Mobula Ray

Mobula Ray

Mobula rays are also called "Sea Devil". Its back is dark brown to bluish black, often with a large darker mark on the nape of the neck. The ventral side is white.

The sea devil lives from the surface up to 20-30 m deep. It is a species that frequents mainly oceanic surface waters, above the continental shelf. We often see them in school when they are feeding, or when they jump out of the water!

In Nosy Be, it is possible to meet two species: mobula japanica and mobula mobular.

When can you see mobula rays in Nosy Be?
We can meet them all year round at Nosy Be, but the most frequent meetings are during the planktonic season, between October and December.
How tall are they?

Mobula mobular is the largest of the mobula rays. Specimens of around 5 meters and 300 kg have been studied in the Mediterranean.

Mobula japanica can reach more than 3 meters and weigh 150 kg.

What do they eat?

The manta ray feeds on plankton, crustaceans and occasionally small fish which it directs towards its very large mouth with the help of its cephalic fins. The lower jaw has hundreds of very small teeth, the function of which is unknown, but whose shape and arrangement constitute a criterion for distinguishing between species.

How do we differentiate the two species?

Mobula japanica and Mobula mobular are two extremely similar species: With very few dissimilar morphological characters, they are difficult to discriminate, perhaps even identical, which generates controversies in the respective distributions of the two species; a fortiori in underwater observations.

However, you can sometimes see a white spot at the tip of the dorsal fin of Mobula japanica, possibly a clear area behind the head. The back is dark blue to black, the white belly is sometimes speckled with gray.

In Mobula mobular, the back is dark brown to bluish black, often with a large darker mark on the nape of the neck. The ventral side is white.

Are mobula rays endangered?

In recent years, mobula ray fishing has been stimulated by the surge in their gills in the traditional Chinese medicine market. Medicinal pseudo-virtues are conferred on them, without any proven scientific basis, as well as a clever marketing strategy generating significant demand. Whatever the type of fishing (artisanal, targeted or unfortunate catch), the impact of the latter on a population with a low fertility rate, late sexual maturity and long gestation can only be seriously harmful for these species which can only compensate for losses over several decades. These reasons have led to the classification as near threatened of mobula rays by the IUCN.