in Chinese medicine. Manta rays are particularly valued for their gill plates, which are traded internationally. 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 public aquariums are large enough to house them.