Manta Ray
(cc flickr photo by tlindenbaum)

For the first time ever, scientists have used satellites to track the movements of the Giant Manta Ray. Six rays were tagged and followed along Mexico’s Yucatan Peninsula over two months, and much was learned about their migratory habits.

Roaming the coast, the rays traveled more than 1,100 kilometers (621 miles) over the study period. That’s pretty far! They spent almost all their time within 200 miles of land, where zooplankton and fish eggs were plentiful.

Big Friendly Giants

Manta Rays—the largest rays in the world—can be 25 feet (7.6 meters) wide. They are huge creatures with gigantic wings, which they use to move through the water, leap out of the waves and fight off attackers. They are found in every ocean but the Arctic, living and migrating through tropical and subtropical waters.

Manta Rays use filters in their mouths (gill rakers) to feed on tiny plankton, swooping through the water with their mouths open wide. They eat crustaceans and fish as well. Around coral reefs, Manta Rays travel to cleaning stations, where smaller fish clean parasites off the rays’ skin and gill rakers. The cleaning can take over an hour. Rays will even line up for the service!

Mantas feeding; Courtesy Wikipedia

The breeding season for Manta Rays is December to late April. Manta eggs are laid within the mother’s body and hatch inside. She then gives birth to live ‘pups’ which are rolled up like a burrito, their wings folded around themselves. As soon as the mother gives birth, the pup falls to the sea floor, where it unfolds its wings. Mantas give birth every year or so, to one or two pups.

Devilfish? Not at all!

There are two different species of Manta Ray—the Reef Manta Ray, and the Giant Manta Ray. Some people call these rays “devilfish” because of folktales of Manta Rays upsetting boats and hugging sailors to death. Luckily, this is not true.

Unlike the stingray, these gentle creatures have no stinger in their tail. If you swim above a stingray, it will want to protect itself, and chances are you’ll get a barb to the body. This will possibly kill you. Mantas, on the other hand, pose no threat at all to humans.

Threats

Manta rays are naturally curious and gentle. This is nice for tourists, because they have a chance to get up close to them. But their curiosity makes them an easy target for Manta hunters, who hunt them for their meat and gill rakers, used in traditional Chinese medicine. Rays are also caught in fishing nets, and as the recent study shows, they travel through shipping routes, which increases their chance of getting hit and killed. Only 11.5 percent of rays’ migratory route is through marine parks, so these animals are possibly in big trouble.

Manta Rays are listed as vulnerable by the International Union for the Conservation of Nature, and their population is declining worldwide. Scientists and conservationists are hopeful this satellite study will help protect their future.