Livebearers – essential facts

Lovely delta tailed golden guppy male

Introduction to livebearers

guppies and platies in a community tank
guppies and platies in a community tank

(Livebearers – the essential facts that you should know)

More about breeding livebearers here

More about keeping healthy livebearers here

Although a beginner’s fish livebearers have a fascination breeding behaviour and birthing method. The females give birth to live young. Baby fish that are the exact miniature version of the adult. There is also something for the advanced fish keeper. There are other exotic species of livebearer. Good examples are the mexican topminnow and endlers guppy as well as the half beaks. There are many other uncommon species almost as good as the common livebearers.

In the tropical fish hobby, there are four families of live-bearer available.

1. Livebearing tooth carps (Poeciliidae). This is the largest group of live-bearers and includes some well known aquarium favourites. Mosquito fish, guppies, platies, sword tails and mollies are all members of this family. There is an international fish club called “American Live-bearer Association” that is open to livebearer keepers all over the world. There is also a British version available to hobbyists in the UK called “British Livebearer Association”.

goodied livebearer xenotoca eisini male
goodied livebearer xenotoca eisini male

2. Goodeidae includes the Mexican topminnow. These are rare livebearers in the hobby.

More about Goodeids here

3. Half-beaks(Hemirhamphidae). These fish are straight long fish with a long pencil like beak shaped mouth. There are 20 species of half beak. Half beaks are occasionally found in the hobby.
4. Four-eyed fish (Anablepidae). These fish are interesting for their ability to equally see above the surface of the water as well as in the water simultaneously. Their eye balls have evolved into two bulbs with the upper part of the eye above the waterline and the lower part under the surface. They are incidently livebearers.

Where are livebearers found in the wild?

Live bearers are mostly from the Americas but some species are found in Asia. Their range extends from north America to Argentina in South America. Most livebearers eat mosquito larvae especially the mosquito fish. This ability of livebearers to eat lots of mosquitos and breed rapidly led them to be used in coutries with mosquito and malaria epidemics in S.E. Asia and the Philipines. However, these livebearers were so successful that they spread all over sub-tropical and tropical asia and even into parts of Southern Europe.

male and female halfbeaks fighting
male and female halfbeaks fighting

Goodeid livebearers (Mexican Topminnow) live in the rivers and lakes of the Mexican plateau and all the way down the rivers that lead into the Pacific.

Halfbeaks are found all over S.E Asia and can be found in both fresh and brackish water.

Four-eyed fish are found all along the west coast of South America. They are nearly always found in brackish water.

Livebearers’ early history

European aquarists started keeping livebearers from 1890 onward. They were in popular demand when they first appeared because they gave live birth. Because of their popularity they were very expensive. Prices quickly fell when hobbyists started breeding them and selling on the young. Livebearers have always been easy to breed in the aquarium so became widespread throughout Europe.

Livebearer social and reproductive behaviour

Most live bearers are shoaling fish, so do best in a group of 6 or more fish. This group or shoal of fish will develop a pecking order of dominance where an alpha male will dominate other males. The alpha male will show off brighter colours and display his fins better that the subordinate males. The dominant fish will always get to the food first. He will either chase away others or they will retreat as he approaches. The alpha male will always get a better chance to mate with the available females. The females will be more likely to accept him as a mate and he will chase off rival males too.

Most livebearers are non-aggressive community fish but the males may get territorial. Also larger species such as mollies can be boisterous to timid tank mates. Swordtail males are the most aggressive to each other. Keeping 2 or 3 will lead to bullying and death of the weaker males. Surprisingly keeping 5 or more males does actually reduce the bullying against weaker males because the bullying is spread around. Always keep more females than males. A ratio of 2 females to each male is a good starting point to reduce male attention to manageable levels.

Nearly all livebearers do not recognise their young. They will eat any young that appear in their tank as if it was a form of live food, even when it is their own young they are eating.

Courtship behaviour of livebearers

Guppy and swordtail males are very flirtatious and ardent lovers. Males will swim back and forth in front of the females while flexing their bodies in display to the female.

male mollies will present their bodies in front of a females and then spread their fins to their full extent so that the female gets a good display before trrying ti impregnate her.

Other species have a wham bam, thank you ma’am method of mating. The males will lie in hiding waiting for a suitable female. When a female passes by the male will pounce and mate by inserting his gonopod into the females opening and fertilising her.

Some species of livebearers have males that have a hook on the end of their gonopod so that it firmly attaches to the female’s opening while he is inseminating her as she struggles to get away. Not every mating results in successful fertilisation of the female. The ratio is about 10% chance of success. So the males are always trying to repeat the process to guarantee fertilisation of the female.

If the female is not interested in mating she will make a determined effort to escape the male’s attention. Since males are nearly always trying to mate and you might get several males trying to mate with a single female, it is best to provide several females for every male while also providing bushy plants for the females to hide in when they need a break.

Reproduction in livebearers

Livebearing is the most advanced form of reproduction. It is almost universal in all species of mammals. In reptiles and fish it does occur in the occasional species. Most fish species lay many eggs which are fertilised by the males in open water. The livebearers have developed internal fertilisation of the eggs with hatching of the eggs internally. Most species of livebearers eggs hatch shortly before birth and young fully formed livebearers which are miniatures of the adults ae born.

In Goodeid livebearers, reproduction is even more evolutionary advanced. The eggs hatch early internally and the young embryos develop internally and nourished through a form of attached umbilical chord, which is similar to mammals.

Some species of livebearers have females that can store sperm internally following a successful mating. The stored sperm not only fertilises the present batch of eggs but also can fertilise future batches of eggs as they develop following a pregnancy. It was demonstrated in an experiment that a mosquito fish from one fertilisation was able to produce 11 broods one after the other for a period of a year without any access to a male mosquito fish.

 

Setting up a beginner’s community fish aquarium

beginners aquarium

5 Key tips on setting up a beginner’s community fish aquarium

Child choosing fish in aquarium storeIf you are new to the world of keeping tropical fish, there are a number of key considerations that you should keep in mind when you are choosing your very first community fish aquarium. These considerations are important for anyone who would like to keep a healthy, productive and colourful community aquarium, since fish are notoriously sensitive creatures and the choices you make in this regard will seriously affect them.

Often, people who are just starting out in the wide and wonderful world of tropical fish community aquarium keeping will simply walk down the aisles of the aquarium section of their local pet store and collect the most colourful combination of fish they can find there and throw them all into whatever aquarium seems to fit their tastes. While a good eye for beauty is great to have, it is critical to apply some forethought and expertise to your choices as well to ensure that your fish lead happy lives.

See also set up beginners aquarium

and avoid these mistakes

Tip Number One: Choose The Right Fish

choice of beginners fish aquarium storeIn general, your interest in keeping an aquarium should remain focused on the fish that you would like to have living there. While it is perfectly reasonable to see an aquarium you really like and then choose the fish afterwards, it is important that the fish you keep are chosen based on their compatibility with the environment that you wish to keep them in.

Some species of fish, for example, are very difficult to keep alive and happy in a community environment. They can be overly sensitive to water quality, require special marine conditions to survive, or represent a species that does not get along with other fish in your community fish aquarium. It is always best to start with hardy, well-disposed community species.

Here are some examples of popular fish that are ideal for living in a freshwater community aquarium:

selection of beginners tropical fish• Barbs And Rasboras; (But not tiger barbs)
• Corydoras Catfish;
• Danios (including the popular Zebra Danio);
• Loaches;
• Guppies;
• Black Mollies; (or any coloured molly)
• Swordtails;
• Tetras;
• Rainbowfish.

There are numerous other species of fish that are well behaved and offer an easy experience for fish enthusiasts to plan their first aquarium. As always, good research is important before any purchase so that you know what to expect.

See also suggested compatible fish groups

Tip Number Two: Choose The Right Size Tank

choice of fish tanksThere is a common misconception among beginning aquarium owners that smaller tanks are always easier to keep than larger tanks. This is not true— in fact, smaller tanks make it harder to control the water quality correctly and make it easier for a tiny mistake to end up with disastrous results.

Ideally, a tank in the range of 200 litres allows for small changes in pH, ammonia, or nitrite levels in the tank to have a less drastic effect than if you begin with a tiny tank. The water quality will change over time and you will need to be ready to address those issues before their consequences become realised.

For a beginner’s community fish aquarium, it is important to appropriately measure the amount of space that you have for your tank and to relate that with the size and number of fish you would like to keep. Two useful rules of thumb can be applied when choosing the size of your tank. In general, you want to have:

• 1.5 litres of water for each centimetre of fish length;

• 30 square centimetres of surface area per centimetre of fish length.

These are not strict rules and they do not take into account the activity level of the fish, social behaviour, and their eventual growth. However, they are very helpful for beginners to gauge the right size of their tank in relation to the fish they’d like to keep: miniature tanks for small schools of tiny fish, and large tanks for larger specimens or greater numbers.

Tip Number Three: Keep Live Plants In Your Aquarium!

selection of beginners aquarium plantsWhile it is possible to successfully keep a thriving community fish aquarium without live plants, it is advisable for beginners to keep a healthy number of live plants in their aquariums for a number of reasons:

• Plants oxygenate the water that your fish and for the essential bacteria rely on to survive.

• Plants, as living organisms, are notably more complex than algae and utilize waterborne nutrients more effectively and readily than algae can. Having a mixture of the two is a good option to consider.

• Plants offer additional decorum that double as an important part of the living ecosystem you are creating. In terms of their natural beauty, they are vastly preferable to little pirate ships or plastic pieces for creating a pleasant aquatic environment.

See also beginners plants

Tip Number Four: Invest In Your Filter

different types of filter
canister, power, sponge, internal filters

Your water filter is one of the most important elements of your community fish aquarium. While you may hear that it is okay to purchase an aquarium filter that turns your water two or three times per hour, it is recommended that you get a filter that will do so at least four or five times per hour for the best results.

When in doubt, remember that it is perfectly okay to get a filter slightly larger than necessary, but that a smaller filter can easily lead to frustrations in your community fish aquarium. Under-investing here can undermine your entire attempt at successfully keeping a thriving aquarium environment.

Tip Number Five: Use A High Quality Submersible Heater thermostat

There are a number of aquarium heaters available on the market, and you owe it to your fish to choose a high quality submersible heater instead of a more expensive titanium solution or a hanging heater. This piece of equipment is vital to your community fish aquarium and, if chosen correctly, will provide years of service without causing any problems.

There are certainly better and more complicated heating solutions on the market, but simple submersible heaters represent the best choice for beginners. Hanging heaters may require you to cut a hole in the aquarium hood in order to make room for the head of the heater, and submersible titanium heaters are more expensive solutions meant for tanks with large, boisterous fish.