Sexing and Breeding Your Axolotl
How to Tell the Sex of Your Axolotl
First off, how to tell if your axolotl is male or female. If your axolotl is less than a year old, then sexing it may not be accurate. An axolotl can look female for a long time then suddenly a bump will appear, and turns out it is a male.
A male axolotl will have a swollen cloaca, the area under his tail where he poops. There will be an obvious bump around the whole area, not just a small bump at the opening. A female can have a small bumpy opening, but without the swelling circling the cloaca.
The picture to the left is of a male axolotl cloacal region. You can see the slight swelling starting from the leg and reaching past the cloaca.
The tips of your axolotls toes will also change as they reach sexual maturity. A wildtype will get white toe tips, and lighter coloured axolotls will get black toetips. However, this isn't always an accurate indicator that your axolotl is ready to be sexed or bred.
As in the picture bellow, you can see the left two are female, with their rotund bellies, and the two males on the right, with their skinnier, longer bodies.
The number one thing about axolotls is that they won't breed when you want them to, they will when you don't want it, and they will start breeding when you've given up hope of them ever reaching sexual maturity. The main point is that each axolotl will breed when it is ready.
However an important thing to keep in mind is to not let your axolotls breed before they reach 18 months of age. While they can hit sexual maturity at about a year old, it is incredibly stressful on their bodies to give birth so young. They have not finished growing, and breeding so young, especially for females, will take it's toll, stunting their growth and shortening their life spans.
It is best to keep males and females separated until this time, either by a tank divider, or separate tanks. After breeding, the female should be separated from the male, for a few months, to give her body time to recover.
There are two breeding seasons for axolotls each year, which varies depending on where you are in the world. In New Zealand, the first starts around mid-february, and the second begins around June-July, and can last through until September. Breeding occurs with seasonal change, so sometimes axolotls can be tricked into breeding by simulating these changes, such as temperature change and light duration changes. If the tank drops or rises a few centimeters, it can spur them on. In this same way, if you shorten or lengthen the amount of light they get, it can trigger mating. However, these only tend to work on the male, and he won't always convince the female to breed.
A supposed method for initiating breeding quickly is to keep the male and female in separate tanks until breeding age. When you introduce them into the same tank, that first meeting can influence mating.
The axolotl mating ritual is an interesting one, and a tank full of randy lotls is a sight I don't really want to see again. It starts with the male laying spermatophore, small conical packets of sperm, and doing a seductive dance of sorts, moving around with a rigid, pink tail, bumping the females cloaca, and trying to guide her onto the sperm packet. What I witnessed was a conga line of axolotls with their faces in each others cloaca, all red tails, gills bright with bloodflow, swishing their tails side to side. This sight alone was strange because axolotls often sit completely still, only moving their tails to swim around. I felt like I walked in on something secretive, and wish to forget it.
If the male is successful in his seductions, anywhere from a few hours to a few days later, the female will begin to lay eggs. A good indicator of a pregnant axolotl is when a normally docile axolotl restlessly swims around the tank, not only side to side, but going up onto things as well, like she is hunting for egg-laying places. When she is ready to lay, she becomes quite bouyant, and moves around the tank, fixing eggs to plants and anything stable enough. Laying can take several days. A female can lay up to 1000 eggs, so be prepared for a messy time.
It is best to remove the eggs from the main tank, kept attached to the plants if possible. If you intend to raise those eggs, it is time to start separating them, prepping tanks for eggs, and securing a live food source or 3 asap. For advice on raising axolotls from eggs, look here.
Tail Boner (Sir Lancelotl of Chai)