Guppy Mating Behavior Explained (3-minute read)

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Guppies are very active breeders. Male guppies spend most of their time trying to mate with females and female guppies spend much of their lives pregnant. Guppy mating behavior mainly involves the male constantly chasing and trying to ‘rub’ his body against a female guppy so he can fertilize her.

Guppies have been one of the most popular breeds of freshwater tropical fish for decades. Since the 1960’s hobbyists and professional breeders alike have been keeping and selectively breeding guppies to give us the wonderful selection of colors and tail shapes we have in the hobby today.

I started keeping guppies in the mid-1990s and I don’t think a day has passed since then when I didn’t have at least one tank full of guppies in my fish room. I have bred them for fun, for-profit, and for competition!

If you are new to guppies, you may be wondering what all the chasing and apparent fighting between your male and female guppies is all about. What you are probably witnessing is guppy mating behavior.

What Does Guppy Mating Behavior Look Like?

Unlike so many fish in our hobby, guppies don’t lay eggs. In fact, guppies are a live-bearing species of fish, which means the female guppies retain the fertilized eggs inside their body until they have developed into live, free-swimming baby guppies.

Guppies are very active breeders. Male guppies spend their entire lives doing one of two things, eating and trying to mate!

The physical process of mating involves the male guppy passing his ‘milt’ into the female guppy to fertilize the eggs inside her. He does this by using a modified analfin known as a gonopodium.

To carry out this process, the male guppy has to be alongside and slightly below the female guppy. She will only allow this to happen if she is receptive to his advances.

How Does A Male Guppy Make A Female Guppy Receptive?

Male guppies are show-offs! They have those long, flowing, colorful tails for one reason, to impress the female guppies.

To convince a female guppy she should mate with him, a male guppy will dance for her. He will twist and turn in front of her and swim around her. He will wave his tail and ‘shimmy’ at her.

Newcomers to guppy breeding often confuse the act of mating with aggression. Guppies are generally not aggressive breeders, but the males are very persistent

What If The Female Guppy Isn’t Receptive?

Sometimes, female guppies aren’t receptive to the male guppies’ advances. She may well already be pregnant, or she doesn’t feel the male vying for her attention is colorful enough.

When the female isn’t receptive, the male guppy will often attempt a ‘sneak’ fertilization whereby he quickly gets alongside her and passes his milt across before she can swim off. Smaller males often attempt this method of fertilization.

If a female guppy isn’t receptive to the males’ advances, try feeding her an enhanced diet. It will almost certainly increase her desire to breed.

How Long Are Female Guppies Pregnant For?

After successful fertilization has taken place, the female will be pregnant for between 28 and 35 days (largely dependent on water temperature). She will retain the fertile eggs inside her body while they develop.

When the babies are ready they will be born as free-swimming, fully independent baby guppies (referred to as fry). Guppies take no parental responsibility for their offspring.

In Conclusion

Whilst guppy mating behavior may appear aggressive, it really isn’t guppy mating behavior largely revolves around the male showing off his colors to the female whilst trying to copulate with her.

Male guppies are extremely persistent breeders and spend almost their entire day trying to find female guppies who are receptive to their advances.

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James