Livebearers are becoming Weaker

Livebearers are becoming weaker.

In many older books and magazines, you’ll read how livebearers like Endler’s Livebearers and Guppies are great for beginners because they’re hardy. Although this was true once upon a time, many of these livebearers have lost their wild stock. Most livebearers have been mass-produced. As we all know, when things go into mass production, the quality will decline. I hope to offer some tips to help you be successful with livebearers in spite of the new challenges.


How Livebearers can be bred

Let’s first understand how most livebearers were bred. Most livebearers are raised in warm climates that keep them warm throughout the winter. Florida, Thailand, Hawaii are all popular spots for people to have a fish farm. A pond is all that is required to raise the livebearers. Place a large number of livebearers into a large pond. You can then harvest the livebearers as they reproduce. This process makes it very easy to produce a very large amount of livebearers with much less work than aquariums.

These systems have several undesirable consequences. The first is inbreeding. With no one to make sure siblings and children don’t breed with one another, genetics defects can run wild, until they are culled before being sold to wholesalers. Each farm will have its own way of breeding the fish. Some use cages to prevent culls from breeding etc) Many fish farms now harvest the fish from the ponds and then select quality specimens from sorting tanks in a warehouse. They can inherit the weak genes from their parents, so even though they appear acceptable, it is possible for them to look bad. The “potbellied” varieties of platies and mollies, which are all genetic deformities, have been commercialized to illustrate this point. These deformities resulted from downbreeding.


Parasites are another problem in pond-style breeding. While the farmers try their best to set up nets and keep pests out of their farms, the fish are exposed to outside influence such as bird parasites. This can have a devastating effect on populations of fish. Fish farms are quarantining the fish for a few days before shipping them out now to watch for parasites. However, if the fish isn’t stressed, they will be able to keep the parasite dormant. It is when the fish becomes stressed during shipping that the parasite is able to grab hold.

Breeding Facilities

Concrete is another problem. Concrete can leach chemicals into the water, which can raise pH and Hardness. Brackish water can be substituted for straight freshwater to save money. Although this isn’t necessarily a problem, it can lead to uninformed hobbyists or stores falling into a trap. The fish are coming from a high pH and hard water to local water tap conditions normally. This can put the fish into osmotic shock. Which can kill the fish in a few days or leave it very weakened for underlying conditions to finish it off.


We now know the breeding methods of the livebearers that we want to keep, but what can we do about it? One option is to buy locally bred fish. Even if their stock came from a fish farm, the fry will at least avoid osmotic shock from the huge change in water parameters.

Wild Livebearers

The wild option is also an option. These animals will be genetically more pure. These will not help you with “Fancy strains” of livebearers. You might still find parasites in their blood or they may be subject to osmotic shock. You might also want to think about whether the species is threatened in the wild, and what this may mean for you. Some aquarists intentionally breed wild, endangered fish to up the populations while others avoid them in hopes of keeping more in the wild.

Mimic Natural Water Parameters

The final option is the one most people will ultimately choose. Setup your aquarium closer to the breeder’s water parameters.

It was an accident. Mollies were one of the first fish to be severely mass produced and hybridized to get all the great colors we have today. These mollies did not live long. After quickly searching for information, breeders saw that mollies could live in brackish water. Many stores and hobbyists soon added aquarium salt to their tanks to make their tanks brackish. Miraculously, the mollies fared much better. We thought we had figured it out, but some people were using Aquarium Salt and others were using marine salt. It was the minerals found in marine salt that gave the greatest benefit.

Keeping Livebearers Healthy

The battle plan to keep healthy livebearers coming from a fish farm starts with setting up your aquarium for the right pH and hardness of water. Then find out what day your local fish store receives fish. Acquire your fish ideally before they go into the store’s tanks (assuming your local fish store are not livebearer nerds who already set up these types of conditions), take them home and quarantine them in your own setup pH and hard water. They should thrive once they’re done acclimating. Over the next few months, you can slowly bring them back to the pH of tap water. Eventually, you’ll have fry and they’ll have never known anything other than your tap water. You can then supply your fellow hobbyists with a more stable livebearer.

The trick to the common day livebearer is to minimize stress so that our super colored, extra long finned, genetically down bred fish don’t have to test their immune system. Every new livebearer strain brings its own beauty and defects.

I hope you will get your tank set up and give livebearers another chance. They are my favorite type of fish to work with. They can be kept alive for many years once they are stabilized.