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You are watching: How long do molly fish stay pregnant

Did you recognize that end 12.5 million (source) family members in the US store fresh-water fish together pets?

And in as lot as world rear different species of fish, mollies are the most well-known fish in aquariums. This is mainly since they room beautiful, cheap, easily available, hardy and most importantly, easy-to-breed. Additionally, mollies have actually quite a tranquil temperament, which renders them right for ar aquariums and tanks

Nonetheless, you’ll need the right details if you to prosper in rearing mollies.

Here are several pointers to overview you during your mollies’ breeding periods:

Molly Fish Gestation Period

Molly Fish Gestation Period

Mollies breed via internal fertilization– the eggs get fertilized by the sperms, develop, and also hatch in ~ the female’s body.

As such, mollies nothing lay eggs, however the young persons come the end swimming after hatching occurs internally. The gestation period for pregnant mollies is about 60 days. A mrs molly can store sperms for lengthy periods so the it impregnates itself every thirty days.

Still, over there are species of mollies through 50-70 days lengthy gestation period. One instance is the Dalmatian molly fish, i beg your pardon births young ones come out all set to live like adults.

What’s more, many female mollies relax close come 60 newborns, recognized as fry, at a time. Most newborns space usually small-sized copies of adult fish. However other fried food mollies can have different shapes and also colours depending on the parental fishes that mated through each other.

Check the end my thorough guide on exactly how to each other molly fish in residence aquariums.

How to Tell once a mrs Molly is Pregnant?

Since females store sperms, many mollies you’ll uncover in stores are already pregnant.

To confirm if her mollies space expectant, inspect for the following signs:

A swollen stomachThe female fish adopts unusual behaviours choose spending a many time near the heaterA triangular dark spot appears near the anal ventThe fish is much less active, eats more, and secludes chin from various other fish in the tank

Also, you can spot the fry’s eyes close to the anal vents together the ship grows bigger and also stretches out.

Molly Breeding period Diet

During pregnancy (gametogenesis), many female fish require a diet it is richer than usual in lipids and proteins.

This is due to the fact that these aspects are the main source of nutrients for the occurring embryo, specifically at the at an early stage larval stage. The lipid and proteins acquire progressively stored together yolk, i beg your pardon the emerging embryos feed on. Therefore, moist food and also dry pellets room the most ideal food alternative for ‘expectant’ molly fish.

For the pellets, go for products with nutritional facets such as n-3 PUFA (poly-unsaturated fatty acids), due to the fact that they are vital for the breakthrough of an ideal larvae. If you feed her pregnant fish a poor diet, their bodies use the perivisceral fat, which is rich in fat acids for yolk production.

The an outcome is poor-quality eggs as well as reduced larval viability.

How to treatment for newborn Mollies?

Care because that Molly Fish Fry

Take note that mrs mollies don’t treatment for their young ones.

Once the young ones gain hatched, they space on your own. This is why it’s command to develop a breeding system that will certainly protect and also nurture the fry. Psychic you, mothers and other adult fish have the right to feed on the fry.

Now there room two significant kinds of reproduction apparatus you have the right to use:

The Breeder Box

Also recognized as breeder net, the breeder box is a little container the gets inserted in her aquarium to quarantine off the pregnant female.

The finest time to place a woman in a breeder box is when she is exceptionally close to providing birth. This enables the molly fry to fall (after obtaining hatched) straight into a small, isolated chamber the protects them from any kind of harm.

The fried food can flourish in the different chamber unabated it rotates adulthood.

The Nursery Tank

Nursery tanks optimize your possibilities of raising healthy and balanced and solid molly adult fish.

The ideal nursery tank because that molly fry is a six- come ten-gallon tank. And the most critical features in the tank include:


The filter is quite essential in any type of fish tank. Its key purpose is to remove decaying organic matter, free-floating particulate, overabundance food, waste, and also dangerous chemicals.

If this waste matter doesn’t gain removed, the toxicity in the water build up, and also when high enough concentrations, it poisons the fry.

Ensure that your filter has actually a filtration foam so that the tiny fry don’t gain sucked up v the waste.


Whether herbal or artificial, plants cover and also protect the fry during the at an early stage days after ~ hatching.

Thus provides sure to have broad-leafed plants like Java ferns set up in her nursery tank. Also, float number of plants so the newborns get an area come hide instantly after the mother provides birth. Fried food are naturally programmed come hide for a while after birth.

They will also avoid anything the moves as lot as possible.


Because mollies are tropical fish, it’s essential to produce a dry climate for them and also the fry.

This means keeping the tank water at a temperature the 72 to 80 levels throughout. Consequently, you’ll require a water heater and an aquarium thermometer to ensure that the warm temperature is consistent.

All in all, preparation is an essential when it comes to creating the best fry-care environment. Separating the pregnant fish from other adult fish saves you the effort and time of make the efforts to move newly-hatched fry. Therefore invest in a nursery tank or reproduction box immediately you acquire yourselves a

Raising the Molly Fry

It’s recipient to begin feeding her fry appropriate after they get born.

The best component is the newborn fries have actually a similar diet to the of adults. Still, you’ll need to feed lock in incredibly small-sized amounts so that they deserve to ingest the food easily. Most molly owners go for optimal quality flakes and fish-food for your fry.

Alternatively, you feed them infant brine shrimp. However ensure that all the food is either ground or churned thoroughly prior to feeding the fry. You should only feed them food that is in flour form.

Additionally, strive to keep a continuous feeding schedule. It’s preferable to feed fry a pinch the food number of times a day. Other things the you should incorporate while caring for newborn mollies include:

Changing the Water

Even with a filter, it’s an essential to adjust your tank’s water routinely to save the fry healthy.

With this in mind, replace the fry’s water v water from your traditional aquarium so the the newborns begin acclimating come their eventual home. It’s ideal to change around twenty every cent that the water in the nurturing tank every day. So if you own a ten-gallon aquarium, take it out two gallons a day, and replace it using the very same amount native your constant aquarium.

Watch the Growth

You shouldn’t present the fry to the traditional aquarium till they’ve grown come a dimension that’s larger than the mouth the adult molly fish.

In essence, the takes around one to two months for fried food to become large enough for traditional aquariums.

How to move Fry come Nursery Tank

When it comes to moving fry from the nursery tank come the conventional aquarium, one of the safest methods involves:

Finding a breeding Trap

The breeding trap acts together the acclimating medium when relocating the fried food to the regular tank. Ensure come rinse or clean the trap before placing that on the next of the preferred aquarium. Clean the trap guarantees good health because that both the adult fish and also the brand-new fry.

Transfer the Fry

Using a typical aquarium net, deliver a couple of fry come the breeding trap.

Make certain to relocate several fried food at a time so the the trap doesn’t obtain so overcrowded that the fry can’t swim roughly comfortably.

Acclimate the Fry

Let the fried food acclimate for about one hour before releasing them right into the aquarium.

Acclimatization permits the fried food to change to the change in their atmosphere including the PH, temperature, humidity, pH, and altitude.

Sexual Dimorphism: informing the Difference between Female and Male Molly Fish

As the fry prosper into full molly adults, the paramount to understand the sex of every fish for reproduction purposes.

Male Molly Fish

Both male and also female mollies have unique features the make it straightforward to identify them. Firstly, males have actually a an ext torpedo-shaped human body while females attribute bulky figures. Also, males have actually a pointed gonopodium- amendment anal fins for mating.

Also, leading male molies grow big fins and have a an ext intense herbal colour. The fins obtain used during mating reflects or once showing prominence over other males. Top top the various other hand, females have much shorter fins.

Female Molly Fish

In fact, their anal fins space triangular while they feature a wider abdomen behind for breeding purposes. What’s more, females embrace a lumpy, bulging appearance as soon as pregnant. In regards to colour, the females have the right to have a pale, or pale bluish colour.

But it’s typically softer and lighter when contrasted to the of masculine mollies. Moreover, males attribute blazing-hot red coloured pectoral fins while females have no colour on their pectoral fins.

Final think on Pregnant Mollies

In as lot as mollies room arguably the ideal breeding livebearers, your success rearing them depends on exactly how well friend prepare for your females’ gestation periods.

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To get healthy and solid fry, constantly ensure the the fish are in a appropriately cleaned environment. And also don’t forget to feeding them appropriately.