aquariums are usually reserved for fish, but they also make great
habitats for freshwater aquatic insects. Dragonfly naiads,
diving beetles, and giant water bugs are all common in Kentucky
streams and ponds and can thrive in a properly maintained aquarium.
When several kinds of aquatic insects are kept in an aquarium
along with fish, plants, and other organisms, an entire miniature
ecosystem can be observed. Listed below are some of the things
that are needed to establish an aquatic insect habitat, along with
some common wild aquatic insects that will thrive in a properly-maintained
Aquatic insects will need a ten-gallon or larger aquarium. A
filtration system is not needed, but air should be pumped into the
tank. The tank should be well-covered with a fine-mesh screen
top because many aquatic insects can fly or crawl out of an uncovered
aquarium. Fill the tank only about 1/2 - 3/4 full -- the insects
will be less likely to escape when the water level is low. Line
the bottom of the aquarium with rocks or gravel purchased from a
pet store. Rocks from local streams and creeks can also be
used, but can sometimes cause a chemical imbalance in the water,
so it is usually best to use pet store rocks.
The most important thing about any home aquarium is the quality
of the water. Chemicals that are present in tap water and
that are generated by aquarium organisms can kill even the hardiest
of creatures. One of the easiest ways to minimize these effects
is by allowing aquarium water to "age." To "age"
aquarium water, fill your aquarium with tap water to a few inches
above the desired level, turn on your air pump or filtration system,
and allow the water to sit for at least a few days. This will
allow most of the tap water chemicals to evaporate. In the
meantime, keep a separate bucket filled with tap water The
water in the bucket will age without a filtration system or air
pump, but more slowly. As the water in your aquarium evaporates,
refill with small amounts from the bucket to the desired level.
After the aquarium has aged for a few days, add 2-3 hearty
freshwater fish (such as mosquito fish or goldfish) to the tank.
Maintain the fish for an additional week or so -- as the fish
eat and produce toxic waste chemicals, microorganisms will gradually
build up in the aquarium and consume the waste chemicals. Once
green algae begins to grow in the aquarium, it is usually a good
sign that it is safe to add aquatic insects and other organisms.
We don't have enough space here to go into all the details
of maintaining healthy aquarium water -- and we are not aquarium
experts! -- so it is best to seek advice for your freshwater
aquarium from a pet store. Note: it is best
NOT to use water from lakes, ponds, and streams. It is difficult
to transport and may contain disease organisms that will kill your
Aquatic insects thrive best when aquatic plants are also growing
in the aquarium. Plants provide a place for insects to crawl
and hide, and can even be a food source for some insects. Ask
your local pet store for recommended freshwater aquatic plants.
A Word About
Mosquito Fish: Mosquito fish are a great resource for those
of us who love to keep freshwater insects. Mosquito Fish (also
called "Gambusia," from their genus name) are very common
in Kentucky streams and ponds, where they eat mosquito larvae and
other small creatures. They are a very hearty fish, and can
be used to condition aquarium water (see above). They are
also a perfect food source for predatory aquatic insects. Immature
mosquito fish, in particular, are a great, easy to capture food
source for many aquatic insects. Many aquatic-insect enthusiasts
raise mosquito fish in a separate aquarium (such as a small, 2.5
or 5 gallon tank) to guarantee a constant food source for their
It is best to keep your aquarium at temperatures between 60 - 72
degrees F. Do not place the aquarium close to a window: direct
sunlit can quickly heat the water to temperatures that are deadly
for aquatic organisms.
Predatory insects are generally the easiest to find and the easiest
to take care of in an aquarium. Examples include: dragonfly
and damselfly naiads, predacious water beetles,
giant water bugs, and water scorpions.
All of these insects can be fed with small minnows captured in local
creeks and ponds, or with small feeder fish (such as guppies) purchased
from a pet store. For a continuous food supply, breed guppies
or other small fish (such as mosquito fish) in a separate aquarium,
as mentioned above. Predatory insects will often feed on other
creatures in your aquarium, including each other. To reduce
this problem, keep only a few predatory insects in the aquarium
and provide them with plenty of feeder fish. Also, hiding
places like rocks and aquatic plants help reduce aquarium casualties.
our Case Files: Giant
Water Bugs, Dragonflies,
for more information about these insects, including where to find
them and how to identify them.
and Damselflies: Note that dragonfly and damselfly naiads
are only aquatic for a part of their lifecycle: after a few days
or months (depending on their age when they are caught), these insects
will shed their skins and become flying adults. Adult dragonflies
and damselflies cannot be maintained in captivity, so it is best
to release these insects near the same water source where they were
captured as soon as they emerge.
AND SCAVENGERS: Although not as commonly kept as predatory
aquatic insects, there are several herbivores and scavengers that
will thrive in captivity. Water scavenger beetles
(pictured on the left) and crawling water beetles
are both common in Kentucky ponds and streams. They will feed
on aquatic aquarium plants and they will also help keep the aquarium
clean by eating waste and dead organisms. They will also feed
on fish food.
There are a few non-insects that are often found in Kentucky
aquatic habitats that will thrive in captivity. Crayfish,
in particular, are easy to find and will live for years in a healthy
aquarium. They will feed on fish food, especially the large
pellets designed for bottom-feeding fish. Beware that crayfish
will tend to dominate an aquarium by killing and eating the other
There are several aquatic insects commonly found in Kentucky streams
which do not thrive in a typical freshwater aquarium. Mayfly
and Stonefly naiads, in particular, are very common,
but usually need to live in fast-moving water. They are good
prey items for predatory aquatic insects, though.