Are Mollies Schooling Fish, Keep in Group, or Solo?

Last Updated on July 2, 2022 by cmoarz

You might be wondering how many mollies you should be kept in one tank, and if you can have just one on its own or not.

Many people believe mollies are schooling fish and require large numbers to be happy, but this isn’t always the case.

Mollies are in fact not schooling fish. Rather, They are shoaling fish. The difference is small but important.

What’s the difference between schooling fish and shoaling fish?

Schooling fish are those that swim in coordinated groups, often in tight formation.

This type of behavior is often seen in fish that travel in open water, such as tuna or anchovies.

Shoaling fish, on the other hand, tend to congregate in shallower areas and do not swim in such tight formations.

Corydoras and tetras are two examples of shoaling fish. While both schooling and shoaling fish travel in groups, there are several key differences between the two behaviors.

Schooling fish are more likely to be predators that rely on coordination to hunt their prey while shoaling fish are typically smaller and more vulnerable to predators.

Shoaling fish also tend to prefer calmer waters where they can more easily hide from predators, whereas schooling fish are often found in open oceans and salt water, with several freshwater exceptions.

So, if mollies are shoaling fish and not schooling fish, how many should you keep together?

The short answer is that it depends on the species of molly.

Some molly species, such as the sailfin molly, are happier in groups of six or more.

Others, like the short-finned molly, do just fine with two to three fish.

The best way to determine how many mollies you should keep together is to research the specific species you have or are interested in.

When in doubt, err on the side of keeping more rather than fewer mollies together. A good rule of thumb is to keep them in a group of four minimum, with only 1 male for every 3-4 females to keep aggression down.

Females can also live just fine without any males at all.

Can you keep a molly on its own?

Just as schooling fish, Shoaling fish are social creatures that do best when kept with others of their own kind.

This means that, in general, it’s not a good idea to keep mollies alone.

There are always exceptions to every rule, however, and some mollies will do just fine living solo if they have to, but they won’t be happy about it.

If you must keep a molly on its own, provide it with plenty of hiding places and a tank at least 20 gallons in size.

The molly will likely be shy and stressed in a smaller tank and may not do well long-term.

Will different species of mollies shoal together?

The answer to that is… Sometimes.

Different species of mollies can and do shoal together, but it’s not a guarantee.

The best way to ensure that different species of mollies will shoal together is to introduce them to the tank at the same time when they are young.

If you add an adult molly of a different species to an established tank of mollies, it’s less likely they will shoal together.

So, if you’re looking to keep different species of mollies together, your best bet is to start them out together when they are young.

One thing to consider is if you have multiple different species of mollies in your tank, They may still be unhappy because of this.

Shoaling fish like to be with their own species and be kind.

While it’s possible for different species of mollies to shoal together, it’s not a guarantee, and they may still be happier with their own kind.

Bottom line, Are mollies schooling fish? No, They’re shoaling fish. A similar but important distinction.

How many mollies you should keep together depends on the species, but a good rule of thumb is four minimum, 3 females to every 1 male, or no males at all.