1. FreshwaterFreshwater
Aquarium fishAquarium fish
BreedingBreedingSameer G ChebbiSameer G Chebbi
Dept. of ZoologyDept. of Zoology
Industrial fish and fisheriesIndustrial fish and fisheries
Karnatak Science College, DharwadKarnatak Science College, Dharwad

3.  Breeding aquarium fishes requires a goodBreeding aquarium fishes requires a good
amount of care and patience.amount of care and patience.
 There is a remarkable difference in theThere is a remarkable difference in the
techniques involved in breeding the eggtechniques involved in breeding the egg
layers and live bearers.layers and live bearers.

5.  Breeding fish in the aquarium comprisesBreeding fish in the aquarium comprises
of the following stepsof the following steps
1.1. Setting up of spawning tankSetting up of spawning tank
2.2. Selection of spawnersSelection of spawners
3.3. Conditioning the brood fishesConditioning the brood fishes
4.4. SpawningSpawning
5.5. Rearing the fryRearing the fry

7. 1.1. Setting up of spawning tankSetting up of spawning tank
 Each fish has its own specificationsEach fish has its own specifications
regarding physio-chemical andregarding physio-chemical and
environmental factors related toenvironmental factors related to
spawning.spawning.
 In the spawning tank always try toIn the spawning tank always try to
provide an environment similar to one inprovide an environment similar to one in
its natural habitat.its natural habitat.

9.  Care must be taken to control theCare must be taken to control the
followingfollowing
1.1. TemperatureTemperature
2.2. pHpH
3.3. HardnessHardness
4.4. Water column levelsWater column levels
 According to the requirement ofAccording to the requirement of
individual fish.individual fish.
 Unless proper care is taken, the eggs orUnless proper care is taken, the eggs or
the fry have very little chance ofthe fry have very little chance of
surviving.surviving.

11.  Spawning grids or traps may be used inSpawning grids or traps may be used in
the breeding tank in order to save thethe breeding tank in order to save the
eggs from being eaten by the parents.eggs from being eaten by the parents.
 The place where the aquarium is kept isThe place where the aquarium is kept is
also important since some fishes like thealso important since some fishes like the
Dwarf Gourami need sunlight, while otherDwarf Gourami need sunlight, while other
like the Neon or Cardinal Tetras prefers alike the Neon or Cardinal Tetras prefers a
dark aquarium.dark aquarium.
 Even the development of the embroys ofEven the development of the embroys of
Neon and Cardinal tetras are affected byNeon and Cardinal tetras are affected by
harsh sunlight.harsh sunlight.

13.  But, the general rule is to cut down theBut, the general rule is to cut down the
illumination to its minimum in case theillumination to its minimum in case the
breeding fish is an egg eater.breeding fish is an egg eater.
 Temperature also plays a very importantTemperature also plays a very important
role in spawning.role in spawning.
 A few degrees rise or fall in temp. mayA few degrees rise or fall in temp. may
change a listless (lethargic) fish into achange a listless (lethargic) fish into a
glowing one anxious (nervous) to breed.glowing one anxious (nervous) to breed.
 Most of the Tetras prefer soft acidic waterMost of the Tetras prefer soft acidic water
while the live bearers are totally thewhile the live bearers are totally the
opposite, preferring hard alkaline water.opposite, preferring hard alkaline water.

14.  The choice of the breeding tank is alsoThe choice of the breeding tank is also
very important.very important.
 Even if the fish is small and requires veryEven if the fish is small and requires very
little space, the rule is to use as large anlittle space, the rule is to use as large an
aquarium as possible for the breedingaquarium as possible for the breeding
purposes.purposes.
 In a large tank, fluctuation or variation inIn a large tank, fluctuation or variation in
temp. caused by the heater is lesstemp. caused by the heater is less
affected than in a small tankaffected than in a small tank
 The aquarium may be thickly planted inThe aquarium may be thickly planted in
order to prevent the fish from exploring fororder to prevent the fish from exploring for
eggs after spawning is over.eggs after spawning is over.

15.  Selection of spawnersSelection of spawners
 The next step regarding spawning ofThe next step regarding spawning of
aquarium fishes is the selection ofaquarium fishes is the selection of
spawners.spawners.
 Always select fishes that are healthy,Always select fishes that are healthy,
having the required/desired qualities orhaving the required/desired qualities or
those equalling standards.those equalling standards.
 Similar eliminate diseased fishes andSimilar eliminate diseased fishes and
those with visible anatomical or geneticthose with visible anatomical or genetic
deformities like tumours, deformed spinaldeformities like tumours, deformed spinal
cord etc.,cord etc.,
 To get best results, employ selectiveTo get best results, employ selective
breeding.breeding.

16.  Select spawners from different sources toSelect spawners from different sources to
minimise in breeding.minimise in breeding.
 In the case of live-bearers, the only way toIn the case of live-bearers, the only way to
avoid inbreeding is to separate the malesavoid inbreeding is to separate the males
from females, once the sex could befrom females, once the sex could be
distinguished.distinguished.

17.  Conditioning the brood fishesConditioning the brood fishes
 Most of the spawners have to beMost of the spawners have to be
conditioned before spawning.conditioned before spawning.
 The male and female fishes are rearedThe male and female fishes are reared
separately for one or two weeks.separately for one or two weeks.
 During this period, the fish are fed on liveDuring this period, the fish are fed on live
food available in its natural environment.food available in its natural environment.
 Fishes like the barbs and tetras areFishes like the barbs and tetras are
usually conditioned on a diet of live foodusually conditioned on a diet of live food
like mosquito larvae, tubifex worms etc.like mosquito larvae, tubifex worms etc.

18.  Some aquarists often provide a menu withSome aquarists often provide a menu with
varying diets of live food each day.varying diets of live food each day.
 Not all egg layers are to be conditionedNot all egg layers are to be conditioned
separately.separately.
 Some fishes like the Angel and OscarSome fishes like the Angel and Oscar
need to be kept together in a shoal or pairneed to be kept together in a shoal or pair
for a long time before breeding takesfor a long time before breeding takes
place.place.
 In such cases the school may be fed on aIn such cases the school may be fed on a
varying diet of live foodvarying diet of live food

19.  They are not to be separated once theyThey are not to be separated once they
pair up for spawning.pair up for spawning.
 Considering live-bearers, conditioning isConsidering live-bearers, conditioning is
not always necessary.not always necessary.
 Hence before breeding fishes should beHence before breeding fishes should be
conditioning is required for better result.conditioning is required for better result.
 Conditioning of fishes helps in success inConditioning of fishes helps in success in
breeding activity.breeding activity.
 Different fishes having differentDifferent fishes having different
conditioning factor which is based on theirconditioning factor which is based on their
breeding behaviour.breeding behaviour.

20.  SpawningSpawning
 The conditioned fishes are usuallyThe conditioned fishes are usually
released into the breeding tank at duskreleased into the breeding tank at dusk
(evening).(evening).
 In some cases, the females are releasedIn some cases, the females are released
atleast a day or two prior to the release ofatleast a day or two prior to the release of
the male.the male.
 This is to familiarise the female with theThis is to familiarise the female with the
aquarium conditions and to minimise fear.aquarium conditions and to minimise fear.

21.  Fishes are to be released in a school or inFishes are to be released in a school or in
pairs, depending on their spawningpairs, depending on their spawning
behaviour.behaviour.
 Fishes like the Danios are to be releasedFishes like the Danios are to be released
in schools with larger number of males.in schools with larger number of males.

22.  Rearing of fryRearing of fry
 Rearing the fry is the most difficult part.Rearing the fry is the most difficult part.
 If the eggs and fry are not given properIf the eggs and fry are not given proper
care, all your effort will be in vain.care, all your effort will be in vain.
 The eggs are to be tendered properlyThe eggs are to be tendered properly
preventing them from fungal attack.preventing them from fungal attack.
 A few drops of methylene blue into theA few drops of methylene blue into the
tank will minimise the fungal attack.tank will minimise the fungal attack.

23.  The eggs infected further fungal attack.The eggs infected further fungal attack.
 There is nothing more difficult than findingThere is nothing more difficult than finding
the right food for the new born fishes.the right food for the new born fishes.
 The dietary requirement of the fries ofThe dietary requirement of the fries of
different aquarium fishes are given withdifferent aquarium fishes are given with
different live food and artificial food.different live food and artificial food.

24.  Breeding techniques and devices involvedBreeding techniques and devices involved
in breeding differ according to spawningin breeding differ according to spawning
behaviour of the fish.behaviour of the fish.
 The spawning behaviour differ with eachThe spawning behaviour differ with each
family.family.
 Variation also present among members ofVariation also present among members of
the same family.the same family.
 The egg layers can be classified intoThe egg layers can be classified into
different categories depending upon theirdifferent categories depending upon their
breeding habits.breeding habits.

25. 1.1. Egg scattersEgg scatters
2.2. Egg depositorsEgg depositors
3.3. Mouth broodersMouth brooders
4.4. Bubble net buildersBubble net builders
5.5. Live bearsLive bears
 Egg scattersEgg scatters
 Examples: Danios, gold fish, hatchetExamples: Danios, gold fish, hatchet
fish,fish,
Glass fish, kissing gourami, tetras, flyingGlass fish, kissing gourami, tetras, flying
barb, barb etc.,barb, barb etc.,

26.  The egg scatters release eggs in aThe egg scatters release eggs in a
haphazard manner, scattering the eggs inhaphazard manner, scattering the eggs in
all directions.all directions.
 Once the spawning is over, they oftenOnce the spawning is over, they often
consume the eggs.consume the eggs.
 The eggs scatterers show no parentalThe eggs scatterers show no parental
care.care.
 Hence it is the job of the aquarist toHence it is the job of the aquarist to
protect the eggs from being eaten by theprotect the eggs from being eaten by the
parents.parents.

27.  A thickly planted aquarium with lessA thickly planted aquarium with less
swimming space may e used for eggsswimming space may e used for eggs
which are adhesive in nature. (eg. Eggs ofwhich are adhesive in nature. (eg. Eggs of
gold fish).gold fish).
 This often helps the eggs from beingThis often helps the eggs from being
eaten.eaten.
 In the case of non-adhesive eggs (eg.In the case of non-adhesive eggs (eg.
Eggs of danios), an aquarium with lowEggs of danios), an aquarium with low
water column and a bottom laid withwater column and a bottom laid with
ebbles or marbles may be used.ebbles or marbles may be used.

28.  The eggs scatters usually show lessThe eggs scatters usually show less
interest in the eggs while the spawning isinterest in the eggs while the spawning is
in progress.in progress.
 They start feeding on eggs only afterThey start feeding on eggs only after
spawning is over.spawning is over.
 Breeding traps and grids may be installedBreeding traps and grids may be installed
for better survival rate of the eggs.for better survival rate of the eggs.
 For eggs scatters, spawning grids are toFor eggs scatters, spawning grids are to
be placed with mesh size relative to thebe placed with mesh size relative to the
size of the eggs.size of the eggs.

29.  Usually mesh size of 3x3 mm to 6x6 mmUsually mesh size of 3x3 mm to 6x6 mm
are used.are used.
 The grids can be constructed in two ways.The grids can be constructed in two ways.
 A net with required mesh size may beA net with required mesh size may be
attached to the upper side of a 5 cm thickattached to the upper side of a 5 cm thick
plastic frame with frame sizeplastic frame with frame size
corresponding to the inner dimensions ofcorresponding to the inner dimensions of
the aquarium.the aquarium.
 The frame should be lowered to theThe frame should be lowered to the
bottom of the tank so that a water columnbottom of the tank so that a water column
of 5 cm exists between the net and theof 5 cm exists between the net and the
bottom of the tank.bottom of the tank.

30.  Precaution must be taken not to leavePrecaution must be taken not to leave
space between the sides of the tank andspace between the sides of the tank and
the plastic frame, for the fish to enter.the plastic frame, for the fish to enter.
 Another method is to place a piece of netAnother method is to place a piece of net
with required mesh size across thewith required mesh size across the
aquarium with the central portionaquarium with the central portion
immersed below the surface providingimmersed below the surface providing
sufficient swimming space.sufficient swimming space.
 Care must taken not to provide escapeCare must taken not to provide escape
routes while placing the net.routes while placing the net.
 In both cases, the eggs fall through the netIn both cases, the eggs fall through the net
and are collected at the bottom of theand are collected at the bottom of the

33.  Egg DepositorsEgg Depositors
 Ex: Cichlids like Discus and Angle fish,Ex: Cichlids like Discus and Angle fish,
Firemouth cichlid, Oscar cichlid etc.,Firemouth cichlid, Oscar cichlid etc.,
 The egg depositor are more for theirThe egg depositor are more for their
young than egg-hangers or scatters.young than egg-hangers or scatters.
 These are mostly cichlids when showThese are mostly cichlids when show
parental care.parental care.
 They need substratum like leaves, rocks,They need substratum like leaves, rocks,
flower pots, tiles or slates to deposti theflower pots, tiles or slates to deposti the
eggs.eggs.

34.  Hence the spawning tank should containHence the spawning tank should contain
hard substratum like rocks, slanting slatehard substratum like rocks, slanting slate
or tiles etc., which can be easily removed.or tiles etc., which can be easily removed.
 Most of the depositors select their ownMost of the depositors select their own
pair/ mate.pair/ mate.
 It is be to remove the fry once theyIt is be to remove the fry once they
become free swimming, even though thebecome free swimming, even though the
fish show parental care.fish show parental care.
 The tank should be similar waterThe tank should be similar water
conditions and the water column very lowconditions and the water column very low
(5-10 cm).(5-10 cm).

35.  If the fish fail to show parental care,If the fish fail to show parental care,
remove the eggs along with substratum toremove the eggs along with substratum to
another tank.another tank.
 If the eggs are attached to the sides of theIf the eggs are attached to the sides of the
tank, remove they by scarping the sidetank, remove they by scarping the side
panes or by means a fine brush andpanes or by means a fine brush and
transferring the eggs to tank treated withtransferring the eggs to tank treated with
methylene blue.methylene blue.
 The eggs are to be give profuse aeration.The eggs are to be give profuse aeration.

36.  Mouth BroodersMouth Brooders
 Ex:Ex: TilapiaTilapia
 Some of the egg depositor take theSome of the egg depositor take the
fertilized eggs into their mouth andfertilized eggs into their mouth and
incubate them.incubate them.
 These mouth brooders usually prepareThese mouth brooders usually prepare
breeding pits on the bottom sand on whichbreeding pits on the bottom sand on which
spawning take place.spawning take place.
 Hence the aquarium bottom should beHence the aquarium bottom should be
made of sand or fine gravel.made of sand or fine gravel.

37.  In the case of tilapias, the female carriesIn the case of tilapias, the female carries
eggs in her mouth.eggs in her mouth.
 The eggs hatch inside the mouth and theThe eggs hatch inside the mouth and the
parent carry the fry also for some time.parent carry the fry also for some time.
 Some of the mouth brooders tend to gulpSome of the mouth brooders tend to gulp
the eggs.the eggs.
 This may be due to numerous factor likeThis may be due to numerous factor like
young and inexperienced spawners,young and inexperienced spawners,
insufficient space or unfavorableinsufficient space or unfavorable
conditions.conditions.

38.  This can be prevented by trapping theThis can be prevented by trapping the
female in a fine net without disturbing thefemale in a fine net without disturbing the
fish much.fish much.
 Then the fish is to be held in hand with theThen the fish is to be held in hand with the
head immersed in a small bowl.head immersed in a small bowl.
 Slowly open the mouth by applyingSlowly open the mouth by applying
pressure on to the lower jaw with indexpressure on to the lower jaw with index
finger.finger.
 Then shake the fish gently in water, soonThen shake the fish gently in water, soon
egg/ fry are released into the water.egg/ fry are released into the water.
 Then these eggs/fry transferred to newThen these eggs/fry transferred to new
rearing aquarium and given profuserearing aquarium and given profuse
aeration.aeration.