Spotted Eagle Ray

 

The spotted eagle ray (Aetobatus narinari) is a cartilaginous fish of the eagle ray family, Myliobatidae. It can be found globally in tropical regions, including the Gulf of Mexico, Hawaii, off the coast of West Africa, the Indian Ocean, Oceania, and on both coasts of the Americas at depths down to about 80 meters (262 ft). The rays are most commonly seen alone, but occasionally swim in groups. Rays are ovoviviparous, the female retaining the eggs then releasing the young as miniature versions of the parent.
This ray can be identified by its dark dorsal surface covered in white spots or rings. Near the base of the ray’s relatively long tail, just behind the pelvic fins, are several venomous, barbed stingers. Spotted eagle rays commonly feed on small fish and crustaceans, and will sometimes dig with their snouts to look for food buried in the sand of the sea bed. These rays are commonly observed leaping out of the water, and on at least two occasions have been reported as having jumped into boats, in one incident resulting in the death of a woman in the Florida Keys. The spotted eagle ray is hunted by a wide variety of sharks. The rays are considered Near Threatened on the IUCN Red List. They are fished mainly in Southeast Asia and Africa, the most common market being in commercial trade and aquariums. They are protected in the Great Barrier Reef.
Spotted eagle rays have flat disk-shaped bodies, deep blue or black with white spots on top with a white underbelly, and distinctive flat snouts similar to a duck’s bill.Their tails are longer than those of other rays and may have 2–6 venomous spines, just behind the pelvic fins. The front half of the long and wing-like pectoral disk has five small gills in its underside.
Mature spotted eagle rays can be up to 5 meters (16 ft) in length; the largest have a wingspan of up to 3 meters (10 ft) and a mass of 230 kilograms (507 lb).
Spotted eagle ray preys mainly upon bivalves, shrimps, crabs, whelks, and other benthic infauna. They feed on mollusks and crustaceans, particularly malacostracans. and also upon hermit crabs, shrimp, octopi, and some small fish.
The spotted eagle ray’s specialized chevron-shaped tooth structure helps it to crush the mollusks’ hard shells.The jaws of these rays have developed calcified struts to help them break through the shells of mollusks, by supporting the jaws and preventing dents from hard prey. These rays have the unique behavior of digging with their snouts in the sand of the ocean. While doing this, a cloud of sand surrounds the ray and sand spews from its gills. One study has shown that there are no differences in the feeding habits of males and females or in rays from different regions of Australia and Taiwan.
Source: Spotted Eagle Ray
Photo :  Spotted Eagle Ray formation, Keauhou Bay, Big Island, Hawaii by Steve Dunleavy on Flickr