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All rays
belong to the superorder Batoidea, which includes stingrays, electric
rays, skates, guitarfish, and sawfish. Like sharks—their close
relatives—batoids have skeletons made of tough connective tissue called
cartilage. About 480 species of batoids are distributed worldwide,
particularly in warm and temperate climates, and are found in oceans,
estuaries, freshwater streams, lagoons, lakes, shallow offshore waters,
and coastlines.
Rays
primarily feed on molluscs, crustaceans, worms, and occasionally smaller
fishes. Some rays crush their prey between their blunt teeth, sometimes
referred to as bony plates. Often completely burying themselves in the
sand or soft sediment, rays are camouflaged by a grayish-brown, often
mottled coloration.
Reminiscent of birds in flight, some rays gently flap their enlarged
pectoral fins, or "wings," to "fly" through and sometimes even leap out
of the water. A ray’s wingspan, or disc-size, can range from about 30 cm
(12 in.) in yellow stingrays to over 6.1 m (20 ft.) in manta rays.
Among the
best know rays are stingrays, which have long, slim, whiplike tails
armed with serrated, venomous spines. A stingray lashes its tail only as
a defensive measure when it is caught, stepped on, or otherwise
disturbed.
When
wading in shallow waters, people should shuffle their feet to avoid
stepping on a buried stingray.
In many
parts of the world, some rays are commercially important food sources,
yet currently, rays are not considered threatened or endangered. Due to
humankind’s impact on the marine environment, however, concern is
mounting for the future of rays throughout their range. |
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