Molly is a livebearer fish species that gives birth to live fish instead of laying eggs, as is the case with most fish. Therefore, the fish goes through different pregnancy stages, just like humans, before giving birth. As a result, it’s important to know your black molly pregnancy stages to prepare well for her delivery.
Black molly pregnancy stages include conception, embryo formation, embryo development, pre-birth, and birth. The conception stage starts when the male molly fertilizes the eggs in the female’s belly. After fertilization, the rest of the processes follow until her due date.
In the rest of this article, I’ll discuss black molly pregnancy stages and how to prepare your molly for delivery. Keep reading!
Conception is the first pregnancy stage for all mollies. The process involves successfully joining the female molly’s eggs with sperm from the male. It takes place in the female’s belly.
Conception in molly fish is an easy process that happens naturally if you have male and female mollies in the aquarium.
Male mollies are always in reproductive competition. Due to this competition, mollies mate every month. The intense mating competition among the males means you should have more females than males in the tank. As a rule of thumb, it’s recommended to have at least three females for every male in the aquarium.
It’s worth mentioning that you don’t always need a male molly in the tank for conception. Female mollies can store sperm in their bellies for future conceptions. Therefore, the fish continues to give birth even without mating.
The following is the conception process for molly fish:
- The male molly sticks the gonopodium into the female’s body.
- The male molly transfers the milt, a sticky substance that contains the sperm.
- The sperm fertilizes the female’s eggs.
2. Formation of the Embryo
After conception, the female’s eggs gets fertilized in the belly. The fertilized eggs undergoes transformation to develop into embryos.
The development of fertilized eggs in female mollies into an embryo takes approximately seven days. After this, it becomes clear that the female molly is pregnant. You can confirm this by looking for a gravid spot in the belly.
It’s normal for pregnant mollies to eat a lot. Besides eating food to sustain herself, the fish needs enough nutrients to support the developing fries.
3. Embryo Development Into Fry
As the pregnancy advances, the embryo develops into molly fries in readiness for delivery. This occurs within 20 to 30 days after conception.
Since the fries are bigger than the embryo, they make the molly’s stomach larger. At this point, you’ll start noticing a swollen belly that gradually picks on a squared shape.
4. Pre-Birth Stage
This is the point when the fries are fully grown and ready to be born. Due to the grown fries, the female molly will have a fully squared-out belly with an opaque gravid spot.
You can see the fry’s eyes by looking closely at the female molly’s belly.
5. The Birth Stage
Birth is the final among black molly pregnancy stages.
The gestation period for mollies is between 45 and 60 days, after which they give birth. The fish delivers between 40 and 100 small fries that must be protected from the other fish in the tank. Moreover, the mother molly can eat her fries since they are tiny.
How to Prepare Your Molly for Delivery
If you want to breed your molly and have many fish, you need to prepare it to deliver safely. Besides the safe delivery, you also need to protect the fries from their mother and other fish in the main tank.
The following are some tips to help you prepare your molly for a safe delivery:
Feed Her the Right Foods
A pregnant molly needs nutrients to support the growing fries and herself.
When your molly gets to around 20 days of pregnancy, you should start giving her foods with the right nutrients to support the development of the fries. At this point, the fish needs more protein in her diet.
You should prioritize feeding your molly the following:
- Newly hatched brine shrimp
- Crushed flake food
- Powdered fry food
- Vinegar eels
Separate the Molly From the Main Tank
It’s advisable to separate your molly when she displays signs of delivery. You may put her into a separate tank or use a breeding net or box to separate her within the main tank.
Separating your pregnant molly is necessary if you want to breed her for more fish. This protects the fries from being eaten by the other fish in the main tank.
Once the molly has given birth, you should also return the mother to the main tank and nurse the fries separately. The mother can eat the live fries since they are tiny. A 5 to 20-gallon nursery tank is effective for this role.
When removing the mother molly from the main tank into the separating tank, it’s recommended to get some water from the main tank. This is to avoid stressing the fish by putting it into a new environment with fresh water. Doing this can be detrimental to the survival of the fries.
Here are tips to help you keep the fries in the nursery tank healthy:
- Provide filtration: Set up a foam filter in the tank to enhance the quality of the water. The filtration system removes debris, ammonia, and nitrites. These substances are toxic and can hinder the survival of the fries.
- Consider the tank’s Size: Size is essential since mollies give birth to many fries. Keeping them congested can also hinder their survival. Therefore, it’s recommended to have at least a 10-gallon fish tank.
- Provide sufficient aquarium plants: Aquarium plants are necessary to cover up the fries. You should have artificial or live aquarium plants in the tank to provide the necessary environment for the survival of the fries.
- Provide optimum temperature in the tank: Molly fries need a temperature between 23 and 28°C to thrive. You should use a thermometer to monitor the tank’s temperature and ensure it’s within this range. If not, install a heater and keep monitoring the temperature.
- Feed the fries: You have to feed the fries so they don’t starve. The good thing is that you don’t need special food for these fish. You can crush the usual molly fish before feeding them three to five times a day. Giving your fries whole molly fish can be detrimental as they won’t swallow it.
You can transfer the fries into the main tank after at least 3 weeks. At this point, they will be old enough that other fish can’t eat them.
How to Care for a Pregnant Molly Fish
Although pregnant mollies don’t need special care, you need to enhance the quality of their lives to ensure safe delivery. You must ensure that the fish is not in a stressful environment that can affect the fries’ health or hinder the mother’s ability for safe delivery.
Here are some practices to help you care for a pregnant molly:
Ensure Optimum Tank Conditions
Poor water parameters are the main cause of stress in fish. The good thing about keeping mollies is that they don’t require special tank parameters. However, you must maintain the recommended water parameters for community tanks.
Due to molly fish’s notoriously high bio load, you must conduct regular water changes to keep them healthy. A 10 to 20 percent weekly water change is necessary to remove the toxic ammonia and nitrites that can affect the fish’s life.
As a rule of thumb, you should maintain the following optimum water conditions for your pregnant molly:
- Temperature: 21 to 27.7°C (70 to 82°F)
- pH: 7.5 to 8.5
- Water Hardness: 15 to 30 dGH
- Ammonia/Nitrite: 0
- Nitrate: <30 ppm
It’s worth mentioning that mollies can’t thrive in soft water. Therefore, you need to add minerals to the tank water if you live in an area with soft water. You can add crushed coral to your substrate or mesh bag in the filter.
Provide Hiding Spaces
An aquarium without good hiding spots can be stressful for your pregnant molly. Pregnant mollies enjoy being in the dark and isolation. You may have noticed your pregnant molly staying away from other tank mates most of the time.
Here are some excellent ways to provide hiding spots for your pregnant molly:
- Aquarium plants: Ensure the aquarium has fine-leaved plants where the fish can hide. These plants include java moss, java fern, and oriental water fern.
- Aquarium rocks: Adding and securing the rocks properly in the aquarium will provide good hiding spots for your pregnant molly. Moreover, rocks add a natural feel to the aquarium.
- Aquarium ornaments: These ornaments provide crevices where the pregnant molly can take refuge. Pipe aquarium ornament is an excellent option for hiding purposes.
Give the Fish Sufficient Food
A pregnant molly needs to be fed well to get relevant nutrients for her fry’s development. The mother also needs energy from food to carry her developing fries.
A pregnant molly’s diet should contain the following:
- Protein: The fish needs sufficient protein for the development of her fries. Some protein sources to prioritize for your pregnant molly include microworms and newly hatched brine shrimp.
- Vegetables: There are many vegetables that provide dietary fiber for fish. You should prioritize vegetables like zucchini and leafy greens.
- Usual molly food: You should not ignore the usual foods you give your molly, like flake food. Your pregnant molly needs these foods to keep her nutrient supply consistent.
Frequently Asked Questions
How can you tell if a black molly is pregnant?
You can tell if a black molly is pregnant by looking for an opaque gravid spot on her belly. A swollen belly is also a sign of a pregnant molly as it indicates that the fries are growing. You should start preparing for delivery when you notice these signs of a black molly about to give birth.
How long does it take for a black molly to give birth?
It takes between 45 and 60 days for a black molly to give birth. The gestation period of black mollies takes between 45 and 60 days, after which the fish gives birth to live fries. After birth, you should separate the fries to prevent them from being eaten by other fish or the mother in the tank.
There are five black molly pregnancy stages to monitor as you prepare for the fish to give birth. As you monitor these signs, it’s advisable to take note of the signs of a molly about to give birth for sufficient preparation.
You should separate the molly when it’s clear she is about to deliver. This ensures the other fish in the tank don’t eat the fries.