Colloquially known as Bishop ray or Spotted eagle ray, Aetobatus narinari is a species of the family Myliobatidae belonging to the order Myliobatiformes. It is a semi-pelagic species of coastal waters, generally associated with coral reefs, estuaries or beaches, of the tropical and subtropical seas and depths of less than 60 meters.
Aetobatus narinari is a ray of considerable dimensions, especially in the longitudinal sense, being able to measure up to 8.8 meters, of which 3.3 meters correspond to the length of the disc. The disc adopts a rhombus shape of considerable thickness, and is approximately 2 times wider than its own length. The head is placed in an elevated and differentiated position with respect to the disc. Its head is rounded and relatively short, protruding from the area delimited by the large and highly developed pectoral fins, which have slightly angled corners. In a lateral position on the head, the eyes are located and behind them the spiracles. In the ventral part, we find the mouth which is practically straight and has a row of wide plate-shaped teeth, as well as the gill openings, which in this species are a total of 5 on each side. At the back of the disc, we find the base of the tail, in which we can observe a small dorsal fin and behind it one or more spines with serrated edges. The rest of the tail is very thin and long, its length can be up to 3.5 times the length of the disc. The tail has the appearance of a whip, and its color is dark. The entire dorsal surface of Aetobatus narinari can be grayish, olive gray, or brown, and has a pattern of whitish, yellowish, or blueish spots of varying sizes and shapes (circular, elliptical, and ringed). In contrast, the ventral surface is completely white with dark margins.
Aetobatus narinari can form large schools of several hundred individuals. This occurs mainly during the reproductive season. A curious fact of these congregations is that very often the different specimens jump out of the water. The reason for this behavior has not been fully understood, although it is hypothesized that it may be to impress rival females or males, or to de-worm. Aetobatus narinari is a migratory species, whose specimens travel great distances.
In relation to reproduction, they can give birth to between 4 and 10 offspring per litter, which at birth are between 18 and 36 cm wide.
The International Union for the Conservation of Nature (IUCN) has catalogued Aetobatus narinari as a species almost threatened and has included it in its red list of species.Photos: