Breeding Egg-Laying Aquarium Fish, Part One


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Breeding Egg-Laying Aquarium Fish, Part One: Introduction.

Thank you for taking the time to look at this article, the first in a series. Together with the succeeding articles, its purpose is to help you successfully breed, (spawn and raise the fry), one or more species of egg-laying small tropical fish commonly kept in an aquarium.

These articles are based on my experiences, both the successes and failures, with propagating aquarium fish. I don’t pretend to be writing a “gospel” of proper fish raising, but simply passing on techniques which have worked for me. They should work splendidly for you also, but I can’t guarantee it. Besides, you may be more clever, disciplined, and energetic than I am, and come up with some techniques of your own which are better. BY ALL MEANS, please feel free to share any improvements to these techniques in the comments.

As anyone whose guppies have had “babies” knows, breeding our pets can bring a whole new level of excitement and enjoyment to our hobby.

Breeding the live-bearing fish, such as guppies, platies, swordtails, or even mollies, is a fairly straightforward process, accomplished by many novice aquarists. You simply give the newborn young a place to hide! However, breeding an egg-laying species of fish is perceived as more difficult. This perceived difficulty may be so intimidating to some that they don’t even try!

What I hope to do is explain to you various simple means by which you can successfully breed a few common egg-laying aquarium fish. These techniques can then be expanded upon to breed many other egg-laying fish. Who knows? As you gain experience, you may even successfully breed the striped headstander, Anostomus anostomus, or some other finicky species.


Have you even had a fishtank, and experienced the thrill of seeing your fish have “babies”. These babies are usually guppies, mollies, platies, or swordtails, which are all common live-bearing aquarium fish. “Livebearers” will often successfully breed in a tank with other species of fish present, if there is sufficient cover, (plants, decorations), for the young to hide in while they are still small enough to be a tasty meal to their tankmates.

Not as many people have successfully bred the egg-laying fish. This is a shame, because there are many, many more species of fish who lay eggs than give birth to free swimming young. And, depending on the species of fish involved, it can be almost as easy to breed an egg-layer as a livebearer.

The basic fact of life is that all living things want and need to reproduce. A species that doesn’t won’t be around long! What we as aquarists simply need to do is provide conditions that encourage reproduction, eliminate as much as possible the obstacles to reproduction, then get out of the way and let the fish do the rest. As a species, they’ve been at this for a long, long time; they know what they’re doing.

We are going to go over three basic factors for success with your first attempt at breeding an egg-laying fish:

1. Selection of the proper species of fish. Obviously, some fish are easier to breed than others. Choosing a fish such as Anostomus anostomus, the striped headstander, would not be a good idea for your first attempt, as I believe no one has gotten it to consistently reproduce in captivity. Nor would Epalzeorhynchos frenatum, the rainbow, or red-fin shark, be a good choice. Starting out, we want to set the odds for success in our favor as much as possible, so we should choose fish that are relatively easy to breed.

2. A suitable environment. With very rare exceptions, you will not succeed at breeding egg-laying fish in a community tank. If you want to breed egg-laying fish, then you will have to accept the fact that you will need to have at least one species-only tank. What I mean by a “species-only” tank is that only one type of fish, the one you want to breed, will be in it. For example, if you foolishly decided that you were going to breed rainbow sharks, you would have a tank that only contained rainbow sharks. (Good luck!)

3. First Food for the young ‘uns. There is nothing more distressing than watching a set of newly free-swimming fry slowly die of starvation. You will need to have a source of “first food” for some very, very small mouths. This source of food must be readily available until the fry are large enough to eat, and accept, small particles of flake food.

Before we examine these factors in more detail, I need to clarify that the methods we will discuss are NOT intended for commercial production. Breeding tropical aquarium fish as a commodity is a completely different endeavor. I am assuming we are all hobbyists, and as such keep our fish for enjoyment, not employment. The business of aqua-culturing ornamental fish is beyond the scope of these articles.

Okay then, let’s roll up our sleeves, and starting in Part Two we will cover in more depth the factors to successfully breeding the egg-layers.




On to Part Two