Dr. Andrea Marshall has been studying manta rays for five years. Mantas fascinate people because of their strangeness and their sheer size (specimens over 7m across and weighing over two metric tons are on record).
Mantas have traditionally been assigned to one species (Manta birostris), although there are questions about whether the distinctly marked variant called "Beebe's manta" should qualify as a species in its own right, and at least two other species (Manta ehrenbergii, Manta raya) have been proposed at various times. Now Dr. Marshall is convinced she has ended this confusion by determining there are at least two species, and there may be three.
As a release from her supporting organization, "Save Our Seas," puts it:
"The two species have mainly overlapping distributions, but their lifestyles differ greatly; one is migratory and the other is resident to particular areas along the coast. Other differences between the two species lie in their colour, skin texture, reproductive biology, and the presence of a non-functioning type of sting on the tail of one of the species."
The commonly known species is the one tending toward (though not exclusively residing in) coastal zones. The migratory animal is larger, and very little is understood about it.
COMMENT: Here we have, in the 21st century, the discovery of one of the largest fishes on the planet. It can be argued that, when Dr. Mitchell publishes her formal paper naming the new species, it will be a reclassification rather than an entirely new discovery, but this does not diminish the impact of her findings.
It's interesting to note that this episode, with its determination of new species based in part on range and migration, is reminiscent of the debate over whether "resident" and "transient" orcas are members of the same species. In that case, too, there is speculation about a third, poorly understood, population which may qualify as a species. That a huge fish and a huge marine mammal raise similar questions is a thought-provoking hint about how much we still have to learn about the denizens of the sea.