Rajiformes

Taxobox
name = Rajiformes


image_width = 250px
image_caption = Spotted eagle ray, "Aetobatus narinari"
regnum = Animalia
phylum = Chordata
classis = Chondrichthyes
subclassis = Elasmobranchii
superordo = Batoidea
ordo = Rajiformes
subdivision_ranks = Families
subdivision =
Anacanthobatidae
Dasyatidae
Gymnuridae
Hexatrygonidae
Myliobatidae
Plesiobatidae
Potamotrygonidae
Rajidae
Rhinobatidae
Urolophidae

Rajiformes is the order of true rays and skates, flat-bodied cartilaginous fishes related to sharks.

Classification

There are several proposed classifications of fish in the superorder Batoidea. In some classifications the order Rajiformes is split into two or three orders, the additional orders being Myliobatiformes, containing the eagle rays and their relatives; Rhinobatiformes, containing the guitarfishes (which may be further split into Rhynchobatiformes, containing the shovelnosed guitarfishes, and Rhiniformes, the guitarfishes).

* Anacanthobatidae (smooth skates)
* Dasyatidae (stingrays). Named for the venomous spines along the tail; these contain a poison that causes pain and may cause symptoms such as nausea, vomiting, fever, chills, muscle cramps, tremors, paralysis, fainting, seizures, elevated heart rate, and decreased blood pressure (depending on the species). In addition, some species' toxins can be fatal to humans.
* Gymnuridae (butterfly rays)
* Hexatrygonidae (sixgill stingrays)
* Myliobatidae (eagle rays). The largest of rays, including the giant manta rays. Most eagle rays have one poison-carrying spine.
* Plesiobatidae (deepwater stingrays)
* Potamotrygonidae (river stingrays)
* Rajidae (skates)
* Rhinobatidae (guitarfishes). They have a body structure similar that of the sawfishes, but are not thought to be closely related.
* Urolophidae (round rays)

References

*
* [http://www.elasmo-research.org/education/shark_profiles/batoids.htm Batoids: Sawfishes, Guitarfishes, Electric Rays, Skates, and Sting Rays]
* J. D. McEachran, K. A. Dunn, T. Miyake (1996). "Interrelationships of the batoid fishes (Chondrichthyes: Batoidea)". In "Interrelationships of Fishes", Academic Press.
* [http://www.elasmo-research.org/education/shark_profiles/skate_or_ray.htm "Skate or Ray?"] . ReefQuest Centre for Shark Research. "Accessed 20 March, 2008".