GIANT MANTA RAY
(Manta birostris)
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Note:
Giant Manta Rays are commonly referred to as the Atlantic manta ray. However some specialists recognize two other species of manta, known as the "lesser" devil rays, Manta hamiltoni (Pacific manta ray) and Manta alfredi (Prince Alfred's manta ray).


Geographic range:
M. birostris can be found between 35 degrees north and south latitude in coastal regions of Atlantic, Pacific and Indian oceans. In Mexico it can be found along both coasts.

Physical characteristics: The most prominent feature of giant mantas are their large, wing like, pectoral fins and front lobes extending on both sides of the large mouth opening. There are no dorsal or caudal fins. Mouth is large, rectangular and in terminal position. Teeth, which are small, can be found only in the lower jaw. Gills are present on the underbody. Tail is whip like and has no barb.
When newborn, mantas weigh about 10 kg, but can reach up to 1200 - 1400 kg when adults. The largest individuals span over 6m between the tips of the pectoral fins. There is no sexual dimorphism, but females tend to be a little larger than males. The entire skeleton is cartilage, just like in sharks. Skin is rough. Overall upper body color is dark brown to grayish black, underbody is whitish.

Food habits: Planctivorous surface filter feeder. The large, gaping mouths and cephalic lobes are used to herd plankton crustaceans and small schooling fish. The teeth of Manta birostris are nonfunctional during feeding.
Mantas feed often at the water surface in slow and long sweeping circles.

Reproduction: Sexual maturity is reached at 5 years of age. Mating occurs seasonally around rocky reef areas from 10-20 meters in depth. The males swim closely behind the tail of the female at faster than usual speeds (9-12km/h). This courtship will last for about 20-30 minutes at which point the female decreases her swimming speed and a male will grasp one side of the female's pectoral fin by biting it. He arranges his body under that of the females. The male will then insert his clasper in the cloaca of the female and insert his sperm, this usually lasting around 90-120 seconds. The gestation period of Manta birostris is 13 months, after which females give birth to 1 or 2 live young. Pups are born wrapped up by their pectoral fins, but soon after become free swimmers and fend for themselves. The pups are between 1.1 and 1.4 meters big when they are born.

Behavior: Solitary, non territorial. A tendency to visit certain areas was observed. These are called "cleaning stations" with wrasse fish swimming about them picking off parasites and dead skin. Atlantic manta rays have no special anti-predator defense system other than their tough skin, but due to their size they do not have many natural predators. Large sharks have been known to attack Atlantic manta rays.

Habitat:
Surface ocean waters to max. depths of 120 meters (photic zone), prefer in -shore, warmer waters where food sources are more abundant, but occasionally can be found further from shore.

Biomes: reef, temperate coastal, tropical coastal
 

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