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DIFFERENT WAYS FISH SPAWN
By Michael
Baumann
All you wanted to know about tropical fish breeding. There are a few
different types of breeding. First we have the egg layer, who will pick a
spawning site whether in a cave or on a rock or some sort of substrate. (Eg:
slate, tile terra-cotta pots etc.) The pair will clean the substrate by
mouthing it until it is clean from debris, sometimes the male will do most
of the cleaning to entice the female. Now that the site is clean the
female will pass over the substrate a few times but not lay any eggs, this
is called dry runs, if she is not happy with the site she will clean some
more.
Once she is happy with the site a couple more dry runs, then a pass
over the spawning site with the spawning tube just touching the substrate
and depositing a row of eggs, up to twenty on every pass. The male will be
close behind fertilising the rows in the same manner as the female, by
passing over the eggs with his tube just touching the eggs. The female's
tube is larger than the male's, fairly round and flat at the bottom, where
the male's tube tapers to a point. Now all the eggs have been laid and
fertilised, the next step is the pair takes turns in fanning the eggs to
stop debris falling on them. Some pairs will even pick out the infertile
eggs to stop fungus from attacking the good ones.
Usually eggs will take around fifty hours for Discus, Angels and some
small cichlids. Where larger cichlids can take four to five days to hatch,
depending on the temperature of the water.
The Gouramis and Fighters twenty-four to thirty six hours to hatch, the
Killi-fish, anything up to three months. Once hatched the young are called
fry, Angels and Discus fry stick to the substrate with suction cups on
their head until they have eaten their egg sacks, which is around three to
four days.
Once the egg sack is gone the young release themselves from the
substrate and start to free swim. The fry at first will swim close to the
bottom then rise to the surface; this is when to commence the feeding
program. Small micro foods crushed flake foods and newly hatched brine
shrimp. (Discus do not have to be fed until the fourth to fifth day as
they will not take food, they start to free swim and then graze on the
parents skin, they eat a mucus on the skin of the parents which they
produce for feeding young.) Other cichlids when the eggs start to hatch,
the parents will move the hatchlings to another spot. If there is
substrate on the tank floor some cichlids dig a pit and drop the fry into
it, as they take a few days to free swim. The parents might move the fry
two or more times a day until they free swim. Once free swimming the
parents try to control them in a tight bunch. Feed the same as Angels.
The next is the bubble nest builder like the Siamese fighting fish and
the Gouramis; there is a cat fish that builds a bubble nest as well called
the Hoplo. With these types of fish the male takes care of building the
nest by gulping air from the surface and mixing it with saliva then blows
bubbles amongst floating weeds.
Once he has finished his nest, he tries to coax the female to his nest,
if the female is ready she will nudge the male in the side and the male
will embrace her, as he raps his body round the female. She lays approx.
twenty eggs at a time while the male fertilises them at the same time;
they slowly fall to the tank floor. The female will lay motionless after
the embrace, which gives the male enough time to pick the eggs up in his
mouth and deposit them under the bubble nest, then embrace her again and
again until she has laid around two hundred and fifty eggs for the Siamese
fighting fish and up to one thousand eggs for the Gouramis. When she has
finished she will hide from the male, for sometimes the males get fairly
rough and actually kill the female.
It is best to remove the female after spawning. The male will look
after the eggs and fry when they hatch while tending to the bubble nest,
repairing it as it breaks up. The eggs take around twenty four hours to
hatch and the fry hang with their heads facing the sky, if they fall the
male will pick them up and spit them back into the nest. The young take
approx. three days to free swim and this is the time you can take the male
out and start to feed the fry. (Micro foods, liquid fry and brine shrimp
to name a few).
Next is the larvophile mouth-brooder, this is a fish that spawns on a
flat rock or similar, they guard the eggs for a couple of days then pick
them up in their mouth. Sometimes the eggs are already starting to hatch
before they pick them up. Both parents will keep the young in their mouths
and release them when ready. Example of a larvophile is the Geophagus
Surinamensis
Next is Fish that release their eggs as they swim through or over
plants. The native rainbow fish releases her eggs that have a fine thread
attached, the thread will cling to weed or plant as it floats in the
current of a stream. Tetras, Danios, Barbs, to name a few also scatter
their eggs, none of these fish tend to the eggs or fry.
Next the live bearer, Swords, Mollies, Guppies, Platies and Halfbeaks
are all live bearing fish. If intending to breed these fish, most
newcomers to the tropical fish scene start with at least a couple of this
variety, with plenty of plant cover for the young as the parents and other
fish in the tank will eat the fry when born.
Next we have the mouth brooder; this is a fish that spawns on the
bottom of the tank near some shelter. (Rocks or cave or even a pit), then
the female will pick the eggs up into her mouth, while the male sprays
milt just in front of her mouth (as she takes the eggs into her mouth.)
The eggs are incubated in the mouth and when the fry are of age she will
release the young, which is around six weeks. With most cichlids the males
pick a territory in a tank, then entice a female that is full of roe to
spawn.
All mouth brooders have their own way of displaying, some lock jaws and
look like they are kissing, others, the male races up to the female
quivering and shimming then race down to where he wants the female to
spawn. If the female is interested in his display she will follow him and
they will spawn. The female drops two to three eggs at a time, as she
picks them up the male is in front of her with his anal fin close to her
mouth.
The anal fin on the male has false egg spots on it to make the female
think these are more eggs to pick up, and while she persists to take these
false eggs the male is releasing sperm which fertilises the eggs the
female has in her mouth.
Some cichlids only have a few young that they release and others can
have several hundred, it all depends on the type of cichlids in question.
All of the mouth brooders that we breed, the eggs are taken from the
female usually on the fourth day, this is when the head and tail is out of
the egg. This method is called spitting the female. To do this, you are
guaranteed a higher yield, as the male and other tank mates, which can
cause the female to eat the eggs or the fry in her mouth, will hound the
female. The way to breed cichlids is in colonies and the amount of fish in
a colony depends on the species, usually one male to three females will do
if you only want small colonies. This is for the African cichlids; some of
our colonies are in large tanks and as many as two or three males and
fifteen to twenty females.
I hope this information will help not just the beginner but all that
are interested in fish keeping and breeding. All information in this
breeding section is a guide and helpful hints.
The difference between this article and many of the other books
available on breeding fish is that the information in this article is
'straight from the horse's mouth'. In this chapter you won't find
information on how to breed every fish that's ever been bred. That's
because I haven't bred every fish there is to breed. What you will find is
specific, tried and true information on how to breed and rear the many
species that I have bred over the last thirty years.
Livebearers (Family; Poeciliidae)
What better place to start than with the trusty livebearers. Like many
avid fish breeders my interest in breeding fish stemmed from these little
beauties. I started breeding guppies and since then have bred nearly all
of the varieties of livebearers including mollies, platies and swords.
Livebearers have a wide natural range, The Swords, Platies and Mollies
natural habitat is Mexico and the humble little guppy is found in Central
America. They prefer very hard or brackish water, which can be
accomplished in an aquarium by the addition of salt (to create a brackish
environment) or coral rubble or limestone (to increase hardness). When
using salt I add about 3 teaspoons to a standard two foot tank and if
increasing hardness just a few handfuls of coral rubble will increase the
hardness and the pH to keep these fish in good condition. If the water is
very soft like it is here in Townsville Qld. You can purchase straight
from the pet stores a buffer that has all the natural salts you need to
make the water the pH and hardness that is desired for the fish you intend
to keep.
Sexing these fish couldn't be easier. Males have a modified anal fin,
known as a gonopodium, which acts as the sex organ for fertilisation. In
addition many varieties have other physical differences distinguishing the
two sexes.For example, male guppies have the famous fancy tail and male
swordtails have an extension at the base of the caudal fin from which they
derive their name.
The reproductive strategy of giving birth to live young is quite
unusual in fish and it has some advantages and disadvantages to the
aquarist. The disadvantage is that not many young are produced at a time
(generally 40-80), although their prolific nature means you should never
be short of fry. The real advantage of this breeding strategy is that the
young are very well developed and quite large when they emerge, which
makes them very easy to feed. Another advantage is that the female can
have up to six batches of fry from one fertilisation. Another benefit of
the livebearers is that they will tolerate a wide range in temperatures
and can therefore be grown in outdoor ponds in many parts of Australia.
Their temperature tolerance range is approximately 18OC to 30OC.
My set-up for breeding livebearers consisted of two 3 foot tanks for
breeding and another four 2 foot tanks for growing the young. I used tap
water (with chlorine neutraliser added) which ranged in pH from 7.5 to
9.0. The hardness was around 8 DH and a heater maintained the water
temperature at about 28C. If your tap water is soft I recommend you add a
few handfuls of coral rubble or some pieces of limestone which will
increase the pH and the hardness of your water.
Livebearers really are very easy to breed and it doesn't take a great
deal of effort on the aquarist's behalf to get them going. Some varieties
are, however, more difficult to breed than others, such as the sail-fin
mollies. Most of these have still born young. The black mollies can be
converted to a salt water aquarium and still be happy. If your breeders
are in good condition and well fed, the elaborate courtship behaviour and
mating should be an ongoing event in the breeding tank. I bred the guppies
and mollies in separate tanks as this made it easier to separate the fry
for growing. All the fish that I have bred, have been bred on their own no
other species were in the tank. In the guppy tank I would house a dozen
good quality males with twenty to thirty females. Molly tank had twenty
ripe females and six good males. They were fed on a variety of foods
including flake food and live food such as brine shrimp and mosquito
larvae.
A 'pregnant' female is very easy to spot, as they are very rotund and
have a characteristic black spot, or gravid spot, at the posterior end of
the gut. Gestation period is around 4 weeks for guppies and between three
and five weeks for mollies, swords and platies. Once hatching time
approaches, adequate cover for the emerging fry must be provided, as the
parents are renowned for their cannibalistic fetish for their offspring.
In my breeding tanks I used Javier moss and water sprite as cover for the
young. This combination provided excellent cover throughout the tank, as
the Java moss sinks and the water sprite floats.
As soon as I noticed the fry, I would net them out and place them in
the two-foot tanks to grow. I fed the young to saleable size within 8 to
12 weeks on a diet of quality flake food, blended to the required size.
There are breeding traps on the market, which can be used for
separating the fry from the hungry parents, however, I have never used
one. I think if you have enough cover in the tank, this should be
adequate. Breeding traps are fun for the kids with a new tank and a couple
of Livebearers, however, they are not very practical if you are trying to
produce a large number of fish.
I no longer breed Livebearers but I used to produce enough to supply
all the shops in my local area. Once I began producing fish for the
wholesale market I found the wholesalers wouldn't pay enough for the
Livebearers to make it worthwhile.
Cichlids (Family; Cichlidae)
The cichlids are a diverse group with a wide geographical range, many
different breeding strategies and water requirements and many different
shapes, sizes and temperaments. Cichlids are found in many places
throughout the world including Africa, South Asia, Mexico and Central and
South America.
The water requirements of the cichlids are very diverse and cover the
entire range of water chemistry parameters in which fresh water fish are
found. For example, discus are found in very soft water with a pH as low
as 4, whereas the African cichlids thrive in very hard water with a pH as
high as 9.
All cichlids are egg layers and provide some degree of parental care;
however, there are a number of different reproductive strategies within
the family. For example most American cichlids are open or sheltered
breeders whereas the majority of African cichlids are mouthbrooders and
only a few are sheltered or open breeders.
American Open and Sheltered Breeders
Most American cichlids lay their eggs on some type of substrate and
provide a high degree of parental care. Despite the many different types
of egg laying cichlids, their basic reproductive strategy is very similar.
General description of courtship with most American cichlids is, a male
will pick a spawning site. Try to coax any suspecting female to the site
by making dashing moves toward her while quivering his body alongside her,
if the female is interested in the display she will follow him to the site
and inspect it. After this it isn't long before the female starts to clean
the site and they spawn. When it comes to pairing it all depends on the
species of fish, some will pair for life, some spawn with one and ten
minutes after are spawning with another fish and another.
The first job for the pair is to find a suitable spawning substrate.
Open breeders lay their eggs on a flat rock, plant leaf, on the bottom or
sides of the tank or any other suitable surface you provide for them. As
the name suggests, sheltered or cave breeders lay in a cave or other
sheltered site such as a plant pot.
Once a site has been selected or provided the pair will remove any
debris with their mouths. Sometimes the male will do most of the cleaning
as part of his courtship behaviour (all us fellas know we can get into the
good books if we do a bit of housework!). At this point you should also
notice the sex organs protruding from the fishes bodies. The female
spawning tube, or ovipositor, is larger than the males and fairly round
and flat at the bottom. The male's sperm duct is a smaller tube, which
tapers to a point. Once the site is clean the female will do a few 'dry
runs', passing over the substrate without laying any eggs - just to make
sure it is clean enough.
Once satisfied she will pass over the site with her spawning tube, or
ovipositor, just touching the substrate whilst depositing a row of eggs.
The male should be close behind fertilising each row as it is laid. When
all the eggs have been laid and fertilised the pair takes turns in fanning
the eggs to stop any debris settling on them and to keep them well
oxygenated. Some fish will also pick out any infertile eggs to stop fungus
from spreading to the good eggs. For angels, discus and most small
cichlids the eggs hatch in approximately fifty hours. On the other hand,
the eggs of larger cichlids can take up to four or five days to hatch.
When the eggs hatch the parents usually move them to another part of the
tank. (Maybe this is instinct from the wild as a safety precaution for the
survival of the fry.) They wriggle as a large mass for approximately three
to four more days until their yolk sac is absorbed. Once absorbed they
become free swimming.
Some species or individual parents might move the fry two or more times
a day until they free swim. At this point feeding commences and
All-American cichlids will take newly hatched brine shrimp from day one of
free swimming. The first food for all of the American cichlids I breed
(with the exception of the Discus) are newly hatched brine shrimp Artemia.
After 2 days I generally begin introducing flake food blended to a
suitable size, then placed in an airtight container to keep dry. By day 10
I begin to phase out the brine shrimp and by 3 weeks most species will be
able to take my specially prepared food. I am able to get most species to
sellable size by 8 weeks of age. Discuses are 12 to 14 weeks.
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