How Do Aquarium Fish Mate, Reproduce in A Fish Tank

How Do Aquarium Fish Mate, Reproduce in A Fish Tank

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Keeping fish as a hobby is a fulfilling endeavor, but it can be quite expensive, meaning any way you get to reduce on purchases is a chance to jump on ASAP.

An easy way to do this is to breed your own livestock.

For starters, it’s going to be cheaper for you, you’ll get fishes with traits that you desire, and it’s a chance to breed your animals ethically, contrary to how it’s done in commercial fish farms.

Besides, it’s almost impossible to keep your fish from breeding when you have male and female individuals of the same species in your fish tank; you’ll most likely have babies at one point.

So, how do fish mate and reproduce in the fish tank.

Well, it depends on the species…

…most kinds lay eggs that are then fertilized by the male fish as they exit a female’s body or while inside a nest, cave, plants, or on plants.

However, there is another common group of aquarium fish called livebearers (guppies, mollies, platys, swordtails) that give birth to live babies.

Usually, they are pregnant (gravid) for a period anywhere from 20 to 40 days, then release the babies into the water column.

In regard to how aquarium fish mate, there are a variety of ways, but on most occasions, the female with either lay her eggs, which are then fertilized by the males, or will be inseminated and fry will grow inside her body (livebearers) until they are ready to be birthed.

Get more insight below.

How Do Aquarium Fish Have Babies

As I mentioned above, different species of aquarium fish reproduce in either of two ways.

First, we have the livebearers like guppies, mollies, platys, and swordtails, that give birth to live one after a gestation period lasting 28 days, give or take.

Then we have other species that lay eggs that hatch into young ones.

Generally, most fishes kept in aquariums are egg-layers, though livebearers are very popular and are kept by new and seasoned hobbyists alike.

With eggs laying fish like betta, corydoras, plecos, and cichlids, you only need to know their breeding maintenance needs, including where they prefer to lay their eggs.

For instance, African cichlids and bristlenose plecos both prefer to spawn in caves. As such, having some in your fish tank is recommended.

On the other hand, fishes of the gourami family, including betta, don’t need caves because they make their own bubble nest. The male makes the nest and blow the eggs laid by the female once they are fertilized.

You will also come across some fishes, particularly cichlids, that brood their eggs in the mouth (mouthbrooders). After the female releases her eggs and the male fertilizes them, she gathers them carefully in her mouth and keeps them there until they hatch.

How Do Aquarium Fish Get Pregnant

Before we get to how some aquarium fish get pregnant, it’s imperative to note that it’s only livebearers that give birth to live young ones. As such, they are also the only species that would be visibly gravid in your fish tank.

The male livebearers, which are usually smaller in size than females, have a modified anal fin, which they use to directly fertilize the females.

Naturally, male livebearers are eager to mate when kept in a tank with females, so you do not need to do a lot to induce reproduction. However, setting up an environment that encourages your fish is recommended if you regularly need to increase your population.

How To Tell Whether Your Fish is About to Give Birth

A pregnant (gravid) fish will initially behave the same as she does normally. But as time progresses, her aggression levels may pick up, and the fish might hide more.

The gestation period is pretty short (28 days on average), and the few noticeable changes progress quickly.

The body of a gravid fish will be fuller than usual because of the fry developing inside her, and tiny eyes become visible through the stretched translucent abdomen wall just before birth.

Closer to the birth date, the gravid spot will also become large and darker, and the belly will take on a boxy, rectangular appearance, and bulge almost like it’s about to burst.

Your fish will retreat to a secluded area just before birth as she gets ready to release her fry.

How Do Aquarium Fish Give Birth

Livebearers carry their eggs inside them, that once fertilized, develop into fry, which are then released in the water in due time.

As such, mating is necessary for live-bearing fish for you to get more fish.

Temperature and light is also crucial, with the optimum setting being anywhere from 77 degrees to 88 degrees Fahrenheit.

Once the young are perfectly formed inside the mother, they lie in a semicircular position and are delivered, usually tail first, one at a time, over a period of hours.

The fry then fall a few inches through the water, quickly straighten, and either take cover among plants or sink to the bottom to hide in the sand, rocks, wood, and other decorations; read more

How Aquarium Fish Lay Eggs

Most fish release thousands of eggs, scattering them in the water where the male fish fertilize them. The eggs then develop and hatch into larvae without much help from the parent.

Even so, some species are known to provide parental care to their young, which then tend to have better survival rates. Consequently, these fishes also tend to lay a smaller number of eggs compared to other breeds.

In an aquarium environment, most egg-laying species prefer to scatter their eggs on plants, rocks, wood, or the substrate (gravel or sand), with most of them going to waste.

Therefore, keep an eye out for when your fish are spawning so that you provide them with the relevant support they sometimes require.

For instance, if you have egg scatterers that prefer to strew their eggs on gravel or sand, adding spawn mats or carpets plants like Java mosswill aid reduce the number of lost eggs.

Some species like betta and gouramis blow their fertilized eggs in bubble nests, while others like plecos, prefer to spawn inside cave-like structures.

But unlike dwarf cichlids that also use caves, plecos require a longer structure that will support their elongated shapes, preferably, a hollow, wooden old trunk or pipes.

On lesser occasions, you will also get species that hold their fertilized eggs in the mouth until they hatch. You only need to provide such species with the correct environment for breeding.

One last thing to note is that with fishes that build bubble nests, this is usually the first sign that your fish are spawning. More so, if the female fish does not destroy the nest build by a male.

What Do Fish Eggs Look Like in A Fish Tank

Fish eggs inside a fish tank look a lot like tiny balls jelled together in a slimy, thin-layered substance. They are often scattered on the water surface, though some species place them in nests, plants, or caves.

Another way to describe what the eggs look like in the aquarium, considering they may vary between species, is like thousands of tiny-round-clear-globules that range in color from white to yellow-orange.

The eggs are very sticky, probably as a survival trait. The stickiness is what helps them attach to plants, wood, rocks, and substrates.

If you want to find out whether the eggs are fertilized, look for tiny eyes inside the sac, which appear as little specks two to three days after they are laid.

How Long Does It Take For Fish Eggs to Hatch in A Fish Tank

Most fish eggs will take anywhere from 36 to 72 hours (2 to 3 Days) to hatch from the time they are laid, but depending on the species, it could go up to 7 days.

How fast the eggs hatch will also depend on the conditions of your fish tank. Usually, they bear much faster when the water is warm (tropical temperature: 74 to 80 degrees).

Thats all. See you on the next one.

Happy fish 🐠🦐 keeping.

Eddie Waithaka

Resident Content Creator and Marketer at AquariaWise who talks about aquariums and fish and aquascapes a lot.

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