Cyprinodontiformes vivíparos e ovovivíparos

Livebearer Cyprinodontiformes

Aquariofilia > Reprodução em cativeiro

Aquaristics > Livebearer Cyprinodontiformes captivity breeding

















Livebearer Cyprinodontiformes captivity breeding


How can we carry out a process to encouraging reproduction ?

Where and how to arrange a suitable setting for these species to breed ?

After delivery, what’s next ?


Unfortunately, a common evaluation for the success of most aquarium keepers is still the reproduction of their captive fish species.

Ovuliparous and oviparous fish are considered more challenging ones, due to some species posture highly demanding conditions as well as by means of their minuscule descendents, quite more difficult to rise. By this reason, many hobbyists perform the first steps with most popular ovoviviparous species available in the market.

This situation lead to a panorama in which the majority of fish lovers don’t pose the question of going further with ovoviviparous, as these fish are considered a too rudimentary challenge, according to this point of view. Fallowing the same way of deal with this issue, livebearers stand only as the beginners ideal livestock, an in rather irrelevant rank for nearly everyone and not only for the determined minds.

In general, one of the greatest ambitions is to accomplish a tropical coral reef sea aquarium, but when confronted with the real needs of such task, many start to look for something different as “ colourful “ as possible, but less expensive and a lot easy to maintain. To carry out such aspiration, new comers that don’t have yet basic principles regarding the sustainable aquarium keeping, put together, in the same tank, freshwater multi-coloured bright species from rather different environments.

If one can triumph over initial difficulties and hypothetical failure, the next step can lead to another level. In fact, after the typical significant stage of initial complications, there is a great chance that this relation can grow up in to a long “ happy marriage “ with the hobby. By than usually a particular family of fishes or a precise ecosystem can catch our attention and passion, so many persons on this point sacrifice for good the idea of a tropical coral reef sea aquarium.

Even so, after attain a substantial practice and a fairly strong liaison to the hobby, only a very small number of persons give up from the illogical idea that ovoviviparous fish are all trivial as well as easy species, satisfactory just for the beginners.

To understand and realize that rearing some livebearers is as exigent as any other difficult to rise and reproduce fish categories, is something only endorsed to a small privileged group of people.

It becomes impossible to ignore and we can’t refute that these Cyprinodontiformes, during their evolution process, have arrive at a reproductive practice which allowed many of these remarkable species to triumph over ecological niches and even environments on which, otherwise, they couldn’t have make it if breeding on a different way.

Even so, besides this strict way of reproduction, on average available domestic strains are definitely easy to breed. After a long term in captivity, at the present they have acclimatize themselves to less demanding ecological requirements, becoming this way extremely prolific and suitable for someone with no practice in fish keeping.

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How can we carry out a process to encouraging reproduction ?

Conditioning is the key word and fundamental rule.

Any fish specie, no matter the reproduction strategy or biology, needs to be in shape and induced to breed in captivity.

The conditioning concept, in this particular case, must be seen as the roll of measures as well as the environmental conditions created with the main intention of persuade or allow fish to have descendents.

On the livebearer Cyprinodontiformes huge number of species we must consider two distinct groups in terms of reproductive cycle.

The first big division can be complete by all seasonal breeders or, by different words, those viviparous and ovoviviparous species that only deliver babyish in a specific period of the year or according some precise environmental conditions taking place now and than in the wild.

Seasonality can be, more often than not, an effect of climate circumstances, but food profusion cycles as well as foodstuff class variations within the year or fallowing special events can also pay an important role on these species reproduction routine. Also the influence of hydrological variation can also pressure them in to breeding periods.

On the other segment we will classify all the other species. These produce offspring continuously or at least that don’t interrupt deliveries unless special circumstances happened.

In both groups, some details like water temperature, nourishment amount and quality, and the relation of these with fish breeding, are quite easy to understand but other are not as accessible. Along with the primary demands there are other smooth influences, including some very reasonable as the water chemical property, but some unfamiliar incentives too, generally associated with stimuli not very well studied. The atmospheric pressure influence, the moon phases, the rain effect, the lighting intensity consequence, the day and night cycle, among other more complex to understand ( but specially not easy to simulate in captivity ), are still not quite considered.

Above all it becomes easier to say than to realize in terms of the different relations as well as the proper combinations between all these factors to produce the expected results.

Unfortunately, after so many years of contact with some of these species, we can say that it is only safe to evaluate with some awareness the basic environmental needs for the most popular domestic strains.

Almost all livebearer Cyprinodontiformes are quite prolific fish due to their sophisticated reproductive strategy, which allowed them to be relatively unaffected by habitat surroundings. Even so, although manifest a more effective way of reproduction, there are always a few imperative basic needs common to other species to take in consideration on captivity.

To improve success, or simply to achieve some results at all, ( specially with wild animals or less prolific species ), you must consider the fallow aspects :

a) One of the most significant decisions to accomplish success with the livebearer Cyprinodontiformes breeding is to select healthy youthful breeders, ( as near as possible of the best fertility age ).

Especially concerning those species of continuous procreation season as well as those with short longevity, the use of younger females will guarantee that they can uphold more offspring each time. On the other hand, these mothers will assure lower rates of unsuccessful conception or complications during gestation period as well on deliver work.

Younger males also present several advantages. Their reproductive cells tender to be more viable and mating vigour are also evident when compared with older males.

During numerous generations under artificial selection, some domestic strains males have attained long fins that don’t allow them to swim in the most excellent conditions and sometimes, in extreme examples, let them out of mating as well as from regular female insemination. Industrial breeders keep these forms throughout artificial fertilization, using inaccessible methods to common hobbyists.

One other standard method in large farms is the use of only youngster males for breeding purpose, specifically on more exotic domestic strains. In most cases only older full developed males get full secondary sexual dimorphism ( like long fins ). After a few weeks following sexual maturity these poor fishes are not anymore successful breeders because they become too sluggish and mating is disturbed by physical developments induced by human selection.

Unfortunately some of the males found in pet shops are not anymore what we can consider young males ( in the best condition to breed ), so after carry out their best performance at the original farm. Even so, these males are not sold at the best price and consumers pay the same as if they were juvenile.

As important as youth on breeder’s selection is their general health.

Some hilliness symptoms are unknown to hobbyists and sometimes, after a very well prepared conditioning period, nonetheless fish don’t breed because their wellbeing and vigour are not the suitable for it.

Some syndromes like stress are quite often ignored or unfamiliar to hobbyists but their consequences are simply so significant that they can collapse any attempt of fish reproduction. On the other hand, anxiety, tension and hassle can have dramatic effects on gestation and deliver.

Some less damaging pathologies can in fact allow fish to keep breeding however, as result, the number of deliveries is quite fewer and the newborn are weaker. Another prospect of conception in the presence of certain infirmity is complications during gestation or delivery.

b) Environmental circumstances are also extremely significant.

Even to descendents from long term captive animals, conditioning process should never reduce importance of best water parameters according with the demands of their biology.

Parametric best values can reveal to be hard to achieve for most hobbyists. Usually the majority just have access to drinking water supply from the domestic distribution system. Unfortunately barely by atypical coincidence the local standards will be near to the original biotope of our fish in some ways.

Besides that, water has unique physical properties, so modify them requires some know-how that can be difficult to achieve for some livebearer enthusiasts.

Domestic water supply presents also a few risks to live aquatic animals. In fact, to become drinkable, or at least for domestic consumption purpose, some chemistry must be added by the companies in order to eliminate hypothetical dangerous agents to human wellbeing. Furthermore, during all the way from the collection point right to our houses, many piping systems can add metal remnants and other important pollutants as well as even some radiation.

Without expensive and very high-tech equipment it is impossible to realise the amount and concentration of toxic components to live.

Without any intention of sensationalize this situation, please don’t panic and simply be sensitive to this problem. To accomplish the best results or to provide essential conditions to most demanding species, you should do your best to know about your fish needs in first place. Than, try all the best you can to ensure acceptable water values, quality and purity, when breeding livebearer Cyprinodontiformes, even if we are talking about long term acclimatized domestic strains.

In addition to parametric values and water cleanliness, temperature is also extremely important. To breed any kind of fish, the thermal range must be held inside the more favourable or ideal limits.

More to this point and what's rather crucial is to respect original ecosystem thermal daily and seasonal amplitudes during breeding period in the wild on reproduction attempts in captivity.

To keep your fishes at the same and single temperature all the time or for long periods, in addition to negative impact on animal’s healthiness, doesn’t permit them the recognition of seasons as well as a reproduction specific stage. Even species from equatorial climates have develop a physiological need for a monthly ( if not even daily ) thermal little disparity.

In locations where seasonal breeding cycles take place, scientists can testify variations on the gestation episodes, the fecundity level as well as the number of deliveries, according to the time of the year. In captivity these variations must also be replicate as best as possible.

Fish coming from temperate climates are prepared to stand for daily temperature variation, and most of these species can even live in habitats where huge differences can take place between the limits, so these animals typically require a coldest period before the conditioning in to be physiologically ready for breeding.

In some cases, species from such environments must be submitted to lower temperatures season prior to be persuaded to reproduce. If not, those breeders will not have proper conditions to rise or resulting born will be under regular numbers and the newborn will reveal to be weaker. Some bad experiences, specifically when a lot of fry die and females appear to have gestation complications, result from disrespect of colder annual period on temperate wild habitat species.

Alternatively, in some cases, salinity variations can outcome extremely benefit for populations dealing in the wild with such seasonal flows and inflows from sea water into their freshwater biotope.

Please check with each species profile available at this website for indications regarding water parameters. Despite that, a research about local environment conditions concerning original habitat is always crucial.

c) Another quite essential and indispensable part of conditioning is an adequate diet disseminated in a large number of daily fractions.

Some species that perform continuous reproduction cycles in the wild can stop breeding from time to time, due to be deficient in of some diet components of adults or even fry on that period.

If we are talking about domestic strains tailored to captivity in a long-standing, this seams that it isn’t the case since these fish seems to reproduce even while feed only with flake food. Nevertheless this sort of diet must be considered very poor and completely out of question with reference to the reproduction of wild strains.

Whatever the case may be, as consequence of an unsuccessful feeding, especially when fundamental diet components are absent and the composition is not balanced on the subject of the species biological needs, even so some of these fish can still breed. If that happens, some persistent debility will be imposed to the new generations; follow-on as consequence some physical condition problems as end result from substantial nourish fail.

One of the most noteworthy motivations to invest on a high quality balanced diet to breeders it is not a matter of mating stimuli, like on the ovuliparous and oviparous species, but instead to favour supplementary resources to future mothers. As a rule viviparous as well as ovoviviparous don’t need sudden extra energy support for sexual cells development in a precise moment, like the many other species.

Well-built in good health embryos and enhanced gestation condition is rather more important on these species. This will contribute largely for survival of newborn and recent mothers in good physical shape. Apparently, pregnant females are submitted to an additional huge effort during embryos growth and all conception process is very demanding.

Those females having better nutritional care during pregnancy reveal to recover rather easier than quite the reverse.

Any way it is fairly simple to understand the amazing result of a simple diet change for better on these fish. This can even become obvious in terms of sexual activity and in general fecundity.

Remember that many of these species had faced an evolutionary process during thousands of generations, during which seasonal food availability together with step up on environmental circumstances would produce demographic booms straight away.

Most important is also never forget that besides a nutritional improvement, during conditioning fish must receive extra food doses daily.

The main idea is to keep same average amount each time to avoid water pollution, but increase frequency and quality. By other words, more repeatedly the same prescribed amount and a bit more of components quality like live food and so on.

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Where and how to arrange a suitable setting for these species to breed ?

When water capacity is as much as necessary and fauna composition in the tank allow it, livebearer Cyprinodontiformes will breed, as you would expect without any help. This is why they are so often considered as easy breeders suitable for beginners.

Honestly there are no big secrets to share about this matter, but the fallow recommendations must be seen as fundamental for conscientious hobbyists.

To setup an ornamental but simultaneously suitable for reproduction tank is obviously not an easy task, so usually one need to consider other solutions.

The closest model with reference to the above idea is no doubt a mono-species ( species-specific ) aquarium, or colony aquarium. These two classifications are about the same and mean that only one fish species is present in the referred tank, where the animals live, breed, and die without segregation of the females or fry. Eventually some invertebrates can be added to share the space as well as to increase biodiversity and on the way to help maintenance work, eliminating algae and unconsumed fish food.

In contrast, the so-called community tank, a largely popular preference inside the hobby, only hardly ever can provide conditions to save a few newborn, unless species selected fallow exceptionally restricted guidance.

In face of this limitation the market comeback was a number of plastic cages models, geared up to save on each delivery as much as possible young from their own mother, inside a constrained environment free from around predators inside the tank.

Even if you could incarcerate in one this cages a pregnant female only a fey days ( or hours ) before delivery, this approach it’s absolutely incorrect either from an ethical point of view either from the sustainable aquaristics point of view. On the other hand, for someone potentially well versed on these species basic biology, this is considered an outrageous act.

Remember that delivery exact instance is roughly impossible to conclude. Only with a lot of experience with these fish ( and lots of luck ) someone can in fact glance the moment.

It is rather common to read that for a specific species gestation takes exactly a certain period of time. In reality, with some experience we can find this is only partially true.

Only under “ ideal “ conditions as well as a good conditioning preparation fish do come within of such strict period.

When constrained in one of these enclosures, some species females can hold-up the delivery for a much-extended time, as they would moreover done in nature, specifically in face of some kind of remarkable event that could put in danger their progeny as well as their own physical integrity.

Cage maternity must be seen as torment chambers. Even the exceptionally rare species that can withstand this situation can unmistakably give you an idea about the main advantages of this custom.

Countless inconveniences become obvious. Higher rates of premature born, females manifest anguish ( causing loss of immunity ), water pollution made by waste food, cannibalism, aggressive behaviour and some other observable problems.

To avoid these malicious end results, additional space is crucial as well as some practical alternatives as fallows :

1) The community tank working simultaneously as a breeding place.

As a rule this idea is simply a utopia, but for the majority this is in fact the single feasible solution, specifically for those who live on small accommodations. There are also those to whom only one tank is all they will ever get, not only by the room prospect but additionally by other whatever reasons.

The community tank working like a successful breeding place can be accomplished taking in consideration countless livebearer Cyprinodontiformes species. To carry out that plan, a number of easy guidelines have to be assured.

First and exceptionally important is that all the species selected to populate the community need to be elected carefully.

Absolutely out of question is the traditional assortment of fish from wide-ranging types, derived from different continents or biotopes. On this kind of settlement, the community is put together according fish colour and unusual body appearance.

As you might expect, piscivorous or predator species as well as animals that feed on the little fry, must be eradicated from this type of aquarium.

On the other hand, a community selection is far from being simple task. Unfortunately, often we aren’t familiar with important biology details from fish included on such tank by sentimental reasons. Alternatively, there is always the potential risk of an unexpected change of feeding habits from some specimens in captivity.

Another important facet to consider is cannibalistic behaviour.

For the most part of the species cannibalism can be regarded as a abnormal conduct ( almost always related to an unbalanced diet and captivity stress ). Despite that, a marginal number of species do have expected cannibal instincts even in the wild.

Whatever the case may be, if you are thinking to save at least a few newborn fish delivered on a community tank, please remember that in any circumstances a good area of natural shelter must be provided to assure protection to the little ones. Adults and older brothers can sometimes become violent and even impulsive attacks can take place now and then with lost of lives between the baby fish.

In addition remember that, at least during the first weeks, the little fry search for safety and protection according to instinct as well as to genetic inheritance. Some species will take refuge inside dense aquatic plants and submersed roots; others will look mainly for fluting plants, a few prefer rocky areas with plenty of re-entrances or fissures and a smaller number will simply feel protected in hardly any millimetres of water, ( as back in the wild in the natural habitat shore lines ). The safe cover preference will above all depend on the original biotope and species evolution.

Nevertheless, under attack any newborn and fry will run straight away without any delay to any available safe place around, so something must be there to provide a kind of sanctuary for them.

Besides any of the above reflections, the tank water capacity is still as important as any other rule.

The best set up and community selection will never work properly if vital space was not provided. To avoid the wholly lost of a livebearer delivery as well as to support several generations simultaneously, the community tank personalized for the breeding function must be as large as possible.

2) Mono-species ( species-specific ) aquarium.

This class of tank can ( and must ) comprise conditions to allow breeding. When cannibalistic behaviour is not a rule, it’s quite easy to observe newborn and fry swimming around.

Please take in consideration every bit of what was said above with reference to the community tank set to stand livebearer fish reproduction.

Never forget also the sentences regarding natural refuge for the fry.

Most species when raised on this kind of aquarium will share with us a few generations living as a single group.

Despite that, remember that space is essential. Even more than with the community tank prepared to breed several species, a colony settlement is further demanding in terms of vital room.

3) Maternity aquarium.

Within this class we can look upon all containers specifically prepared to place pregnant females, from their final gestation period to the delivery moment.

For this specific solution we are talking about less significant water volumes than usual captivity habitat, as these tanks will receive only one female each time. Nevertheless, remember that a lesser amount of water presents higher difficulties on quality management.

A maternity tank, besides one of the most crucial breeding solutions for those who have only a community aquarium, it has more significance according to the rarity of the species or in the presence of ordinary cannibalistic conduct.

Whenever the newborn survival is essential, this is the most conventional alternative.

If a large the number of offspring who can subsist after delivery, more excellent will be the end result on those circumstances in particular, ( like when we are dialling with a fish already instinct in the wild or one of those threatened in nature but almost gone from captivity ).

It’s important never forget that a larger amount of effectives from a particular population or colony in a certain moment can income less endogamy consequences, as well as additional availability to spread the species among other hobbyists, ( a safety basic achievement to preserve endangered fish ).

Also quite important motivation for your decision about a maternity tank is the predisposition to show natural cannibalistic conduct in some species. Some are so effective to eliminate their own progeny that this can be the final resource to save from no less than a few newborn to them at all.

There are basically to concepts about the maternity aquarium; the natural set up and the mechanical obstacles.

As for the natural set up, we can say that it will be something like a larger community or mono-species aquarium miniature, ( please take a look on image nº1 ).

Basically it’s a container with no less than the critical water capacity to ensure least conditions to particular species female ecological needs. 

The main differentiations from a typical ornamental tank, on this specific case, are some supplemental details that are added to allow extra refuge to newborn, ( just in case mothers can sudden change ideas and see their own young as prey ). 

The functionality and aim of this solution are more important than the decorative idea, so every put forward of the tank is primarily to provide safety refuge for the brood.

The tank bottom can be covered of a sand or gravel thin layer, ranging from 2 to 3 centimetres. 

This option is needed if the natural plants don’t leave us any other option, but in any other circumstances an empty bottom is preferable.

The unfilled tank base will allow an easy cleaning task. Using any simple sucking system effortless efficient maintenance becomes evident.

Occasionally round pebbles or non-transparent marbles are very helpful to provide safety to some species when newborn look for refuge in bottom background if under attack during the first hours or days.

Generally, minimum water capacity for a maternity aquarium can be calculated multiplying the female size in centimetres by 4.16, obtaining this way a value expressed in litres. Anything greater to the calculated volume is always better.

If you want to find more information about standard best tank water capacity, according to these species minimum demands in general, there is an area on this subject on this website in fish density in aquarium settings.

Image 1 inscription :

1 - refuge platform ( mezzanine )

2 - underwater aquatic and floating vegetation

3 - external filter water aspiration tube

4 - external filter water income

5 - airstone

6 - bottom cover ( see text )

In such limited space is also important to assure one ( or several ) filtering systems, besides an airstone to improve water dissolved oxygen, because pregnant females do have higher breeding demands. Also at night, when plants start to breathing like animals, carbon dioxide has a tendency to rise up to dangerous levels. 

Remember that a tank of this class must be densely planted at least in anticipation of delivery and until female removing.

Another safety measure is to isolate with the proper mesh the filter water income to avoid the little fish been sucked by the system.

Now, about the mechanical obstacles maternity aquarium, there are a few differences, as this solution is conceived to the most problematic species in terms of cannibalistic behaviour. In a few words, it means that a part of the tank is inaccessible to the future mother by explicit barriers, ( please take a look on image nº2 ).

On this other class, water capacity must be greater than the one from the natural set up. This difference has to be with the reduction of vital space available to the female, due to the reserved areas where she can’t swim.

Minimum water capacity for a mechanical obstacles maternity aquarium can be calculated multiplying the female size in centimetres by 5.12, obtaining this way a value expressed in litres. Again, anything greater to the calculated volume is always far better.

Rather effective is the so-called “ L “ model, which can allow newborn to escape to safe areas, independently from their natural instinct.

In any of the above motherhood solutions, after delivery the females must be transferred to another tank ( even if she didn’t have prey her own offspring ).

The fry can remain on the birthplace at least during first stages of live as we will see further ahead.

After the female be transferred a large part of the plants and refuges can be removed too. This way we can have a better control over the very young fish as well as maintenance operations will turn out to be rather easier.

Also with the mechanical obstacles maternity aquarium some changes must take place after the female is gone. Only floating plants can remain and, above all, the barriers shall withdraw by the same reason than with the natural set up.

As a last call of your attention, while all the time the two solution are catalogued as maternity aquariums, has it was written in the beginning, any kind of water container with the same water volume can work in the same way.

Image 2 inscription :

1 - barriers ( railing, grating or network of bars )

2 - underwater aquatic and floating vegetation

3 - external filter water aspiration tube

4 - external filter water income

4) Lakes, fishponds, reservoirs and other options of generously proportioned water volume.

Even if you don’t inhabit in a tropical region or in another kind of climate bear a resemblance to the wild ecosystems of these fish, there is at all times an approach to the greatest conditions by the use of outsized areas of free space. Engaging on this solution you are generating exceptional circumstance to breeding.

Also when dealing with those species that have natural predisposition to cannibal behaviour, in such large space conditions in captivity, the fry survival go beyond any suspicion, without any human intervention.

To use containers with capacities of over 2.000 litres is not any longer a matter of professional breeding projects.

Some hobbyists sudden become conscious about the return of raising their fish in large room, ( at least as long as the weather conditions could allow it during the suitable seasons ).

For those who can afford to have enough space and some inspiration, there are a few alternatives, from common low-cost children swimming pools ( available in any superstore or local suitable shop ), to garden fishponds or even biological swimming pools.

These last ones consist on ornamental fishponds that work as swimming pools where humans can swim and take bath without any risk for health. Generally are built to conciliate leisure swimming pools characteristics with a wild biotope recreation.

Another option on the opposite side of cost and difficulty is no doubt a simple site, excavated on the ground and covered with a simple PVC layer as well as any other kind of liner.

Above 37º North or below 37º South latitudes is somewhat unusual to find proper climacteric conditions to keep livebearer Cyprinidontiformes outside all year round. Anyhow some cold resistant species can stand winter lower temperatures outside outdoors on these marginal regions and even further North or South of the 37º parallel.

Particularly in Europe and North America there are large-scale breeders of traditional domestic strains using containers of around 2.500 litres inside green houses all year round.

Some hobbyists also decide on extra room, placing the fish ( independently from the season ) in some large water capacity solution indoors, like inside a well illuminated attic, oft or garage.

One very popular resolution in this particular example is the use of a canvas children swimming pool with around 1.000 litres of water capacity, ( say something like 1.90 m x 1.27 m x 0.45 m ).

For those who can enjoy such especial space conditions, becomes easy to discover how some species can really be extremely prolific as well as some common nicknames like “ million fish “ have come in to popular tradition.

Besides prolificacy as well as huge dimensions attained by individuals kept in plenty of room, the additional return is more general good physical condition but also some exceptional behaviour conduct impossible to detect inside the close environment of an aquarium.

There is no fish room provided with large tanks that can even be compared to the performance of a small lake or with any full-size large container. Nevertheless, nothing can be compared with a garden fishpond outside. If your weather conditions allow it all year round, you’re a fortunate hobbyist indeed.

On temperate regions is possible to breed these species in large scale with a little management exercise. During warmer months fish are raised outside, returning back to greenhouses or into tanks at colder months to preserve a breeding group.

Hobbyists that keep some species outside as long as weather conditions allow it have to bring them back inside when temperatures start to fall below safe limits. With limited space, is only possible to have a breeding group is preserved inside, while all the others are after that distributed by friends or sold to local pet stores, ( providing this way a little financial return to compensate maintenance costs ). Under this scheme hobby clubs or associations after fall colder period can also spread rare species.

When fallowing this strategy with continuous reproduction cycle species ( namely those of short live time ) please note that they cannot stand a long breeding absence.

Except of the above example, a breeding interval is really vital, specifically for those fish from temperate regions or for those species that have faced during evolution limited breeding seasons or discontinuity in face of specific conditions in the wild. Remember that for wellbeing reasons in addition to to assure fertility, some tooth carp must stand in lower temperatures, at least during a short winter period.

If you intent to raise your fish outside, ( specially on a fishpond ), be prepared to find exceptionally large exemplars after the hot season. Anyhow take in consideration that there are also a few problems to face, unless this non-natural environment is placed inside a greenhouse.

First of all it’s very important to consider some basic safety measures, in particular if deeper fishponds or lakes are placed in locations where some kids play around.

Also when we are talking about any outdoor installation the next concern is fish integrity. Water contamination and predators are in the top of the list. Take in consideration domestic cats, aquatic rodents ( like the Water Vole ), some batrachians, fishing birds, water snakes, aquatic insects as well as many others.

The appropriate place to keep and breed livebearer Cyprinodontiformes doesn’t need more than 50 centimetres deep. Such depth allows larger surface areas as well as some protection concerning children fall down, but the most evident negative attribute is no doubt the thermal amplitude plus a more close relation with the air temperature up and down variations.

Independently from the species for outdoor options there are a few essential conventions too.

Please keep always in mind that :

a) Never leave simultaneously in the same site more than one species from one particular genus. Crosses are sometimes quite easy between members with such close genetic relations. If more often than not such crosses will reveal to be easier said than done, ( particularly in plenty of room ), we never know and some nasty surprises do happen.

Also take into account that efficient juvenile predators should be all the time kept apart and raised in a mono-species place.

b) Preserve at least 35% of the available space to sub-aquatic dense vegetation. On remain space available you can add some floating water plants too.

c) Consider that changing the proprieties of thousands water litres is far from to be a straightforward task if practicable at all. So if you will try a fishpond or any other oversized solutions look for species that can stand local water conditions in first place.

d) Some shadow will bring no harm at all. You may consider it even indispensable during summer or in tropical regions. Always be aware that vegetal matter like tree leaves falling down in to the pond water can become a problem. Chemical alterations from vegetal matter decomposing on the bottom are favourable only for an irrelevant number of species. Even so such special conditions from the natural habitat are very difficult to recreate in captivity, as the water properties and plants aren’t the same.

e) As above was written, birds ( fishing specialists above all ), snakes, amphibious, psicivorous bats, aquatic rodents ( like the Water Vole ), domestic cats, are among the most frequent small fish predators outdoors.

Livebearer domestic exotic strains have no natural survival arguments in the presence of predators. Besides weaker mobility ( especially long fins ones ), out of the ordinary amazing body colouration, and lack of preservation instinct in the first confrontations with the out-of-doors reality. This way they turn into very easy “ snacks “ for all other animals that prey on them.

As soon as any of these natural predators understand how a garden fishpond can become an effortless food source, their feeding expeditions start to develop into, at least, a daily basis.

When this takes place, in no time you will be a witness of the fast end about an entire colony of these small fish.

However, simple methods can prevent your fish predation. If you are facing domestic cats attack, for instance, a simple disparity of about 15 centimetres between the edge of the pond and the water surface happen to be enough to turn that fishpond a safer place to your livebearer Cyprinodontiformes.

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After delivery, what’s next ?

Livebearer breeding although considered an extremely easy task for many hobbyists doesn’t mean that it can be seen with less responsibility. In all phases since fecundation to delivery all the same principles must guide our action.

Only after the babies are born, a lot of keepers start to understand some basic concerns they should have reflected about if the all process was planned from the beginning to the consequences of fish reproduction. Only than numerous less experienced on the hobby realise that many females do need some rest period before new gestation, for instance.

Back in the wild there was enough room to recent mothers, right away after a recent delivery, isolate themselves from the persistent males, other are sexually active all time long, allowing males to copulate at once.

Females that need to avoid male contact can’t have enough seclusion even in a large tank, so in these situations they are jeopardizing the healthiness. After a few consecutive births these mothers can be really down if not even in bad shape. Next gestations can go wrong and consecutive babies tender to have also poor physical condition.

Maternity aquarium is no doubt the best solution in these cases .

The number of survival fry can also become soon a problem.

Some domestic strains from Poecilia or Xiphophorus genus larger species can reveal to be tremendously prolific.

Long tradition of captivity maintenance can also show the way to the acceptance of less demanding environmental circumstances for breeding.

A very well developed adult female of Giant Sailfin Molly ( Poecilia velifera ), can deliver more than 200 offspring each time.

Besides the above concern about healthy rise of the young, you need to be committed with a balanced resources management as well as water quality. To fulfil this aim and keep your fish wellbeing, there are limits to a tank fish population. You can have an idea about it looking for some details in Fish density in aquarium setting.

On the other hand, only a minority is aware of the disaster caused by genetic problems in small populations.

It’s quite natural to invest some time, know-how and our best hard work in to species breeding. As a reward, fish turn out to be exceptionally productive under such care.

It’s difficult to imagine something worst than lack of space to preserve as much as all the fish we are called for to keep, because there is no other alternative. Overcrowded tanks are a terrifying nightmare with certain bad consequences in terms of fish healthiness. Just imagine what a sudden contagious infirmity can do under such conditions…

When thinking about brood growth one should also consider the space versus body increase relation, which becomes so important as feeding quantity and diet quality on the first stages of live. Health and physical development problems can start to be retaliated with simple measures like enough room and a careful nutrition.

A few last words concerning those situations when a maternity aquarium is needed or if this happen to be the only possible answer.

Please take in consideration two separate periods after delivery.

In a first moment, between birth and 10 up to 20 days ( depending on the species ), newborn and fry should remain on the same tank after a partial removing of vegetation or total eradication of physical barriers.

Unless the space is below the minimum required area, this tank is the appropriate environment to a safe brood management. Here the very young fish can be under tight control, which can help us to propitiate them the best conditions of development. As soon they can attain enough size to join adults at the colony tank, most excellent the results will be, ( especially if we are talking about cannibalistic behaviour species ).

On a second phase, it is also vital to separate males from females inside a single brood. The essence of this act is to avoid any possibility of mating between brothers and sisters, the shortest and straightway course to endogamy.

At all times you can find conditions to do it, young fish must be separated by sex and mix up with opposite gender same age or adults with less consanguinity as possible.

Unfortunately, these efforts are not viable for a dramatic majority of hobbyist breeders. There is no better solution than an organized or informal fish exchange program between several keepers of that same species.

As soon as practicable, the young fish should put together with adults of their own species.

However, when the maternity thank becomes too tight for them, another larger area should receive the entire group, allowing this way improved hygiene and growth circumstances.

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