Take one male guppy. Take a female guppy. Put them both in an empty glass bowl with a pinch of flakes and a little water.
Wait six weeks. Return to discover that two fish didn’t multiply. Instead, there are hundreds (a small), wriggling army of bright, neon-colored specks darting about your bowl.
Hobbyist delight in it. Beginners is confounded by it. For more than a hundred year now, the scene has been repeated.
The nickname Million Fish isn’t an exaggeration. It’s a compliment wrapped in a biological warning label. The common name are Guppies.
Understanding Why Guppies Are Called Million Fish
The Million Fish Reputation
*Poecilia reticulata*, otherwise known as guppies, have this amazing ability to reproduce like mad. This single property define them, making what should of been an uncomplicated task (keeping fish) a logistical nightmare. Unless you know how they breed, your tank will no longer be a quiet community but a crowded cafeteria.
How Guppies Reproduce
This matter primarily because they don’t bother asking for anyone permission when getting busy. Guppies is built for speed, literally. They aren’t egg layers.
They don’t deposit eggs into water to float while they develop. Instead, guppies are livebearers. That is, females gives birth to live young that are fully formed and ready to go.
How long does this take? Guppies has a gestation period of about twenty-eight days, although warmer water will accelerate this (up to four weeks), while cooler water will slows it down (but seldom stop it). Because of this, under favorable conditions one female will have a brood nearly monthly.
That’s not the surprising part, it’s the month-to-month pregnancy cycle. But even more shocking: a female guppy keep a supply of sperm on hand. That means following one mating session, she’ll be fertile for months.
What’s more, she doesn’t require the presence of a male to produce following generations of offspring. Why? Because this evolutionary biological quirk enable guppies to thrive under conditions where males may be scarce and/or consumed by predators.
Exponential Population Growth
If you have several males in your home aquarium, though, there will always be enough. And so begins an endless cycle of reproduction unless you’re prepared. A single female guppy can gives birth to anywhere from twenty to forty fry in a single birth.
Twenty doesn’t sound too bad until you multiply it by twelve times per year. Three months later those twenty babies becomes adults. They then get thrown into the mix.
They are now breeding fishs. The population doesn’t increases at a steady rate. The population increases at an exponential rate.
In less than six months, you can go from two fish to easily having fifty in your tank. This is where the nickname Million Fish connects. It is not because there really are millions but because of its potential.
Why Guppies Are Popular
Guppies are easy to breed. Like ridiculously easy. All you need is them.
You don’t need odd foods or special tanks. You just need water, food, and guppy. That’s what makes them so popular as first fish.
They’re so easy to breed you’d better have a plan. Do you want a peaceful minimalist tank? Then you’ll be disappointed.
Want an aquarium full of crazy colors like neon blues and fiery reds? Then you’ll love ’em. It’s a fair trade off.
Volume for beauty. So what do we do with the population? Well, there are three ways.
Managing Guppy Populations
The first way is stressful and time-consuming: you move the fry out to another tank. 2) Change the dynamics in your tank completely by adding predator fish. 3) Live with it and just maintain good water quality.
Poor water = bad. Bad water = disease. So overcrowding equals poor water and then poor water cause disease.
It’s a simple equation, but it can get messy for new keepers. The guppy’s history add even more to its reputation. Originaly guppies were brought into tropical areas as mosquito controllers.
Because they could feed on mosquito larvae, they became a valuable public health tool. The reason why they worked so well was because they can reproduces rapidly. A million fish might be a pest in your home tank, but in nature, that is a desirable trait.
Things change with context, yet biology doesn’t. If you know that guppies are called the Million Fish, this information will change how you see them. Suddenly it’s no longer about keeping some pet.
It’s about having a colony and actively managing it. They can have the capacity. So plan for the onslaught.
Preparing for Guppy Fry
Give them plenty of hiding places, filtration, and space so the fry have a chance at life if you desire them. Otherwise, get rid of the female or male(s) before the explosion happens. So next time you’re watching a school of little fish swirl around and make your heart race with excitement, keep in mind the math that makes that beauty possible.
It is impressive, yes, but it is also demanding. And that’s how the Million Fish got its name. It is pure biological efficiency.
Now all you gotta do is ask yourself if you’re up for the party they put on.
