Dive The World logo Dive The World Global website banner Dive The World Global website banner
 Choose Language:
  English Version   Deutsche Version 
 More Destinations:
Worldwide

Diving with Manta Rays

Rays of Light - Graceful Gliders

We have done some of the world's best manta ray dives and know that the joy of diving with mantas is difficult to overstate. They capture divers' imaginations since they move so gracefully and majestically through the water - whether frolicking in the surf, or enjoying the skin care treatment of a cleaning station. Find out more about these beautiful and mysterious fish ...

Manta ray - Dive The World

There are few sights more awe inspiring for scuba divers than watching manta rays performing their graceful somersaults. These magnificent creatures are frequently seen feeding alone or in small groups near the surface and other near shore waters near coral and rocky reefs. Sightings are common in the Maldives, particularly during the August to October feeding and mating spectacular at Hanifaru Bay, Baa Atoll, in the northern atolls of the Maldives. Other great places to witness these majestic creatures include Koh Bon in Thailand, Komodo and Raja Ampat in Indonesia, Black Rock in Myanmar, Kadavu in Fiji, Cabo Marshall in the Galapagos Islands and Mexico.

Manta rays are strong pelagic swimmers, possibly able to cross the open ocean and so often host 1 or more clinging remora, or sucker fish. Remoras have their first dorsal fin modified into a sucking disc. While the remoras do not harm their host directly (apart from sore skin where attached), mantas do use more energy in swimming with them.

Manta Ray Fact Sheet

Family name: Myliobatidae, subfamily Mobulinae
Order name: Batoides
Common name: Manta ray
Scientific name: Manta Birostris and Manta Alfredi

Distinguishing Features

Mantas can grow to 6.7m wide, weigh up to 1,400 kg, and are the largest of all rays. The Spanish word for blanket is 'manta' and aptly describes the unique body shape of this animal. With graceful pectoral 'wings', manta rays are easily recognised by their paddle-like cephalic lobes projecting forward from the front of the head (actually extensions of the pectoral fins, supported by radial cartilages), and a very broad, rectangular terminal mouth.

Mantas vary in colour from black, grey-blue, to red-brown on the upper surface of their cartilage body, sometimes with white shoulder patches and blotches, and almost pure white on the lower surface of their pectoral fins and body disc. Their body patterns show individual variation and helps identify individuals, as well as species.

There are also regional differences in manta ray colour patterns. For example, specimens from the eastern Pacific often feature dusky to mostly black undersurfaces, while those from the western Pacific are typically snow white underneath.

Although it's difficult not to recognise an adult manta ray, juveniles can be similar in appearance to mobula rays (of which there are 9 species) that grow to 3 metres and share cephalic lobes and gracefully curved pectoral wings. However, mobulas don't have paddle shaped lobes, they have shorter pointed ones which look a little like horns, earning them the common name 'devil rays'. Mobula rays can also be distinguished by the position of the mouth - mobulas have sub-terminal mouths (located underneath the head, similar to many sharks), whilst mantas have terminal mouths (located at the front of the head).

Until recently manta rays were considered to be of a single species. The genus was recently re-evaluated into 2 distinct species, The giant manta ray (Birostris) and the reef manta (Alfredi) officially identified in 2009 by Andrea Marshall. They both have worldwide distribution and sometimes exist in the same region. Their genetic divergence has been confirmed by DNA testing.

Manta birostris is the larger and more widely distributed of the 2 species. It is more commonly found off shore and is believed to be more migratory. Manta alfredi is smaller and is found closer to shore. A possible 3rd species, is being investigated around the Atlantic coast of the Americas.

There are many differences between the 2 identified species. From photographs of the manta's underside, sufficient of these differences can be seen to assist with identification. These include ventral markings which occur higher than the lowest gill openings only on Manta alfredi. Also there is a dark band that runs all along the rear of only Manta birostris from wing tip to wing tip.

Behaviour

Mantas - photo courtesy fo ScubaZoo

A manta ray is capable of rapid speed and juveniles sometimes leap well clear of the water, landing with a loud slap, sometimes performing 2 or 3 of these jumps in succession. The act seems to be playing or social behaviour - the great, crashing splash of their re-entries can often be heard from miles away. Getting rid of parasites may also play a role, much like breeching whales.

Manta rays frequently visit reef-side "cleaning stations" to let cleaner wrasse remove small parasites from skin and gill cavities, sometimes several lining up to wait their turn.

Seemingly inquisitive, manta rays may sometimes approach and even solicit attention from divers, apparently enjoying the tactile stimulation provided by human contact as well as the bubbles from scuba units. In areas frequented by divers, however, they often become very wary and cease to approach.

When approached rapidly or grasped, they roll onto their backs, dive, or swim away rapidly, righting themselves only when some distance away. Entering the water carefully so as to not scare mantas away will greatly increase the enjoyment of your encounter and protect them from injury. Hovering and staying still will eventually allow the manta ray to approach you. It's best to position yourself a long the bottom or near a cleaning station to observe them close up.

Touching a manta ray, even if they present their bellies for a rub, will remove some of the mucus that protects them against marine infections. Stay within their vision and let them decide if they want to approach you. Although some manta rays seem to enjoy the bubbles from the SCUBA unit on their bellies, avoid exhaling bubbles into their face, as it may scare them off.

Flash photography and video doesn't seem to bother the manta ray, but do not disturb them if they are engage in feeding, cleaning or mating. Direct eye contact is considered a friendly connection, which they also seem to enjoy. Remember to never ride on one, even though it may appear as if they present themselves for a ride.

Feeding Habits

Even though mantas have up to 300 rows of small peg shaped teeth (the size of pin heads) only on the lower jaw, they really are gigantic filter-feeders, preying on planktonic crustaceans and small schooling bony fishes.

The 2 fleshy lobes of cephalic fins are unrolled and held at a downward angle to create a funnel guiding prey into their enormous mouth. Feeding often occurs near or at the surface where plankton accumulates. They may simply swim along allowing plankton to pass into their mouths, or if it is concentrated they may practise "barrel swimming" 'head-over-heels' to make the most of the localised bounty. They have also been seen to feed by swimming along the seabed if the plankton is concentrated near the floor.

Reproduction

The manta ray is ovoviviparous with a usual litter size of 2 - each pup wrapped in a thin-shell that hatches inside the mother, later to be born alive. Birth occurs in relatively shallow water, where the young remain for several years before expanding their range further offshore. Like sharks and other rays, mantas are fertilized internally.

Male manta rays have a pair of penis-like organs called claspers, along the inner part of their pelvic fins. During courtship, males chase the female, eventually 1 grasping the tip of 1 of her pectoral wings between his teeth, and pressing his belly against hers.

Then, the male flexes one of his claspers and inserts it into her vent. Copulation lasts about 90 seconds. The fertilized eggs develop inside a mother manta's body for an unknown length of time that may exceed 12 months.

Life Cycle

A newborn manta ray is about 125 cm wide and growth is rapid, doubling in size during the first year of life.

Males mature when they reach a size of about 4 metres, females at about 5 metres; it is unknown what age this is. Likewise, it is not known how long manta rays live, but best guesses are about 25 years.

Predation

Only large warm water sharks, such as the tiger shark are known to prey naturally upon manta rays.

Distribution

Manta rays feeding at Koh Bon, Thailand

Manta ray distribution is circum-tropical, around the globe, generally between 35 degrees north and south latitude.

This area includes South Africa, Madagascar, Mozambique to Somalia; in the Gulf of Aden, Red Sea, Arabian Sea, the Bay of Bengal, Burma (Myanmar), Thailand, Malaysia, Indonesia, Philippines, Cambodia to southern Japan, northern Australia, Micronesia, New Caledonia, Fiji, New Guinea, Solomon Islands, Hawaii, southern California to northern Peru, North Carolina to southern Brazil, the Azores, and Senegal to Liberia.

Manta birostris appears to be more widely distributed, reaching as far north as California and Rhode Island in the USA, North Africa and Japan. They also reach as far south as South Africa, New Zealand and Uruguay. Manta alfredi is widespread throughout the Asia Pacific region as well as the Indian Ocean.

While there is considerable overlap, it is worth noting that the coastlines of the Americas seem to be the preserve of Manta birostris while sightings in the central Pacific region are overwhelmingly of Manta alfredi.

Ecological Considerations

Found in every tropical ocean, mantass stand apart as the largest of all rays; but just as they are obtaining star status with scuba divers, promising increased eco-tourism revenues, their populations around the globe are in peril.

The harvest of manta rays in eastern Indonesia has increased exponentially in just a few years. It has been estimated that over 1,500 mantas have been taken over a period of 6 months. In the Philippines, increasing pressure on local fisheries has forced fishermen to look to these giant rays as an alternative meat source.

Another factor leading to increased manta ray harvests is the new demand for brachial gill plates which are used in traditional Chinese medicine. Its skin has also been exploited for such as wallets and handbags. Overall this represents a 10-fold increase in farming over historic levels and it is feared that this increased harvest will spread to the Western Pacific.

In the Philippines fishermen are licensed to catch mantas using 1 km-long drift nets about 30m in height. These nets also catch dolphins and endangered turtles, which are being marketed as shark meat. This overexploitation of species population, together with low birth rates and small litters, leaves manta rays highly vulnerable.

When it was discovered that entire populations of whale shark and manta ray had been decimated in the Philippines, a ban prohibiting the harvesting of mantas was imposed in 1998. But this was short-lived. 4 years later, due to the lack of resources to implement a sustainable management system, and political pressures from fisherman, the ban was lifted.

A delicate balance exists between the economic well being of small fishing villages, demand for Chinese medicine and the protection of manta rays. Helping local groups protect ecosystems that are frequented by these rays for tourism may be the only viable solution. Conservation efforts need to work internationally and with local communities to protect these majestic creatures.

Dive Sites

More detailed information on manta ray diving destinations:

The Americas

  • Belize • Cocos, Costa Rica
  • Galapagos in Ecuador • Socorro Islands, Mexico

Australia

  • Osprey Reef • Ribbon Reefs

Burma - Myanmar

  • Mergui Archipelago

Fiji

  • Kadavu • Koro Sea and Bligh Waters

Indonesia

  • Komodo • Raja Ampat

The Maldives

  • Hanifaru, Baa Atoll • Maldive Islands

Red Sea

  • Egypt • Sudan

Thailand

  • Koh Bon • Hin Daeng - Hin Muang
  • Racha Noi • Richelieu Rock

Dive The World Recommendations: Raja Ampat, Komodo, Mexico, the Maldives, Black Rock and Koh Bon.


Enquire Now

 
Liveaboard Search
Departure date: between
and
 
Contact us
 

Special Offers

Dive The World

Discount diving packages from around the world ...

 
 

Cocos Safaris

From US$ 318 per day ...

 
 

Maldives

Liveaboard diving cruises from US$ 175 per day ...

 
 

Mexican

Liveaboard Trips

Diving cruises from US$ 350 per day ...

 
 
Dive The World RSS blog news feed (opens in a new window)  Watch Dive The World's diving videos on YouTube (opens in a new window)  Join Dive The World on Facebook (opens in a new window)  Follow Dive The World on Twitter (opens in a new window)
Follow us on Pinterest (opens in a new window)  Join us on Google+ (opens in a new window)  Follow us on Linkedin (opens in a new window)
Testimonial
... Dear Dive The World team, we would like to thank you for the excellent organization of the tour, quick reply of e-mails and be sure next time we will book through you. Always quick answer (within 24 hours), detailed information, easy payment procedure (with creditcard), reachable by phone. Everything works very well, no recommendation for improvement. An excellent service ...
Martina Fleckenstein, Germany
[ More customer reviews ]
 © Dive-The-World.com Share Like this site?: 
Privacy Policy | Terms   
Home |  Destinations |  Liveaboard |  Dive Resorts & Day Trips |  PADI Courses  
Dive Videos |  Travel Info |  Trip Reports |  Creatures |  FAQs |  Parks 'n' Reefs |  Maps  
Why Book With Us? |  About Us |  Testimonials |  Newsletters |  Site Map |  Contact Us  
 DIVE THE WORLD   
Unit 702, 7/F Bangkok Bank Building,
No. 18 Bonham Strand West, Hong Kong
Tel.: +66 (0)83 505 7794
Fax: +66 (0)76 281166
E-mail: info@dive-the-world.com
Website: http://www.dive-the-world.com