Mobula birostris

Mobula birostris belongs to the Myliobatidae family within the order of Myliobatiformes. Known as the atlantic manta ray or devil ray, this species is distributed throughout the temperate and tropical seas, inhabiting both coastal and deeper waters.

Source: FAO

The body of Mobula birostris, that can reach up to 6.7 meters in length (including the tail), contrast with its food source, the smallest organisms in the ocean, the zooplankton, which they obtain by ingesting large amounts of water that they filter with their gill structures to capture them. The body of these large animals is twice as wide as their own disc length. They have a relatively wide mouth which is located in a terminal position in front of the head. On the sides of the mouth we find the cephalic fins. The pectoral fins, very developed, adopt slightly convex anterior margins that end in sharp points. In contrast, the posterior margin of the pectoral fins are deeply concave. Mobula birostris has 5 gill openings on each side of the body, located ventrally and behind the mouth. A characteristic feature of this species, and one that can be used to differentiate it from the similar Mobula alfredi, are the often black spots that occur just after the 5th gill opening. Returning to the dorsal region of the body, we find just before the end of the base of the pelvic fins, a very reduced dorsal fin in terms of dimensions. Finally we find the tail, with a length shorter than the length of the disc of the animal, which takes the appearance of a whip. At the base of the tail, it has a spine with serrated edges and is enclosed in a calcified mass. The calicification that covers the spine is another of the distinctive features of Mobula birostris. As for the color of the body, the dorsal part is of variable color, from reddish-brown to black, sometimes presenting small spots. The ventral part is whitish with sporadic gray spots.

We can see Mobula birostris both solitary and in pairs or even small groups of individuals. As previously mentioned, its diet is based on zooplankton, although occasionally it may ingest small fish and crustaceans.

As for the reproduction of Mobula birostris, it is an ovoviviparous species, which acquires sexual maturity when the specimens reach 380-413 cm in length. At birth, the young are usually 122-127 cm wide.

Mobula birostris is listed by the International Union for Conservation of Nature (IUCN) as a vulnerable species, and has therefore been included in the red list of threatened species.


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