Feeding a Pet Stingray -
the essentials of maintaining a varied Diet.
Brendon Turner
Stingrays will eat a wide variety of foods. Maintaining a varied
diet is extremely important in captive animals, as monocultural
diets incur a risk of nutritional deficiencies. Stingrays are
very active, and should be fed at least once a day, preferably
twice or even three times daily. The daily diet can be varied in
order to create some environmental enrichment as well as balanced
nutrition for the rays.
First Foods
First foods for newly acquired rays should be blackworms or
tubifex worms. These foods seem to be the most readily accepted,
and are small enough to be inadvertently ingested either by mouth
or through the spiracle, thereby giving the ray an opportunity to
taste these possibly unfamiliar foods by chance. Foods that have
been used for very small specimens, such as the teacup rays, are
small insect larvae such as mosquito larvae, small shrimp known
as ghost shrimp or glass shrimp, live adult brine shrimp, and
blackworms. Chitinous foods such as shrimp provide less
nutritional value than do soft-bodied foods, and so should not be
used as sole food items.
The best way to be certain that your new stingray is feeding is
to watch the spiracles as the ray passes over food on the bottom
of the tank. If it is eating, you will see the spiracles opening
and closing rapidly, or fluttering, as the food is ingested and
water is passed from the mouth and out the spiracles. Once you
observe a newly acquired ray readily feeding on black-worms or
redworms introduce finely chopped night crawlers in small
quantities. Once stingrays recognize these as food, most will
readily eat them. Later, experiment with other types of food.
Types of Food for Stingrays
Live Foods
Feed live foods, including blackworms or tubifex worms, in
quantities adequate to allow a small amount to be left in the
tank so the rays can browse later. However, when cleaning the
substrate, note whether a significant amount of living worms is
present; blackworms and tubifex worms will colonize the substrate
if not eaten and add to the nitrogenous waste production in the
aquarium.
Nonlive, Nonaquatic Foods
Chopped earthworms, redworms, or night crawlers and any nonlive,
nonaquatic foods should be fed in smaller quantities to prevent
any overlooked food from decomposing in the tank. Keep in mind
that stingrays have relatively small mouths-a 10-inch (25-cm) ray
may have a mouth that is 1/2 to 3/4 inch (13 to 19 mm) wide, so
chopped food items must be small enough to be eaten easily. If a
ray ingests a piece of food and repeatedly spits it out and
ingests it again, this usually indicates that the particle is too
large. Some ray species, such as antenna rays, have extremely
small mouths relative to their size.
Once acclimated, rays often develop techniques for eating larger
pieces of food; for example, newly imported rays may have
difficulty consuming even small chopped pieces of night crawlers.
Eventually, however, they learn to eat an entire worm by sucking
it into their oral cavity without chewing. Newly acquired rays
also often ignore feeder goldfish but they quickly learn to chase
down and consume feeders, even learning where they hide in the
tank.
Commercially Prepared Stingray Foods
Stingrays may learn to eat other unfamiliar foods such as brine
shrimp, pellet foods, or other commercially prepared foods. While
there is probably no harm in offering these foods to rays, it is
best to use fresh, live, or frozen foods as the dietary staple.
Although stingrays often do not initially accept frozen or other
nonliving foods, they may soon learn to eat these foods after
they have been acclimated. A benefit of frozen foods is that they
are less likely than live foods to introduce diseases or
parasites.
Hand-feeding Stingrays
Occasionally, a well-acclimated specimen will fail to gain
weight, even though you are offering enough food. Several things
may cause this problem; the most likely possibility is that it is
not competing efficiently for food against other fish in the
aquarium, or it may have a parasitic infestation. Stingrays
occasionally do not seem to learn where foods can be found during
feeding times, and are always in the wrong part of the tank
during those times. In these cases, it is helpful to hand-feed
such specimens. By this I do not mean feeding with your hands.
Although some aquarists do this with stingrays, I do not
recommend it because of the possibility of being accidentally
stung. Remember that stingrays are wild animals, and no matter
how accustomed your specimens become to your presence, it is
impossible to always accurately predict their response to humans.
Instead, you should always perform the hand-feeding of specimens
with long forceps or a similar instrument. Stingrays generally
avoid metal objects and appear to be frightened by metal;
however, because they can sense metal, they will quickly learn
that when there is a metal object in the aquarium, food is being
offered. In this way, you can teach your stingray to feed
directly from forceps, and selectively feed it more food.
Simply hold a night crawler (or a piece of night crawler) in the
forceps, and hold the worm in the aquarium so that the ray can
touch it with its fin. It should eat the worm immediately. After
a few feedings in this manner, allow the forceps to touch the ray
while it is eating the worm. It will quickly learn to associate
the forceps with feeding and soon you will find that the ray will
pounce on the forceps as soon as it touches it, eagerly looking
for a treat!
How Much and How Often to Feed Stingrays
The key to having well-fed stingrays in your aquarium is
providing plenty of food. Unlike most fish that swim quietly
between feedings, stingrays search constantly for food, looking
under and around tank ornaments, moving driftwood, rocks,
filters, and even other fish! This high activity level translates
to a high metabolic rate, which means that while searching for
food rays continue to burn energy. If they use up energy looking
for food, but do not find any, they will lose weight. To
compensate for this loss of energy, it is essential to provide
adequate food. I cannot stress this enough. Hobbyists sometimes
tell me that they feed their rays three times weekly, thinking
that this is adequate. Stingrays should be fed at least twice,
and usually three times, daily. In spite of these frequent
feedings, rays will still constantly look for food between
feedings!
When feeding significant quantities of live feeder goldfish, it
is wise to add vitamin B1 to the feeder supply. Goldfish contain
the enzyme thiaminase, which destroys thiamin, or vitamin B1, and
this vitamin must be replenished. It should be your practice to
add one 50-mg tablet to each 500 gallons (1893 L) of water every
two weeks. You can add the tablets directly to the sump of the
wet-dry filter; or as an alternative, the tablets can be added
directly to the tank.
Brendon Turner maintains The Animal Gazette - a weekly edition of
helpful articles for pet owners. Visit
www.AnimalGazette.com for
information about cats, dog breeds and tropical fish.
