Watch: Pregnant manta ray spotted 6,000km from home

A pregnant reef manta ray has been spotted for the first time at the remote Cocos Island near Costa Rica, some 6,000km from its normal home.

The threatened species, which can grow up to five metres in length, usually lives in coastal waters, prompting scientists to question how this pregnant fish had come to roam so far across the open ocean.

Footage recorded by the Marine Megafauna Foundation in September shows the ray cruising through the ocean while visibly carrying its young.

Randall Arauz, of marine research and conservation organisation Fins Attached, said: “Reef mantas may travel several hundred kilometres, although they tend not to travel too far offshore.

“It is unclear how this individual could have steered so far off course, leading us to assume it was not intentional.”

The pregnant ray was found to be three-and-a-half metres long, or slightly smaller than a car.

It was fitted with an acoustic tag to track its movements and recordings have so far indicated it has stayed in the area.

Manta rays only give birth every two to five years and no-one has ever seen them give birth in the wild. Scientists will continue to monitor the manta ray’s movements to make sure it is not in harm’s way.

Dr Andrea Marshall, co-founder and principal scientist at the Marine Megafauna Foundation said: “I have been studying mantas for 16 years and they still constantly surprise me.

“This extraordinary sighting challenges everything we currently know about the migratory behaviour of this species and its ability to undertake long-distance movements across open ocean environments.”

The study, co-authored by scientists from the Marine Megafauna Foundation, Fins Attached, Pelagios Kakunja in Mexico, and CREMA (Centro Rescate Especies Marinas Amenazadas) in Costa Rica, was published in the journal Marine Biodiversity Records on March 20 2019.