Articles on Foods (live and otherwise) and Feeding Killifish (1996-2000)
An archived collection of articles, tips, and information about tropical fishkeeping in general, and killi-keeping in particular, from past issues of the G.C.K.A. Newsletter. To read an article, please click on the title (in blue).
All material is copyright © G.C.K.A. or the authors, unless otherwise noted. Reproduction is permitted for non-commercial purposes only (i.e., club bulletins). We do request that you provide source credit, and send us a copy of the publication in which the article appears. Please forward to G.C.K.A., c/o Recktenwalt, 4337 Ridgepath Drive, Dayton, OH 45424.
More than you ever wanted to know - about Blackworms
Bloodworms ... a cautionary note - some may have allergies
to this killi food.
A few views on hatching out Brine Shrimp
Another Method for Brine Shrimp - one breeder's method for
hatching nauplii.
Brine Shrimp Nauplii - diminishing supplies of eggs, rising
prices.
Brine Shrimp as a Major Food Source - one killikeeper's
technique.
Raising Adult Brine Shrimp
Can you Overwinter Daphnia? Of
course!
Cheap Killie Food - by George Davis. Alternate sources for fishfood.
Collecting Live Foods - an overview of what you can find in
your own backyard.
Confused Flour Beetles
Culturing
Greenwater
Daphnia - an overview of this always useful live food.
Decapsulating Brine Shrimp Eggs
(1) - a few methods shared.
Decapsulating Brine Shrimp Eggs
(2) - more tips and techniques.
An Easy Live Food - Microworms - one of the simplest live foods for your small
fish.
Feeding Our Fish - some basics about this important aspect of
fishkeeping.
Feeding Killifish ... A Few Useful Recipes
Feeding Killies - Dry Food for Killifish
Foods for Small Fry - A review of some of the alternatives to
baby brine shrimp.
Foods
for Fry - Cyclop-eeze
Fruit Flies - Drosophila melanogaster
How I Do It - Baby Brine Shrimp - One aquarist's technique.
How I Do It - Whiteworms - Tips from Al Anderson.
Live Foods - Moths
Nutritive Additions ... Spirulina
Paste Foods - Another Alternative - Two proven recipes.
Puttin' Live Food By - a few ways to preserve some of that summer
bounty.
Red/Black/Tubifex Worms - a Safe Food for
Killies?
Vinegar Eels - culturing this easy live food.
White Worms the Easy Way - by Tom Cook. An alternate, non-soil
method of culturing white worms.
You, Too, Can Feed Live Foods - some of the live foods that are
as close as your own back yard.
Yumm ... Mosquitoes - they may be a bother when they bite, but
killifish love 'em!
More than you ever wanted to know about ... Blackworms
Tubifex worms have
long been known in the killifish hobby as an "egg-building" food, but
they have a downside: they often carry a number of fish pathogens, resulting in
unexpected outbreaks of disease in breeders’ tanks.
The Carolina
Blackworm, an aquatic relative of the earthworm, is a clean and easily handled
alternative to tubifex. Hardy, nutritious and inexpensive, they come from clean
water sources, and carry no potential pathogens.
Under the
proper conditions, blackworms can be kept for significant periods of time
without trouble, and may even increase their numbers by segmentation and growth
of the fragments. Storage for blackworms is fairly straightforward: use shallow
refrigerated trays. Keep the worms wet, just covered in water. You can add a
layer of wet newspaper or paper towels if you like. Once daily, rinse the worms
twice. If you cover the storage tray, be sure it is not airtight.
Feeding
blackworms to your fish can be a challenge, since they swim freely. Once in the
aquarium, they will live indefinitely, actively scavenging on debris and hiding
where fish often cannot reach them. Try using a shallow glass dessert dish to
give the fish a better chance at them. "After the second rinsing,"
says Charlie Nunziata, "I pick up the worms with a turkey baster… then
slowly insert the baster into the aquarium to just above the dessert cup."
Gently squeezing the bulb of the baster pushes out a quantity of worms, which
sink into the container. Larger fish may throw worms out of the container while
feeding, and some worms will usually manage to escape. Just retrieve them with
the turkey baster.
Almost all
killies will feed heavily on blackworms, but young Nothos and Fundulopanchax may
occasionally overeat to excess, resulting in loss of the fish. As good as they
are as killifish food, blackworms are a bit large for some species, and may need
to be chopped up for feeding.
One caveat:
Blackworms are extremely sensitive to salt. If you use salt in your tanks, watch
blackworms carefully when feeding, to prevent a mass die-off that will foul the
tank.
Reference: Nunziata, Charlie. "Blackworms: A
Great Food," Suncoast Killifish Society Newsletter, Volume 5, Issue 2.
-- G.C.K.A. Newsletter, June
2005
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In recent months (mid-summer 2000), the killifish e-mail lists
have contained a number of discussions about the pros and cons of feeding bloodworms to
killifish.
There is little debate that bloodworms are a
good food for killifish, being eagerly taken and providing a high rate of nutrition. But
food value aside, bloodworms may pose a hazard to killikeepers, particularly those who
tend to have allergy problems. Based on the limited input of those participating in the
e-mail discussion, allergic reactions to bloodworms are not that uncommon, and seem to
take two primary forms a contact dermatitis and a respiratory response.
The contact form, usually resulting from
handling the frozen product, can result in itching, swelling, cracking and peeling and/or
blistering of the skin of the hands or swelling of the fingers.
"I have an allergic reaction to frozen
bloodworms," says Joe Ponnath. "My hands break out in tiny blisters and itch
horribly. My reaction to freeze dried bloodworms is completely different. I have fits of
uncontrollable sneezing.
The dust gets in my eyes and causes conjunctivitis."
Another killiekeeper reports that his fingers swell when he handles the frozen bloodworm
product.
The respiratory response can be immediate or
delayed by some number of hours, and usually involves some combination of runny nose,
watery eyes, and sneezing, and varying degrees of respiratory difficulty. The reaction may
merely be a mild nuisance to many, but in some people can cause acute respiratory distress
or asthma leading to hospitalization.
"I dont use [freeze-dried
bloodworms] anymore because Ive developed an allergic reaction," says Bill
Vannerson. "This happened after about two years of use. The first time I got a
reaction I thought I was just suffering from a cold.
I woke up all wheezy and
clogged up.
The next time I used them during the day. The reaction was unmistakable,
and strong. It scared me.
"If you are not allergic to them,"
he continues, "bloodworms are an easy food source for killies, which they readily
accept. But if you ever develop symptoms or believe you may be developing systems, get rid
of them. There are too many alternatives available" to afford taking the risk.
"I also developed a major respiratory
allergy to freeze dried bloodworms," says Joe Bulterman. "It took a while to
develop as I had been using them for quite some time." The symptoms are quite severe
with a delayed onset and a sustained acute phase (4 hours).
Bruce Turner offered a possible explanation
for the allergic reactions."The allergen in the bloodworms is probably the red
hemoglobin-like protein that gives them their characteristic color," he says. This
protein, erythrocruorin, is also found in many other invertebrates, including annelid
worms and molluscs. "If I had such an allergy," Bruce suggests, "Id
stay away from worms too."
A bloodworm (a larval midge of the genus
Chrionomus) "is little more than a slightly impure preparation of
erythro- cruorin
its there in gigantic amounts," he continues. Why erythrocruorin should
provoke such a response no one seems to know.
"One suggestion for people who have a
sensitivity but still want to use bloodworms," suggests George Trumbull, is to
"use frozen bloodworms (the kind that come in individual portions), pop them out into
some (clean or tank) water, swish them around a bit and add the bloodworms with the water
to the tank. Ive done this for years and it has had no adverse effect on water
quality." The trick also works well with frozen brine shrimp.
For handling freeze-dried bloodworms, Joe
Gardner suggests this technique. Soak the freeze dried bloodworms in water to get rid of
the dust, then use a turkey baster and a small clear container that hangs on the side of
the tank.
"What I do now when feeding
freeze-dried bloodworms," says Joe Ponnath, "is hold my breath, squint my eyes,
and feed the bloodworms very quickly. I then immediately
[leave the
fishroom,] wash
my hands, and wait 15 minutes before going back to my tanks."
"Make sure you pay attention to your
breathing while you feed so you can detect any early symptoms," warns Bill
Vannerson.
Wear rubber or latex gloves, or even a surgical mask. "Allergens develop through
contact over time. Any barrier you can place between the body" and the allergen will
slow down any potential reaction.
In short, if you have any hint that
youre developing a sensitivity to bloodworms, handle them with great care, minimize
any required physical contact, and be alert to developing symptoms and problems.
Hopefully, few of us will have to deal with such allergies, but for those who do, some
careful precautions may go a long way to reducing (or preventing) a problem.
Reference: Reichenback-Klinke, H-H, and Baur, X. "Allergic reactions after
contact with dried fish food (Chironomids)." Aspects of Human Health in Connection
with Fish and Fish Food. Contributions to Bish Biology, Gesundheitsprobleme des menschen
im zusammenhang mit fischen. Beitrage zur fischereibiologie, 1982, pp. 9-17. Fisch
Umwelt/Fish Envirion., no. 11. A report is given about allergic reactions in man after
contact or breathing of the dust of freeze-dried fish food. As responsible agent the blood
component hemoglobin of chironomids (erythrocruorin) was detected.
-- G.C.K.A. Newsletter, August-September 2000
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A few views on hatching out Brine Shrimp
Another Method for Brine Shrimp
"Everybody but me uses an inverted pop bottle," says Lee Harper about his brine hatching setup. "I use right side up 2 liter plastic bottles with the top cut off" just above where the neck flares out. Dont throw the top awaythis cut off piece makes a useful funnel.Want to Raise Those Naupli?
Raising Adult Brine Shrimp
Brine shrimp have
long been a staple of aquarists, in both their nauplii and adult forms. Brine
shrimp can provide a reasonable source of both carotenoids and hemoglobin in the
diet, but should not be used as a sole food source.
For some
aquarists, collecting live brine shrimp from the wild is possible. Most of us
must buy or raise our own. Hatching out brine shrimp cysts is easy; raising them
to adulthood may be quite difficult, requiring volumes of water, gentle
currents, sunlight, and time.
"About 10
years ago … I raised brine shrimp on a regular basis," reports Brian
Watters, "but more for my own amusement than as a source of live food. Even
when successful, the number of brine shrimp one can raise is not worth the
effort." Brian worked with several container sizes, the largest being 10
gallons. He used marine salt to reach a specific gravity of 1.040 (about twice
seawater). A small sponge filter provided moderate circulation. He inoculated
the setup with newly-hatched nauplii and fed yeast (just enough to turn the
water cloudy), growing the shrimp to adult size in 2-3 weeks. Later on, Barry
tried various other foods, with varying results. "The bottom line," he
says, "is that it is an interesting experience to raise brine shrimp."
Some time back,
an article in Aquarium Fish Magazine suggested using a series of 2-3
liter pop bottles, cut and mounted as you would for a brine shrimp hatchery.
Newly hatched nauplii were added and the bottles set in a sunny window. After
the nauplii had reached 1/8", green algae from the bottom glass of an
aquarium cover was blended with water to feed them. "Many aquarists kill
brine shrimp with kindness by overfeeding them," the article continued.
"Neglect them and you are more likely to get a brine shrimp culture
established."
An internet
source (Artemia FAQ 2.0, available at http://www.aqualink.com/marine/z-atemia.html),
suggests using a 10-20 gal glass tank with acrylic panels set into the corners
to make an oval. Add to this a series (6-8) of lift tubes to provide a constant
circular water flow. Best growth rates are achieved at 25-30°
C (77-86° F) with salinities of 30-50 ppt and low
light levels. Recommended foods were microalgae and inert foods such as yeasts,
rice bran, whey, etc.
Andrea Caiola,
from Italy, reports some success using 6.6 gal. glass containers filled with
very hard tap and distilled water in a 50/50 mix. He added non-iodized salt to
reach a density of 1035, placed the container outdoors where it was exposed to
sunlight for part of the day, and left the water to age. After more than a month
(the water had turned quite green) he introduced some nauplii and waited. In
another couple of weeks he began to feed them, using a blend of wheat flour (85
g.), brewer’s yeast (10 g), and spirulina powder (5 g). He fed a small amount
daily, being careful to not overfeed. "I have seen a friend’s tank filled
with more than a hundred adults raised this way," he reports.
The bottom
line? For feeding your fish adult brine shrimp, it may be less expensive to
simply purchase them from wholesale suppliers.
-- G.C.K.A. Newsletter, February
2003
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Dedicated fish breeders have long known that
the newly hatched nauplii (larvae) of Artemia salina (brine shrimp) are a perfect
food for small and newly hatched fish, providing essential proteins, fatty acids,
carbohydrates and carotenoids in an easily eaten, moving prey package.
Brine shrimp eggs are easy to hatch; the
nauplii are simple to feed. Although hatching devices take many forms, all utilize nothing
more than salt, water, and an airstone. The results have proven worth the effort in
healthier, faster growing fish.
However, brine shrimp eggs are subject to
the economic law of supply and demand.
Due to a worldwide boom in commercial
aquaculture and several years of poor harvests, prices have risen sharply. Most (but not
all) brine shrimp eggs are harvested from Utah's Great Salt Lake, where more than
13,000,000 pounds were harvested in 1991. In 1996, the take was less than half that. Part
of the drop was due to changing conditions in the lake, which resulted in the birth of
live young by the shrimp, rather than deposition of cysts (eggs), but part of the decline
may also have been due to overfishing: the number of licensed boats numbered less than a
dozen in the early 1990s; by 1996 the number had topped 60.
The result has been a rapidly escalating
price spiral. Fortunately, when stored properly in a cool, dry, dark place, brine shrimp
eggs will last for years, and although commercial hatcheries may need to pay close
attention to the guaranteed hatching rates, this is less of a factor for the hobbyist. So
if you find a supply of brine shrimp eggs at a reasonable price, you might want to stock
up.
Reference: Davis, Chuck. "Brine Shrimp," Aquarium
Fish Magazine, April 1998.
-- G.C.K.A. Newsletter, Sept/Oct 1998
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Foods
Brine Shrimp as a Major Food Source
By Donna M. Recktenwalt
"Brine shrimp eggs/artemia cysts have been the life source for
my killies for nearly 25 years," reports Dave Koran. "My cost in feeding mainly
newly hatched brine shrimp, supplemented weekly with daphnia and occasionally with white
worms and microworms, is not much more than 50 cents per day, and Im feeding maybe
200 containers with fish each day."
Going through that much "shrimp"
and depending on it as a main (and sometimes only) food for his fish, Daves supply
must be dependable. The keys to dependability are:
1)
the eggs,
2)
a dependable source of air,
3)
sufficient eggs in various stages of hatching, and
4)
a rigorous routine for preparing the shrimp for feeding.
Each day he sets up from 1 to 3 gallon-sized
jars with approximately 1/8 cup of eggs/cysts per jar. When he prepares a gallon hatching
jar, he cleans it, adds water and 1/4 cup of salt, and then places an air tube in the jar,
letting the salt dissolve and the solution come to room temperature for a day before
adding the cysts. The air supply must be sufficient to keep the entire contents of the jar
in motion.
Hatching is a function of temperature: the
cooler the hatch water, the slower the hatching process. In Daves case he keeps the
hatching jars on his basement floor at 60-72°F; under those conditions, it takes 2 to
3-1/2 days for a hatch, which means that he must keep 4-8 jars in process all the time.
There is usually a 24-hour
"window" for prime harvest. After that, quality deteriorates rapidly. To harvest
the shrimp, he drains the entire jar through a fine mesh net and rinses the contents
multiple times. He then returns them to a container with fresh water and allows the
contents to separate: empty cysts float to the top, nauplii and unhatched cysts settle to
the bottom. These he drains off for feeding to his fry. He tries to rinse as much salt
from the shrimp as possible to avoid introducing too much salt into his fish containers.
If you want to keep the "cleaned" shrimp for more than a day, return them to a
new soluion with double the strength of salt.
Some years ago Dave "discovered" a
feed grade of salt at his area agricultural/farm supply store, which he now uses for
hatching brine shrimp. It is a crystalline, evaporite material intended for mix into
animal feeds, and is not intended for human consumption, so contains trace elements and
probably sufficient carbonate for buffering purposes.
A Few Words About Shrimp Eggs
A number of suppliers are now trying to
supplement their brine shrimp egg sources with "Asian" artemia cysts, which come
from the salt pans of central Asia. Russian cysts are also being used. The domestic supply
is directly dependent on the health of the Great Salt Lake, and on the Utah Division of
Natural Resources regulated harvest.
For the last few years Sanders (of Ogden,
Utah) has sold short shelf life eggs, which means that they dont last long once
opened. If you can get them, the short life eggs will often run 1/3 to 1/4 the price of
equivalent grade regular eggs. Occasionally, however, youll get a bad can of eggs.
Usually Grade A eggs are pretty consistent in hatching, with B and C grade eggs having
more duds (on a per can basis). If you decapsulate your eggs for feeding, purchasing the B
or C grade eggs may be a way to save you money, since the decapsulated cysts are
nutritious for fish food even if the embryo does not hatch.
G.C.K.A. Newsletter, January 2000
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Tired of spending megabucks per pound for fish food? Then read on ...
Cheap Killie Food
By George Davis
Tired of spending megabucks per pound for
fish food?
The way I figure it, if it's good enough for
the U.S. Government, it's good enough for my fish. If I can eat it, it has to be OK for
them, and there's no chance of bringing in the problems from Tubifex or other live foods.
Clams - Minced clams at the grocery
store sell for about $4 a pound. Run them through the food processor, then freeze them.
When you want to feed, slice with a razor blade and feed the flakes. For some reason my
rainbows don't seem to relish it, but most others do.
Mussels - $1 to $2 per pound live.
Stick the whole mussels in the freezer. take them out one by one, open with a screwdriver
and slice with a razor blade. My killies haven't complained yet. You probably could
harvest all the meat, dice and freeze, but I haven't tried that method yet.
Squid - $2 a pound at the fresh
seafood shop. Skin the squid, pull out the beak and cartilage, and chop finely with a
sharp knife. Freeze, then shave off small pieces. Don't run it through a blender, as it
makes a muddy mess.
Soft Shell Crab - Left over fish
bait? Those soft shelled crabs make excellent fish food, and one of the most enjoyed by my
fish. My reef tank enjoys left over minnows, but I'm out of those and haven't had the
opportunity to try them ground up for killies.
Earthworms - I haven't tried this
myself yet. Collect the earthworms from a clean, organic garden area, wash off the dirt,
freeze, and slice with a razor blade. Your fish will love them. I have heard that you can
purge the worms of dirt with cornmeal, although I haven't tried it.
Blue Crabs - Some crab get a little
too old for you to enjoy it? Even cooked, the fish seem to love it. For other foods, I
would definitely recommend raw.
Others may disagree with me on the above,
but my fish are happy and I'm not spending $25-$50 a pound for fish food. I feed this
stuff to my Africans, mollies, catfish, whatever. I wouldn't suggest it for any of the
vegetarian fishes.
-- G.C.K.A. Newsletter, May 1997
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"At this time of year my fish get extra
special food," says Jim Robinson. Within two weeks after the ice melts, live food
becomes plentiful.
"Fish in general, and killies
specifically, do better on a large variety of live foods." Frozen and prepared foods
are excellent, but live foods are better. In some fish the egg count may triple to
quadruple when live foods are a major part of the diet.
Where to find live foods? "Look in
temporary or permanent ponds where water collects and stays for more than a month,"
suggests Jim. Suburban sites are possible, but in many cases you will have to go beyond
the city boundaries to find good live food collecting spots.
"My favorite spot," Jim says,
"is a large ditch on both sides of a country road. Water drains into this marshy area
from a farm that houses horses. The runoff from the manure pile eventually disgorges into
this swampy area." From this site he collects fairy shrimp, mosquito larvae and
daphnia in large quantities. Be certain to ask permission to collect from sites that are
on private property, although most folks are quite willing to have you collect
bugs from their ponds.
"I went collecting
[in my
favorite pond] in the middle of February," reports Greg Niedzielski. "I
wasnt really sure what to expect as I had never been to the pond so early in
the season. I was pleasantly surprised by large numbers of half-grown fairy shrimp
.
There was still some ice on the pond, but
I had no difficulty collecting enough
Fairy Shrimp and Daphnia to fill my bucket." A couple of weeks later the pond was
totally ice-free. As the season progresses the population of the pond changes.
"The pond I visit these days is under
an old highway bridge," Greg says. "There are railroad tracks running past it
and a couple of small businesses nearby. The water collects between the concrete bridge
supports, and early in the year when the pond is at its greatest extent it is three feet
deep or so."
The fish certainly seem to enjoy the results
of such collecting trips: "they attack the food with far more vigor than they do
frozen or flake food, and eat much more of it." Daphnia and Fairy Shrimp will survive
for a few days in a tank, so you can load up the fish and simply wait for them to finish
it off.
"There is always the possibility of
introducing less beneficial organisms into the aquarium when feeding live food," Greg
cautions. "Later in the season dragonfly larvae become more abundant, and a small,
unnoticed hitchhiker can grow to become a fish-eating monster very quickly."
And then there are the benefits to the
aquarist: "there are worse ways to spend a sunny, if cool, early spring afternoon
than walking through a field to get to your favorite pond," says Greg. If your pond
is in a wild enough area, you may see numerous birds, or even a deer.
As far as equipment is concerned, a few
buckets with lids and a fine mesh net will do when youre collecting live foods,
although you can get considerably more fancy than that. From scientific equipment
suppliers you can buy nets specifically designed for live food collecting; plankton nets
are perfectly sized for easy water flow and efficient retention of any live foods you may
wish to collect. Adding an old broom handle or an extendable painters pole to the
net for extra length can be highly beneficial.
Collection itself is simple: "simply
make a figure 8 motion in the water with your net and lift out your catch," says Jim.
"The figure 8 motion draws the bugs into the net and brings them up from
the bottom. Do this gently," since you dont want to stir up the bottom and
bring excess debris to the surface. Once youve brought them home, keep your buckets
of collected critters outside, in the shade to keep them cool, until you can either feed
or process them.
What Might You Find in the Spring?
Fairy Shrimp (Eubranchipus spp.)
These are found, only in the first month or so after the ice melts, in temporary pools
which completely dry up at some time during the year. Their restive eggs incubate dry in
the mud and hatch from months to years later. Their life cycle takes about 5 weeks and
they reach only 1-1/4 inches in length. On sunny days they can be seen as red patches
close to the surface of the water, making collection easy.
Mosquito larvae (Culex,
Anopheles., and Aedes spp.) These can be found from early spring through
summer in permanent and temporary pools. Rafts of eggs are laid on damp, low ground that
will be flooded, or directly in the water. Larvae grow to 1/2 inch long, then pupate (they
look like commas at this stage) before reaching adulthood. Keep these critters outside,
since they metamorphose quickly, and can cause discord within the family as adults.
Daphnia (Daphnia spp.)
These are perhaps the most versatile of all collected foods. They can be cultured, but
that is subject for another article. Daphnia range from 1/50 to 1/5 inch in length,
depending on species. Under favorable conditions, Daphnia produce only live female young;
if conditions worsen, males may be produced. These then mate with the females, which then
produce resting eggs (ephippia) that remain inert until conditions are favorable
again.
Other Daphnia-like creatures include Moina
spp., Ceriodaphnia spp, and Bosmina spp. All thrive under similar conditions
and have similar life cycles.
Glassworms (Chaoborus
spp.) are the larvae of flying insects known as phantom midges. These 1/4 inch larvae are
found in temporary pools, and hatch from eggs that must freeze before hatching in the
spring. Use caution when feeding glassworms: they are carnivorous and will eat fish eggs
and young fry.
Bloodworms (Chironomus
spp.) are really midge larvae, and not worms. Bloodworms can appear in tremendous
quantities in the water, and their bright red color makes them conspicuous and easy to
collect. The larvae can be up to 1/8 inch long, with the pupae reaching 3/8 inch. They are
fairly easy to keep alive, since they thrive in oxygen poor water.
And In the Summertime?
Late spring/early summer provides other
types of food than you can find in the spring. Although daphnia and mosquito larvae are
still around, other things become more common. A change of technique is useful, too: bring
up more of the bottom mud by moving the net faster and deeper. Youll have to sort
out more twigs and debris; youll also have to sort out some types of insect larvae.
Feeding dragonfly larvae or hellgramites to your smaller fish simply wont work,
although some of the larger species may take them. Leaving a predacious Diving Beetle in
one of your tanks can lead to disaster.
"Many new organisms appear in the
summer," says Jim Robinson. Among them are Rotifers, Cyclops, Diaptomus,
Cypris, Amphipods, Isopods, Caddisfly larvae, Mayfly nymphs, Stonefly nymphs, Crane
fly larvae, and Housefly larvae.
Rotifers are found all over
the world, swimming in the water or crawling through the bottom mud or plants. They are
very small, thus require a much smaller net mesh. For killifish, rotifers fit perfectly
between the smallest infusoria and the next larger foods. Rotifers develop by means of
unfertilized eggs which are distributed by the wind or by animals. Like daphnia, males
only develop during deteriorating conditions, and the resulting resting eggs remain in the
mud until conditions are more favorable.
Diaptomus are closely related to
Cyclops and are often found with them; their major difference is their longer antennae.
Cyclops (sometimes called
"water mites") are often found with daphnia, or under the same conditions, and
are most readily available from May through September. The ovoid females carrying their
paired white egg cases are easily identifiable. They can be found in large masses near the
surface of the water, and they can easily be cultured.
Cypris are often overlooked by
collectors; they look like small black specks. These "seed shrimp" or "hard
shell daphnia" resemble miniature clams and adapt well to poor water. They are a good
food once the fish learn to recognize them as such. Their life cycle is similar to that of
daphnia.
Amphipods, commonly called
"scuds" or Gammarus, are best suited for larger killifish, due to their
hard shell and their size. They will live in almost any aquatic conditions, but seem to
require rotting plant material. Inspect this live food carefully: if they have small red
spots, dont use them, since the spots are the larvae of parasitic worms, which could
become established in your tanks. Scuds breed almost continuously from March through
November. Reproduction is sexual, and prolific.
Isopods, more commonly known as
"sowbugs," are most commonly found beneath damp wood, but there are some aquatic
members of the family. Asellus is the most common, and can be collected by running
your net through a patch of underwater vegetation. Young Asellus make fine killie
food, but the adults are too large and hard-shelled.
Mayfly nymphs can be easily
collected in deeper water by using a vigorous figure 8 motion; they have strong claws for
holding on to rocks and debris. They are easily distinguished from other aquatic larvae by
their three "tails." You will likely have to do some sorting with mayfly nymphs,
since youll probably pick up a lot of vegetation with them.
The confused flour beetle has been around a
long time; remains of them have been found in Egyptian tombs and archaeological sites in
the near east dating to before the time of Christ.
Especially for top feeding killifish, both
the adult beetles and their larvae provide an ideal food.
Culture of confused flour beetles is simple.
To a well covered container such as a gallon size plastic ice cream tub with holes punched
in the lid for ventilation, add an inch or so of flour, powdered milk, or a combination of
the two, and a starter of adult beetles. Put on the cover, set in an out of the way place,
and ignore for a while. The cultures require little care beyond occasional freshening of
the culture medium.
Although they are easy to culture, and are
an ideal size for killifish food, the beetles do have a downside.
Adult beetles crawl actively; a few always
seem to get loose when being harvested. Given the chance, they will infest foodstuffs. And
the larvae can be difficult to separate from the food medium and their own empty pupal
cases. Using a fine mesh kitchen strainer effectively separates the insects from most of
the flour, but not from the shed skins; some of each always end up in your tanks,
necessitating more frequent water changes.
However, some aquarists have recently found
that confused flour beetles can be successfully cultured in powdered milk, either with or
without the addition of a small amount of flour. To feed, simply scoop a batch of the
adults and larvae from the culture medium, then rinse off using a fine mesh (brine shrimp)
net. Result: clean, wet, sinkable food, with no residue to pollute your tanks.
-- G.C.K.A. Newsletter, May 1998
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Aquarists have long known the value of
greenwater.
Basically, its green because of the
photosynthetic algae and protozoans it contains, such as Euglena. Its an excellent
food for daphnia, but its also food for zooplankton such as rotifers, and the larger
protozoans such as paramecium, making greenwater an excellent food for fry. "The
beauty of greenwater is that it is a sort of balanced ecosystem and you dont have to
worry so much about overfeeding the fry," says Eric Lund. "In the best setups,
greenwater is produced in the fry tank and no feeding is required at all until the fry get
large enough to eat baby brine shrimp, at which time they can be dipped from the tank and
reared in a grow-out container."
This contradicts the generally accepted rule
of "keep fry in clean water," but has been proven to work by numerous aquarists.
Benefits cited include fewer water changes, faster growth rates resulting from the
constant presence of food, and the ongoing "cleanup" activities of
microorganisms.
There is no doubt about the benefits of
greenwater, but how do you startand then maintaina viable culture?
Start with Aquarium Water
"The microorganisms that make up
greenwater are already in aquaria," points out Scott Davis, so the basics are simple:
well aged tank water, starter, and a source of bright light, either natural or artificial,
that is available 14-24 hours a day. Within a few days to a week from the start the water
will take on a greenish tinge, and microorganisms will be visible under a microscope.
Eventually, given enough light and enough nutrients, the water may turn dark green and
become quite opaque.
Remove any plants, which compete with the
algae for the available nutrients. Keep the water moving with an airstone or a small box
filter filled with stones. Add fish to eat quantities of food, stir up the water, and
produce waste material. "Under optimum conditions greenwater reproduces at an
incredible rate," with 40% removal possible every few days.
There are a number of "recipes"
for making greenwater. Dave Lains uses a small but effective system: one goldfish, one
gallon bowl, leftover brine shrimp, and lots of light.
Or try this one from Mack Fukada: to tank
water, add a crushed (or microwaved) lettuce leaf and some liquid plant nutrient, such as
Miracle Grow fertilizer. (Many aquarists with plant tanks have found that fertilizers
result in unusually high nitrate and phosphate levels, which result in unwanted algae
blooms; for greenwater production, this situation is ideal and poses no problems to fish
or snails.)
Dave Webb, too, begins with Miracle Grow
fertilizer, then adds iron drops such as Sequestrene (available at garden stores) or
Duplaplant 24. "If you let the iron levels drop," he says, "the water may
not stay green."
Others, like Dale Deck, use water left over
from boiling potatoes, placed near a sunny window. To feed the culture, add more potato
water or cooking water from any starchy cereal grain. Alternatively, use a bit of liquid
or powdered milk. These cultures are not odorless, but do produce a culture quickly.
If you feel adventuresome, you might try
this recipe from Scott Page. In a blender place 2 cups of RO/DI water and one sheet of
Nori (dried algae, for wrapping sushi; available in red, brown, and green). Liquify for 5
min. Filter first through window screening sized mesh, then through the finest mesh you
can find. The resulting liquid will feed rotifers or baby brine shrimp. The remaining
jelly can be used fresh or frozen as food for small-mouthed herbivores, daphnia, brine
shrimp, etc.
Live Foods
Daphnia
There are probably as many methods for
culturing daphnia as there are people making the attempt. But what most agree on without
question is that daphnia makes an excellent (although not exclusive) food for tropical
fish, including killifish.
There are two species of these small
free-swimming shelled crustaceans, Daphia pulex (fairly small and dark colored),
and D. magna (larger and pale colored). Daphnia can be collected from the wild or
they can be cultured, although cultures do tend to experience normal "bloom and
bust" cycles. This problem can best be dealt with by having several cultures active
at any one time, so when one fails another is still producing.
Daphnia have long been a staple of the
aquarium hobby, and have been successfully cultured in a variety of containers, from small
buckets and indoor aquaria to outdoor stock tanks, ponds, and children's wading pools.
Proper water for daphnia culture is not a
major concern; they have been raised in hard well water and in soft rainwater.
"I keep my daphnia in a 300 gallon
stock tank," says Barry Cooper. "I [first] filled it with tap water (well water,
180 ppm, pH 7.5), added some soluble fertilizer, and watched it go green. Then I added a
culture of mixed Daphnia species." The next year it filled with rainwater and
had lots of dead leaves, mostly ash and maple, fairly clear, reddish brown water, and it
teemed with daphnia. Resting eggs had survived over the winter and hatched when the tank
filled in the spring.
Gary Sutcliff uses small plastic wading
pools kept outside. He feeds the daphnia in the spring with yeast and pea flour, which
gets them off to a good start. "It's important to harvest heavily when they
bloom," he says. "In any culture you want the population to be on the growing
part of the curve." His daphnia occasionally disappear for about a month, but then
came back.
Robert Nahn uses a slightly different setup.
"I have three big 32 gallon plastic containers, one with green water and about 10
comets [goldfish]." The other two containers are for daphnia culture. Every few days,
he collects daphnia from the culture tanks, feeds the daphnia cultures with green water
fom the comet tank, and then feeds the comets with flake food. The cycle works.
Opportunistic filter feeders, daphnia have
been successfully raised on green water, yeast, powdered pea soup mix, alfalfa meal, skim
milk, and a variety of other foods, commercial and homemade, as well.
Charley Grimes, writing in Aquarium Fish
Magazine ("Feeding Live Foods"), found that his best results with daphnia
occurred when he fed mashed sweet potato baby food mixed with water, up to twice a day.
"I prefer the baby sweet potatoes [because] they make the daphnia a reddish color
that I like." Neither the daphnia nor the fish they're fed to seem to have a
particular color preference. Charley's daphnia culture tanks have an airstone for water
movement and receive 50% water changes weeky. When doing water changes, use a strainer, a
piece of old tee-shirt, or a fine mesh net to recover any daphnia, then return them to the
tank. Eventually, you'll have to remove the mulm buildup. Siphon it into a bucket, let it
settle , then recover any daphnia you've missed.
Many feel that greenwater is the best food
for daphnia cultures. It can be produced by keeping the containers in sunlight and feeding
them with well composted cow or horse manure or fertilizer. Other foods that will help
keep a daphnia culture producing include:
Powdered milk (produces
a 5-15 day daphnia population curve).
Soy flour recipe. Blend
together 2 tsp. soy flour, 1 multivitamin tablet, 1 spirulina vitamin tablet (from a
health food store) and 6 oz. water. In a separate container put 8 oz. tank water and a
pinch of yeast; allow to sit for 20 minutes. Add two teaspoons of the soy flour mix to the
tank water, then feed some of this mixture to the daphnia. The rest can be stored in the
refrigerator.
Vegetable juice mix. Juice
together some spinach, a carrot, and a beet (optional). Feed about 1 teaspoon of the
mixture at a time. Store the balance in the refrigerator, or freeze in ice cube trays;
feed a cube as required.
One critical thing that daphnia need,
besides a steady food source, is plenty of light. Recommendations vary, but lighting may
reach 24 hours per day without harm, as long as the water temperature remains below the
mid-70s (F). At higher temperatures the daphnia may go dormant. With cooler temperatures,
the daphnia usually will resume active growth and reproduction.
-- G.C.K.A. Newsletter, January 1998
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Of course, say
several fishkeepers who have been raising daphnia for years.
"I had a
culture of Daphnia in upstate New York, outside in a 300 gallon stock
tank," says Barry Cooper. "I rarely fed it anything, except very
occasionally some yeast… They over-wintered for about 4 years before I moved
to Oregon. That stock tank regularly froze solid. It had lots of dead leaves and
other detritus on the bottom, which I think harbored the organisms that the
daphnia fed on." Barry also over-wintered D. magma and D. moina in
Oregon, where the water froze over in his stock tanks.
Patrick Coleman
reports that he when he lived in "primitive" conditions in Montana, he
kept an old wooden water trough for infusoria and native daphnia. In the spring,
it always seemed to bloom back to the abundance of the previous summers, despite
the cold. "The addition of elk, deer and bear droppings ... added
occasionally, helped it even more."
"I just
[leave] the container outside," says Al Boatman (Florida). "When it
warms up after a cold snap I can see the daphnia swimming along the top of the
water."
You can siphon
out the bottom debris, place it in a gallon jar or a 10 gallon tank and warm it
to about 78ºF, with about 14 hours of light a day. This triggers the eggs into
hatching. The addition of small amounts of organic fertilizer (in the form of
animal droppings or traces of Miracle-Grow) encourage a good bloom of green
water and bacteria on which the daphnia feed.
– G.C.K.A. Newsletter, December
2002
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Those who breed fish are well aware that for
fry to get off to a good start, they must be well fed. Among the many live foods that are
suitable for small fry, perhaps one of the most popular are baby brine shrimp, or nauplii.
These can be fairly easily hatched in the fishroom and are relished by most fry large
enough to eat them. The dried eggs store well, sometimes for years. Standard hatching
procedures involve salt, water, heat, and light, then harvesting of the free swimming
nauplii for feeding.
In recent years, decapsulation (removal of
the chorion layer) of brine shrimp eggs before feeding has become more popular. There are
several advantages to this process:
1. The strong chlorine (oxidizing solution)
completely sanitizes the cysts, reducing
potential introduction
of bacteria or disease.
2. No separation of shells is required when
feeding the naupli.
3. There is no loss of unhatched cysts; even
those that do not hatch are edible, since the
thin "hatching
membrane" that is left is digestible. Also, unhatched nauplii have expended
no energy stores in
swimming.
4. The hatching nauplii require less energy to
hatch, which can increase the hatch rate
10% over undecapsulated
cysts.
The process of decapsulating brine shrimp
eggs need not be a mystery. In the paragraphs that follow, two breeders share their
techniques.
"I've been decapsulating brine shrimp
eggs with good success using the following formula," says Chris Graseck.
1. Soak 1 tsp. of brine shrimp eggs in 3 oz. of
cold water for one hour to rehydrate them.
2. After they have rehydrated, add 2 oz. of
bleach and stir for 3-5 minutes. The eggs will
change color, from
brown to gray to gold. Remember to keep stirring; you're done when
the mixture turns
golden.
3. Pour through a brine shrimp net and gently
rinse with cool water until no smell of
bleach remains.
4. In a separate container, prepare a mixture
of one cup cool water and one tbs. of white
vinegar. Use a low,
wide mouth jar you so can drape the net with the eggs over the top
to let the eggs soak
for a minute or two. This will neutralize any leftover bleach.
5. Place the brine shrimp eggs in salt water
and hatch normally. If you hatch out these the
regular way and have a
lot of orange dead shrimp at the surface cut back a little on
the bleach.
Jay Exner's technique is similar.
"You will need: a small bowl (I use
one of those tiny clear Pyrex bowls), bleach, brine shrimp eggs, a fine mesh net, and
dechlor liquid. To the small bowl, add the brine shrimp eggs you wish to decapsulate. Pour
bleach directly on the eggs. You may add some water, it doesn't matter. Gently agitate the
bowl. After a few minutes you should notice the color changing. When ready, pour the
mixture into the brine shrimp net while holding it over the sink. Rinse the bowl out into
the net, then gently rinse tap water through the net. Add dechlor liquid (a few teaspoons)
to the empty bowl with a small amount of water, then dip the net into this for a few
moments. You can pour the dechlor water through the net and gently rinse the net and eggs
one more time. (It shouldn't smell like bleach anymore). Add eggs to culture."
-- G.C.K.A. Newsletter, January 1999
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Decapsulating Brine Shrimp Eggs
More Breeders Share their Techniques
Richard Sexton
"What you will need
one pint or 16 fl. oz. of fresh water, 2 oz. of liquid chlorine bleach, 1 tbs. of white
vinegar, 1 tsp. of brine shrimp eggs.
"Begin by adding 3 oz. of chilled fresh
water and one teaspoon of brine shrimp cysts to a glass container. Using an air stone,
gently aerate the cysts for approximately one hour at room temperature. This will fully
hydrate the eggs in preparation for the decapsulation process. After one hour, pour in 2
oz. of liquid bleach. Increase the aeration or stir continuously for the next 5-10 minutes
(until decapsulation is complete). The eggs will change from brown to gray to white, and
finally to orange in color. When almost all of the cysts are orange, stop the reaction by
pouring the solution into a fine mesh net and rinse immediately with fresh water. Continue
rinsing until the smell of the chlorine bleach is gone. Mix 1 cup of cold water and 1
tablespoon of white vinegar in a container and soak the net mesh with the cysts for about
one minute. This will remove or neutralize the residual chlorine bleach. Rinse the cysts
one more time with fresh water. Your cysts are now ready for hatching!"
Chris Durkin
Soak 1 tsp. eggs in 3 oz. water
for an hour with an airstone to keep them suspended. Add 2 oz. chlorine bleach and stir
for 4 minutes. Pour into a brine shrimp net and rinse well. Add rinsed eggs to 8 oz. water
with 1 tbs. vinegar added to neutralize bleach. Stir for 30 sec. to 1 min. Rinse again in
brine shrimp net, hatch as usual.
Use cold water in the bleach step; the
reaction produces heat, and if too much is generated, it could kill the artemia. You will
notice the cysts turn from brown to rust-orange by the end of the bleaching. I have used
this procedure many times and have always gotten very good results.
Jeff Bilbrough
"My experience with
dechorinating (removing the chorion) from brine shrimp cysts in a solution of 50% each of
bleach and water generates some degree of heat. With one cup each of bleach and water and
one teaspoon to one tablespoon of cysts the heat generated seems to do no harm. Ive
tried a quarter cup of cysts in the same quantity of liquid and the container got quite
hot." The result was a poor hatch; the non-scientific conclusion was that the heat
killed the cysts.
Decapsulating eggs may take a bit more time
and trouble than simply hatching out nauplii, but use of those eggs which traditionally
did not hatch may make the effort well worthwhile.
-- G.C.K.A. Newsletter, May 2000
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On the whole, microworms are one of the most
dependable and simplest of the live foods you can culture. With a minimum of attention,
you, too, can have live food for your juvenile fish and fry, whenever you need it.
Nearly every aquarist, it seems, has a
different recipe to culture microworms, but basically you need: a starter culture
(available commercially, or from a fellow aquarist); a culture medium; water; regular
baker's yeast; and a suitable container.
Any appropriate plastic or glass container
with a lid (to keep moisture in and pests out) is suitable for microwormsplastic cups,
cottage cheese or margarine containers, plastic shoeboxes, etc.
The culture medium should be starch based.
Most cultures are based on baby cereal (Hi-Protein, Rice, Oatmeal, etc.); instant mashed
potato mix; or regular flour; but any good breakfast cereal without fruit will also work;
as will cooked porridge; or a mix of cornmeal and whole-wheat flour. Some aquarists
successfully raise microworms on well soaked white bread.
Add water to the culture material and mix it
to make a thick slurry. Place 1/2" to 3/4" of the culture medium in the bottom
of a suitable container, add a pinch of yeast and the starter culture and mix well. Put a
cover loosely on the container and place where it will be moderately warm, 70-75F or so.
Wait a few days, then check the culture for
activity. The culture is "working" properly when the surface shows a ripply,
satiny appearance.
There are almost as many variants to
collecting microworms for feeding to your fish as there are culture media. Among the
recommended methods:
With your finger or a spoon, scrape off the
layer of worms that have crawled up onto the sides of the container.
Soak a popsicle stick in water, then insert
it into the container. The worms will crawl up onto the wood.
Or simply scrape off a bit of that top
"working" layer. Any extra nutrients in the fry tank from the culture media will
help support a culture of infusoria.
If you want to get a bit fancier with your
microworm culture you can put the culture medium (Roger Sieloff uses flour and water) into
glass jars, then use an autoclave to set the culture medium, drive off any chloramines,
and sterilize it. Once cool, inoculate with starter culture. This method will produce a
culture that will last approximately 3 weeks.
Since cultures will not continue
indefinitely, most aquarists maintain several cultures at one time, and start new ones
regularly. In addition, they add new culture media and/or yeast from time to time to keep
existing cultures in production longer.
Several problems are often encountered with
microworms: limited culture life, cultures going bad (souring, liquefying, or drying out)
and dirtying of the tanks where they are fed.
To prevent your microworm cultures from
failing completely, keep several cultures going at once, and start new ones on a regular
basis. To avoid cultures drying out, keep the top covered before and after feeding, and
occasionally stir in a little additional water. Be sure to use water with the chlorine
removed, or a bit of tank water.
Sour, "funky" cultures can
sometimes be revived by the addition of fresh media and yeast. For a discolored culture,
scrape off the darkened top layer first. One aquarist suggests adding a pinch of baking
soda when the culture gets "funky." Occasionally, a culture will
"liquefy," with the top surface turning thin and runny, or developing a
"skin". Sometimes such a culture can be revived; sometimes nothing will help.
Some "dirtying" of tanks is
inevitable when feeding microworms by all but the popsicle stick method. In most cases,
this causes little problem, and actually benefits fry by providing nutrients for
infusoria. To deal with the additional dirt, you may have to add a couple of snails, or
step up your schedule of partial water changes.
-- G.C.K.A. Newsletter, August 1997
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As aquarists, we know that feeding our fish
a variety of quality foods is important, and we have developed a good feel for how much to
feed at any given time.
To be healthy, fish require appropriate
conditions (water, temperature, appropriate tank size, compatible companions), light, and
food. Since an aquarium is an unnatural situation, the aquarist must also be observant, to
see that all the fish are eating, not just the bolder individuals. If fish receive too
little food or food inadequate to their nutritional needs, they will merely survive at the
expense of good color, vitality, and reproduction.
Feeding fish is more than just dropping a
pinch of dry food into the tank once or twice a day. For fish to be healthy and show their
best colors, they require a diet that fulfills all their basic nutritional needs. If we
want the fish to be well nourished, we need to understand their needs and requirements and
feed them good food.
Like humans, fish require a diet containing
a balanced mix of fats, carbohydrates, protein, vitamins, and minerals. If so inclined,
the aquarist can make quality fish foods at home, using fresh or frozen ingredients and
already proven formulae. However, most commercially available dry and flake foods meet
basic piscine requirements and form a good basis for their diet. Lee Harper has used
ground Purina Trout Chow as the basis for his fish feeding regimen for years. However,
even for fish that are not being stressed by breeding, it's a good idea to use a variety
of formulations in addition to the occasional live foods, to provide variety.
How Much and How Often to Feed?
In nature, fish feed continually. In the
aquarium, the aquarist controls the feeding cycle not only by the selection of foods, but
by the choice of feeding times.
Most aquarists recommend feeding at least
twice a day, with more frequent feedings for fry. With dry foods, feed as much as the fish
will clean up in about five minutes; after that, most foods will begin to pollute the
water. Some live foods, such as daphnia, glassworms, mosquito larvae, and bloodworms, may
be left in the tank with the fish for "snacking" later. Tubifex worms may burrow
into the substrate, out of reach of the fish. If not eaten in a day or two, mosquito
larvae may reach their adult form; be forewarned that for them, the aquarist may make a
good meal!
If you choose to feed only once a day,
morning is preferable. In well planted aquaria or those with green water, chlorophyll in
the plants generates oxygen (O2) in the presence of light and releases carbon dioxide
(CO2) when dark. Fish require extra oxygen in order to aid digestion. Feeding early in the
day assures that plenty of oxygen is available, particularly in aquaria with heavy fish
loads. In aquaria with less fish, the actual feeding times are less critical.
Feeding Breeding Fish
Breeding fish are under greater nutritional
stress than are fish merely maintained in an aquarium. In addition to meeting their own
basic nutritional needs, they must also develop strong eggs and sperm, and have sufficient
energy for courting and spawning. For breeding fish, the addition of live foods is highly
recommended. However, observation by aquarists have shown that some live foods are more
beneficial than others.
Brine Shrimp:
Newly hatched brine shrimp nauplii are an excellent
food for any killifish, from those newly hatched fry large enough to take them, up to
breeding adults. However, egg production by adults fed solely on brine shrimp nauplii has
often been minimal. Adult live or frozen brine shrimp are also good, although some loss of
nutrition occurs during the thawing process.
Worms (earthworms, bloodworms, tubifex worms, whiteworms, etc.):
Feeding
worms has long been known to increase egg production in breeding fish. Earthworms,
tubifex worms, glassworms, and whiteworms are particularly good, as are fresh
or frozen bloodworms. Black- and tubifex worms have a dubious
reputation, and should be used with care.
Mosquito Larvae:
When available, this is probably one of the best
possible live foods for any killifish.
Daphnia:
When used with brine shrimp, daphnia can increase egg
production, but not to the extent that tubifex will.
References: Speice, Paul. "Guppies to Groupers," Freshwater and Marine Aquarium, January
1986.
-- G. C. K. A. Newsletter, July 1998
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Feeding Killifish
A Few Useful Recipes
Lee Harper: This recipe, adapted from Roger Hoelters recipe for Fishfood from
a Gelatin Base, was published in the Novem ber 1998 newsletter of the Keystone Killy
Group.
Recipe: 2 cans fish-based Friskies cat food or fresh fish (tuna, salmon,
whitefish); 1 jar baby food (carrots); 4 packets Knox gelatin in 4 tbs. (or more) hot
water. Optional - a bunch of fresh parsley or baby green beans; 1 can drained small
cocktail shrimp or clams.
Blend all ingredients but gelatin and water in blender until uniform. Heat gelatin and
water, stir until dissolved (do not overheat!); pour into blender and mix for another
minute. Pour into small plastic bags and freeze. To feed: grate a quantity of the frozen
food and disperse into 1/2 cup water, then feed with an eye dropper or baster.
GCKA Newsletter, May 1999
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Feeding Killies
Dry Food for Killifish
By Donna M. Recktenwalt
One of the complaints often
heard about killifish is that they wont eat dry food.
Not true. In fact, the staple food for many
killikeepers is commercially produced dry foods. These are of various types, including
flakes, freeze-dried, and pelleted forms. Of course, all fish will do better if they have
variety in their diets, and breeding fish especially benefit from generous helpings of
live foods.
"I have 26 varieties of plant-spawning
killies," John Burns writes. "The core diet I feed is Hikari Sinking Carnivore
Pellets." In a blender, he processes the pellets to a fine powder; this floats for a
time, then remains in the water column for even longer. He feeds this to all his fish,
with juveniles and adults receiving bloodworms as well. "They all eat with
gusto, " says John.
"Ive observed that most killies will
eat ground up Purina Trout Chow [primary ingredient fish meal] but will not touch flake
foods," says Lee Harper. "They will also eat without much persuasion any of the
dried shrimp, worms, etc. They apparently dont care for cereal-based foods. In any
circumstance, no one food should be used alone; a variety including live foods is
essential."
"Every killie I have ever kept has eaten
flake food," reports John van Rompu. "Some are reluctant at first, but after a
few days they get the hang of it." However, John agrees, "you must give them a
varied diet. All my killies also receive at least one feeding of baby brine per day and in
season, mosquito larvae, etc. Do not feed just one food if you want healthy robust
fish."
"I have raised more than 10 generations of
Epiplatys dageti Monroviae on a basic diet of TetraMin, with irregular additions of
frozen brine shrimp, live brine shrimp, and small earthworms," says Bruce
Stallsmith.
"My Rivulus marmoratus, on the other hand, definitely need real
meat on a regular basis, although they take TetraMin too. Interestingly,
wild-caught native Fundulus species will start eating TetraMin after several days
in captivity."
"Most killies will eat flake food,"
agrees George Slusarczuk. "The best method to teach them to accept dry flake food is
to start feeding early, when the fry are about 1/2" long, one feeding a day. I
usually feed dry food in the morning, when they are the hungriest." George uses
TetraMin Staple and TetraMin Ruby, crushed and sieved to proper size.
Sue Katz says that many of her killies relish
OSI freshwater flake food. "Even many of the well fed but picky fish
have transferred to eating the OSI. Theyve refused some of the other flake
foods Ive tried, so it might be something OSI alone has."
"I dont recall ever having a killi
species that never eats dry food," says Wright Huntley, "and I usually have
close to 50 species around. Some new wild fish are tough to get going [on dry foods] but
all others can be taught." The trick is to introduce quality foods they will
like, into a "feeding frenzy" situation. "I have found Brine Shrimp Direct
brine shrimp flake to be accepted by all, once they know it is good to eat. Introducing it
into the competition of the rearing tank is sure to get them going."
"Many of my fish would just starve to
death before eating the standard Wardley and Tetra flake stuff," he continues,
"I dont know why." Wright usually feeds mostly live foods, but includes
dry foods of various types: micro-pellets, flake foods, etc., especially "right after
vacations and field trips, when they are good and hungry." That way, when the live
food sources fail, the fish will still eat and remain healthy.
"My favorite food to teach babies to eat
dry stuff is Hikari Oranda Gold minipellets, ground in a hand pepper
mill," says Wright. "Most of it floats, but enough sinks to get them striking at
it. Once they find out how good it tastes they are off and running. An advantage of the
Oranda Gold is the high quantity of color-enhancing algae in it."
"Another good [starter] food is crushed
spirulina pellets from either JBL or Tetra," suggests David Skop. For smaller
surface-feeding killifish fry, Artificial Plankton Rotifer (APR) is an invaluable early
dry food, and high in fish protein. The fish will take it from the surface, or as it falls
through the water.
G.C.K.A. Newsletter, November 1999
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Feeding small, newly hatched fry can be a
problem, especially for those species whose fry are unusually tiny. The foods must small
enough for the fry to take, they must palatable, nutritious, and fairly easy for the
aquarist to use. There are a number of possibilities available. The following reviews a
few of them.
One of the traditional standbys for feeding fry
is newly hatched brine shrimp. These are nutritious food, and as active, free swimming
larvae, most fry will take them with gusto. However, hatching out brine shrimp takes time,
equipment, and attention. There are other answers.
"I wonder," says Al Anderson,
"if anyone remembers that before brine shrimp eggs we used to use boiled chicken egg
yolk to start young fish with."
An Old Standby Egg Yolk
Boil an egg or two and remove the yolk,
then store in the refrigerator.
When ready to feed, squish the egg yolk between
your fingers or through a very fine sieve or linen handkerchief. Either mix the resulting
material in water, or with your finger apply a bit to the water surface. Liquid vitamins
can also be added to the egg yolk.
"Feed small amounts," cautions Al,
and make frequent water changes," since it is easy to foul the water. As with other
non-live foods, strong aeration is recommended.
Some Other Possibilities
Artificial Plankton, Rotifers.
This finely powdered material can be mixed in water and fed to even the tiniest fry.
"A little bit goes a long way," says Tony Terceira. " I simply mix a
quarter teaspoon in a small jar, shake" vigorously, and then feed the resulting
emulsion. Although made for saltwater use, the product is readily taken, and does not
pollute the water.
Micron Fry Food. Extremely
fine, thus suitable for very small fry, this product contains an assortment of
microorganisms, and is readily taken.
Sanders Small Fry Gold. "I've
been using this product with some success," reports Donna Recktenwalt. It is an
extremely fine powder that can either be fed dry on the surface or mixed into an emulsion.
Small fry seem to do well on a combination of it and microworms. "Be sure to add a
snail to help clean up any leftovers, and keep up the [frequent] water changes."
Artemia Golden Pearls, or
Decapsulated Brine Shrimp Eggs. You can decapsulate brine shrimp eggs
yourself using unhatched cysts, or purchase them already processed.
"No," cautions Wright Huntley,
"the fish will not eat them cold. If you have been feeding baby brine shrimp so they
know the taste and color, they'll eagerly scarf them down. Just don't expect them to be
perceived as food by either those tiny babies that still need movement to trigger feeding,
or any fish not accustomed to 'small orange/pink things.'"
"Of course," Tony Terceira comments,
"a little bit of everything will get some food into fry. Like all good practices,
diversity of diet, and small water changes are the key to raising small fry."
Live Foods:
We all know that live food on at least an
occasional basis is one of the best things we can do to foster good health, good growth,
and regular spawning in our killifish. But what live foods can we feed during the
"off" seasons, when mosquito larvae aren't available, and the daphnia cultures
have gone dormant?
A regular standby of many aquarists is
fruitflies. Most killifish will gladly accept them, as will many amphibians and reptiles.
"You're raising WHAT in the house?"
If your spouse asks this, keep in mind that
she or he has a legitimate concern. Ask anyone who has ever been plagued by a cloud of
them around softening fruit. However, a larger, wingless strain of cultured fruit fly is
now available which not only cannot fly, but is more prolific and will breed true unless
contaminated by wild stock.
Sometimes this information alone is enough
to overcome spousal resistance.
Containers for culturing fruit flies should
be large enough to contain sufficient culture medium, but not too large to handle easily.
Glass containers iced tea or juice bottles, or suitably sized canning jars are a good
choice, and can be easily run through the dishwasher between uses. Plastic containers (2
liter soft drink bottles with the tops cut off, or juice/iced tea bottles) also work well,
and can simply be recycled or thrown away when they have served their purpose.
Growth medium for fruit flies is a matter of
preference. Fresh, decaying fruit or fruit based mixes will work, but tend to be smelly,
messy, subject to mold and to attracting unwanted insects.
Commercially available cultures are easier
to use and considerably neater to work with. The fruit fly medium from Carolina
Biologicals is recommended by many. According to Barry Cooper, "You put a scoopful in
the bottle, add an equal volume of water, wait a minute, add a sprinkle of yeast, then add
the fly innoculum. Very easy."
Alternatively, try using instant mashed
potatoes. Several variations of the recipe are available, but all begin by preparing
instant mashed potatoes according to label directions. Then:
1) add some sugar, a drop of blue food
coloring (if you like), and some yeast. Sprinkling the yeast on top works better than
mixing it in, which usually results in the culture "rising"; this can get messy.
The result of this recipe is very similar to the culture medium sold by Carolina
Biologicals, at a fraction of the expense.
2) add one tablespoon of sugar per cup of medium (brown sugar or
cane syrup will also work) and a pinch of salt.
3) to the basic mixture you can also add
flour, producing a "doughier" consistency. This can then be frozen into
appropriately sized portions for later use.
For an entirely different recipe, try this
one suggested by Art Abramovitch: add yeast to a quantity of beer; wait half an hour or
so, then add dry baby food oatmeal to a consistency that is moist but not sticky.
Spoon your culture medium approximately one
inch deep into containers and add a "scaffolding" for the flies to crawl on.
Plastic fly screen from the hardware store, cut into strips, works well, as do popsicle
sticks or crumpled paper.
Add fly culture innoculant, then cover the
container using a piece of fine mesh cloth or old nylon stocking held in place with a
rubber band; or a "plug" of cotton or plastic foam.
Feeding Fruit Flies
When preparing to dispense the adult flies,
first rap on the side of the culture container once or twice to knock the flies to the
bottom. Remove the cover, then GENTLY shake the flies out. Immediately recover the
container, and be certain to cover the tank you're feeding as well, to avoid escapees.
Known problems
The potato culture medium can get messy if
bacteria cultures take hold before the yeast. To avoid this, try dissolving the yeast in
aged dechorinated tap water, then add the instant mashed potatoes and the yeast on top.
Let sit for a couple of days, then add the flies.
The culture also may develop mold. If the
culture medium is too dry, mold is inhibited, but it may be difficult to remove the flies
for feeding.
Live Foods
Moths: Another Group of Live Foods
By A. Lexeyev
This article originally appeared in Rybovodstvo (a Russian
magazine), #5,September/October 1985, p. 48.
Some people successfully breed various types of moth at homethey can be useful
as food for the inhabitants of terrariums [or aquariumsEditor].
Cereal Moth (Ephestia kuehlniella)
Was brought to Europe from America in the 19th
century and has become widespread since then. It is easy to find these tiny moths in
cereals, flour, or bran.
An artificial culture of moths can be kept in
plastic shoeboxes, no less than 1 liter. A tight lid is a mustit must have a small
ventilation hole sealed by dense metal or plastic mesh. The shoebox is 2/3 filled with
wheat flour or cornflakes, adding a few teaspoons of sugar and dry yeast. No more than 10
pairs of moths are loaded in 1 liter shoeboxes. It is recommended to run several cultures
in parallel, since they may degenerate quickly. The optimal temperature for breeding moths
is about 25°C (77°F). At these temperatures the eggs develop in four days, the larvae
develop for 30-36 days, and pupae in 8 days. The moths reach sexual maturity when one day
old.
Fruit Moth (Plodia interpunctella)
Similar to the cereal moth, it feeds on the
remains of human food. This moth can be kept in similar conditions, except for using wheat
grains as a substrate. The eggs develop in five days, larvae in 25-30, and pupae in 8.
Sexual maturity is reached when one day old. It is recommended to add a small amount of
dried fruits as a food for these moths.
Large Wax Moth (Galleria melonella) and Small Wax Moth
(Achroia grisella)
Wax moths can be found anywhere near beehives
and honeycombs, even old ones. Sometimes the two species can be found at the same time. It
is recommended to cultivate the two species separately to avoid combination of one of
them. The larvae of both species develop on wax, but they also require other products
resulting from the lifespan of bees: pupae shells, excrement, propolis, etc. Before
starting up a culture of wax moths, one should find out whether he will be able to have
old honeycombs regularly. Wax moths are bred in plastic shoeboxes with tight lids (2/3 of
the lid cut and covered with a mesh). The box is filled with paper or cardboard. Optimal
temperature is around 28°C (85°F). Eggs develop in four days, larvae in 35, pupae in
7-9. Moths reach sexual maturity when 1-2 days old. To collect the larvae of large moths,
paper or cardboard tubes are used; pieces of paper are laid on the surface of the
substrate for collecting larvae of small wax moths. The larvae collect under such
"shelters" to develop into pupae.
German experts recommend the following food for
breeding moths: 100g of dry yeast, 200g of wheat flour paste, 200g of skimmed milk powder,
200g flour, 400g corn or semolina, 500g honey, and 500 g glycerin. The dry components are
mixed first, then the mixture of honey and glycerin is added. This food can be kept for a
long time in the refrigerator. Nut-sized balls can be made and several such balls wrapped
in paper for feeding to the moths.
--G.C.K.A. Newsletter, December 1999
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Al Anderson is
well known in the midwest for his skill at breeding exotic fish. To support them, he also
breeds quantities of live foods, among them whiteworms.
"Whiteworms do best at 55-65ºF," Al
says. He cultures them on Magic Worm Bedding mixed according to directions, but at half
the amount. He puts a dry layer on the bottom of the container (usually a large bucket),
puts the culture in the center, then surrounds the edges with more dry bedding. He then
feeds and waters in the center of the culture. To feed, he dunks break in tank water and
lays it on top of the culture. The bread will keep, covered, in the refrigerator for a
couple of days.
"Keep the worms in the dark," he
says, and they should do fine.
-- G.C.K.A. Newsletter, December 2000.
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Paste Foods Another Alternative
Every aquarist has his or her own "recipe" for successfully feeding his/her fish, although almost all agree that variety in the diet will improve overall vigor, color, and health. Most successful aquarists rely on a combination of foods, including fresh or live foods, frozen foods, flake foods, and in some cases, paste foods.Dale Decks Paste Food Recipe
3 pints water
1/2 lb. beef heart
1/2 lb. beef liver
1/4 lb. fish fillet
1 small can clams
8 oz. shrimp
1 tsp. Salt
2 c. oatmeal
1/2 c. Parmesan cheese
1 tsp. Anise oil
1 envelope Knox unflavored gelatin
Optional items include: 1 small can cat food, 1/2 c fish meal, 1/2 c shrimp meal, dried
Krill, spinach, carrots, or anything else that is nutritious.
Steve Shine's Variation on Bower's "Omnivore Diet"
5 oz. whole shrimp (less tails)
5 oz. haddock fillet
4 oz. crab meat
1 Tbl. Parsley
1 Tbl. carrot shavings
1 Tbl. green peas
1 Tbl. oatmeal
2 tsp. Brewer's yeast
2-3 dashes Paprika
1 drop Anise extract
2 packets unflavored gelatin
1/2 tsp. Poly-Vi-Sol baby vitamins
Puree all ingredients but the gelatin with 2 oz. of water. Dissolve gelatin in 10 oz.
boiling water. While running blender, slowly add dissolved gelatin to rest of mixture. If
you want floating food, pour directly into a thin layer in zip lock bags. If you want
sinking food, allow to sit for a while to allow air bubbles to escape. Lay the bags flat
in the refrigerator to chill and set up for 24 hours. Do not put directly into the
freezer, or the gelatin won't set up properly! After 24 hours move containers into
freezer. Cut frozen food into chunks or slices; thaw only what you need for a single
feeding.
Note: If the consistency of the preparation seems too wet, add some flake food.
-- G.C.K.A. Newsletter, June 1999
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Live Food
Puttin' Live Food By
or
Carryin' That Summer Bounty Into Fall
Fall is here, and with it the eventual end
of the bounty of live foods that we have been able to collect and/or culture outdoors
through the warmer months. Some of these cultures can be brought inside for the winter and
continue to produce live food for our killifish; others are done for the season,
unavailable until next year.
But the end of good weather doesn't
necessarily mean the end of good food for your fish. With a little work and attention to
detail, you can preserve some of that bountiful harvest for later use.
Freezing
Perhaps the simplest and best method for
preserving most live foods available to the hobbyist is freezing. It is particularly good
for such freshwater creatures as daphnia, mosquito larvae and eggs, bloodworms and
tubifex. Brine shrimp will also freeze well, but few of us grow enough of them to adult
sizes to bother. Before freezing, drain off most of the water using a net or strainer. It
isn't necessary to remove all of the water, but the more you remove the less space will be
required in the freezer. Freeze in thin sheets or as small cubes in ice cube trays. Once
solid, the material can be removed and stored in freezer bags. Feeding is simple: break
off a piece and thaw, or drop directly into the tank.
Drying and Pickling
For animal matter that does not freeze well,
such as insects and their larvae (such as mealworms), drying may be the best answer.
Create a shallow "cage" using an aluminum pie or cake pan. On the bottom place a
layer of aluminum foil with small holes poked through (to enhance air circulation), then a
layer of metal window screening cut to fit inside the pan. A second piece of metal window
screen should completely cover the top of the pan. Set your oven at 200-250F. Put the live
food on the bottom screen, cover with the top screen, and put in the oven with the door
left ajar so heat rises through the pan and out. Check every ten minutes or so. When a
specimen breaks easily in half and shows no sign of moisture on the inside, drying is
complete. The resulting food can be stored in screw-top jars in a cool, dry place until
needed.
What about soft things, like slugs,
earthworms, and the like? These can be pickled. Using rock or unspiced pickling salt,
place as much as will dissolve easily into a pan of boiling water. Pour into sturdy,
heated jars and cool slightly before adding the live food. The hot water will kill the
creatures immediately. When the jars have cooled to near room temperature, screw on the
lids. Refrigerate until use. Soak in fresh water for half an hour or so before feeding to
remove excess salt.
Reference: Volkart, Bill, "Live Food," Freshwater
and Marine Aquarium, November 1990, pp. 59-62.
-- GCKA Newsletter, November 1997
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Red/Black/Tubifex Worms - a Safe Food for Killies?
Long known as a quality food for fish, redworms, blackworms and tubifex worms are related tubificid species, each with its own benefits and drawbacks. The question is not one of palatabilitymost killifish will readily take any of thembut rather one of availability and cleanliness.Health Concerns
There have always been concerns about
feeding black/red/tubifex worms to fish, since the worms often breed and grow in stagnant
water and heavily polluted mud. There is a long circumstantial history of disease problems
in tanks where they are fed, and tubificids are known to carry and transmit a simple
single segment tapeworm that is of no consequence to aquarium fish.
"Regarding intestinal parasites and
black/tubifex worms: I think you have to remember that fish fed on worms eat more and
therefore excrete more," says Barry Cooper. Whether the worms are causative of
disease or not, "without rigorous water changes and tank cleaning this would make the
fish vulnerable to all sorts of bacterial infections."
Richard Sexton counters this observation.
"I can have spotlessly clean tanks with daily water changes but feed worms, and there
are diseases that I dont get when I dont feed worms. This has been observed
over a long period of time. On the other hand, Ive seen fish live in all manner of
...[dirt] but never get the hemorrhagic septicemia outbreaks that accompany worms,"
and those oubtreaks always seemed to be proportional to the amount of worms fed.
Keeping Blackworms
Blackworms