Spotted Eagle Ray

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 behind the pelvic fins. The front of the 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 spotted eagle rays have a wingspan of up to 3 meters (10 ft) and a mass of 230 kilograms (507 lb).

As traditionally defined, spotted eagle rays are found globally in tropical regions from the Indo-Pacific region from the western Pacific Ocean, the Indian Ocean, and the western Atlantic Ocean. They are found in shallow coastal water by coral reefs and bays, in depths down to 80 meters (262 ft).

Spotted eagle ray preys mainly upon bivalves, crabs, whelks and other benthic infauna. They also feed on mollusks (such as the queen conch) and other crustaceans, particularly malacostracans, as well as echinoderms, polychaete worms, hermit crabs, shrimp, octopuses, 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.

Spotted eagle rays prefer to swim in waters of 24 to 27 °C (75 to 81 °F). Their daily movement is influenced by the tides; one tracking study showed that they are more active during high tides. Uniquely among rays they dig with their snouts in the sand, surrounding themselves in a cloud of sand that spews from their gills. They also exhibit two motions in which the abdomen and the pectoral fins are moved rapidly up and down: the pelvic thrust and the extreme pelvic thrust. The pelvic thrust is usually performed by a solitary ray, and repeated four to five times rapidly. The extreme pelvic thrust is most commonly observed when the ray is swimming in a group, from which it will separate itself before vigorously thrusting with its pectoral fins. The rays also performs dips and jumps; in a dip the ray will dive and then come back up rapidly, perhaps as many as five times consecutively.

One male, or sometimes several, will pursue a female. When one of the males approaches the female, he uses his upper jaw to grab her dorsum. The male will then roll the female over by grabbing one of her pectoral fins, which are located on either side of her body. Once he is on her ventral side, the male puts a clasper into the female, connecting them venter to venter, with both undersides together. The mating process lasts for 30–90 seconds.

The dorsal spots make the spotted eagle ray an aquarium attraction, although because of its large size it is likely kept only at public aquariums. There are no target fisheries for the spotted eagle ray, but it is often eaten after being caught unintentionally as bycatch. There have been several reported incidents of spotted eagle rays leaping out of the water onto boats and landing on people. Nevertheless, spotted eagle rays do not pose a significant threat to humans, as they are shy and generally avoid human contact. Interactions with an individual snorkeler in the Caribbean has been reported especially in Jamaica involving one, two and even three spotted eagle rays.