Who Wants A Millionfish?

What is the easiest fish for hobbyists to breed? It turns out, that when we all sit down to talk about this question, there is not a consensus opinion. Some of us swear by Convict or Firemouth cichlids, and others by Platies and Guppies. However, no matter which of us you ask, Guppies are either at the top, or near the top of the list. I think the reason they don't dominate everyone's list is because while they are pretty much impossible to stop from breeding, getting good results takes a more in depth approach.

Often called “Millionfish,” guppies are prolific breeders. Males will breed with as many receptive females as they can. Females can store sperm from one breeding for months over several gestation periods. They can give birth to between 10 and 100 plus live fry at a time, and 30 days later can do it again without repeating the breeding process! The females can pull this trick off for at least 3 months! In all honesty, if you have warm enough water, and a good mix of male and female guppies, it would be nearly impossible to stop them from breeding.

Looking at these numbers, you can see how a guppy tank could quickly get overpopulated, and they do. However, Guppies aren't exactly “Parent Of The Year” candidates and if you just allow them to breed in their display aquarium, many fry will be eaten by other guppies and the parents themselves. Guppies will eat just about anything they can fit in their little mouths. Honestly, this is probably a good thing. They will naturally cull all of the slowest and weakest offspring, conversely, your guppies will not cull for good looks, so if you're interested in breeding guppies for the flashiest fish, a little more work will be required.

If you're interested in getting started down this path, you should start with the conditions of your tanks. While guppies are tolerant of a huge range of conditions, they are fairly intolerant of large swings in temperature or water quality. Make sure filtration is strong enough to maintain good water quality without producing so much flow that it makes it difficult for them to swim. Use a heater to maintain a temperature between 75 and 80, and remain there. If you keep nitrogen in check, keep the temp stable and feed a quality food, your fish should remain healthy, happy, and start to produce offspring.

The next order of business is choosing your breeding stock. First, how do you differentiate males and females? Well, its pretty easy once they hit maturity; males are the ones with the long, flashy tails, with brilliant colors. Females will have colors that are more muted and much shorter, less flashy tails. Females will also get nearly twice as large as males; the males max out at about one and a quarter inches long while females will get to about two and a half inches long. You're going to want 2 (or so) females for every 2 males in a general population aquarium. Obviously, you want to choose the largest fish that look the healthiest, show the best activity and are the most colorful / or attractive. Spend some time on www.aquatropic.com and you can see pictures of a huge variety of Guppies to help you make some choices.

When the females are ready to spawn, males will approach them from below and once in position they will briefly make contact. What's happening here is that the male has extended a “gonopodium” with which he deposits conglomerations of sperm called spermatozeugmata into the females urogenital pore. These conglomerations will then break up into thousands of separate sperm. As previously referenced, the females can keep these sperm alive for several broods. Females that are gravid (the fish version of pregnant basically) will develop large spots on their swollen abdomens. Guppy embryos are nearly completely formed within a week and live young are born between 21 and 30 days later; this timing is dependent on a few factors, with water temperature being a primary influence.

If your intent is to have a display that is constantly changing, through random breeding and you aren't worried about the looks of the fish, you're pretty much done here. You'll likely want to add cover for the fry, many people like java moss for this job as it is easy to grow/maintain, is attractive and offers great cover for the tiny baby fish. The fry will be somewhat ravenous, eating anything and everything you can throw at them. The consensus around here is powdered flake food, though if you are advanced enough to have baby brine shrimp available, this makes a great food source too. (Raising baby brine shrimp is another article.) Really the only remaining job here is to remove excess population from your display tank and give them to friends, or share with your local aquarists club. This removal offers you the opportunity to select for the features you want. Remove the ones that are the least healthy and attractive, or the ones with any deformed features. Anything that is left in the aquarium will breed again, so you want those fish to have the traits you want handed on.

Now, for those of you who want to try and breed for specific traits, like an even more gorgeous fish, or larger guppies, or even hardier fish, you'll need to take some further steps. This will entail more attention than what we have discussed so far. The breeding basics are the same, but the process will require more tanks, a little more hardware, some record keeping and selective culling. So tune in next time for a primer on how to get started with both inbreeding and linebreeding techniques. For those of you who just want to have a dynamic Guppy display, what we've covered so far should get you started. Head to your LFS ask ask them for whatever Guppies you love from Aquatropic today!