Transcript:

Today on Animal Fact Files we’re discussing manta rays. There is more than one species of manta ray. Currently there are believed to be two or three living manta ray species, however, these big fish have recently been reclassified from the genus Manta to be included in the genus Mobula with the similar looking devil rays. So, to keep things simple, we’re going to discuss the entire Mobula genus in this episode! Of course, devil rays are generally not as well studied as manta rays who themselves aren’t even fully known in terms of life history, so a lot of this information will pertain to manta rays specifically, though, in total, there are about a dozen living species in the Mobula genus.

Manta rays and their cogenerics live in tropical and temperate oceanic waters throughout the world. Some may travel great distances between islands and seamounts where food resources can swell depending on the season. Others may be found on reefs but still dive at night to find food off continental shelves. Manta rays are generally easier to study because devil rays are more shy, though devil rays are known for gathering in huge groups where individuals propel themselves from the water. Scientists are unsure why this happens but it’s likely a mating thing. It’s thought the rays communicate by making big splashes. Female manta and devil rays retain fertilized eggs in their bodies. These hatch after 9-12 months and are born live. Usually, there is only a single baby per litter and the female may not breed again for two to five years! So they have a slow, low birth rate, which makes them all the more vulnerable to human threats. Natural predators to manta and devil rays include sharks and orcas but these large fish can accidentally land in fishing nets and may also be fished for gill rakers. Manta rays use their gill rakers for collecting food, like basking sharks. These fish must continue swimming to breathe as this is how oxygen is passed over their gills. However, they’ll take up a different look depending on if they’re eating.

While eating manta and devil rays unfurl the lobes on their heads to create a vortex for trapping food in their mouths. Prey for these animals consist of planktonic organisms. Manta and devil rays are often seen towards the top of the water column, but they can also dive deep to find food in the depths of the ocean, not unlike the squid eating sperm whale. Mobula rays may live anywhere from fifteen to more than thirty years in the wild. Some devil rays may be less than three feet (1m) across while the giant manta ray can be more than 23 feet (7m) wide. They also have the largest brain to size ratio of any living fish, and manta rays have been observed recognizing themselves in a mirror!

These fish often come with white patterns on dark brown, grey, or black bodies; some come in all black; and there was even a pink manta seen off the great barrier reef. Because they look similar to stingrays they may be assumed to be harmful with a stinger on their tail, but they don’t have a barb to sting with! They’re considered harmless to humans and people often dive with them, well manta rays anyway, devil rays are more skittish which has made them more difficult to study! Mobula rays are the only known living vertebrates with three pairs of functional limbs: the head lobes, their wing like pectoral fins, and their pelvic fins under the body. So we would argue they’re technically the closest thing to a six-limbed dragon alive today!

Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! Thank you to widget and elephant puppet for today’s request! For more facts on manta and devil rays, check out the links in the description. Give a thumbs up if you learned something new today, and thanks for watching Animal Fact Files!