Molly Reproduction: How Mollies Give Birth and What to Feed the Fry

If you have molly fish, sooner or later you will probably notice that one of the fish has become noticeably rounder. Congratulations — your aquarium may soon have a new addition! These popular fish are known for not laying eggs, but giving birth to fry that are already ready for life.

The molly birth process itself is an amazing sight. The fry are born fully formed and immediately try to swim away to hide in the vegetation. Nature has endowed them with this instinct because in the first days of life, they can be eaten not only by other fish, but even by their own mother.

In order for the babies to survive and grow up healthy, they need special care and proper nutrition. Fortunately, feeding molly fry is not that difficult if you know a few simple rules. Let's figure out how to help the new generation of your pets safely get on their fins.

General characteristics of the species

Mollies are aquarium fish from the genus Pecilia, belonging to the order Cyprinodontiformes. The main feature of their phenotype is that mollies are livebearing fish, capable of carrying and giving birth to offspring that are fully ready for independent life immediately after birth.

In the wild, mollies look modest and inconspicuous, but thanks to the painstaking work of breeders, pet stores offer a wide variety of decorative fish species that differ in color and body shape. The color of molly scales varies from charcoal black to white and orange, and the body shape can be disc-shaped or balloon-shaped.

Some aquarists use fishing line or synthetic thread to attach the plant to driftwood or large roots.

Mollies are livebearing fish, meaning they do not lay eggs but give birth to fry that are already ready to live. Pregnancy in females is noticeable by their rounded belly and usually lasts 4–6 weeks. They usually give birth in the morning, and 20 to 100 fry may appear at a time, depending on the age and size of the female. In order to survive, it is important for the fry to have immediate access to small food — crushed granules for fry, artemia nauplii, or special dry mixtures are suitable. The main thing is to feed them often and in small amounts so that the food does not pollute the water. If there are adult fish in the aquarium, it is better to separate the fry or provide dense plants for shelter, otherwise they may be eaten.

Hornwort does not have standard roots. It can attach itself to almost any surface with its rhizoids. However, the strength and tenacity of this connection is very low. Large fish, touching the stem, can easily detach it from the surface, unless the stone is rough enough.

It contains not only iron, which is necessary to maintain the red color of Ludwigia arcuata leaves, but also potassium and manganese. Additional substances contained in the fertilizer slow down the growth of algae.

It is best to choose soft, diffused lighting, with a standard of about half a watt per liter. If other inhabitants of the aquarium require brighter light, it is better to place hornwort in shaded areas and place floating plants above it.

Mollies can only spawn at 5–6 months for females and 8–12 months for males, as this is when the fish reach sexual maturity. To avoid conflicts, aquarists choose not a pair of mollies for breeding, but four individuals: one male and three females. After a pregnant molly gives birth, fertilized eggs remain in her body, and even if the male parent is removed from the aquarium, the females can still reproduce. Pregnant mollies give birth after 20–40 days, depending on the water temperature.

Another distinctive feature of the phenotype is the ability to change sex if necessary to preserve the population.

How to distinguish females from males

Before breeding mollies, you need to be able to distinguish between males and females. Experienced aquarists use the following external characteristics as a guide:

• males are smaller in size, their anal fin is shaped like a sexual organ, and their tail fin is lush and large.
• females are larger and plumper, and their anal fin is triangular in shape.

The sex of a fish can be determined at 6–8 weeks of age, and its formation depends on the temperature of the water in the aquarium: in warm water, males predominate, and in cold water, females.

Preparing fish for reproduction

Mollies give birth and reproduce only under certain conditions, otherwise pregnancy may not occur, or the offspring will be premature. Fish can be bred in a common aquarium, but experts advise placing the parents in a separate tank so that nothing distracts or disturbs the pets. The spawning tank is prepared as follows:

• volume is selected from 60 liters;
• live vegetation is planted in the nursery;
• daylight hours should last 12 hours.
• water acidity — 7–8 pH;
• hardness – 20–30 dH;
• temperature – 26–28C.

To obtain healthy offspring, the best fish are selected, among which there should be three females and one male. The selection is made according to the following criteria:

• your pet's activity and mobility;
• integrity of fins;
• brightness and uniformity of color, absence of spots or plaque;
• fish size;
• future parents belonging to the same species.

Before transferring the fish to the spawning tank, it is necessary to keep the future parents on a plant-based diet for two weeks. Mollies begin to reproduce one or two months after being moved to the spawning tank: the male fertilizes the female with his reproductive organ, but the first attempts may be unsuccessful.

Interesting fact: molly fry are almost always born at dawn.

How to determine pregnancy

Given that fertilization does not occur on the first attempt, many aquarists wonder how to determine if a molly is pregnant. It should be noted that only fish of the same species should be bred together in order to obtain evenly colored and beautiful offspring. In pregnant mollies, the abdomen becomes significantly rounded and protruding, so it is easy to notice the interesting condition of the fish. Reproducing fish can produce offspring within six months after mating, as fertilized eggs remain in their bodies. Before giving birth, the fish becomes anxious and restless, begins to rush around the aquarium, and its abdomen takes on a rectangular shape. Mollies give birth in an average of 3-6 hours, producing each baby in turn, and it is extremely important not to miss the moment when the mollies are born – from 10 to 200 pieces. The fact is that the mother poses a threat to the babies, as she is not averse to eating her offspring, so the fish is quickly transferred to the old tank.

Interesting fact: the number of babies born depends on the size of the mother.

Caring for fry

Newborn mollies are independent and active, but despite this, caring for fry is necessary. The most important thing for raising viable and healthy fish is information about what to feed molly fry and how to care for them.

Molly offspring reach 7 mm in length, but the species' endurance is much lower than that of other phenotypes, so it is important to watch over the molly fry at first. After birth, the babies lie on leaves or the ground for a while, and then begin to move in search of food. Feed small mollies 3-4 times a day, giving small portions of the following foods:

• daphnia;
• tubeworms;
• cyclops;
• crushed dry food;
• artemia;
• micro worms;
• infusoria.

Thanks to live and protein food, the fry grow faster and will soon turn into well-fed adult fish. Feed portions are gradually increased.

Care for the fry as follows:

• Provide a 30-40 liter tank for the babies, which must have an aerator and filter.
• Set the temperature to 26°C.
• The water is changed weekly, replacing 20% of the volume.
• Place vegetation and shelters in the aquarium.

To ensure that the pets grow up healthy and resilient, the water can be slightly salted: 1 teaspoon per 20 liters. After 1-2 months, the fry begin to show signs of sexual maturity, and as soon as the owner can distinguish between females and males, the mollies are separated into separate tanks.

Breeding mollies is easy, but it is also a big responsibility. Before you start breeding your pets, you need to prepare a spawning tank and study the characteristics of the phenotype. Only by following the rules and recommendations will you soon see little mollies swimming gracefully in your artificial pond.

Breeding mollies in a home aquarium is a fun and fairly simple process. These livebearing fish are capable of producing offspring without any special conditions, making them an excellent choice for beginner aquarists.

The main thing is to ensure the safety of the newborn fry. To do this, it is better to place the female in a separate tank with dense vegetation before giving birth, and then return her to the main aquarium after the fry appear. This will protect the offspring from being eaten by adult fish.

The fry need to be fed often and well. Special dry food for young fish, ground into dust, or live microorganisms such as infusoria are ideal. As the fry grow, they can be transferred to larger foods, such as Artemia nauplii.

If you create favorable conditions for the little ones—clean water, regular food, and shelter—they will soon begin to grow rapidly and delight you with their activity, filling your aquarium with new colors.