Manta rays are large rays belonging to the genus Manta. The larger species, M. birostris, reaches 7 m (23 ft 0 in) in width while the smaller, M. alfredi, reaches 5.5 m (18 ft 1 in). Both have triangular pectoral fins, horn-shaped cephalic fins and large, forward-facing mouths. Mantas are found in warm 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.