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Stingrays have had to develop certain modifications to
overcome obstacles they encounter in their natural habitat.
Breathing
Stingrays spend most of their time at the sandy bottoms of coral
reefs. A stingray's mouth and gills are located on the ventral
side of its body. When a stingray is feeding, it buries itself in
the sand, making it difficult to breathe. To adapt to such
conditions, the stingrays developed extremely large spiracles (right).
Spiracles are openings behind the eyes that allow the ray to take in
oxygen-rich water and flush it over the gills. Not only do these
spiracles aide in breathing during feeding, they also help the stingray
to remain completely still for several hours at a time while in the
sand. |
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Stinging Barb
Stingrays are highly preyed-upon creatures. Hammerheads are
their most frequent predator and are obviously MUCH greater in size than
the ray. To compensate for their small size, the rays have
developed a stinging barb at the end of their tail. Many researchers believe that this is a
modified dermal denticle, or tooth-like scale. When threatened,
the stingray can curl this venomous barb over its body to sting their
predator. |
Mouth and Teeth
The location of the stingray's mouth is crucial to its feeding
habits. Since stingrays dig for food in the sandy bottoms of
reefs, their mouths are located on their ventral side. Also, the
stingray's teeth are made of strong, blunt cartilage that can easily
crush shells. |
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Body Shape
Stingrays swim very close to the ocean floor so their bodies are
wide and flat, making locomotion easier around their habitat. In
addition, these rays posses large pectoral discs that they easily
undulate to glide through the water. |
No Bones About It
A stingray's body consists completely of cartilage. Cartilage
is a tough, elastic, fibrous tissue that makes up the entire skeleton of
the stingray. |
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