It is 16 years since diver, marine biologist and manta expert Dr Andrea Marshall proposed the existence of a third species of manta ray. Now that proposal has been officially vindicated, with a formal description in a new study of the Atlantic manta, or Mobula yarae.
This recognition is being celebrated by the Marine Megafauna Foundation (MMF), the body co-founded by Marshall. Earning the epithet “Queen of Mantas”, she had revolutionised manta ray science in 2009 by separating what had always been considered as a single species, so that the giant oceanic manta (Mobula birostris) was recognised as distinct from the reef manta (Mobula alfredi).
That breakthrough had taken her six years of intensive study based on frequent dives, observations and photography – but her research had also raised the possibility of finding a third species.
Marshall initially encountered Mobula yarae in the Caribbean Sea, writing later that after completing the first study it had been “one of the shocks of my life to jump into the warm waters off the Yucatan in Mexico about a year later and come face to face with what I instantly knew was a third species of manta ray.”
Marshall moved on from Mexico to Brazil to collaborate with researcher Ana Paula Balboni Coelho’s Mantas do Brasil project – and found the third manta there too.
The tropical and subtropical waters extending from the eastern USA to Brazil and including the Caribbean and Gulf of Mexico are M yarae‘s favoured territory, and the scientific name is taken from Yara, a mythological Brazilian water spirit.
Marshall had to wait eight years before Jessica Pate, who founded MMF’s Florida Manta Project, succeeded in identifying a dead 2.4m juvenile female ray off Pompano Beach as an Atlantic manta, providing the intact type specimen required to formally describe the new species.
The full story of how that ray was transported to the Smithsonian Institution laboratories can be found on the MMF website.
Marshall was still working on the project in Mexico in early 2024 when she suffered a severe brain aneurysm and stroke. She survived after weeks in a coma, but is now said to live with life-changing impairments.
The international research team continued to work on the study, which has now been published in the journal Environmental Biology of Fishes.
“Andrea’s 2009 taxonomic work on manta species flagged the likely existence of a third Atlantic manta species based on careful field observations, and this formal description brings that work to completion,” says MMF executive director and co-founder Dr Simon Pierce.
“It had been pretty shocking to everyone that there were two species of manta ray and suddenly I had to argue that there were three,” recalled Marshall in 2022. “To be honest, I was not sure if anyone would believe me. But there was never a doubt in my mind.
“That confidence came from the fact that it had taken me six years to differentiate the first two species and I knew them inside out at this stage. This manta didn’t look like either of them.”
The differences are subtle. From above, the black dorsal coloration and pectoral fin shape of M yarae resemble those of a giant oceanic manta, while from below the lighter face and spot patterns look like those of a reef manta.
Key distinguishing features from above include V- rather than T-shaped white shoulder patches and lighter coloration around the mouth and eyes than seen on giant mantas. From below, the ventral markings are dark spots typically confined to the abdomen rather than extending between the gills, as in reef mantas.
M yarae can grow to 5-6m, as do giant mantas, but prefers the sort of coastal waters inhabited by reef mantas. The genetic evidence suggests that the species evolved relatively recently from the giant manta.
“It’s rare to see a new species like this, and even rarer to watch the process behind it,” says Pate. This rarity make M yarae valuable for understanding how large marine species adapt and evolve.
The concern now is that its coastal inclination makes the species more vulnerable than its oceanic relatives to population decline through fishing, boat-strikes or entanglement – but the formal recognition could prove helpful in that regard.
“Now that we’ve proven that this Atlantic manta ray is distinct, we can tailor our research and conservation initiatives to protect the species,” says Pate. All three manta species are classified as Threatened on the IUCN Red List, and MMF plans to work with the countries in M yarae’s range to develop appropriate conservation measures.
Future research priorities include population assessment, movement pattern studies using satellite telemetry, habitat use characterisation, and threat assessment in key areas.
