Care Sheet & Photos provided by Zen Reptiles
Axolotls are one of the most unique vertebrates on the planet. Their genome is so complex, that they are studied extensively for their self-regeneration ability. These exceptional creatures are able to grow back limbs, gills, even body parts as complex as an eyeball, with ease.
They are a sad and compelling example of human interference in the natural world. Despite their natural gift of regeneration, there are less than 500 remaining in the wild. Axolotls are expected to become functionally extinct in their native range by 2017. This has been due to pollution & the introduction of tilapia to their native lakes.
They are completely aquatic & make an excellent, easy to care for pet. Despite being aquatic, they do not take as much attention as fish.
Axolotls (axies) are a critically endangered mole salamander from Mexico’s Lake Xochimilco. This lake is the last remaining native axie habitat, a unique endorheic basin; a body of water that does not drain into the ocean. Being close to Mexico City, this unique habitat has turned into a deathtrap, full of pollution & trash that cannot drain out of the lake. The native population has introduced tilapia fish into the lake as a food source, which eat axolotl eggs & babies. Axies are expected to become functionally extinct in the wild by 2015-2020.
Most lakes in the world flow into the sea by rivers or streams. Being endorheic, Lake Xochimilco retains water until it is dispersed underground or evaporated. This has created a unique habitat in which axies evolved in a never-ending abundance of water – which means they remain in their larval stage their entire lives because they never had to go on land to breed. Most salamanders are subject to wet & dry seasons, with their water supply often drying up; forcing them to go on land to survive.
The majority of salamanders, such as the closely related Tiger Salamander, morph into terrestrial form to travel across land & breed. Lake Xochimilco also has a very low iodine content*. Iodine acts as an ‘activator’ for metamorphosis in some salamanders, so this lack of iodine in the lake has also contributed to the axolotl’s fully-aquatic nature. Axies reach sexual maturity in the water – remaining completely aquatic their entire life. They keep their gills which they breathe oxygen through.
Note* when adding salts & minerals to your aquarium water, make sure to use non-iodized versions.
Axolotls As Pets
Axolotls are ‘People Safe’…meaning they don’t have teeth, no claws, they do not bite & they are not poisonous. They live an average lifespan of 7-9 years. It is quite something that they will be extinct in the wild in the coming years, but can live a happy life in your living room.
A 10 gallon aquarium is ideal for 1 axie. They are social creatures & can be kept in groups. Even with mild aggression, even the unlikely loss of a limb does not phase an axolotl; it will regrow in a few weeks. 20 gallons is fine for 2-3 adults. 40 gallons for a group of 3 or more. The bigger the better.
Your aquarium should be at least 60% full of water or have a 4 inch gap at the top so they can’t jump out. The water should be aerated with a simple bubbler or a low-flow filter that aerates, such as the Fluval U1, or an internal filter with a spray bar. Lake Xochimilco is a cool-water lake & warm water will kill your axie. Temperatures should be between 62-72F – this can be achieved simply by having no heater in the tank.
In the summer, frozen bottles of water can be placed in the water to act as an ‘ice cube’ to cool it down – or keep them in the basement. You can use fine sand such as silica or fine-grade aquarium sand, or large smooth river stones. Slate or Tile is cheap & can be cut to size, this is the best option. You can also keep nothing on the bottom.
Lake Xochimilco has relatively hard water – this means there are a lot of dissolved minerals in the water. Soft water can kill your axolotl. To attain the proper water parameters, you can purchase Fluval Shrimp Mineral or similar products, Catappa leaves are an excellent addition, so is Mopani Wood.
With a bubbler, 50% water changes can be done once every few weeks; or 20% per week. With a filter, 50% can be done once a month, or 10% per week. This depends greatly on the amount of food being consumed, the amount of axies in the aquarium, and whether or not Tadpole Tea is used. It is best to do your own water tests to determine the best water change schedule, you will want to check for Nitrites & Ammonia. You can have water tests done for free at most pet stores.
In the event of a water quality crisis which is noticed by either a foul smell or cloudy water, (generally from overfeeding, or overheating), you can change out 90% of the water. It is important to always keep at least 10% to keep beneficial bacteria in the tank. Beneficial bacteria will establish naturally – it is wise to add in some fish to ‘cycle’ the tank, such as danios or white cloud minnows. These fish should survive several days before being eaten, and the act of being eaten/digested/excreted will help establish good bacteria in the water & filter.
Axolotls don’t require strict water parameters like fish, and can handle more vigorous water changes than fish. They can also go longer without as many water changes as fish require.
Baby axies will only take live food for the first several weeks, this is important to know if you are offered baby axies, or plan to breed them yourself. We raise brine shrimp, microworms, daphnia & gammarus shrimp for this.
Axies can be fed a small amount of food every 2-3 days (1 tsp), or a large meal every 4-5 days (3 tsp). Remember that the more you feed them, the worse their water quality will be. Live or frozen worms & shrimp, sinking trout/salmon pellets, guppies & minnows can be offered. You can use tongs to feed them crickets. Avoid any insects with a hard or waxy exoskeleton or shell (beetles, superworms, snails) as axies have difficult digesting this.
Axies open their mouth quickly to create suction like a vacuum, sucking in everything in front of their mouth like a quick trap.
Gravel & course sand should never be used for axies because they will swallow some and choke.
This causes impaction, which is a buildup of foreign material in the digestive tract, and will cause bloating & death.
We have started keeping cherry shrimp as food for young axolotls. They seem to be nutritious & make an interesting pet themselves!
Axolotls can go without food for some time, and if you need to leave them during a vacation it’s a good idea to add a few fish such as zebra danios into the tank.
This is probably what draws people to axolotls the most. Due to extensive breeding in labs, axolotls have shown many genetic mutations such as leucistic, albino, melanoid, golden albino, piebald, calico & even GFP (glowing).
Axies have one of the most complex genomes on the planet. They are essentially ‘made of stem cells’, able to grow lost limbs & damaged organs with ease. They are studied extensively in labs & universities for their regenerative qualities, which is ironically the only reason they will survive extinction. It is sad such an amazing animal is being lost in the wild only to survive in labs & aquariums.