Blue Spot Stingray
Scientific Name: Taeniura lymma
The blue spot stingray is appropriately named. Its covering of bright blue spots warns predators about the dangers of two venomous tail spines or stingers. The tail of this fierce ray is so long, it can jab at pesky creatures from over head and well in front of its face.
The oval-shaped body of the blue spot stingray can be up to 3 feet (90 cm) in diameter. This ray is mainly a yellowish-olive color with bright blue spots all over the top. The brightly-colored blue polka dot skin is warning coloration. Warning coloration alerts other animals that it is poisonous or venomous.
This ray also has countershading, meaning its dorsal or back side is dark and the ventral or belly side is light. When viewed from below, the white belly blends in with the sunny waters above. When viewed from above the dark, splotchy back blends in with the dark ocean floor below.
The tail has stripes of the same color blue as the body and is almost twice the length. It has a large tail barb and an additional medium-sized barb.
Vivid yellow eyes are located high on the head toward the front of the body. The position of the eyes allows the blue spot stingray to see almost behind it. A large spiracle or hole in the head that helps the stingray breathe is located just behind each eye. The gills and mouth are found on the underside of the body.
Blue spot stingrays live alone or in small groups on the sandy and rocky bottoms of coral reefs to depths of 65 feet (20 m). They are usually found on the deeper reef areas but move up to shallower reef flats and lagoons at high tide. As the tide drops, blue spot stingrays hide in reef caves, under tabletop corals and overhangs. Unlike most stingrays, blue spots rarely bury themselves in the sand.
These stingrays live in the warm waters of the Pacific Ocean and the Red Sea.
As the tide rises, groups of blue spot stingrays swarm to shallow, sandy reef flats. There they feed on worms, shrimp, crabs, mollusks and small fish. After they eat, they settle under the sand to rest in coral caves or on the reef bottom. These rays most often eat during the day, but sometimes eat at night.
This ray overpowers its prey, pinning it to the bottom with those huge wing-like fins. The blue spot stingray doesn't really have teethinstead, the mouth is outfitted with food-crushing plates. Located on the bottom of the body, the mouth of the blue spot stingray is perfect for scooping up animals hiding in the sand.
Blue spot stingrays are ovoviviparous. This means they give birth to live pups or baby rays after the young develop inside egg cases inside the uterus. Egg cases are thin, leathery cases that protect each developing pup. Each developing egg is enclosed within an individual egg case. A developing pup feeds off its egg's yolk. The pups remain inside the egg cases until fully developed and then hatch out while still inside the mother's uterus. Soon after, the mother gives birth to the pups.
Blue spot stingrays have up to seven pups per litter. When the pups are born, they look like miniature versions of the adults.
>A species or group of organisms that is in danger of extinction or disappearing
from the face of the earth in the near future if its situation is not improved.
A species that can be found throughout its natural range but is declining in number and may become
endangered in the absence of special protection efforts.
A species that is not declining in number but is of special concern because it is sensitive to pressure by
particular human activities or natural events.
A species that is not declining in number and is not sensitive to pressures by human activities or natural
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Threats and Management
The blue spot stingray is classified as stable, although it faces many population threats and is close to being qualified as vulnerable.
These stingrays are hunted throughout their range by near shore fishers. These near shore habitats like coral reefs are also being destroyed by people due to poisoning by farming aids like pesticides and fertilizers and by cyanide, used to capture reef animals for the pet trade.
Because this fish is very unique, it is frequently collected for the pet trade. But these rays don't make good pets. Blue spot stingrays get so big, they outgrow most home aquariums.
Reefs are being destroyed throughout the western Pacific. Blue spot stingrays rely on coral reefs to live. As the health of coral reefs decline, the amount of these stingrays decline.
Did You Know?
Rays dart away when they sense trouble approaching. When caught off guard, these fish fend off predators with a flick of the tail, which is equipped with two venomous spines. Since its tail is so long, the blue spot stingray can even strike at animals directly in front of it.
The large tail spine of the blue spot stingray is dangerous and even deadly. The barbs in the tail are so large, people have bled to death from a sting.
Blue spot stingrays can often be found getting a grooming at a cleaning station. A cleaning station is an area on the reef where large fish line up and a tiny fish or shrimp picks off all the dead bacteria and skin off the customers.
The pectoral fins or fins located on the sides of a stingray's body near the gills are actually attached to the head. On sharks, the pectoral fins are attached to the body.
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IUCN Red List:
Dozier, T.A. 1977. Dangerous Sea Creatures. United States of America: Vineyard Books, Inc. 128p. ISBN# 0-913948-04-7.
Michael, S.W. 1993. Reef Sharks & Rays of the World. A guide to their identification, behavior, and ecology. Petaluma, California: Sea Challengers. 107p.
Perrine, D. 1997. Mysteries of the Sea. Lincolnwood, Illinois: Publications International, Ltd. 312p. ISBN# 0-7853-2430-5.
Tricas, T.C., Deacon, K., Last, P., McCosker, J.E., Walker, T.I. and Taylor, L. 1997. Sharks & Rays. The Nature Company Guides. McMahons Point, Australia. 288p. ISBN# 0-7835-4940-7.
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By-catch - The part of the fisher's catch which is returned to the sea either because it has no value to them. Fishing boats search the seas for target animals, like tuna, and discard anything else they accidentally catch-like stingrays. The unwanted animals, called by-catch, dry out or suffocate on the deck, or get thrown back into the ocean all but dead.
Cleaning station - A place where large animals like stingrays, sweetlips, and sea turtles congregate in order to get their skin cleaned of parasites, bacteria and dead skin by various fish and shrimp.
Countershading - A form of camouflage in which an animal has a dark-colored back and a light-colored belly. Using fish as an example, when viewed from below, a fish blends in with the brightness of the sunny waters above. Viewed from above, the animal blends in with the dark ocean bottom. Countershading camouflages the animal, allowing it to sneak up on unsuspecting prey or hide from predators.
Dorsal - The back of an animal. The large fin on the back of a shark; the fin that sticks out of the water when a shark swims near the surface.
Egg case - A leathery protective container that enables shark eggs to mature until hatching.
Extinction - An organism that has not been present on the face of the earth for over 50 years.
Gills - Structures used for breathing; gills extract oxygen out of water.
Organism - A living thing.
Ovoviviparous - A form of reproduction in which the young, or in this case pups, develop inside thin leathery egg cases inside the mother. Each pup receives food from a yolk sac inside the egg case. After the pups fully develop, they hatch from their egg cases. Soon after, the mother gives birth to the pups.
Pectoral fins - The paired fins on the sides of a fish behind the gills.
Pet trade - An industry or business in which animals are taken from the wild and sold to pet stores, zoos, and aquariums.
Pup - A baby stingray.
Species - A group of organisms capable of breeding and producing fertile offspring; organisms that share the same gene pool.
Spiracles - A pair of holes, often located right behind the eyes, which bring water to the gills.
Venomous - Having the ability to release poison by means of injection; through spines or teeth.
Ventral - The belly of an animal.
Warning Coloration - Bright colors or wild patterns warning other animals of the colorful animal's poisonous or venomous nature.
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