How to Breed Livebearers
You will notice that adult male livebearers, even during mealtimes, are
preoccupied with fertilizing the female. This is why plants that serve as
hideaways are important to the "sanity" of the females in a community tank
predominantly occupied by livebearers. When populating your tank, be sure to
always have more females than males. Given the male's natural inclination to
mate, a solo female will tend to be harassed if there are too many males.
Once fertilized, female livebearers will have no qualms about giving birth to
their fry as often as once a month in a community aquarium. The sad thing is,
being very small, the fry will be easy prey for other fish, including their
"parents." Plants with fine leaves that reach up to the surface will offer good
hiding places for the little ones. However, only a few will be tough enough to
When she's almost ready to drop her fry, it is best to transfer the female
into a breeding aquarium rigged with traps to separate and safeguard the young.
Plastic breeding traps are commercially available. After she delivers her brood,
return the female to the community tank and care for the fry separately.
Note that some females, especially the swordtails, grow too large to be
comfortable in the common plastic breeding traps. Be ready to substitute
appropriate devices such as nets or converted aquariums for this purpose.
Most people's first fish to breed are livebearers simply because it's almost
impossible to not get them to breed. There is no special skill or requirements
needed to breed the livebearers, just have a male and some females and nature
will do the rest. Mollies, guppies and platies, do not lay eggs like most fish
but instead give birth to young free swimming fry. Most female livebearers that
are pregnant should give birth to babies within 3 or 4 weeks. Because the babies
are born live and quite large, many will survive and grow right in a community
tank. It is obvious to tell which female guppies are pregnant as they will have
an obvious black "gravid" spot which is the fry's eyes forming inside the
mother, this will form just in front of her anal fin. For platies and mollies
the only way to tell how far into the pregnancy the fish is, is by seeing how
fat they are, platies and mollies which are about to spawn will seem almost
square from the back view and will be very swollen in the middle.
When your female livebearer is big and looks like she’s about to (burst)
release babies there is the option to move her into another aquarium or put her
into a net breeder protect her babies when they spawn, it should be noted that
the mother for approximately 12 hours after releasing the babies has a surge of
a hormone which results in her not being hungry. While this is an option the
difficulty is that often I have found that if I move the female too early she
will abort the pregnancy due to stress, the same may happen if you buy a heavily
pregnant fish from the fish store and yet you find no babies in your tank. For
this reason I have found - perhaps because fry especially from livebears are no
longer unusual or special I just leave the adults in my community tank which has
a planted corner. I have found that even without removing the babies into an
external aquarium/net breeder you'll get some babies which make it to adult
hood... unless you've got some really evil fish in there! I have also found the
use of large marbles on the floor of the tank to be superb as hiding places for
the fry, even so if I wish to save some interesting colour fry or need more fry
then I follow the following procedure.
Aid the Fry: A net breeder is a must if you wish to save large numbers of fry.
Simply place it in a corner of the tank when one of the females has already
spawned or place the female in it just before she spawns. Either way ensure the
fry are the only fish inside the net. As a rough guide, a young female
platy/guppy/molly usually releases 12 to 30 babies in her first batch of young.
In comparison a large molly may be able to release up to 100 babies! I highly
recommend you to purchase a "net breeder" made out of mesh rather than a plastic
one as I have heard too many bad reports about them and my net breeder has
worked flawlessly for me (plastic ones babies escape/get eaten or trapped!) The
net breeder has a frame made of plastic and is covered in fine net to separate
the fry inside the net from the larger fish swimming around in the aquarium.
A few of common problems people have is that they have bought fish which the
store said were pregnant and yet you don't have any babies. If this is the case,
and you are sure that you have both females and males in your tank preferably at
the ratio 2 females to 1 male livebearer then you can do a couple of things to
enhance your chances.
1) Change 20% of the water in the aquarium each day replacing it with
dechlorinated water which is as close to the temperature already in the water as
possible, remembering any differences will result in stress to the fish and more
chance of your livebearer aborting her pregnancy.
2) Supplement your livebearers diet with vegetables which form an integral part
of a livebearers diet in the wild I would reccomend blanched zucchini
(courgette) or cucumber, flakes are only so good and try to add to the meaty
part of your livebearers diet with blood worms or adult brine shrimp.
3) This should probably be number 1 as it is the most important... Patience!
there is nothing to stop your livebearer giving birth and the odds are stacked
in her favour if you have followed the procedures already mentioned.
Now you've got the fry leave them in the net breeder or their own aquarium, feed
them little and often - 3 times a day for maximum growth- with finely crushed
flake food (as fine as you can crush it, use your fingers and rub them together
really grinding it up very finely because any large bits will remain uneaten and
will rot polluting your tank). When your baby fish have grown to about one inch
which will take between two and four months you can release them back into the
aquarium with their parents. This is also the size fish stores will be willing
to buy livebearer fry off you. Growth will vary on quality of food and also of
tank temperature, 79 degrees fahrenheit is about the maximum recommended and at
this temperature the fry will grow faster than at a lower temperature. Not
recommended if you have other fish in the tank though and step up the
temperature increase slowly.
I would be suprised if you had poecilid that wasn't "hit". Technically these
fish don't get pregnant as this is a term reserved for the mother providing
nutrients during development. Although it would appear to be a pregnancy since
the young are born alive it is not. The eggs are developed by the female and
then fertilized by the male (or by stored sperm). The fry then develop from the
egg without any nutrition from the female other than an oxygen supply. The term
used for a female with developing fry is "gravid".
Size of the female is indicitive of a drop
growing closer. One trait that is often a tell for many species is the squaring
off of the ventral area of the fish. Many claim that they can tell by the
darkening of the gravid spot (which may not be visable on all poecilids
especially mollies). The gravid spot is somewhat valid as the darkening is often
the eyes of the developing fry, a dark gravid spot is not an absolute indicator
however. Some fish don't get dark gravid spots due to their natural coloration.
Other fish may have a dark gravid spot all the time.
Livebearers are generally very easy to breed. Like most other fish, the hard
part is raising the fry. Generally the parents and other fish in the tank become
predators to newly hatched fry but there are several solutions to this problem.
The easiest solution is to provide good cover and hiding places for the fry in
the form of plant cover like anacharis and hornwort. This will help but some
will still get eaten. Another solution is to buy a breeding net, which provides
a separate compartment in the aquarium for the mother before she drops the fry.
After dropping the fry the mother can be removed so the fry are separated from
the rest of the tank by the breeding net. Along the same lines the mother and
fry can be placed in a separate aquarium so the mother can be separated from the
fry when they are born. Breeding traps are also utilized which keep the mother
confined with a grating that the fry can pass through.
Most livebearers are schooling fish, and so you should keep more than one of
each species. It is also very important to have at least three females to each
male, as the males will become to aggressive towards each other and pursue the
females without end. A large densely planted tank with open areas for swimming
is ideal. Go easy on the Driftwood. Livebearers will accept all types of food,
but should have some plant material in their diet.
If your interested in watching courtship behavior, then the Livebearers are for
you. The males are continuously in courtship display, always chasing after the
females. If more than one male is present a pecking order is established with
the dominant male driving away all others. This continues down the order line.
Most livebearers can be kept without any problems with other active schooling
fish. Stay away from the larger Cichlids.
For almost all the livebearers, the water in the aquarium should be medium hard
to hard and a pH on the Alkaline side, between 7.0 to 7.8. As with all fish
regular water changes are important.
One of the theories prevalent in the fishkeeping communities Is that the
egglayers are more difficult to breed than livebearers, this is easy to
understand because a group of livebearer species placed in a tank will usually
produce fry. Whereas egglayers under the same conditions usually do not. The
instinct to produce young is very strong in most animals, and all will do so
given the right conditions, and that it is usually the difficulty with egglaying
How Can I Breed Livebearers?
Most of the common livebearers (the Big Four; swordtails, mollies, guppies, and
platies) are fairly easy to breed. Livebearing aquarium fish belong to several
fish families. Most of the common livebearers: Guppies, swordtails, platies, mollies, endlers,
etc belong to the family known as Poecilidae. Most poecilids constantly have
eggs/fry developing. Under good conditions these fish will drop fry about every
30 days. Under other than favorable conditions these fish can suspend/delay
development or even reabsorb the eggs. Since these fish store sperm
(superfoetation) once they have mated they can deliver to as many as 7 or 8
drops (maybe more). There are some very beautiful wild forms of livebearers, but
there are also a great many cultivated varieties that are very popular. Through
selective breeding their colors and fin shapes have been changed to create some
unusual effects.There is another family of livebearers, Goodeidae, that are less common, but
sometimes kept in the hobby. These fish require refertilization for each brood.
The gestation period is about twice as long as poecilids or 60 days. The females
in this group of fish get huge before a drop (you have to see it to believe it)
and the fry are born very large. Interestlingly enough these fish do provide
nutrition to the developing fry, which is part of the reason they are dropped so
large. They fry are delivered with something like an umbilical cord called a
trophotaenia. For this reason this is very close to being pregnant but.... Since
the trophotaenia only absorbs nutrients from contact rather than being actually
attached to the bloodstream it is still not a pregnancy. We have had our best
success using trios (two females and one male). Males only seem to think of two
things...eating and breeding. When the set-up consists of a low female/high male
ratio the females will have a hard time even trying to eat and seemingly will
never get any rest.
Because the eggs cells of female livebearers are fertilized inside her body, the
male has developed a sexual organ to accomplish internal fertilization. It is a
modified anal fin. Because of differences in appearance, it has different names,
Gonopodium in the livebearing tooth carps and the andropodium in the families
Goodeidae and Hemirhamphidae. The Andropodium is folded when inserted into the
female, while the Gonopodium is flipped forward. The development of the embryos
happens in two different way depending on the species.
The young develop inside eggs inside the mothers body, hatch there, and then are
"born", the Swordtail is an excellent example.
The young develop without an eggshell inside the mother, receiving nourishment
through an umbilical cord, the American Splendens is another excellent example.
An interesting function of mating that occurs with many Livebearing fish is the
ability to drop several batchs of fry from a single mating. Many times a
solitary female will deliver fry for several month. The sperm is delivered in
"packets" to the female and she has the ability to use them as she needs. It is
this ability that makes the early separation of males and females important for
a quality breeding program. Some of the fish become sexual active prior to the
observable color distinctions. Many mongural fish are dropped by fish purchased
in the fish shops...which accounts for the phenomion of orange fish being born
to golden fish parents.
Any experienced aquarist produce fry, whether it be from livebearers or
egglayers, but it is an art of producing good quality fry that the real skill of
the breeder lies.
The question is then is how do we save the whole of the brood each time, and not
just part of it. Most advice suggests a thickly planted tank, so that the fry
can hide from the parents, or alternately suggested breeding traps. Most of us
try to keep breeding traps free from gravel and rooted plants because it is much
easier to service bare tanks, particularly if there are several tanks involved,
also any mulm can be seen on a bare base and can be removed, thereby keeping the
water in better condition and cleaner.
Breeding traps are not as efficient as they are claimed to be, they are usually
much to small and restrictive, and in quite a number of cases result in the
death of a gravid female from one cause or another. So, if a thickly planted
tank is not a complete success (the parents can still chase the fry in the
plants) and breeding traps not satlsfactorv in all cases, what does one do.
Whatever measures are taken they can only be palliative and not a complete
answer, since the fry have to be with the mother when they are born, but we can
make sure that if they can survive long enough to get away they can be protected
from them, until we can remove the mother after the completion of spawning. This
being done as quickly as possible.
Newly born fry are a little similar to brine shrimp in that they usually
progress to the light, so one of the things we can do, is place the tank in such
a position that one end is facing the light. This can be done by placing one end
towards a window or lighting the whole tank and shading part of it. Do not use
to small a tank, a long narrow one would be ideal.
It does not need depth, with livebearers depth is not critical. It is necessary
to make a barrier to keep the parent out whilst the young fry can pass through
If you can knock four panel pins into wood without damaging your thumb, you can
do the next bit easily.
Either 1/2" or 3/4' square wood cut to fit a frame easily into the tank, no
fancy joints are required as there will be no stress, plain butt joints will do
and when assembled cover with some nylon netting. like the grocer receives his
greens in. Fairly fine to prevent the parents from swimming through. nylon
curtain material will do. Partition off a quarter of the tank at the lighted end
for the fry and put In this section some floating plants, nitella, duckweed etc.
Add some fine flake food.
Place a few plants in the other area to keep mother happy and add a bit of
shelter if she tends to be nervous. Above all take her out at the first
opportunity since the fry may be daft enough to stray back into the mothers
section despite the light, food etc. designed to tempt them.
Under these conditions it is possible to rear almost the whole brood of peaceful
livebearers and to save a good number from the most ferocious ones.
How Do I Know When My Female Livebearer is Ready to Give Birth?
Is my livebearer Pregnant?
Please realize that this is not an exact science (much like birth in humans), so
an exact determination is not possible. However with some observation on your
part you will soon be able to tell about how far along your livebearer is.
The most common of the livebearing fish can drop a new group of fry every four
to eight weeks depending on diet, temperature, and other conditions. When the
female is ready to deliver, the gravid spot (a triangular-shaped area just above
and behind the anal fin that turns darker as the delivery date approaches) will
be well developed. Now there are exceptions to the gravid spot rule, X. "nezzy"
being one of them...the males can show what will resemble a gravid spot. Many
livebearers (most of the light bodied swordtails for example...and many of the
goodeids) will show a darkened area whether they are holding fry or not.
We like to keep track of when a female last dropped her fry. If we are dealing
with a species that will be dropping again in about a month, we remove the
female to a maternity tank about a week before she is scheduled to drop again.
Many livebearing fish are canabalistic and if your main tank is a community tank
you will find that most fish consider fry a very tasty snack. We have found that
the easiest and maybe the best drop tank is a 5 gallon or a 10 gallon tank with
lots of cover for the female to feel comfortable and for the fry to hide in when
they are dropped. We like to use Java Moss for the cover, but many fine leafed
plants will work. At times we use yarn mops just as we would for Killifish. We
don't like to use "breeding nets" or "breeding traps" as we have found that they
are too small for most of our fish and seem to stress the fish. Besides, once
the fry are dropped in the 5 or 10 gallon drop tank and the female removed, the
fry can simply be kept in the drop tank for a week or two, giving them an
We have found that most drops are in the early morning hours and may take
several hours. We remove the female to a holding tank as soon as the birthing is
complete. If you leave her in the tank, most females will try to eat the
fry...and if you put her into the tank with the males they will immediately try
to breed. We're not sure if the female needs a break or a rest, but the constant
attention of the males just seems to be well...too much. We give the female
several days to rest and eat without being harrassed.
Not all livebearers are capable of this packet storing function. For the vast
majority of livebeares it does not occur, but the Big Four are all capable of
How do I take care of livebearer fry?
Some general consideration that would apply to most fry also apply to the fry of
Livebearing fishes. All fry are sensitive to being moved from one container to
another for the first few days (or more) of their lives. So it is important that
you plan for the birth and give them a good start.
Feeding the fry is an important consideration. Most fry from Livebearing fishes
will take flake food from their first day (particularly the top feeding
livebearers with up-turned mouths). Frequent feeding is preferred to once a day
feeding. Remember that the fry have small stomachs and feed them appropriately
sized foods. You will find literature that recommends you feed the fry upwards
of 6-8 times per day. While perhaps an ideal frequency, the practical
application of the schedule is very difficult. We find that feeding a couple
times in the morning and a couple more times in the evening with the feeding
spaced perhaps an hour apart will give the fry a pretty healthy amount of food.
Most livebearing fish drop fry that are large enough to eat baby brine shrimp
(which is usually purchased frozen, or can be hatched from brine shrimp eggs) or
microworms from the first day. Also pulverized flake food, which is sold as baby
fish food (you can grind up standard flake foods into a powder to create a food
fine enought to feed) and hardboiled egg yolk strained through a cloth. We have
had fantastic growth when combining the live foods with a balanced diet, as
compared to the prepared foods alone. We understand the extra effort that caring
for and harvesting the live food presents to most hobbyists. However, we also
know just how easy microworms in particular are...you should think about it.
Don't over look the importance of regular water changes. For all of the same
reasons that you need to change the water in the tanks of the adults...the
changes in the fry tanks is equally important. Even to the casual observer, the
growth of fry in the first weeks of their lives is enhanced if water is changed
on a frequent basis. We change 50% of the water every day, siphoning ditritus
from the bottom of the tank.
We like to use mature sponge filters in each of the fry containers. Not only
will the sponge provide media for the bacteria to live within, but the sponge
will probably house a healthy colony of rotifers and other infusoria...both
excellent food for the young fish.
When the fish are large enough not to be consumed by their parents you can
probably add them to the tank with the parents. However, not all Livebearers are
peaceful. Some are downright mean to any fish smaller than themselves...Gambusia
coming quickly to mind...so use some common sense and draw on the research you
have done on the particular fish you are working with to determine when to add
the fish back into the tank with the parents.
If you are going to be involving yourself with a serious breeding operation with
guppies you will need to have several tanks. Not because of the volume of fry,
but more to separate males and females and young from the breeders.
A good forum is