Manta ray

Manta ray

Manta rays are phenomenal fish that are often found in tropical or subtropical waters as they prefer warmer climates.  In The Red Sea they can be spotted in open waters in the south.  They share many similarities to sting rays and eagle rays but it is easy for divers to differentiate them in the water.  Manta rays swim in open waters whereas stingrays stay close to the ocean bottom. Mantas also do not have a ‘stinger’ at the end of their tail. This means they are not dangerous at all for divers or snorkelers. They are friendly animals that adapt easily to people.

They can reach a staggering 7m in length; they have triangular pectoral fins and forward facing mouths.  They are considered one of the smartest fish in the sea and are believed to have self-awareness – this means they can even recognize themselves in a mirror.  This shouldn’t be surprising since their brain to body ratio is the highest found in all species of fish! Their brains are particularly developed in the areas associated with learning, problem solving and communicating.

Manta Rays are filter feeders and feed on small fish like plankton.  They can also be found close to the coral reefs as they often hover at cleaning stations to remove external parasites.  Divers are sometimes lucky enough to witness this rare occurrence, usually when the tide is high. Mantas are macro predators which mean they usually circle their prey and herd the small fish, such as plankton into a ball. Once their prey is in position they swim quickly and directly at them with their mouths wide open.  Mantas can eat around 50 of these small fish at one time!  Mantas are usually preyed on by large sharks and killer whales; they use their size and speed to escape as they don’t have a stinger on the end of their tail.

In deep water manta rays swim in a straight line and at a constant rate, however close to the shore or coral reefs they can be found idling. It is rare to catch a glimpse of a manta ray because they are usually in the open water and they move a lot. They can be found alone or in a group of up to 50.  In the open water manta rays often leap, sometimes entirely out of the water. In groups they even perform aerial jumps one after another. They can jump head first, tail first or even somersault. We are not sure about the reasons for this but it could be a way of communication or part of their mating ritual.  Manta Rays are mammals and pregnancy is around 1 year.

Although they are friendly, curious and very intelligent these fish are also very vulnerable.  They are at risk of overfishing because people fish them for their gill rakers; this is the cartilaginous structures protecting the gills. They also can get easily caught in fishing nets since they must swim constantly to flush oxygen rich water over their gills, when they get caught in a net they often get entangled and suffocate.   Manta rays also have very low reproductive rates which contribute to their endangerment. Other factors include climate change, oil spills and ingestion of plastics.

Witnessing a manta ray in the open sea is one of the most thrilling experiences for any diver. Mantas are large and friendly and as long as divers are respectful they are perfectly safe. Divers and snorkelers shouldn’t touch mantas because contact from our skin damages their coating.  This coating on the manta rays skin protects them from harmful bacteria. When humans touch them this protective layer is removed and leaves them vulnerable to harmful bacteria and infections.