Livebearers are becoming more 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. This was once true, however now that we are many generations away from the wild stock, some of them have become quite weak. Most livebearers today are mass-produced. As we all know, when things go into mass production, the quality will decline. I’m hoping to share some tips with you to make livebearers a success despite all the challenges.

How Livebearers Are 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. The next step is to have a pond where the livebearers can be bred. Place a large number of livebearers into a large pond. Then harvest them as they breed. This process makes it very easy to produce a very large amount of livebearers with much less work than aquariums.

These systems can have many unfortunate consequences. One is inbreeding among livestock. Genetic defects can be unchecked because there is no one to ensure siblings and children don’t cross, so they must be culled before they can be 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. Unfortunately, even though they look acceptable, they can carry the weakened genes of their parents. To illustrate the point, all “potbellied” variety of platies, and mollies are genetic deformities that have been commercialized and become popular in the trade. These deformities were the result of 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

A third problem is the concrete used to build ponds. This causes the water to be contaminated with chemicals that can increase the pH and Hardness. Or brackish water is being used, instead of straight freshwater due to cost. This isn’t necessarily bad, but uninformed hobbyists and stores are falling for it. 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.

Buying Livebearers

What can we do now that we are aware of how our livebearers were bred? 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

Wild livestock is another option. They will be more genetically pure. However, this won’t help you with “Fancy” strains of livebearers. They could still have parasites or go through osmotic shock though. It is worth considering whether or not the species may be endangered in the wild. 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

Most people will choose the last option. Setup your aquarium closer to the breeder’s water parameters.

This was not 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 didn’t live for very long. Breeders discovered that mollies could survive in brackish water after quickly researching the subject. Many stores and hobbyists soon added aquarium salt to their tanks to make their tanks brackish. The mollies were able to do much better, miraculously! We thought we had figured it out, but some people were using Aquarium Salt and others were using marine salt. It was the marine salt minerals that gave us 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. After they have been acclimated, they should be able to thrive. Over the next few months, you can slowly bring them back to the pH of tap water. You will eventually see fry and they will be accustomed to tap water. This will allow you to provide stable livebearers for your fellow hobbyists.

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. Once they have been stabilized, they can last for many generations.