Care Guide for Mollies: Feeding, Breeding and Tank Mates
One of the most popular aquarium fish found at pet stores are mollies because of their wide selection of colors, energetic behavior, and ease of breeding. If you are looking for a livebearer (or fish that bears live young) that is bigger than a platy but smaller than a swordfish, then mollies strike a happy medium. While molly fish are fairly easy to care for, beginners sometimes struggle with them, so find out the secret to caring for mollies and successfully breeding them in your home.
What is a Molly Fish?
The livebearer is prolific in all water habitats, including saltwater and brackish. It can be found from the Southern United States up to Columbia. Their bodies are more compact than platies, and they can grow up to 4-5inches (10-13cm) in length. They are surprisingly good at cleaning aquariums, constantly scavenging for leftovers and pulling off hair algae with their flat mouths.
What are the different types of mollies? The most common species in the aquarium trade include Poecilia sphenops (short-fin molly) and Poecilia latipinna (sailfin molly). The hybrids can be selectively bred to produce black, dalmatian and balloon mollies, as well as gold dust, platinum, creamsicle and other varieties.
Mollies are very popular because they come in a multitude of colors, patterns, and shapes.
Do mollies need salt in their water? Many fancy mollies are bred in overseas locations where salt water is cheaper than fresh drinking water. Therefore, the fish farms often raise them in brackish water that has both high pH and GH (or water hardness). When these brackish-bred mollies are transported to wholesalers, fish stores, and home aquariums that use fully freshwater setups, the change in water parameters can cause their kidneys to shut down. Your mollies might not experience any problems if they have hard tap water. However, mollies who have soft tap water may be susceptible to diseases such as ich, livebearer disease, and white spot disease. We recommend adding Wonder Shells and Seachem Equilibrium to soft tap water users. This will increase the levels of calcium, magnesium, as well as other beneficial minerals, in the fish tank.
How to Set Up an Aquarium for Mollies
Depending on the type of molly fish, we recommend getting an aquarium that holds at least 20 gallons of water, but a 29- to 55-gallon tank is more suitable for larger species. For most homes, they require an aquarium heater to raise the temperature to 75-80degF (24-27degC). Given their high tolerance for salt, they also prefer higher pH, KH, and GH.
How many molly fish should I have? As with many livebearers, mollies love to breed, so we recommend getting at least two to three females for every male. This allows the girls to have a break from their constant attention. The gonopodium is a stick-shaped male anal fin, while the gonopodium of a female anal fin is fan-shaped.
Male (left) and Male (right) sailfin moles
Are mollies known to nip other fish’s fins In general, mollies can be peaceful fish. They are active, however, and will often nibble at food to determine if it is edible. Therefore, slow-moving, long-finned fish may not be the best tank mates for them.
What fish can you put with mollies? They do well with other community fish that live in similar environmental conditions and are close in size to avoid predation. Ours have been kept with cory catfish and cory catfish as well as tetras (tetras), loaches, barbs and other livebearers. You should not put larger mollies together with smaller animals such as cherry shrimp, because they are more likely to be eaten.
What do Molly Fish Eat?
Mollies are not picky eaters and are first in line to gobble up anything you drop in the aquarium. Mollies are omnivores and need a variety of protein and vegetable options. If your mollies have strings of normal-colored poop hanging down from their bodies, it is possible that they are being overfed. You might need to reduce their portions. Also, if you find they are outcompeting other fish for food, consider feeding fish foods that scatter all throughout the tank to give other animals a chance to eat.
Balloon moles are bred to be rounder. Check the amount of waste they produce to determine if you’re overfeeding.
How to Breed Mollies
Hobbyists joke that all you need to do is add water and livebearers will multiply. Make sure to have at least one male fish and one female. Then wait between 30-60 days for your baby fish to arrive. While a new female might only give birth to a few fry, a veteran mother can have more than 50 offspring. The adult mollies will predate on their own young, so increase their survival rate by providing lots of dense aquarium plants like water sprite, water wisteria, and Pogostemon stellatus ‘octopus’ as hiding spots.
Baby mollies may be born with relatively drab colors at first, but they will quickly develop the vivid hues of their parents.
Livebearer fry, unlike the tiny fry that hatch out of eggs, are larger and can eat crushed flaflakes, Easy Fry, Small Fish Food, Repashy Gel food (in powder form), or live baby brine shrimp. It can take between four and nine months for a baby mole to reach its juvenile size and be ready to be rehomed, depending on how much food was eaten and the temperature of the water. Learn more about how to sell your extra mollies in our article on How to Breed Aquarium Fish for Profit.