Myliobatis
Rhinoptera
Pteromylaeus
Aetobatus
Aetomylaeus
Eagle rays (Myliobatidae) are a family of mostly large rays living in the open sea rather than at the bottom of the sea. They are excellent swimmers and able to jump several metres above the surface. Eagle rays feed on snails, mussels and crustaceans, crushing their shells with extremely hard teeth.
Sometimes the manta rays are considered to be a subfamily of eagle rays. If they are excluded, there are five genera belonging to the eagle rays: Myliobatis (common eagle rays), Rhinoptera (cownose rays), Pteromylaeus (bull rays), Aetobatus (bonnet rays), and Aetomylaeus (smooth tail eagle rays).
The common eagle rays (Myliobatis)
The Common Eagle Ray (Myliobatis aquila) is distributed throughout the Eastern Atlantic, including the Mediterranean Sea and the North Sea. Another important species is the Bat Eagle Ray (Myliobatis californica) or Bat Ray in the Pacific Ocean.
These rays can grow extremely large, up to 180 cm including the tail. The tail looks like a whip and may be as long as the remaining body. It is armed with a sting. Eagle rays live close to the coasts, in depths of 1 to 10 m, seldom up to 30 m; only in exceptional cases they are found as deep as 300 m.
The cownose rays (Rhinoptera)
Cownose rays are named for their ungainly, odd-looking heads. Apart from that they look very much like the above genus. Their whip-like tail is armed with one or more stings. Species include the Javanese Cownose Ray (Rhinoptera javanica) in the Indian Ocean and the western Pacific, the Australian Cownose Ray (Rhinoptera neglecta) around the Australian coasts and a species which inhabits the Chesapeake Bay (Rhinoptera bonasus).
The bull rays (Pteromylaeus)
The Bull Ray (Pteromylaeus bovinus) is also named for the shape of its head. It is a very large ray, often 180 cm and sometimes up to 230 cm in length. This ray can be found along Atlantic coasts between Portugal and South Africa. It is also distributed throughout the Mediterranean Sea. Another species in this genus, the Rough Eagle Ray (Pteromylaeus asperrimus), is just 80 cm in length and lives around the Galapagos islands.
The bonnet rays (Aetobatus)
The Spotted Eagle Ray (Aetobatus narinari) belongs to this genus. It is a very beautiful ray, bearing numerous white spots on its inky blue body. With a length of 3 m and a weight of 230 kg it is by far the largest eagle ray. Lengths up to 8.8 m were reported, but are doubtful. The Spotted Eagle Ray is distributed in tropical areas of all oceans, e.g. in the Caribbean Sea and the Gulf of Mexico.
The smooth tail eagle rays (Aetomylaeus)
This obscure genus is distributed in the Indian Ocean and the Western Pacific. These rays have their name, because they lack the sting on the tail.