Giant oceanic manta rays are pretty rare; any diver or snorkelers who gets to witness one is a lucky person.
Giant mantas are also known as oceanic manta rays, pelagic manta rays – or by their Latin name, mobula birostris.
About the Oceanic Manta Ray
Oceanic (aka giant or pelagic) mantas grow to over 22 feet (over 7 meters), which gets them the fitting nickname of “giant manta ray”.
The word “pelagic” means that the manta lives in the ocean’s pelagic zone, neither close to the bottom nor near the shore. In other words, their regular habitat is the vast open ocean. They may swim inshore at times (very occasionally), which is when they are usually sighted – each sighting being an unexpected delight.
There are two distinct color types in oceanic manta rays:
- the black and white manta ray variety called “chevron” – where their back is mostly black, and their belly predominantly white
- and the type nicknamed “black ray” – which is almost entirely black on both sides
The Difference Between Reef Mantas and Oceanic Manta Rays
There are two manta rays species: the pelagic manta (or mobula birostris) and the reef manta (or mobula alfredi). The manta rays we regularly encounter on the West Coast of Hawaii are the reef mantas, and we estimate their home range to be 90 square miles: 30 miles up and down the coast and 3 miles offshore.
A straightforward distinction between pelagic and reef mantas rays is the zone around the eyes and cephalic fins – reef mantas are white around the eyes.
Notice the spot pattern on the reef manta in the picture. This unique marking is an identification symbol used when registering the manta with an official name. The oceanic manta also has a cluster of spots, but they are located slightly lower on the body.
How to Know you’re Looking at an Oceanic Manta Ray
Because of the migratory behavior of pelagic (oceanic) manta rays in the open ocean, it’s uncommon to see one individual more than once. In comparison, reef mantas along the Kona Coast get sighted regularly for many years in a row – as reef manta rays are territorial to the area. In general, mantas are mysterious creatures, and not much is known about their movements as they are always swimming.
Reef mantas rays are known to stay within a certain radius to the shore; however, less is known of the pelagic mantas’ habitat and migration.
To be sure you’re looking at a specific manta ray, you’d need to compare the identifying spot pattern on the ventral side against the manta ray database(s). This means you need to capture the ID markings on the underbelly – quite a challenge, as sightings are rare, and not everyone has their underwater camera ready to go when swimming with manta rays.
Video: Rare Sighting of a Pelagic Manta Ray
A manta ray advocate, Captain Justin Summers, found this pelagic manta ray 3 miles offshore during his day charter.
The manta ray Justin spotted is estimated to be 16-18 feet in wingspan. Seeing a manta ray in deep water and far from the shallow reef is rare, but finding one with so much black coloring is exceptionally unusual. As most mantas we identify get their own name, this one got called “Black Ray”, as he’s almost entirely black.
Way to go, Captain; what a remarkable encounter!