Ray, Pacific or Atlantic Manta ray, Devil ray.
Immense size (the largest of all the rays). Terminal mouth has well developed,
flexible cephalic lobes. Single dorsal fin anterior to tail. Small bump at
trailing edge of dorsal. Tail thin and less than body length.
Black Manta colour
variation: Dorsum completely black. Cephalic lobes black. Ventrum black or
mostly black with brilliantly contrasting white central patch.
colour variation: Predominantly black dorsum with symmetrical white patches
a chevron across the shoulders. Wing tips sometimes fade to white. Ventrum
white or pale often with dark symmetrical patches that also sometimes form a
width 7m. Disc width at birth 1.2m. Unsubstantiated reports stretch up to 9m.
offshore waters. A regular visitor to sea mounts and off shore islands where
plankton is forced to the warmer surface layers.
and distribution: Circumtropical and less commonly circumtemperate. I
have one report from as far north as Vancouver island in Canada from the
Behavior: Manta rays
seen where plankton is concentrated. They
unroll their cephalic lobes and use them to channel plankton into their mouths.
Occasionally they can be seen barrel-rolling in the water column when feeding.
They may also breach; perhaps to rid themselves
of parasites. Seen singly or in
aggregations where food (plankton) is abundant.
"Warm blooded" i.e. able to sustain higher temperatures within
and chondocraniums (brains) relative to the ambient water temperature. This may be a tool
for maintaining constant muscle function whilst moving in and out of thermoclines.
Has been known to travel long distances and congregate for coral and fish spawning events.
Gives birth to one or two pups.
Status: Considered 'Vulnerable' by the IUCN.
Quote: "Currently this species has a high value in international trade and
directed fisheries exist that target this species in what is certain to be
unsustainable numbers. Artisanal fisheries also exist that target this species
for food and medicine. Individuals are also taken as bycatch in everything from
large-scale fisheries to shark control programs/bather protection nets.
The rate of population reduction appears to be high in several regions, as much
as 80% over the last three generations (approximately 75 years), and globally a
decline of 30% is strongly suspected. Sustained pressure from fishing (both
directed and bycatch) has been isolated as the main cause of these declines.
Certain monitored subpopulations appear to have been depleted, such as in the
Philippines, Indonesia, and parts of Mexico and are believed to be decreasing in
other areas such as India and Sri Lanka as a result of sustained pressure from
fishing. Of particular concern is the targeting of this species at critical
habitats or well-known aggregation sites where numerous individuals can be
targeted with relatively low catch-per-unit-effort."
Citation: Marshall, A., Bennett, M.B., Kodja, G., Hinojosa-Alvarez, S.,
Galvan-Magana, F., Harding, M., Stevens, G. & Kashiwagi, T. 2011. Manta
birostris. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>.
Revillagigedo Archipelago (Isla
San Benedicto and Isla Socorro), Mexican Pacific.
Manta birostris was once thought to be split into many regional species. There
are currently just two valid species but more may eventually be described.
Manta alfredi is visibly identical to Manta birostris but it lacks the small
bump at the back of its dorsal fin. It also has a smaller maximum size of 5.5m
to divers: Curious,
often approaching divers and in some areas allowing contact (belly rubbing)
which it seems to enjoy. Will sometimes play (somersault) in the divers bubbles.
away when pursued. Will tolerate riding for short periods but this behaviour
from divers is not condoned! Mantas come to plankton rich seamounts to feed
and if stressed and forced to leave this impacts on their ability to get the sustenance
Diving logistics: This
is a commonly seen ray in various locations around the tropics and subtropics. It can be
reliably encountered at Socorro and San Benedicto Islands south of Baja in the
Revillagigedo Archipelago. This is an excellent area to observe and interact
with giant oceanic mantas because the water is relatively clear and the mantas
are exceptionally friendly. Contact
for information about trips to Socorro.
largest aggregations of mantas can be found in the Maldives although the
visibilty in the area where the mantas congregate can be very rich in plankton.
Other diving locations submitted by readers:
Sharks and Rays of the World. Scott W. Michael. Sea Challengers.
and Rays - Elasmobranch Guide of the World. Ralf M. Hennemann. IKAN.