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( Stingrays)
Dasyatis
Himantura
Pastinachus
Pteroplatytrygon
Taeniura
Urogymnus
See text for species. Dasyatids are common in tropical coastal waters throughout the world, and there are fresh water species in Asia (Himantura sp.), Africa, and Florida (Dasyatis sabina). The "typical" freshwaters rays in South America, while superficially similar to stingrays, are members of another family, Potamotrygonidae. While most dasyatids are relatively widespread of the ocean and unlikely to be threatened,in side there are several species (for example Taeniura meyeni, Dasyatis colarensis, D. garouaensis and D. laosensis) where the conservation status is more problematic, leading to them being listed as vulnerable or endangered by IUCN. The status of several other species are poorly known, leading to them being listed as data deficient. Dasyatids are propelled by motion of their large pectoral fins (commonly mistaken as "wings"). Their stinger is a razor-sharp, barbed, or serrated cartilaginous spine which grows from the ray's whip-like tail (like a fingernail), and can grow as long as 37 cm (about 14.6 inches). On the underside of the spine are two grooves containing venom-secreting glandular tissue. The entire spine is covered with a thin layer of skin called the integumentary sheath, in which venom is concentrated.[1] The venom contains the enzymes 5-nucleotidase and phosphodiesterase which breakdown and kill cells; and the neurotransmitter serotonin which provokes smooth-muscle contractions.[2] This gives them their common name of stingrays (a compound of "sting" and "ray"),[3] but the name can also be used to refer to any poisonous ray. Divers often refer to them as "Sea Devils". Stingrays may also be called the "whip-tailed rays" though this usage is much less common.
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