Fish Spawn

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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