Breeding Fish
by Cheryl Miller copyright 9-12-00
From the Youngstown Aquarist, Youngstown Area Tropical Fish Society
Aquarticles
This article is not entirely original. I have been collecting spawning articles from
various club publications for over three years. This is an overview taken from a
collection of these.
Why breed fish?
There are many reasons. In our club, you get points in a nationally recognized Breeder's
Award program. If I ever move to another area of the U.S. there's a good chance that a new
club I join will accept the points I have earned at YATFS. Some people think they going to
get rich - or at least support their hobby - selling the fish that they breed. Others do
it for the scientific interest and fulfillment of seeing different species procreate. What
better way to appreciate the "grander scheme" of life? And how about the ease of
teaching the little humans in the household about the birds and the bees? (Although I must
confess, I thought briefly that I had missed the boat when my then 4 year old daughter
asked if the pregnant cat was an egg layer or a livebearer.) Still others do it for the
competition within the club. On the larger scale, they compete to spawn species that are
considered difficult or have never before been done.
How do you spawn fish?
First, you do some basic research. Read and/or talk to someone who already spawned the
species. Find out what kind of species of fish you have. Is it a livebearer or egg-layer?
What is the best ratio of males to females for that species? What is the best spawning age
for the fish? What are the ideal tank conditions?
You also need to find out the best way to care for the fry. Some need to be left with
the parents for a while. Others need their parents removed to prevent cannibalism. Some
require special foods the first week(s). Others can subsist on average flake foods.
This article is not all inclusive. There are many fish that are considered
"odd-balls." They break the rules and do not fit into any one category.
They exhibit one or more unique spawning traits to set them apart from the others.
That is why breeding fish is so intriguing to many of us. There's always another challenge
or adventure in the hobby.
Livebearers
You usually can't tell exactly when these fish have spawned. The male constantly chases
the female. The eggs are fertilized inside the female's body. The male transfers the sperm
into her vent with his modified anal fin, called a gonopodium. But, if you know the
average gestation period for the species and you watch the female's developing belly size
and shape, you can estimate when delivery will take place. Gestation for livebearers can
be from 25 - 45 days. Most, but not in all, livebearing female fish have a gravid spot
near the base of their tail, which is a sort of window to the developing fry. A day or so
before delivery, you can sometimes see the babies' eyes. Some species get a very square
looking chest right before delivering. The most important reason for knowing all this is
to know when to remove the female to a separate delivery tank. Sadly, most livebearers
will eat fry. Even their own.
Another trick with livebearers is that females can store sperm from previous mating for
many months. Just because you lost the male doesn't mean the female will not any more
babies. Also if you want to breed female A with male B, you may have to make sure that she
is not with any other males whatsoever. Granted, the most recent male will most likely be
the father of the fry. But it is always better to be extra careful with livebearers.
Generally speaking, the delivery tank should be 2.5 - 5 gallons. Use 70% water from the
original tank, a sponge filter and a heater if needed. Live floating plants or artificial
"spawning grass" will give the fry somewhere to hide. Lowering the lights will
calm the female. Some theories say you should avoid exposing the gravid female to the air.
So use a jar to scope her up and transfer her in water to the delivery tank. As soon as
she is done delivering, remove the female back to either the original tank or a recovery
tank away from the attentions of the male. Some species take up to 3 days to deliver their
entire brood. Still others deliver a couple fry every 5-7 days. Again do some research.
Most livebearer fry can be feed crushed flake food from the day they are born. But all
love baby brine shrimp and microworms! They are generally larger than egg-layer fry and
are free swimming almost immediately. Therefore, they do not require parental care.
Egg-Layers
As mentioned before, egg- layer fry are often small and require special foods and/or
varying degrees of parental care. Do the research. As far as spawning, these fish are
divided into seven basic groups according to their different spawning styles:
Open substrate spawners
This is the most common spawning method, mainly used by cichlids. These fish often form
permanent pair bonds. The female lays the eggs on a flat surface, such as a rock . The
male works in close proximity with her to fertilize the eggs. These fish
are often very good at guarding the eggs and defending the fry. Angels, Discus, Severums,
Jack Dempseys, Oscars, Firemouths, Jewel Cichlids, Rainbow Cichlids, Rams, many Aequidens
species, Sunfishes, Darters, Gobies, Damsels & Clowns.
A compatible pair must be found. This is best done by raising a group of 6-8 fry to
maturity and picking out the pairs as they form. Set them up in their own tank, condition
them, watch & wait. If the pairs become regular egg-eaters or fry devourers, you can
remove the eggs to be hatched away from their parents.
Although these do not technically hide the eggs like the next category, some will often
bury them and move them from place to place in the tank. So don't think you lost the spawn
until well past the time when you should see them free swimming. In addition, although
this group are not considered Mouthbrooders some will pick the fry up in their mouths and
move them to a safer territory, especially at night time. Don't think they are eating the
fry until many are actually missing!
Substrate Spawners that Hide their Eggs
Several of these fish also form permanent pair bonds. Most however, do not; it is the
female that takes on the care of the fry. Eggs are usually laid in a hidden area such as a
cave, flower pot or shell. Because of their secretive nature, the spawning is usually not
observed.
Included in this group are many Dwarf cichlids, Apistogramma, Nanacara,
Namachromis, Pelvicachromis, Julidochromis, Lamprologous, Loricaria, Farlowella
& Ancistrus. It is interesting to note that the males of the catfish species
are the ones that take care of the fry.
Set up a pair with several spawning choices. Feed them well and wait for Nature to
takes it's course. The female will lay the eggs within a cave or under a rock and the male
will fertilize the eggs in unison. Sometimes you guess if spawning has actually taken
place or not because the female disappears for about two weeks while she tends to her
eggs. She drives the male out during this time. When the fry are free- swimming, she will
bring them out and parade them around the tank. Pay attention to feeding whatever the fry
require. It is often good to remove the male at this point. In another 3-4 weeks, the
female can also be removed.
Mouthbrooders
An easy group of fish to spawn because they protect the fry the most efficiently. Also,
they tend to be a very hardy group.
Set up a pair with rocks, gravel and caves. A few dither fish will help them keep their
aggressions away from each other. Feed them well, Usually the male digs a pit in the
substrate. The female, when ripe, will begin the circular spanning dance around the pit
with the male. Eggs are laid, fertilized, then scooped up into the female's mouth. In some
African Cichlids the female tries to " scoop up" the egg spots on the male's
anal fin, thereby ensuring that the sperm has reached the eggs in her mouth. The eggs are
incubated in her mouth for about three weeks. She will not eat at all in this time, unless
the eggs have been lost or swallowed. Wait for about two weeks and move her to another
tank. When the fry are old enough, the female will release them and guard them. Often, she
can be seen chewing up and spitting out food for them. When danger approaches the fry fly
at lightning speed to hide in the mother's mouth. When the young have been free swimming
for about three to four weeks it is OK to remove the female. Sometimes she will eat them
if she is ready to spawn again.
Egg Scatterers
This group consist mainly of those fish we call schooling types: Barbs, Danios, Characins,
Tetras & Rainbows. They spawn as they school, scattering eggs all over the tank. The
females release the eggs haphazardly; the males follow close behind, releasing sperm at
the same time. Amazingly, the two meet and the eggs stick to whatever they land on. The
eggs are usually eaten as fast as they are laid by the spawners and their tankmates.
To successfully save the eggs, set up another tank with lots of plants (plastic or
real) or mops. Larger gravel or marbles on the floor also help to catch the eggs. Put in
an air stone and a heater, if needed. Introduce a female only, and condition her on
quality foods for a few days. One evening , introduce a male. The next morning they should
spawn at sunrise. After a few hours, remove the pair. Cover the tank with dark cardboard
or towels. The fry will hatch in three to four days. They are very tiny and are often
described as slivers of glass on the walls of the tank. They require specialized food
(infusoria, APR, etc.) at this stage. In a week or so, they will take live baby brine
shrimp, vinegar eels, microworms and such. After two weeks they can take powdered flake
foods. Growth will then be more noticeable. Rainbows are in this category, but breeders
usually remove the eggs and hatch them like mop spawners.
Mop Spawners
Mainly comprised of Killifish, these fish lay their eggs in mops made of synthetic yarn,
or in plants. The goal seams to be to hide the eggs. Included in this group Aphyosemion,
Aplocheilus, Epiplatys, Rivukus, Simposonichthys and the previously mentioned
Rainbows. What makes these fish different from the egg lay scatterers is that their eggs
are harder and larger, and they only lay about 20 -30 a day. Corydoras catfish
also seem to fit in this group in method, although they lay many more eggs. Typically,
they will attach their eggs to anything in the tank including the mop.
The spawning tank setup is simple enough. Hang several mops, add a sponge filter and a
heater if needed. Add a pair of fish. The female will lay the eggs deep in the mop or the
plant. The male will then fertilize them. Sometimes they will turn right around and eat
them. Another difference with Corydoras is that it is now believed that the
female takes the sperm into her mouth and fertilizes the eggs which she is clutching in
her pectoral fins, while sticking it on the preferred surface.
You must pick the eggs out of the mop daily and put them in a small container with
anti-fungal medication added (methylene blue or acriflavin). Store the eggs in a darker
place, at the required temperature. They will incubate for 14-21 days for killies and 7-10
days for rainbows. As the fry hatch, remove them with an eyedropper or pipette to another
small container or tank with the correct water parameters and some Java moss or similar
floating plants. Some can take live food right away, others need infusoria or APR.
Peat Spawners
This group is made up entirely of Killifish. Cynolebias, Pterolebias, Nothobranchus
and Fundulopanchax. These are the fish we hear referred to "true
annual" killies. In the wild, they have adapted to life in correlation with the rainy
seasons. They hatch, grow and spawn before the next dry season comes along, during which
their watery world as they know it dries up and they die. The eggs are able to survive in
this drying period. When the next rainy season comes along: life anew.
Set up a 5 gallon tank for a trio of fish. In it should be a bowl that contains
about 2" of peat moss. Some people like a slow bubbling sponge filter and some plants
or a mop for the female to hide in. Feed the fish well, but away from the spawning
container. The male will display himself above the peat moss. When the female is
interested in spawning she will come close. They will seem to dive into the peat, where
they will lay a few eggs and fertilize them. This continues several times a daily for many
days.
Most breeders collect the peat and give the fish a new batch about once a week. The
peat is gently squeezed and placed into some newspaper, lightly covered with a plastic bag
overnight. The dried peat is stored in a zipped sandwich bag, in a dark place at a correct
temperature.
Here is were you need to consult the charts in the killifish books for temperature and
drying /incubation time. It can take anywhere from 2-9 months! And incorrect temperatures
can cause poorly developed fry or low hatching rates.
When it is time to hatch the fry, the parents are most likely dead. Wet the peat, then
submerge it in a couple inches of water in a plastic shoe box. Cover lightly to shade the
eggs. With in a few hours, fry can be seen popping up over the layer of peat. Remove them
with a pipette and put into another shoebox with a few inches of water and some peat moss
or a floating plant. after about 24 hours, the peat can be re-dried for another two weeks.
Try to hatch more fry. This can be repeated 1-2 more times. Feed the fry often and well,
paying attention to water quality. Because these fish live such short lives, they grow
quickly.
Nest Builders
As the name implies, these fish build a nest in which to lay their eggs. Fish nests are
built with bubbles, mostly on the surface of the water using pieces of plants. The male
builds the nest. The bubbles stay inflated because of a special mucous he has in his mouth
when he blows the bubbles. The nest builders are mainly the labyrinth fished such as
Gouramis, Paradise Fish, most Bettas and Hoplosturnum Cats.
Set up a separate spawning tank for the pair. A very slowly bubbling, aged sponge
filter should be included to culture infusoria for the future fry. A couple snails will do
the same thing, along with lots of floating plants. A heater will be needed. Some plastic
plants or mops are helpful for the female to hide in. The key to the set-up is an upside
down Styrofoam bowl or something similar, taped to the front of the glass of the tank,
right at the surface of the water. There should be some dead air space inside the
container.
Put the male into the tank, and do not add the female until he has started a bubble
nest and she is ripe with eggs. When all conditions are right, the male will entice the
female under the nest. He will wrap his body around hers until she releases a stream of
eggs. He releases his sperm at the same time. Then he lets her go. She will remain
motionless and sink for a moment or two, but the male will immediately go to work
gathering eggs in his mouth and spitting them into the nest. When the female comes to, she
will often help. This will continue for several hours. When they are finished spawning,
the male will violently drive the female away from the nest. Now is the time to remove
her.
The male will guard, fix and add bubbles to the nest for the next three days. When the
fry begin to hatch, they will wiggle out of the nest. He will actively catch them and spit
them back into place. He should not be fed during these 3-4 days. Otherwise, he might
forget his job and begin eating the fry as well.
At the age of 6-8 weeks the fry will begin to develop their labyrinth organs. Covering
the tank with plastic wrap or taping the cracks in the glass will keep the air temperature
closer to the water temperature and you will lose less fry.
Some exception to the surface bubble nest are seen with the Croaking Gouramis and the
Pygmy Gouramis. They build their nests inside a cave, so breeders usually use 2" PVC
tubing pieces for them.
This Overview should be enough to get you interested in spawning some of your
favorite fish.
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