The eagle rays are a group of
cartilaginous fish
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue ...
es in the family Myliobatidae, consisting mostly of large species living in the open ocean rather than on the sea bottom.
Eagle rays feed on
mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...
s and
crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...
s, crushing their shells with their flattened teeth. 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,
rhomboid
Traditionally, in two-dimensional geometry, a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are non-right angled.
A parallelogram with sides of equal length (equilateral) is a rhombus but not a rhomboi ...
al bodies. They are
ovoviviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...
, giving birth to up to six young at a time. They range from in length and 7 m (23 ft) in wingspan.
Classification
Nelson's book ''
Fishes of the World
''Fishes of the World'' by the American ichthyologist Joseph S. Nelson (1937–2011) is a standard reference for fish systematics. Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the ...
'' treats cownose rays, mantas, and devil rays as subfamilies in the Myliobatidae. However, most authors (including
William Toby White
William Toby White is an Australian ichthyologist. He studies speciation and biodiversity of shark, ray, and skate species (subclass Elasmobranchii) through morphological and molecular systematics.
Education
White received bachelor's (199 ...
) have preferred to leave the
Rhinopteridae and
Mobulidae
The Mobulidae (manta rays and devilfishes) are a family of rays consisting mostly of large species living in the open ocean rather than on the sea bottom.
Taxonomy
The Mobulidae have been variously considered a subfamily of the Myliobatidae by ...
outside of the Myliobatidae.
White (2014) retained three genera (''Aetobatus'', ''Aetomylaeus'', and ''Myliobatis'') in the Myliobatidae, while a fourth (''Pteromylaeus'') was
synoymized with ''Aetomylaeus''.
[ A 2016 paper placed ''Aetobatus'' in its own family, the Aetobatidae.]
See also
* Stingray injury
A stingray injury is caused by the venomous tail spines, stingers or dermal denticles of rays in the order Myliobatiformes, most significantly those belonging to the families Dasyatidae, Urotrygonidae, Urolophidae, and Potamotrygonidae. Stingr ...
* List of prehistoric cartilaginous fish genera
This list of prehistoric cartilaginous fish genera is an attempt to create a comprehensive listing of all genera that have ever been included in the class chondrichthyes ''and'' are known from the fossil record. This list excludes purely vernacul ...
References
{{Taxonbar, from=Q6629661
Taxa named by Charles Lucien Bonaparte
Extant Cenomanian first appearances