Everything you Ever Wanted to Know about Manta Rays

by | Feb 22, 2021 | About Manta Rays, Protecting Manta Rays

Manta rays are the world’s largest rays – and also the most mysterious of all, as not much is known about them. Mantas are slow and gracious animals, and we also call them the “gentle giants of the sea”. They live in temperate, subtropical, and tropical waters.

 

Table of contents

  1. Species and scientific classification
  2. Are Manta Rays Fish or Mammals?
  3. How big are manta rays, and how much do they weigh?
  4. How Many Manta Rays are Left in the World? Are they endangered?
  5. Where do Manta Rays Live? What’s their Natural Habitat and Migration Patterns?
  6. How long do Manta Rays live?
  7. What do Manta Rays eat?
  8. Do Manta Rays Fly?
  9. Can Manta Rays sting?
  10. How do Manta Rays reproduce?
  11. What’s the best place to see Manta Rays? In aquariums, in Hawaii, or elsewhere in the world?
  12. Manta Ray colors: black & white, albino or even pink
  13. How fast can Manta Rays swim?
  14. How deep can a Manta Ray dive?

 

Manta Ray Species and Scientific Classification

In the family of rays, manta rays are the largest ones. Another common name for the manta ray is “devil ray” because their cephalic horns give them something of a devilish appearance.

There are two types of mantas: reef mantas (mobula alfredi) and pelagic manta rays (mobula birostris). The latter is also called “giant manta ray” or “oceanic manta ray”. Oceanic mantas are larger and migratory – whereas reef mantas are smaller (but still huge!) and they live in shallow coastal habitats. You can read about the differences (and similarities) between the two in this article.

  • Kingdom: Animalia
  • Phylum: Chordata
  • SubPhylum: Vertebrata
  • Class: Chondrichthyes
  • Subclass: Elasmobranchii
  • Superorder: Batoidea
  • Order: Myliobatiformes
  • Family: Myliobatidae
  • Subfamily: Mobulinae
  • Genus: Manta
  • Type Species: Mobula birostris and Mobula alfredi

Manta rays are cartilaginous fish in the subclass Elasmobranchii and as such, they are relatives of the shark.

Other Rays (Not To Confuse Them With)

Manta rays are often confused with stingrays, eagle rays, bat rays, cow rays, etc.

They also have the largest brain-to-body ratio in the family of sharks, rays, and skates.

Are Manta Rays Fish or Mammals?

For the longest time, the world thought that manta rays were cetaceans – marine mammals.

However, manta rays are definitely fish and not mammals.

Mantas do have some characteristics of marine mammals though; they have the largest brain-to-body ratio of all fish, and they are fairly more advanced at problem-solving and communicating than your average fish.

They’re often playful and curious, and some studies (where manta rays would recognise themselves in the mirror) have even attributed some level of self-awareness to the gentle giants.

How Big Do Mantas Get?

In Hawaiian waters, we encounter manta ray “pups” with a wingspan of 2-3 feet and reef manta adults up to 12-14 feet. Mature males are up to 10 feet; the females tend to be the larger ones.

Giant oceanic manta rays can have a wingspan of up to 22 feet wide. A picture of unknown origin shows a manta ray in New Jersey in 1920 which measured approximately 30 feet.

How Much does a Manta Ray Weigh?

This is one of the most frequently asked questions – and we can only estimate the answer. Depending on the gender and the type (giant manta or reef manta), most of them would weigh between 50 and 100 lbs (between 22.5 and 50 kilo) per foot of manta ray.

The Manta Ray Population

How Many Manta Rays are Left in the World?

To be honest: no one really knows how many manta rays are left in the world. The database of mantas around the Big Island of Hawaii contains about 320 individual manta rays; however, this catalogue was started in the early 90s, and there’s no way to know how many of these are still alive.

The Manta Trust recently identified the 5000th manta in the Maldives since they started keeping a database. But again, it’s hard to know if they’re all still alive to this day.

Are Manta Rays Endangered?

There are two types of manta rays, and each appears separately in lists of endangered or threatened species. As of December 2020, the giant (oceanic) manta is classified as “endangered” on the IUCN Red List, while the reef manta is labeled “vulnerable with decreasing numbers”.

Where do Manta Rays Live? What’s their Natural Habitat and Migration Patterns?

Manta rays seem to be solitary creatures, coming together only to feed and mate.

They’re lovers of the open ocean, also called “pelagic”. Reef mantas do frequent the reef for the purpose of being “cleaned” by small fish that live on the coral reef. The areas where they hang out are called cleaning stations and serve the manta ray as a sort of “day spa”.

Reef mantas mostly live along the coastlines in the Indo-Pacific zone, while the giant manta roams all the world’s major oceans.

According to scientific studies, manta rays from different oceans have the same mitochondrial DNA.

We don’t have much (if any) official data on migrations or swimming ranges of any type of manta ray.

How far do mantas swim?

Until recently, we believed their home range would be approximately 90 square miles (145 km), which is roughly 30 miles up and down the coast and 3 miles offshore. The “Kona family” we know well (reef mantas who live around Kona, on the Big Island of Hawaii) is most frequently observed at 3 different manta ray viewing sites around Kona.

However, we recently spotted Loulou Ray in two different locations around the Big Island, located 55 miles from each other. We don’t know yet if Loulou is an outlier, or if mantas actually swim further than we thought they did!

How Long do Manta Rays Live?

The manta ray lifespan is believed to be 50 to 100 years of age. Check out Lefty’s story; she’s a manta we have been seeing in Hawaii since 1979.

What do Manta Rays Eat?

Mantas filter-feeder on zooplankton. Their diet consists of copepods, mysid shrimp, crab larvae, mollusk larvae, and fish eggs. A manta ray will eat approximately 12% of its body weight in plankton per week.

Mantas filter the plankton out of the water using a complex system of traps, filters, cephalic fins, and gill combs.

They swim slowly and twirl gracefully when they eat; their large mouths open and their cephalic horns unroll to funnel the plankton into their oral cavity.

Read more about their diet and eating habits here!

Do Manta Rays Fly?

Occasionally we will observe a manta ray jumping out of the water and then falling down on the surface, making a loud noise. This is called “breaching” – and a breaching manta ray is a mighty sight. It sometimes even seems like they’re flying.

No one knows for sure mantas why manta rays breach or what purpose it serves. They might jump up to elude predators, remove remoras or other parasites, or even to communicate with others.

Can Manta Rays Sting?

Manta rays are generally thought of as harmless creatures. They do not have barbs, a venomous stinger, or teeth. Thanks to their large pectoral fins, they are capable of bursts of high speed, which they use to escape predators. Their defence mechanism is simply “flight”; their manoeuvrability and speed make them hard to prey on.

Even though manta rays aren’t aggressive towards humans or dangerous on purpose, it’s important not to startle them. The manta could speed-swim into a diver, snorkeler, or a coral head, which might result in an injury on either side.

How do Manta Rays Reproduce?

Manta rays are “ovoviviparous”, meaning the young hatch from an egg inside the mother and the mother gives birth to a live well-developed pup. The young are almost exact replicas of the adult form; just smaller. The gestation period is 13 months, and a manta mom produces only one pup at a time.

At birth, the pups appear cigar-shaped with the two pectoral fins rolled around them like a burrito. Reef mantas, are about 2 to 3 feet across shortly after birth; pelagic manta pups measure up to 6 feet.

An adult manta female doesn’t care for their pup after birth as they are not paternal animals. This means that after birth, the pups are on their own.

It is believed that both males and females reach sexual maturity at around ten to fifteen years old.

We don’t know as much as we’d like about the lifecycle of manta rays – we’re still discovering new things about them every year.

Read how manta rays reproduce (from courtship over giving birth to raising their pups) in this article.

What’s the Best Place to See Manta Rays?

Where to See Manta Rays in Hawaii

The Kona coast on the Big Island of Hawaii boasts three viewing sites where mantas come to feed at night, with a 60-80% sighting chance on a night dive around those sites.

In Maui (also Hawaii), Olowalu Reef has a solid population of mantas, but it is not as accessible and frequently visited with boats as the Kona coast. There is a “cleaning station” that they often frequent during the daytime, but there’s never a guarantee to see them.

Manta Rays in Captivity

As manta rays can’t stop swimming (and they’re giant animals in themselves), they require huge tanks. Because of this logistical hurdle, there are only four places in the world that are adequate to keep mantas in captivity: the Atlantis Resort in the Bahamas, the Okinawa Churaumi Aquarium in Japan, the S.E.A Aquarium in Singapore, and the Georgia Aquarium in Atlanta, GA.

The most challenging aspect is feeding: as mantas would continuously swim and twirl as they eat, it’s hard to replicate those circumstances in an aquarium.

So far, there have been no studies to determine if manta rays in captivity suffer any health or other issues due to their confinement.

The Atlantis Resort has been successful in releasing manta rays back into the wild; watch the video (and read more about mantas in aquariums) on this page.

Other Places to See Manta Rays Around the World

Other great places to see manta rays in their natural habitat are

  • Indonesia – more specifically around Bali, in Komodo National Park, Flores Island and Raja Ampat, as well as Derawan or Sangalaki
  • The Philippines, where Tubbataha is a protected UNESCO underwater site and a world class dive location according to Art of Scuba Diving
  • The Maldives; that’s where our friends at Manta Trust operate. Try the Ari Atoll or Baa Atoll
  • Tofo in Mozambique attracts over a thousand mantas each year
  • Costa Rica
  • Mexico, where Socorro Island boasts to host more than 500 individual giant oceanic mantas from November to June
  • Ecuador, more specifically Isla de la Plata
  • Thailand – for instance around the Similan Islands or Koh Bon
  • Australia – e.g. Lady Elliot Island in the Great Barrier Reef, or Coral Bay in Western Australia
  • Micronesia: Yap or Palau
  • Solomon Islands
  • Fiji
  • Japan: Ishigaki island or Okinawa

As you can see, manta rays are located all over the world – and every place is unique and offers a slightly different experience.

We love that here in Hawaii the mantas come and feed at set locations (the three viewpoints) so we don’t have to go look for them – but if you’re more of a gambler, it’s also fun to go out on an adventure and hope to spot a manta at a cleaning station.

Manta Ray Colors: Black & White, Albino or even Pink

Manta ray colors are primarily gray and black on the top (dorsal side) and mostly white on their bottom (ventral side) with patches of black pigmentation. The patches or black spot patterns, as well as unique physical characteristics, are used to identify individual manta rays.

There has been one sighting of a pink manta ray in Australia and a cool video on Youtube of a white manta ray (who has also been dubbed “albino manta ray” online).

How Fast can Manta Rays Swim?

In normal times, manta rays would swim at a speed of around 9 miles per hour (around 14.5 km/h). However, they’re capable of short speed bursts to escape from danger – where they reach a speed of up to 22 miles per hour (35 km/h).

In combination with their extreme maneuverability (and their ability to jump out of the water, as described above), it’s enough to escape most predators!

Where are Manta Rays in the Food Chain? What Eats Mantas?

Due to their size, manta rays don’t have many predators – even though they only eat plankton, they’re still quite high up in the food chain.

The only sizeable predator capable of taking on a manta ray is a shark. In Hawaii, those would be tiger sharks. However, sharks mainly work as the clean-up crew of the ocean; they only take the old, the sick and the injured. Young and healthy manta rays are usually safe from predators.

Manta rays compared in size to humans, squid, whales and other marine life - by National Geographic
This NatGeo image shows a size comparison between giant manta rays and humans, as well as other large marine creatures.

How Deep can a Manta Dive?

Based on current scientific observation, we know that coastal manta rays can go deeper than 700 feet (214 m) for short periods of time, but they spend most of their time in shallower waters.

Scuba divers and snorkelers usually encounter reef manta rays from the surface to 80 feet of depth. During our moonlight swims with them, we go to approximately 30-35 feet; sometimes deeper or shallower, depending on ocean conditions and where the plankton forms.

Want to Learn More About Manta Rays?

Download our free ebook with manta ray facts & figures – and become a manta ray advocate today!

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