Manta rays are filter feeders, and eat large quantities of zooplankton, which they gather with their open mouths as they swim.

The giant oceanic manta ray species can grow up to 9 m (30 ft) in maximum length, to a disc size of 7 m (23 ft) across with a weight of about 3,000 kg (6,600 lb), but average size commonly observed is 4.5 m (15 ft).