Keeping and Breeding Black Mollies
Ranked #201 in Pets & Animals, #5,951 overall
Black Molly: Tips For Keeping And Breeding Them
The Black Molly (Poecilia Sphenops) is a popular color variety of Molly that is distinguished by a completely black body. They grow to be about 3" in length and do well in an aquarium that is 20 gal. or larger. Black Mollies are from a species of tropical fish that give birth to live fry called "Live Bearers".
Learn more about Mollies and other freshwater aquarium fish at Bala Shark Bay Aquarium Fish Resource.
Mollies and Other Popular Live Bearers
- Black Mollys
- The Black Molly is an aquarist favorite. They are very easy to keep and an active schooling fish. The Black Molly is a hybrid version of the Silver Molly that is distinguished by a completely black body.
- Fancy Guppys
- Today there are many different variations of the guppy. Because of the it's attractiveness and its adaptability, the fancy guppy continues to be one of the most popular aquarium fish for fresh water aquariums.
- Platys
- An extremely attractive and popular freshwater aquarium fish is the Platy. These fish are very hardy, easy to care for and easy to breed. Platys are peaceful community fish and mix well with other peaceful fish.
- Swordtails
- The Swordtail is a very popular live bearing fish. These fish can be found in most pet stores. They can be found in a variety of colors and mix well with other live bearing fish.
A Healthy Black Molly
Optimal water conditions for a Black Molly is a temperature of about 80 F. pH values between 7.5-8.2 and hardness of about 15-30 dGH. For optimal conditions add 1 tsp of aquarium salt for every gallon of tank water.
With optimal water conditions and a good mix of male and females, Black Mollies will be healthy and live longer in an aquarium.
Tips For Black Molly Breeding
A Black Molly is like other live bearing fish in that they will carry the eggs after spawning and give birth to live fry. Gestation period is typically between 6-8 weeks.To breed a Black Molly there isn't much required of the aquarium owner. A male and female will readily spawn when placed together in a tank that has good water conditions. After the gestation period the female will then give birth to as many as 80 fry depending on the size of the mother. A typical brood is usually closer to 40-50 fry. Molly fry can be fed brine shrimp and pulverized flakes.
One trait of Mollies and other live bearing fish is their tendency to eat the fry right after they are born. It is up to the aquarium owner to separate the fry from the mother to protect them from being eaten. This can be done by using a commercial breeding trap or by providing plenty of plants that will offer hiding places for the fry when they are born.
Protect Your Molly Fry
Because of the nature of Mollies to eat their fry soon after they are born it is important that something is done to protect them from mother after being born. There are a few options available to an aquarium owner to protect the fry.Commercial breeding traps can be purchased at local pet stores. These are plastic containers that float inside the aquarium. They have multiple compartments with a divider that has a small space to allow fry to pass through but not the mother. After the fry have been born the mother can then be removed and the trap can be used to hold the fry till they are big enough to not get eaten.
Special plants can also be bought at local pet stores. These plants are often called baby hides. They are plants that have small enough spaces that the fry can swim into but the mother cannot. Using plants like this is better because it puts less stress on the mother. However there is greater chance that some fry may not make it to the cover provided by the plant.
Popular Types of Mollies
- Black Molly
- Silver Molly
- Dalmatian Molly
- Orange Creamsicle Molly
- Lyretail Molly
- Sailfin Molly
- Balloon Molly
What is the Coolest Type of Molly?
The Black Molly Aquarium
- Fish Tank and Stand
- The most important part is the fish tank itself. The size of the tank will have a very big impact on the amount of Black Mollies that can be kept and how many fry can be raised in the tank before it becomes crowded. The stand needs to be sturdy and able to support the weight of the tank when it is full.
- Hood and Lighting
- The hood provides a cover for the tank and will also hold the lights for the tank. Some hoods have filters built into them.
- Aquarium Heater
- Black Mollies are warm water dwelling fish that prefer temperatures closer to 80 degrees. A heater is necessary to maintain the right temperature for the Mollies to live in. There are many different types and styles of heaters each with their own special benefits.
- Aquarium Filter
- In an enclosed aquarium environment, waste products can build up quickly. Good filtration is a must for any tank that will be the home to Black Mollies. A good filter will remove the toxins from the water and help keep the water conditions optimal for keeping and breeding Black Mollies.
- Home Aquarium Supplies
- Not just supplies. This site gives you tips on buying all the right equipment to set up a fish tank. Be sure to visit this site if you're looking at setting up a black molly aquarium.
Best Book About Black Mollies & Live Bearing Fish
Livebearers: Understanding Guppies, Mollies, Swordtails and Others (Fish Keeping Made Easy)
Amazon Price: $4.89 (as of 02/15/2012)![]()
List Price: $14.95
Add this book to your personal collection and you will always have all the answers to keeping black mollies at your fingertips. Order your copy today!
Usually ships in 1-2 business days
Buy These Great Aquarium Books
Add These Aquarium Books To Your Personal Library.
The Benefits Of Aquarium Salt
From my personal experience keeping Black Mollies I have to say that after I added salt to the water my fish were generally more healthy, more active and generally happier fish. One thing I read is that salt can actually lower stress, promote health and increase the lifespan of Black Mollies. I have to agree with that statement.
If you have Mollies and have never used salt, you can start by adding 1 tsp for every 5 gal of water. That amount for me has been a good introductory amount. If your Mollies are healthy then there really isn't a need to add all the salt all at once.
So if you keep Black Mollies in your aquarium, add a little aquarium salt. Adding 1 tsp. for every 5 gal. is my minimal recommended amount and will improve the health of the Mollies. Adding 1 tsp. for every gal. is what has been ideal for keeping my Black Mollies happy and healthy. Remember to replace the salt when you do partial water changes.
Hybrid Mollies
There are many different types and colors of Mollies found in the hobby today. The Black Molly is just one of them. Lyre-tail and Dalmatian Mollies are a couple popular ones.Hybrid Mollies are more susceptible to disease and special attention should be taken to keep tank water clean. Using salt is highly recommended to promote good health of hybrid Mollies. It is also highly recommended that the tank is fully cycled before keeping any hybrid Mollies in the tank.
Midnight Molly
When keeping and breeding this variety of Molly, it is a good idea to have a larger aquarium than the 20 gal recommendation for Short Finned Molly. This will ensure that the young males will have plenty of space to grow and develop a full sized dorsal fin.
Magazines and DVDs on Amazon
In Summary:
- Keep Black Mollies in a tank that is a minimum of 20 gal.
- Keep Black Mollies in shoals of 1 male for every 3-4 females
- Keep tank water warm at about 78-80 degrees
- Add 1 tsp. of aquarium salt for every gallon of water
- Use plants or a breeding trap to protect fry when born
- Hybrid Mollies are more susceptible to disease
- Only Silver Mollies are hardy enough to cycle a tank
Get Answers to Your Black Molly Questions

Fetching RSS feed... please stand byCheck Out These Lenses
Aquarium Supplies on eBay
Katys Tropical Fish
Katys Tropical Fish - A Complete Guide: Learn The Secrets To Setting Up And Maintaining A Professional Looking Aquarium!
Fish News From ScienceDaily
Fetching RSS feed... please stand byReader Feedback
Give us your feedback.
Please post any comments or questions you have here. All your ideas and suggestions will be taken into consideration. Don't forget to add this lens to your favorites, give a rating and even lensroll it.
-
Reply
-
TheZinc
Nov 30, 2011 @ 12:46 am | delete
- Awesome!
Mollies are great fish, but they are known for the aggressive nature. Having the right ratios are crucial for their survival. 1M/2F
-
-
Reply
-
Kimbesa
Jan 18, 2011 @ 3:21 pm | delete
- Thanks! I had black mollies years ago, and I'm loving this lens to remember those days...**angel blessed**
-
-
Reply
-
fish_problems Dec 24, 2010 @ 5:29 am | delete
- I really enjoyed reading through this! You did a very nice job :)
-
-
Reply
-
tremogg Nov 22, 2010 @ 7:44 pm | delete
- I like your lens presentation. It is informative and a pleasure to read. Thanks!
-
-
Reply
-
WebGazelle
Feb 9, 2010 @ 9:35 pm | delete
- You do not need aquarium salt for Mollies to breed. If you have a male then nature will run it's course. Mollies will eat their own fry after they are born if the fry do not have a place to hide from the mother. You should provide plenty of plants for the fry to hide in when they are born. You can also buy a breeding trap to separate the fry from the mother when they are born.
-
-
Reply
-
pepito76311
Feb 9, 2010 @ 8:52 pm | delete
- i have had my mollies for 4 months and the females look pregnant and are very big but they have been so for 2.5 months. Are my fish fat or am I doing something wrong. Is there something i need to do to bring about birthing? I have one male and he has 3 females. My tank is 40 gal altho I have not added salt. Does this make a difference?
-
-
Reply
-
AbbasAbedi
Jun 7, 2009 @ 7:23 am | delete
- Excellent Lens. 5*
If you get a chance check out my Instant Stress Management lens.
-
-
Reply
-
mw2001
May 23, 2009 @ 9:24 am | delete
- does anyone know how long before mollies are finished giving birth?
-
-
Reply
-
aj2008
May 17, 2009 @ 8:49 am | delete
- Very informative lens from someone who used to have black mollies and we had babies! Blessings from an Angel (that's SquidAngel, not Angel Fish!)
-
-
Reply
-
rms
Apr 22, 2009 @ 1:17 pm | delete
- Hi, I'm one of the Giant Squid Community Organizers and I've been visiting all of the Giants, one by one. We'd like to hear your Giant Squid Suggestions. What would be a great new Giant perk? What can Squidoo do to help you create better and more successful lenses? Please stop by http://www.squidoo.com/Giant-Squid_Community-Organizer and leave us your thoughts in the suggestion box.
-
-
Reply
-
heehaw
Jan 2, 2009 @ 2:56 pm | delete
- it's fun to rare Black Molly, nice fish lens you have. 6 star for you.
-
-
Reply
-
CoolFoto
Dec 7, 2008 @ 10:18 am | delete
- Beautiful lens. Don't know how we have missed each other until now. Please consider joining our Aquarium Fish group www.squidoo.com/groups/tropicalfish.
We would love to have you as a member. :) And of course, 5* and lensroll to my own tropical fish lens www.squidoo.com/tropical-fish.
-
-
Reply
-
Oct 28, 2008 @ 12:04 am | delete
- i have an aquarium with small fishes :) how can i make them more? how to breed them?
-
-
Reply
-
chefkeem
Oct 26, 2008 @ 2:31 am | delete
- Blessed by a SquidAngel tonight... very nice lens!
-
-
Reply
-
Couch-Covers-Melanie
Sep 21, 2008 @ 3:31 pm | delete
- Great lens! I love animals but i admit i didn't know much about Black Mollies. So i appreciate all the informations and for the great video you have here!
5* for you!
Did you know couch covers can be real moneysavers?
-
-
Reply
-
Nancy-Swigart
Sep 6, 2008 @ 1:33 am | delete
- Hi, Very interesting lens!!! I have given you 5*s. If you have time please take a look at my lens Sponsor A Horse...
Sponsor A Horse
-
-
Reply
-
Sazzy
Aug 14, 2008 @ 4:11 am | delete
- Good lens.
Informative lens
Good luck!
-
-
Reply
-
Intercambio
Jul 27, 2008 @ 4:43 pm | delete
- Another great and informative lens.
Great work!
-
-
Reply
-
ANDRI Jun 6, 2008 @ 7:54 am | delete
- great lenses
-
-
Reply
-
May 23, 2008 @ 8:01 am | delete
- Great lens, very informative, I really appreciate your effort.
InternetSurvey
secret affiliate code
-
- Load More
by WebGazelle
I love aquariums and aquarium fish keeping. I have either been around or owned fish since I was really little. I currently ha... more »
- 56 featured lenses
- Winner of 8 trophies!
- Top lens » Keeping and Breeding Black Mollies