When getting an axolotl for the first time, a question that often comes up is whether or not mixing axolotls is a good idea for your tank.
Are there considerations to keep in mind?
Are some factors more important than others?
Let's talk about that in this post.
What is the Max Size Difference for Axolotl Tank Mates?
There are a couple of general rules-of-thumb that some folks have for keeping multiple axolotls in one aquarium.
If an axolotl can fit the other axolotl in its mouth, it could be a problem, especially if the bigger axolotl is cannibalistic.
You can compare the size of the smaller axolotl's head to the size of the bigger axolotl's mouth.
If it could fit in, probably best to separate.
If the axolotl is within 1" of the other axolotl in body length, it is probably okay to mix them.
There can be exceptions to both of these "rules" and some people house axolotls together peacefully with as big as a 4" difference.
Some of it just comes down to the personality of the individual lotl.
Can Male and Female Axolotls Be Housed Together?
Once axolotls have reached reproductive age and it is possible for them to breed, there are some things you need to be aware of.
The first is that axolotls will usually breed on their own twice a year, sometimes more depending on various factors.
In the wild, axolotls would be much more spaced out, so they don't come in contact with potential mates as often as in captivity in a closely confined aquarium.
So there is a potential of what's called "breeding stress" if the animals mate too much.
Frequent breeding can result in the axolotls female experiencing a decline in health that may eventually lead to death.
This is not always the case.
In some cases, the consequences of frequent breeding amount to nothing more than increased nutritional needs on the female.
(Unlike females, male axolotls do not suffer from overbreeding as they will only breed when they are ready.)
It can depend a lot on the axolotl itself and its own hardiness.
Weaker axolotls get stressed more easily.
At what point does an axolotl mate too much?
There's not really a set definition for what constitutes as overbreeding as it varies a lot depending on who is giving you the information.
But there is a risk that the owner incurs by keeping them together.
And the owner should exercise caution in this, as by the time it gets to detecting overbreeding for the owner's specific pair, it may be too late to turn things around.
That is why it is usually recommended to house pairs separately, and only put them together once or twice a year if one is intending to breed.
How Big Should Axolotls Be to Live Together?
Here's the deal:
The general guideline for most owners is to wait until they are 5-6" in length.
At that point their appetite has become less ravenous and they are MUCH less likely to bite each other.
Mixing smaller axolotls can be done
... They would need to have constant access to food to prevent nipping.
Nipping can result in lost gills, toes and even whole limbs.
Believe it or not:
It is actually quite easy to keep them all contented by feeding them live blackworms.
The live blackworms keep them constantly eating and hunting without fouling up the water like dead or processed foods would do if left in the tank all day.
They will also grow like mad.
That tip was free, didn't cost you anything ;)
If you don't intend to keep them fed around the clock, it is probably best to wait and separate until they are big enough.
But don't worry:
Axolotls grow very quickly when fed enough!
Tips for Keeping Multiple Axolotls in the Same Tank
Some occasional nipping is normal and part of their social structure as axolotls develop a hierarchy when they are kept together, but it should never be serious or persistent, much less result in injury.
So if you happen to see a little "hop" here and there when they get near each other it's not always cause for alarm.
But there are some things you can do to help keep the peace and make everyone feel comfortable.
Giving your axolotls a place to hide is a very good idea.
1 hide per axie is recommended as a good rule of thumb, unless perhaps you have a heavily planted tank with rocks and such for them to feel secure in.
Hides block out excess light and give them a place to feel safe.
Keeping the tank interesting with lots of things to crawl around helps keep their focus away from each other and on their environment.
Things like hammocks, rocks, and safe decor for fish tanks can all be employed to create a good community axolotl tank.
And, of course, be sure to keep everyone well fed.
Well fed axolotls are much less likely to be troublemakers.
Also, choosing odd numbers of axolotls is a tip some use to help everyone get along.
Oh, and don't forget:
Adequate space is important.
Overcrowding your axolotls can be a recipe for injury, because they don't have enough space to themselves.
Axolotls utilize much more floor space or surface space than they do actual water space, so that can be an important thing to keep in mind when choosing and decorating your axolotl tank.
Having a colony of axolotls in your aquarium can be a fun focal point for your fish tank.
Observing their interactions together can be interesting and instructive.
The key is to make sure their needs are met and be observant for anyone who might be a troublemaker.