Film crew dives into the incredible secret world of the giant manta ray

Gliding through the oceans like ghosts, these mysterious manta rays have been captured in unique footage filmed off the coast of Mozambique.

Biologist Andrea Marshall is shown performing a ballet-like dance with the inquisitive giant fish, which she described as 'the most beautiful underwater birds.'

Manta rays feed on plankton and sometimes skim the reefs with their mouths. It is not known what they feed on when migrating

Filming a manta at a 'cleaning station'. Injured rays are frequent visitors so their wounds can be cleaned by tiny, butterfly fish

The experienced diver has been based in the coastal African country since 2003. She spent last year swimming with the black-winged creatures alongside a film crew for a BBC documentary.

Until recently it was thought there was only one species of manta ray, but Dr Marshall realised many of the rays - that can grow up to 23ft long - displayed different markings and behaviour.

The mantas were tracked by the team using a GPS system, which revealed they made their epic voyage in just 60 days.

More than a a hundred manta rays, mostly pregnant females, gather in the Maldives each year. They were filmed for a BBC documentary

A juvenile manta feeds in the Maldives. There are two species of manta raves - one with a useless sting and one without

They also retained a vestigial sting adapted from their sting ray cousins - which has become useless over the centuries and is harmless to humans.

The 30-year-old researcher concluded she was observing two separate species of mantas - one of them totally new to science. The larger mantas kept the name Manta birostris, while Dr Marshall named the reef-going mantas Manta alfredi, after an early biologist.

During her close encounters with the rays, Dr Marshall spotted huge scars on their bodies that had been inflicted by large sharks. She also observed them queuing up to have their wounds tended by cleaner fish, which bit off the dead tissue.

 

 

Dr Marshall described the manta rays as ' the most beautiful underwater birds'

Her research also uncovered a unique gathering place for pregnant female reef mantas in the Maldives, which could be crucial to the species survival. Females only give birth to a single pup after 12 months and Dr Marshall found they rarely gave birth two years in a row.

Dr Marshall works to protect the large and charismatic species at the Manta Ray & Whale Shark Research Centre at Tofo Beach in southern Mozambique.

The documentary's director Mark Woodward said: 'Out at sea, giant mantas risk being captured and gutted for their fins by unregulated fishing, to meet the online demand for so-called traditional Chinese remedies.'