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 fins and use them to channel plankton into their mouths. Sometimes
somersaults in the water column when feeding. May breach perhaps to rid itself
of parasites. Seen singly or in
aggregations where food (plankton) is abundant.
"Warm blooded" i.e. able to control its body
and chondocranium (brain) temperature relative to that of the waters in which it feeds. 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
or fish spawning events.
Gives birth to one or two pups.
has a remora above and behind each eye.
Revillagigedo Archipelago (Isla
San Benedicto and Isla Socorro), Mexican Pacific.
Manta birostris was once thought to be split into regional subspecies. There now
appears to be 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.