English Name: Reef Manta Ray
Local Name: En’ Madi
Size: 5.5 m
Family: Mobulidae
Order: Myliobatiformes
Distinctive Characters: An extremely large ray with a vaguely kite-shaped disc and a large protruding head with a wide, terminal mouth. Disc width approximately 2.1-2.4 x length. Pectoral fins narrowly falcate, with convex anterior margins and concave posterior margins. Pectoral fin apices acutely pointed. Pelvic fins very small. One small dorsal fin present at base of tail; not falcate. Head pronounced; extending well forward of pectoral fins. Slit-like spiracles posterior to eyes. Mouth very broad; 14-16% of disc width. Cephalic lobes long, broad, and highly flexible.
No denticle bands or teeth present on upper jaw. Band of vestigial teeth present on lower jaw.
Dermal denticles uniformly distributed; not in bands. Tail whiplike. Without caudal sting or calcified bulge near base of tail.
Colour:Dorsum predominantly black, usually with varying white or grey shoulder markings. Anterior margins of shoulder markings run at an oblique angle; starting at posterior edge of spiracle but slanting backwards at a slight angle towards midline of disc. Diffuse V-shaped marking anterior to tail extends forward to mid-back, occasionally curving outward to reach pectoral fin apices. Mouth and inner surface of cephalic lobes pale to white.
Ventrum mostly white with distinct black spots on 5th gill slits and highly variable spot patterns on chest. A wide dusky band usually present along posterior margin of ventrum. Tail uniformly black.
Note that colour among manta rays is highly variable with both melanistic and leucistic forms of reef mantas being relatively common.
Habitat and Biology: Pelagic in tropical/subtropical seas. Inhabits atolls, islands, and coastal areas with strong upwellings. Sometimes found in the open ocean but usually close to coral or rocky reefs. Surface to at least 432m.
Distribution: Mostly confined to the Indian Ocean, and west/central Pacific, with sparse records from the eastern Atlantic off west Africa. In the Indian Ocean, the reef manta is found around southeast Africa and Madagascar, the Maldives (where it is abundant), south of India, throughout southeast Asia and northern Australia, and around all major tropical island groups in the west/central tropical Pacific.
Remarks: Undoubtedly, the highest concentrations of reef manta rays exist in the Maldives (population estimate ~10,000 animals) but many other locations in the Indian and Pacific Oceans are also very good places to encounter this species including Mozambique, Seychelles, Thailand, Indonesia, Australia, Micronesia, Fiji, French Polynesia, and Hawaii.
HANIFARU BAY, MALDIVES.
Although the mantas at Hanifaru are not as interactive as their oceanic cousins at Socorro, the sheer number of animals makes this encounter absolutely spectacular. Hundreds of mantas visit the small bay to feed; often forming long manta-trains with their mouths agape to scoop up plankton.
As amazing as this encounter can be, there are drawbacks to visiting Hanifaru. Due to the nutrient rich conditions, visibility in the bay is usually quite low and sometimes atrocious. Also, because the area is so popular and shallow enough for non-divers, there are usually so many people that entry into the bay has to be regulated, but there are still too many swimmers to consider this a pristine encounter. Flash photography and scuba gear is not permitted here but elsewhere in the Maldives there are numerous places where smaller aggregations and individuals can be photographed with strobes while on scuba.