 LIVE FOOD
The advantages of live foods over frozen and prepared foods are:
- the uneaten food will not immediately decay and load up
the filtration system,
- foods can be raised in controlled conditions and be free of
pathogenic (disease causing) bacteria
- by using inexpensive media and techniques, costs are
minimized, and
- most importantly, fish love grabbing things that try to run away
(plus, fish owners love watching their fish chase live food).
Here are some live foods the aquarist can easily culture at home, to the
extent that
some people on the NET have had experience with them.
Copyright
The FAQs owe their existence to the contributors of the net, and as
such it belongs to the readers of rec.aquaria and alt.aquaria.
Articles with attributions are copyrighted by their original authors.
Copies of the FAQs can be made freely, as long as it is distributed at no
charge, and the disclaimers and the copyright notice are included.
Contents:
- Uses:
- Baby brine shrimp are a food of choice for the newly hatched
fry of egg-layers and other small fish. They're also eaten
voraciously by some surprisingly large marine fish
and make a good substitute macro-plankton for some filter-feeding
invertebrates.
- Culturing:
- To hatch brine shrimp, one needs very little. A
hatchery
can be built out of almost anything, such as 1 gal plastic milk jug to 12 oz
soda bottles. Also, stores sell "shrimpolators" and plastic
hatching cones. Everything works, but a container with
a concave or conical bottom is the best because the
water flow has no dead spots. Add air tubing connected
to a small pump, put a light over it and keep
temperature around 85 degrees if the shrimp are to
hatch faster.
Ed Warner's book suggests 3.5 table spoons of uniodized
salt per gallon of water. He suggests using the
cheapest salt available, like the water softener salt
at $3 for 50 lb. SF Bay Brand recommends hardening
the water to improve hatching and shrimp survival, so
adding some Epsom salt and a tiny pinch of baking soda
may be a good idea.
In order for the shrimp to hatch and not die, the water in the
culture must be vigorously turned over to keep the
shrimp in suspension. This can be done by aerating the water
just like everyone else, using a 12 inch length of rigid
air tubing attached to a 3 inch tail of flexible tubing
attached to an air pump. The rigid section keeps the
hose from slipping out of the container. Aquarists using
airstones
may find that they crud up and clog
too often in this environment.
To get nauplii (hatched brine shrimp) out, turn off
the air, put a piece of rigid air (1/8") tubing with
2-3 ft of flex tubing attached into the culture, and let
the stuff settle. The shrimp egg cases will collect on
top of the water, the shrimp ought to sink to the
bottom (if the water is not too saline). Then just
siphon the wriggling shrimp off into a brine
shrimp (fine) net, dump the lot into a cup of water and
use an eye dropper to dispense to the fish.
The nauplii will live in the tank for up to 24 hours.
- Sources:
- Eggs can be bought in most aquarium and pet shops or
by mail
order. Eggs bought in bulk (such as 1 lb cans) will be much
less expensive than the
tiny ampoules sold in stores. The cans may be held in the
freezer, with 2-3 weeks worth of supply held in a small, tight-lid jar.
Ed Warner insists that the eggs of brine shrimp need at
least a year of incubation to become ready to hatch. He
goes on to say that a low yield from a newly opened can of
shrimp eggs may be due to insufficient incubation time and
that the best hatches come from the eggs that had been kept
for a few years, with the eggs kept for 5 years in a vacuum
packed airtight container giving perfect 100% hatch rates.
- Uses:
-
Just about all fish under 5" long will readily eat brine
shrimp.
- Culturing:
-
Don't bother. The yields from the cultures are very low
and it's easier to culture Daphnia and buy live brine shrimp
in the pet shops.
Those who REALLY want to try to culture brine shrimp should
get a large open top
container (an aquarium, a garden tub, a baby wading pool),
fill it with real or synthetic salt water and seed it with
some green water and nutrients (fertilizer tabs or what have
you) and wait for the water to turn yellow-green. Throw in
some baby brine shrimp or live adult shrimp (available from
the pet
shop) and wait. Adding small amounts of brewers yeast,
APR and other micro-foods will help promote the shrimp
growth. It helps to put the culture in a brightly indirectly
lit place to promote microalgae growth.
- Sources:
- See above.
- Uses:
-
Daphnia (also known as "water fleas")
are tiny crustaceans of Daphnia pulex and D. magna spp.
They are probably the most ideal food for
the smaller fresh water -- Daphnia do not die in the
tank and will eat microscopic garbage while they live.
They come in a variety of sizes -- from hardly visible
to over 1/8". This is a typical source of food for
many fish in the wild.
- Culturing:
- Daphnia can be cultured in everything from betta bowls
to 32 gal
trash cans. Indoor cultures can be fed various
algae scrapings and tank sludge, as well as deactivated
brewers yeast, powdered milk and APR (artificial
plankton stuff from OSI). The best food to use is green
water, and
can be used in outdoor cultures. Green water can be grown using
a weak solution of Miracle Grow and
chelated iron in dechlorinated water, seeded with
"pea soup" water. If water full of nutrients is left out in
full sun,
within weeks it will turn green from the airborne algae spores.
Blender-pulverized lettuce is rumored to work well
in small amounts.
Fry tanks and bowls can be seeded
with Daphnia -- the Daphnia eat the bacteria that may
be hazardous to the fry and generally purify water and
the fry will eat them as they get larger.
Freshly hatched fry can also be added directly into
Daphnia cultures (about 2 fry/liter) and will feed at their
leisure.
However, fry kept in equivalent sized tanks and fed
more intensively grow faster.
A shrimp net or a fine fish net can be used to catch Daphnia.
- Sources:
-
A clean Daphnia culture may be obtained from a local aquarium club or mail
order.
Daphnia can also be gathered from local lakes with a plankton net.
An inexpensive net can be constructed by the do-it-yourself aquarist.
Sew a conical fine mesh net with something like sheer curtain material, and
attach it to a circular piece of wire (such as a clothes hanger, bent into a
circle).
Add some weights to one side of the wire frame and hang it from a three string
harness.
The net can then be slowly dragged behind a canoe or rowboat in a lake known
to contain
Daphnia. The wire frame will keep the mouth open, and the weights will act
like the tail
of a kite, to keep the net from rotating when it is dragged. Such as setup
can be
remarkably productive, but the aquarist must beware of parasites like Hydra
and
various carnivorous insects, like glass worms. Capturing glass worms are a
mixed blessing,
because larger fish will happily eat them, but the glass worms will also eat
fry, if present.
- Uses:
- Same as Daphnia, but predatory. Can damage eggs
and very young egg-layer fry. Nauplii can be used like
brine shrimp nauplii.
- Culturing:
- As Daphnia (but less numerous per the same volume).
- Sources:
-
Often comes with the culture of worms or as contaminants
in Daphnia cultures. Very hard to eradicate once they
start breeding in the tank. Also mail order and club
auctions, as Daphnia.
- Uses:
-
Most adult fish of smaller species love them. As long as
fish are bigger than the larvae, they'll eat them.
Aquatic larvae of flying insects is the main ingredient in
the diet of many small fish in the wild.
- Culturing:
- Very simple. Put a wide-mouth bucket or a barrel
or a tub of water outside. Throw in small amounts of
evaporated milk or grass clippings in a nylon bag to
seed the water with bacteria and promote the growth of
infusoria, mosquito larvae's food sources; green water
works well, too. Some people even use manure! If
there are mosquitoes in the area, 2-3 weeks later there will
be larva in the water.
Another means of culturing is to use
a child's wading pool with a small amount of grass clippings (no herbicides,
please)
added to encourage the water to stagnate,
then wait for the mosquitoes to breed in it.
After a couple of weeks, large numbers of larva can scooped up with a coarse
fish net.
In this sort of "wild culture", one must sneak up on the pool to net them, so
that the larvae
don't dive to the bottom when they detect
movement.
Other methods include
filling a one gallon bucket with garden pond water (tap water takes too long
to age!), then
adding a cup or two of fine soil and allow it to sit for a few days.
After the larvae begin to appear, one may use a large aquarium net to strain
the water into
another bucket, thus capturing the mosquito larvae that are now present.
A major problem
with these techniques is that the neighbours make take exception to
mosquitos being cultured. However, provided all the larvae can be captured
and used,
an optimist might see it as a means of population control since the mosquitoes
are no
longer breeding in a pond somewhere where all control is lost.
Another problem is that if one adds too many larvae
and the fish don't eat them all, there may be a
significant increase in the mosquito population in your
house, as the uneaten larvae pupate, then develop into
mosquitoes.
- Sources:
- Wait for the little bloodsuckers to discover the
container of
evil-smelling bacterial soup (=culture), or go find "floats"
of mosquito
eggs in a nearby lake or puddle. They look like rafts of
eggs,
all glued together.
- Uses:
-
These disgusting, bacteria-infested stinkers are among the
best sources of protein for the fish and are an excellent
conditioning food for breeding preparation.
WARNING: frequent feedings will cause the fish to become fat
and impair breeding. Also, diseases are far more likely on a
steady diet of worms.
ANOTHER WARNING: if too many worms are fed to the fish at one
time,
the worms will burrow into the gravel and hide, risking fouling the tank.
- Culturing:
-
May not be worth it. Worms will live on the bottom of a tank,
eating scum and breeding. They can be fed banana peels.
Filter
water intensively. Collect them by sieving gravel with worms
through a net. Messy, laborious and there are easier
sources of protein.
- Sources:
- Most aquarium shops have these uglies.
(Tubifex are even uglier and stinkier and the aquarist should
not attempt to raise them. It is possible, but consider --
they live and feed in sewage and may carry hepatitis or other potential
pathogens.)
If one buys
tubifex, it is reported that since it is their, uh,
"food" that smells, not the worms themselves,
they may be successfully kept in cold running water
without producing odour. Alternatively, 2 oz. of worms
can be kept for up to three days in a medium sized bucket
of cold water in a fridge).
- Uses:
- These worms are small (up to 1/2") and can be fed to a
variety
of small fishes. Because of the way they are raised,
they are totally disease free. They do not burrow as
readily as other worms and live in the water for a few
days. Great for bottom feeders and any fish fast
enough to grab food sinking to the bottom or smart
enough to look for it (i.e. just about all fish).
- Culturing:
- Get a plastic shoe box (available at Target on sale
for $1),
fill it with sterile potting soil and peat moss mix (50-50),
or just potting soil, get it moist, perhaps nuke it in the
microwave oven for 5 minutes to thoroughly sterilize it, let
it cool, inoculate with a small starter culture of worms
and add some high protein cereal powder (Gerber, for
instance) every time the previous feed disappears -- and watch
them
breed! Cultures should be kept at 70 F
or warmer. Put a piece of glass on the soil and the worms will
crawl on it. The worms can be washed off the glass into a cup
with
clean water and dispensed into the tank with a large medicine
dropper (1 tsp).
If food is placed in troughs in the soil, the glass will be
free of potentially water-clouding soil. One healthy culture
produces enough to feed about 100 small fish.
Remember to keep the culture moist but not soaked and
soupy. Spray it with dechlorinated water now and then.
Cultures like this often get over-run with mites and/or
gnats. Both pests can be fed to the fish and are readily
eaten, but soon become a nuisance. Should this happen,
take some worms and keep them in a cup of water for 3-4
hours. This will drown the infestation and the worms
can be used as a new starter culture. Old infested cultures can be salvaged,
but it may not be
worth the effort.
If the worms are not growing well, try adjusting the soil's
pH by mixing a bit of baking soda into it to neutralize the
peat's acidity.
An interesting technique of culturing worms is used by some
German killi breeders. They use open-celled foam that sits
in a tray filled with water and is covered by a piece of
glass. This method is cleaner than the soil/peat one.
- Sources:
- Friends, local aquarium clubs and mail order.
White Worms (small worms, related to earthworms)
- Uses:
- These worms are up to 1" long and are good for feeding
fish 3"-6" long.
- Culturing:
- Similar to Grindal worms, but these worms do not do well
at high temperatures. If possible, keep them below 70F;
during the summer, they will survive if kept moist and in
a cool place, i.e. a north facing carport. White worms
can be grown in potting soil in plywood boxes, about
16" x 12" x 6" deep, with a close fitting,
moisture-resistant top such as a sheet of glass. They
will eat the same foods as Grindal worms, but a number of
sources suggest that white bread soaked in milk is a very
good food for these worms. Another option found to work
extremely well is to raid the materials heading for the
compost, and prepare a mixture of old lettuce, fruit, and
bread crumbs or oatmeal. Add water and blend it, as thick
as the blender can handle, and still be able to turn over
this soup. Add maybe a cup each week (it's mostly water
anyway, which is needed to keep the cultures moist), in a
small trench dug down the center of the dirt.
The medium typically and most successfully used by one of
us (DW) is dried, rehydrated bread crumbs with some
brewers yeast added. Bread crumbs are prepared by
collecting old crusts (even moldy ones) and storing them
in your freezer, then drying them in the oven at 175F.
The bread is then crushed into into crumbs and, if stored
in sealed containers (such as plastic ice cream buckets)
the crumbs will last forever. When it is time to feed the
worms, use a large bowl and mix the powdered bread with
enough water to make a slurry, then ladle it into a
trench in the culture. Use only as much as the worms will
eat in a week. The amount of water in the slurry should
be varied - when the worm culture tends to dry out in the
summer months, use a wetter mixture to replace the water
but if the culture is already too moist, use a drier
mixture.
One might ask how long such a culture will
last before going sour. It is a good question, to which
there is no clear answer yet; one of use (DW) has 3+ year
old cultures which have been seen to produce as strongly
as ever, without odour.
Keep these worms in complete darkness. They will come
out of the soil and coat the food, devouring it shortly
and clustering in a writhing mass. The aquarist can pluck
this mass of worms from the soil and use it to feed the
fish. The worms will hide in the soil as soon as the
light strikes them, so be swift about grabbing them!
Another means of separating worms from the dirt is to get
a tin can with both ends removed and fasten a piece of
plastic window screening over one end (with string, an
elastic band, or whatever works). Sit it in some type of
tapered glass container (such as a measuring cup) with
water in the container, so the can sits above the water
(1/2" between the top of the water and bottom of the
mesh). Place some of the soil and worm mixture in the can
and place a light over top (i.e. a gooseneck lamp, with
one of those mini-spot bulbs). The heat will drive the
worms out, through the mesh, and into the water. This
takes a couple of hours or more. The worms come out
clean, and can be fed to the fish directly, placed in a
worm feeder, or frozen for future use. This works well
for white worms, large and small, so assuming Grindal
worms can be grown in soil, it should work for them, too.
However, if you don't mind getting your hands dirty, a
faster, more effective means of separating them is to put
the worm laden dirt into a container, add water, swirl
the mixture, then pour out the dirt. The worms will
collect in knots. Remove the knots by hand to another
container, then continuing to swirl and pour off the dirt
in both the old container and the new one. This way,
clean worms can be obtained within minutes.
Whiteworms should be fed to your fish with a worm feeder,
so that the fish can eat them over time. They can be also
be placed directly into a bowl on the bottom of the tank,
where they will remain until the fish eat them. This may
apparently be particularly useful for killifish breeders,
which have only peat as a substrate. Be careful not to
overfeed by adding whiteworms directly to the tank; the
excess will burrow into the sand, where they will be
inaccessible to all but the most eager diggers, such as Hoplosternum.
Where the aquarist has separated too many worms for one
day's feeding, the remainder should be promptly frozen
and used later.
- Sources:
- same as Grindals.
- Uses:
- Feeding of medium and large fish (over 4" long).
- Culturing:
-
To raise earthworms cheaply and easily:
- Build a box out of wood (any size is fine, a bigger box
= more worms) (apartment dwellers can make do with a 1' x 1' x 8" box)
- Attach the top with two cheap hinges.
- Drill/cut two 2-inch holes in the front of the box
in such a way as to line up the bottom of the hole
with the bottom of the inside of the box
- Paint the box with any outdoor rated, oil based paint.
- Place a small piece of fine plastic screen against
holes that were drilled/cut. Make sure
the screen is placed on the inside of the box. Firmly nail the
screen into place. The screen will allow the box to drain,
but will not allow the worms to escape.
The box is now complete.
- prepare the box for worms
- Buy enough peat moss from a garden supply store or nursery
to fill up the box (remember the peat moss will compact
after it gets soaking wet).
- Place the peat moss in the box and completely soak the
peat moss (stir it up until it is uniformly
wet).
- Get 6 bricks.
- Place one brick at each front corner and two bricks at each
rear corner so that the box slopes forward and can drain
from the holes.
- Place a pan under the holes to catch the future runoff
(unless the box is placed outside). Note, after worms
are growing, the runoff is great for plants.
- Now, for the worms
- Go buy three or four boxes of the smallest worms that
can be found at a fish and tackle shop.
- Put the worms in the box
- Buy some corn meal (a small bag will last forever).
This is all the worms need for adequate nutrition.
- Every three or four days, sprinkle a light layer of corn
meal on top of the peat moss. Note: before each new layer
is applied, use a small, tined garden hand tool to
stir up the peat moss and to mix the corn meal left over
from the previous feeding into the peat moss.
- After about a month, there will be
literally millions of worms ranging in size from
tiny little young worms to fully adult worms. The baby
worms can be used for small fish and very young fish, while
the larger worms will easily satisfy the live food
requirements of even the most ravenous large fish.
- This is an infinitely renewable resource, which is difficult to
overharvest!
- The peat moss must be kept damp by periodic watering.
Don't over water! Do not allow it to dry out! The
worms will die QUICKLY if the peat moss dries out.
Fortunately, peat moss retains water very well, and
watering is rarely needed.
- The worms must not be allowed to freeze. The worms and the
worm box will not smell and can be kept in garages or closets
during the winter. The worms do not like being baked in
the full evening sun in the summer (they will be killed).
Place them in a shady location if they are left outside.
- keep the lid closed, worms like it dark.
- Other uses for Earthworms--
- Potted plants love earthworms!!
- Gardens love earthworms!!
- Lawns love earthworms!!
- Sources:
- the backyard, bait shops, gardening shops, gardens, aquarium clubs.
Infusoria (microscopic aquatic protozoans)
- Uses:
- Feeding of newly hatched fry.
- Culturing:
- Starting with a culture of green or pond water, add plant
material such as lettuce, alfalfa pellets, etc. to your
culture container. Good results have been found with
boiled vegetation, which appears to break down more
quickly. When the plant material begins to decay,
bacteria will initially appear, then the protozoa will
quickly increase in number as they feed on the bacteria.
Note that new cultures may contain largely bacteria, not
infusoria. If the infusoria culture is vigorously
aerated, odour will be minimized. If the aquarist intends
to maintain the culture over an extended period, every 3
- 4 days one must siphon out the "expired"
organic material which settles to the bottom and discard
it, then replace it with new culture media. Optimum
culture size depends on how much infusoria is needed. One
of us (DW) uses a spare 15 gallon tank, which can produce
prodigious amounts of infusoria.
An effective means of concentrating the culture before
use is to turn off the aerator, then place a small spot
lamp beside the culture container and let the culture
settle. Within 15 minutes, the infusoria will begin to
form shimmering clouds around the light or they may form
a distinct whitish layer in the water, often just below
the surface. One may be able to see minuscule silvery
bits of "dust", moving distinctly and
purposefully through the water. The infusoria
concentrations may then be selectively siphoned out and
added to the fry tank..
- Sources:
- Old tank water (especially out of the filter), friends,
mail order
Information provided by Greg Frazier
- Uses:
- Food for very small fry, i.e., those that are too small
to take baby brine shrimp (e.g., Rams)
- Culturing:
- Vinegar eels are small nematodes found in unpasturized
cider vinegar. They live in acidic water and feed on
bacteria in fermenting vinegar. They can survive for
extended periods of time in alkaline water (including
tank water!), but they will not reproduce. As a food for
fry, they are extremely easy to culture, require very
little attention or care (i.e., they can be ignored for
months at a time), and can be harvested at a moments
notice. Hold a starter culture up to the light, to be
able to see the worms wriggling in the cider/water mix.
To
culture vinegar eels, one needs a container (a 1 gallon
jug/jar/pitcher with a mouth wide enough to stick one's
hand through works well), an apple, cider vinegar and
water. Smaller containers should work OK, but a 1 gallon
container provides more than enough eels for everything
short of a professional hatchery. The cider can be cut by
up to 50% with water, but not more than that. Drop some
(peeled) apple cubes into the pitcher (one only needs a
handful of 1" cubes for a 1 gallon culture), and
fill it up with vinegar + water (again, no more than 50%
water). Put half of the starter into the culture. Wait at
least 24 hrs to give the bacteria time to get a foothold,
and then put the second half of the starter into the
pitcher. In about a month, a cup dipped into the pitcher
should come out cloudy with wriggling worms. When the
mixture starts looking really cruddy (e.g., 1/2 inch of
stuff has accumulated on the bottom; this should take
months) re-culture and start again.
Harvest the eels with two cups and a coffee filter.
Dip one cup into the culture, pour it through the filter
into the other cup, and return the liquid to the culture.
Most of the eels will have passed through the filter, but
some will have clung to it. Pour fresh water though the
filter, then invert the filter and flush the worms into a
glass. A filter paper (available at some drug stores) may
also be used. Filter paper will prevent any eels from
getting through, but it also takes quite a while (10
minutes or longer) for the vinegar get through as well.
Let the worms purge themselves in the glass for a
while before feeding them to the fry. Also, be careful to
rinse the eels well -- adding vinegar to a small fry
hatchery could lower the pH suddenly (with disastrous
consequences!). Vinegar eels are longer than brine shrimp
nauplii, but have a smaller diameter - fish can handle
vinegar eels before they can handle freshly hatched brine
shrimp. In a tank the worms will flow with any current,
but if there is no current they will work their way up to
the surface (a big advantage over microworms).
- Sources:
- Mail order, aquarium clubs, etc..
- Uses:
-
These microscopic worms are good for feeding newly hatched fry
and the smallest fish, although fish up to 1" or more
will eat them.
- Culturing:
- Good culture media include Oatmeal pablum, Gerber
high-protein cereal or cooked oatmeal porridge. The
oatmeal porridge is inexpensive and is the media of
choice of one of us (DW). All media should be prepared so
that it is thick, then added to a dish so that it is from
1.5 cm. deep or more. Add at least 1 tsp. (5 ml) of
deactivated brewers yeast (can be bought from health food
stores); the cultures do not do well without the brewers
yeast. Seed with a small quantity of the nematodes. If
you are subculturing from an existing culture, just use
the top 1/8" of the old culture; that's where all
the worms are. Your new culture will be encouraged by
initially storing it in a warm area (such as the top of a
tank).
They can be cultured in 500 ml. yogurt containers, made
out of type "5" plastic (the type of plastic
will be marked in the recycling information on the
bottom). This material is fairly thick, flexible, and
cheap, and the micro-structure of the surface seems to be
such that the worms can crawl up the sides in thick
enough concentrations that they can be wiped off and
collected. The thinner, more brittle plastic containers
work very poorly - the worms do not thrive, and they
can't seem to climb up the sides. Cut a hole, perhaps,
3/4" wide in the lid to provide air, and if the
cultures are piled several cultures high, ensure the
containers are rotated so that all cultures are exposed
to the air at least every second day. If this is not
done, the cultures will die off. Cultures can be grown in
the house, and as many as 24 containers still make up a
compact, but very productive source of live food.
In about a week, microworms can be "harvested"
off the sides of the dish with a finger (the best way), a
Q-tip or a brush. Optionally, once can place a flat piece
of plastic or wood onto the culture and scrape the worms
off with a razor when they become numerous (a popsicle
can be used stick as this "collection
platform"). Wash them out in a glass of clean water
and dump them into the tank, or place them directly in
the tank.
Cultures will last about 2 weeks. As long as the culture
media is fairly fresh, there will not be any offensive
odours produced but when the the odour increases and
production decreases, it is time to subculture.
One can extend the time it takes for the microworms to be
passed into the tank by placing them in a worm feeder
stuffed with filter floss.
- Sources:
- friends, clubs, mail order.
- Uses:
-
The fruit flies are the closest analog to the natural diet
for most killifish and many other small fish.
- Culturing:
- 1/2 gal fruit juice bottles can be used as culture
containers.
The media is a mail
order instant mush that seems to be some sort of
instant mashed potatoes substance that smells like pure
starch mixed with fungicides. Use enough to get a
1/4-1/2" layer of media at the bottom of the bottle and
add enough water to get it to a sour cream-like
consistency. It should be dense enough to not run when the
bottle is tilted.
Next, place a 2 layer roll of plastic
"bug screen" mesh into the bottle, so the flies and
maggots have somewhere to climb out of the wet goo --
it seems to help their survival. Dump in a few fruit
flies, perhaps a dozen. Finally, stopper the bottle with a
wad of filter floss,
so the flies can't get out and wild fruit flies and other critters
can't get in.
Two weeks later there will be newly hatched fruit flies ready to
be fed to the fish. The culture keeps producing for 2
months or so and should be "cloned" after some 6 weeks
of operation. When the previously cream-colored
media become dark and "used up" looking, it's time for
the new culture. It's probably easier and safer to
clone the culture every 4-6 weeks and be ready for the
eventual crash of the old culture.
To feed the fish, sharply shake the bottle to knock the
flies away from the stopper, open a fish tank cover, open
the bottle, turn it up side down and give it a few taps,
shaking out a dozen or more flies every shake. The media
gets thick enough by then to not drip out.
CAUTION! These flies are wingless and flightless, but not
legless. They will walk up the sides of the tank, crawl out
through the cracks and head straight for the fruit which has
been left out in the kitchen. They may be fish food,
but they are still fruit flies. Feed them to fish in small
doses.
There are several different strains of usable fruit flies.
Some are smaller than 1/8", others are over 3/16". Some are
completely wingless or have vestigial stubby wings (wingless),
others have the wings that are so large that they are useless
(flightless).
CAUTION! The "wingless" fruit flies will sprout functional
wings if they are kept at high temperatures, so keep the
culture cool. If this becomes a problem, open
the jar
outdoors, let the winged flies fly away, then make sure the
rest pupate at a cooler temperature.
HINT: a jar of Drosophila can be chilled in a refrigerator
for a few minutes to make them sluggish and/or immobile.
This makes them lots easier to handle when
a new batch is being bred, and also makes them less likely to wander
off. The fish might prefer them to be more active, though.
- Uses:
-
Several large fish, including cichlids and piranhas will eat live fish as
part of their diet.
- Culturing:
-
Generally not necessary. Many fish stores stock offer inexpensive "feeder
guppies" or
"feeder goldfish" as part of their ordinary stock. However, a colony of
prolific cichlids, such as convicts, can practically be used as a source of
feeder fry.
For fish like piranhas, a small piece of raw chicken or a strip
of fish fillet will work just as well as a live fish.
- Sources:
-
Pet stores; excess brood stock; deformed "culls".
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