Eagle ray
| Eagle ray Temporal range: Late Cretaceous–Recent [1] |
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| Spotted eagle ray, Aetobatus narinari | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Superorder: | Batoidea |
| Order: | Myliobatiformes |
| Family: | Myliobatidae Bonaparte, 1838 |
The eagle rays are a group of cartilaginous fishes in the family Myliobatidae, consisting mostly of large species living in the open ocean rather than on the sea bottom.
Eagle rays feed on mollusks and crustaceans, crushing their shells with their flattened teeth, while devil and manta rays filter plankton from the water. They are excellent swimmers and are able to breach the water up to several metres above the surface. Compared with other rays, they have long tails, and well-defined rhomboidal bodies. They are ovoviviparous, giving birth to up to six young at a time. They range from 48 centimetres (19 in) to 9.1 metres (30 ft) in length.[1]
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[edit] Classification
Nelson's 2006 Fishes of the World (4th edition) recognizes seven genera, in three subfamilies. Some systematists place the cownose rays and the manta and mobulas in their own families (Rhinopteridae and Mobulidae, respectively).
[edit] Subfamily Myliobatinae
[edit] Aetobatus
The spotted eagle ray, Aetobatus narinari, also known as the bonnet ray or maylan, belongs to this genus. The ray bears numerous white spots on its inky blue body. It has a span width of 2.5 m (8 ft) and a maximum reported weight of 230 kg (about 507 lbs).[2] Including the tail, it can reach up to 5 m (16 ft) in length. The spotted eagle ray is distributed in the tropical areas of all oceans, including the Caribbean Sea and the Gulf of Mexico. The genus also includes the much smaller longheaded eagle ray, Aetobatus flagellum, which is a widespread but uncommon species of Indian Ocean and western Pacific coasts. This is considered an endangered species due to huge pressure from fisheries throughout its range.[3]
[edit] Aetomylaeus
This obscure genus is distributed in the Indian Ocean and the Western Pacific. These rays were named because they lack a sting on the tail. Species include the banded eagle ray, Aetomylaeus nichofii, mottled eagle ray, Aetomylaeus maculatus, and ornate eagle ray, Aetomylaeus vespertilio.
[edit] 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, 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 body. It is armed with a sting. Eagle rays live close to the coast in depths of 1 to 30 m and in exceptional cases they are found as deep as 300 m. The eagle ray is most commonly seen cruising along sandy beaches in very shallow waters, its two wings sometimes breaking the surface and giving the impression of two sharks traveling together.
[edit] Pteromylaeus
- For other species that go under the same name, see Bull ray (disambiguation).
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.
[edit] Subfamily Rhinopterinae
[edit] 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.
[edit] Subfamily Mobulinae
[edit] Manta
The manta rays are the largest members of the ray family, ranging up to 6.7 m (22 ft) from wing tip to wing tip and weighing up to 1,350 kg (3,000 lb). They inhabit the tropical seas of the world and are often observed around coral reefs.
[edit] Mobula
The mobulas are similar in appearance to manta rays, but differ in having subterminal rather than terminal mouths.
[edit] See also
[edit] References
- ^ a b Froese, Rainer, and Daniel Pauly, eds. (2009). "Mylobatidae" in FishBase. January 2009 version.
- ^ Florida Museum of Natural History Ichthyology Department
- ^ World Conservation Union "Red List" of threatened species
[edit] External links
- Froese, Rainer, and Daniel Pauly, eds. (2005). "Myliobatidae" in FishBase. August 2005 version.
- ARKive - images and movies of the spotted eagle ray (Aetobatus narinari)
General description They have a flattened body with a dark brown dorsal surface coded in white spots. Wing-like appendages. Head is obvious, with a flattened, tapered snout. Caudal fin is heavily modified into a whip-like form. Venomous spines may be found along base of caudal fin's dorsal surface, it can have 1-5 spines. Shape and skin Size Length with-out tail id 1.2-2. Width: 300 cm diet Bivalves, shrimp, crabs, annelids, octopus, whelks, and small fish Groups Speed
Eagle ray swim up to 50 miles per hour. Habitat and range
Eagle rays are found in water 1-80 meters deep in tropical/sub-tropical marine open and coastal waters; occasionally found in brackish estuaries. Eagle Rays can be found in Bermuda, North Carolina, southern Brazil, Gulf of Mexico, Caribbean, Antilles, Mauritania to Angola, Red Sea, South Africa, Hawaii, Japan, south Australia, Gulf of California, Puerto Pizarro, Peru, and the Galapagos Islands.
