Giant manta rays in Indonesia glide right over scuba diver

Manta rays are among the most majestic of all the ocean's creatures. They grow to incredible sizes with wing spans of up to 7m (21 feet). They glide seemingly effortlessly with slow flaps of their enormous wings. Flapping quickly, they instantly reach impressive speeds when needed.

Manta rays are fish, and they have the highest brain to body mass ration of all fish. They are gentle creatures that long ago lost the ability to sting. They outswim or dive to avoid predators. They are capable of diving very deep.

Manta rays have specially designed cephalic fins that they unroll when feeding to funnel water into their open mouths. Zooplankton are filtered on their gill rakes and then ingested by the rays. Most of this feeding occurs at depths between 200 and 1000m (600 and 1000 feet) in the deeper ocean known as the mesopelagic zone.

Because they have cartilaginous skeletons that do not preserve well, there are few fossilized records of manga rays. This leaves large gaps in our understanding of mantas and their lives over time.

Mantas produce one or two pups every second year. These low reproduction rates make the mantas susceptible to environmental changes and overfishing. Populations of manta rays have declined because they are sought for gill rakers that are believed to have medicinal properties. They are now considered an endangered species.