Stingrays (Dasyatidae) is a family of rays, cartilaginous marine fishes, related to skates and sharks. (Click to enlarge images)
Dasyatids are common in tropical coastal waters throughout the world, and there are fresh water species in Asia, Africa, and Florida . The "typical" freshwaters rays in South America, while superficially similar to stingrays, are members of another family, Potamotrygonidae.
Dasyatids swim with a flapping motion, 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. This gives them their common name of stingrays (a compound of "sting" and "ray"), but the name can also be used to refer to any poisonous ray. Divers often refer to them as "Sea Devils".
Some adult rays may be no larger than a human palm, while other species, like the short-tail stingray, may have a body of six feet in diameter, and an overall length, including their tail, of fourteen feet. Stingrays may also be called the whip-tailed rays though this usage is much less common. A group or collection of stingrays is commonly referred to as a "fever" of stingrays.
Dasyatids generally do not attack aggressively or even actively defend themselves. When threatened, their primary reaction is to swim away. However, when they are attacked by predators or stepped on, the barbed stinger in their tail is whipped up. Surfers or those who enter waters with large populations of stingrays have learned to slide their feet through the sand rather than stepping, as the rays are able to detect this and swim away. This attack is normally ineffective against their main predator, sharks.
Humans are usually stung in the foot region (depending on the size of the stingray); it is also possible, although less likely, to be stung by brushing against the stinger. Humans who harass stingrays have been known to be stung elsewhere, sometimes leading to fatalities.
Stingrays are usually very docile creatures. The customary reaction of the stingray is to immediately flee the vicinity of a disturbance. Nevertheless, certain larger species are located in waters where they are easily excitable due to possible attacks from feeding sharks and should be approached with caution, as the stingray's defensive reflex and effort to flee may result in human contact with the stinger, resulting in serious injury or even (though rarely) death.
Dasyatids are not normally visible to swimmers, but divers and snorkelers may find them in shallow sandy waters, more so when the water is unseasonably warm.
Dasyatids are common in tropical coastal waters throughout the world, and there are fresh water species in Asia, Africa, and Florida . The "typical" freshwaters rays in South America, while superficially similar to stingrays, are members of another family, Potamotrygonidae.
Dasyatids swim with a flapping motion, 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. This gives them their common name of stingrays (a compound of "sting" and "ray"), but the name can also be used to refer to any poisonous ray. Divers often refer to them as "Sea Devils".
Some adult rays may be no larger than a human palm, while other species, like the short-tail stingray, may have a body of six feet in diameter, and an overall length, including their tail, of fourteen feet. Stingrays may also be called the whip-tailed rays though this usage is much less common. A group or collection of stingrays is commonly referred to as a "fever" of stingrays.
Dasyatids generally do not attack aggressively or even actively defend themselves. When threatened, their primary reaction is to swim away. However, when they are attacked by predators or stepped on, the barbed stinger in their tail is whipped up. Surfers or those who enter waters with large populations of stingrays have learned to slide their feet through the sand rather than stepping, as the rays are able to detect this and swim away. This attack is normally ineffective against their main predator, sharks.
Humans are usually stung in the foot region (depending on the size of the stingray); it is also possible, although less likely, to be stung by brushing against the stinger. Humans who harass stingrays have been known to be stung elsewhere, sometimes leading to fatalities.
Stingrays are usually very docile creatures. The customary reaction of the stingray is to immediately flee the vicinity of a disturbance. Nevertheless, certain larger species are located in waters where they are easily excitable due to possible attacks from feeding sharks and should be approached with caution, as the stingray's defensive reflex and effort to flee may result in human contact with the stinger, resulting in serious injury or even (though rarely) death.
Dasyatids are not normally visible to swimmers, but divers and snorkelers may find them in shallow sandy waters, more so when the water is unseasonably warm.
