Confusing a manta ray with a stingray can be an easy mistake. After all, they both have large, flat bodies; heads attached directly to wide, triangular pectoral fins; and similar tail-like appendages. Both rays also are members of the Chondrichthyes class of cartilaginous fish, which also includes sharks and chimaeras.
So, what are some other differences? Well let's start with the stingray. Stingrays have flat bodies and large pectoral fins that can either give them a rounded shape or a diamond shape with pointed fins, Erin McCombs, education supervisor for California's Aquarium of the Pacific in Long Beach, says via an email interview. "Unlike manta rays, stingrays have long, thin tails, and many have a small stinger (or barb) near the base of the tail."
A manta ray, meanwhile, is actually a type of stingray. "Through evolutionary history, they have lost their stinger," says McCombs, "but developed several other unique adaptations, including the cephalic lobes (specialized flaps on the front of their face that help them to filter tiny plankton from the water)."
Another difference: A stingray's mouth is found on the underside of its body, while the mouth of the manta ray is located along the front edge.
If it all sounds confusing, don't worry. Once you become more familiar with these two sea creatures, it can be easy to spot the difference. To help, here are seven fun facts that will help you tell the two apart, as well as give you additional insight into both species.
1. Manta Rays Are Enormous
"The giant oceanic manta ray (Mobula birostris) is the largest ray, with a wingspan of up to 29 feet [8.8 meters], says Kim Stone, curator of fish and invertebrates at Georgia Aquarium in Atlanta, in an email interview. "[Others] can grow to 20 feet [6 meters] across from wingtip to wingtip." Stingrays, by comparison, are much smaller. In fact, the smallest is the short-nose electric ray, which grow to just shy of 4 inches (10 centimeters) across.
2. They Have Different Diets
Manta rays are filter feeders, meaning they consume plankton like fish eggs, krill and other tiny floating animals, while stingrays prey on fish, gastropods, crustaceans and other small animals. "During feeding, manta rays may repeatedly somersault under water and also occasionally break the surface," says Stone. "They also feed in a horizontal orientation."
Most stingrays use flat teeth to crush the hard shells of animals such as crabs and clams, adds McCombs. "They live on the seafloor, often burying themselves in the sand to camouflage. Manta rays, however, use their cephalic lobes to direct small food items into their mouths. They live in the open ocean and don't spend time resting on the seafloor," she says. "Stingrays use a specialized sense (ampullae of Lorenzini) to detect the electrical impulses of prey buried in the sand. Manta rays use the same sense to help them find plankton suspended in the water column."
3. Manta Rays Breach
"They launch themselves out of the water," says McCombs. "Scientists are unsure why they exhibit this behavior, but it could be related to communication, mating or the removal of parasites. Manta rays also frequent cleaning stations, where they hover silently above a reef and allow smaller cleaner fish to remove parasites from their body."
4. Stingrays Are More Aggressive
"Stingrays use a stinger at the base of their tail to defend themselves," McCombs says. "Manta rays don't have this venomous stinger. They use their large size and speed as their form of defense — they are able to quickly flee from any potential predators, although they have few natural predators.
"While at the beach, shuffle your feet in the sand to avoid accidentally stepping on a stingray," McCombs adds. "You should never touch wildlife, as it may interfere with their natural behaviors in the ocean."
What should you do if you still happen to get stung by one? "Seek medical assistance for pain relief and to rule out any allergic reaction," Stone advises. "If the barb did break off and is still in the puncture, don't remove it until you seek trained medical help. Warm/hot water will help with the pain."
5. Both Are Pretty Smart
"Recent studies have suggested that manta rays and stingrays are more intelligent than we may have previously thought," says McCombs. "Stingrays living in aquariums are often trained to swim to a particular target or interact with enrichment devices. Recent studies of manta rays have even suggested that they may possess self-awareness. When swimming past a mirror, their method of interacting with the mirror suggests that they realize they are seeing themselves, and not another manta ray."
6. Manta Rays Do Elaborate Courtship Dances
Many stingrays (including manta rays) swim alone and only socialize with others during breeding and migration. But when it's time to mate, manta rays make it interesting. "A large group of males chase a female for hours until only one male remains," says McCombs. "The male then uses its clasper to mate with the female. The female is able to store the sperm for many years, only fertilizing the egg when conditions are optimal."
7. Both Species Are Vulnerable
Stingrays are often fished for their fins and meat. They also are often caught as bycatch, or unintended catch, during the fishing of other animals, according to McCombs. "Due to these unsustainable fishing practices, many stingray species are considered endangered, while even more species lack the research to properly classify their status," she says. "Manta rays share the same fishing concerns as other stingrays, but are also susceptible to target fishing for their gill rakers. Additionally, their open ocean habitat leads them to frequently entangle in large nets. Both species are considered vulnerable by the International Union for Conservation of Nature." Several species of stingray are considered endangered, including the longhead eagle ray, the mottled eagle ray and the longnose marbled whipray.