June 2006
The Stingray
Order
Family
Genus
Batiformes
Dasyatidae
Taeniura, Urolophus
Stingrays are dangerous creatures which are related
to the shark and have a skeleton which
is made of a cartilaginous material, lighter
than bone, allowing them to maintain buoyancy.
Their unique coloring, evident in the above graphic, makes it easier
to identify and to avoid
this stingray species. There is another species, the Urolophus
cruciatus, (banded stingaree)
found in waters off the continent of Australia....which does
not have blue dots but more closely
resembles the manta ray in coloring. These rays are also dangerous.
Stingrays prefer warmer
coastal waters with depths of 350 feet or less
and spend a lot of time
searching for food in shallow waters along sandy
beaches. Some ray species do well in
fresh
water, some in saline and others can survive
in both.
The graphic below shows a Urolophus cruciatus
cruising along the oceans bottom....searching
for food.
The reason stingrays are dangerous is because of the rather
large poisonous spine located on
their tail. This spine is hard and very sharp and is used
to pierce the hard outer covering of
shellfish which makes up a large portion
of the stingray's diet. This sharp spine can grow to
over 12 inches long in some species and
because of these dangerous spines and the poison
it injects, stingrays are often avoided by all
but the hungriest fishermen. Several swimmers
have been killed after being struck by
the poisonous spines and neglecting to get immediate
medical attention.
If wounded by a stingray, get out of the water
immediately. Remove any part of the spine that
may remain in the wound and apply hot water to
the affected area as soon as possible. The
temperature should be around 95-105 degrees
Fahrenheit,
which will be hot enough to detoxify
the poison but not to cause burns. The wound should be treated
with hot water for 1 to 1 1/2
hours. The wound should then be
irrigated with an anesthetic such as lidocaine (lignocaine)
or
longer lasting bupivacaine. This will
help deal with the pain until the wound starts to heal. It is a
good idea to check the wound for fragments of
spine which may still remain..remove all fragments,
apply an antibiotic cream, and bandage the wound.
Stingrays often weigh 650-750 lbs and are 14-16
ft. in length, including the tail. They mate
from March to late September or early October
and lay 2-8 eggs with the normal amount
being 2-5. The gestation period
is from April to late August. The lifespan
of the stingray
is not known but they have lived in captivity
for over 20 years. Stingrays eat crustaceans (crabs,
small mollusks), small fish and floating algae.
Stingrays have a keen sense of smell and
good eyesight and are able to locate food
items
very readily. Notice the long tail of the ray in the above graphic.
As stated earlier, this
tail with its sharp spine is used for killing hard shelled crustaceans,
but it also is often used
for protection and to steer the stingray...aiding
the large fins in propelling the ray through
the water.
One interesting trait of the stingray is to settle
to the bottom of the ocean, flapping its large fins
around in the soft seabed. This causes sand to swirl around and
cover the ray with a layer of
dirt camouflage. The ray then lays
motionless until fish or other prey swims close by. The ray
then swiftly lunges forward, grabbing his meal and crushing its prey
with flattened teeth and
powerful jaws. Shell fragments and other non
digestible
items are spat out.
Although stingrays are not on the endangered list
and more than likely won't appear there
anytime soon... like any ocean creature who prefers shallow coastal
waters, their numbers
are adversely affected by pollution.
In the graphic below, shaded in blue, is the range of the various species of stingray.
Be sure to check back next month for July's "Creature of the Month" The Coral Snake.