Axolotls (Ambystoma mexicanum) are some of the strangest amphibians to be found anywhere, they are large animals reaching up to 12 inches in length and 5 or 6 inches in girth!
Golden Axolotl They are in fact Salamanders and are thought to be a branch of the Tiger Salamander which has evolved along different lines probably due to environmental conditions.
Where Do Axolotls Come From?
Their natural home is somewhat limited to a few lakes in the Bowl of Mexico, Lake Xochimilco and Lake Chalco.
Both of these lakes have almost disappeared now due to the development of the city of Mexico and drainage but a few small patches and tributaries still remain of Lake Xochimilco.
Are Ax olots Endangered?
This amphibian is now an endangered species in the wild and has been classified as Cites 1 listed which means they are almost all gone from the wild.
Recently there has been some activity to re-introduce them to the remaining lake areas that survive, only time will tell if this has been successful.
Whats Do Axolotls Turn Into?
Axolotls have some quite amazing differences from any other amphibian, the most visibly obvious is that they are almost always seen in their larval stage.
Under normal circumstances the Axolotl never (or rarely) actually goes through final metamorphosis, this phenomenon is known as neoteny.
The axolotl is totally aquatic and breathes through external gills which are the frilly organs at each side of the head, they do rarely finally change to a land-living or semi-aquatic amphibian which resembles the Tiger Salamander but in nature such occurrences are rare.
Although living their entire life in the larval stage the Axolotl is still able to breed as they reach sexual maturity whilst still at this stage in development.
Axolotls can be forced through the metamorphic change with the growth hormone thyroxin, this triggers off a change which usually takes a few weeks to fully complete.
During this time the external gills are reabsorbed into the main body, the lungs develop more and their eyes become more amphibian-looking (pop out) and develop eyelids.
Can Axolotls Regrow Limbs?
Another, and more interesting Axolotl ability, is that they can completely regenerate damaged or missing body parts and even grow new eyes if they get damaged.
This is one of the reasons that extensive research is being done on Axolotl, hopefully, someday science may be able to unfold the mystery of this ability for us humans.
An interesting point here is that as soon as an Axolotl undergoes metamorphosis either natural or induced, the ability to regenerate body parts is lost.
What Colours Do They Come In ?
Axolotls come in a wide variety of colours but the natural 'wild' type colouration is blackish to mid-brown, they have also been bred in albino white, albino yellow, grey, black, tan and spotted types known as Harlequin Axolotl.
The albino forms, particularly the white ones when young are opaque and the internal organs can be seen through the sides of the animal.
How Long They Live?
Axolotl have quite a long life expectancy if kept free from disease and in the correct conditions, you can expect them to live for between 8 and 14 years so they can be quite a long-lived companion.
How To Care For Axolotls
Axolotl are entirely aquatic under normal circumstances and so fish tanks are the ideal home, as they can reach quite a large size the best size tank for a single adult Axolotl would be 18 inches long x 12 inches wide x 15 inches high and the water level though need not be more than 6 - 10 inches.
You can, if you want, keep them in a smaller tank but this may cause some stress to the animal and for the sake of a little extra money you may as well give them more freedom to move around.
Setting Up The Tank
Aquarium FilterThere are lots of types of filters available for aquariums such as under gravel filters, external filters and power filters, for this demonstration we are using an under gravel filter as they are the most inexpensive and widely available type.
Strictly speaking, the Axolotl tank doesn't need to be filtered if you are prepared to remove 15 - 20 % of the water each week but this is a time-consuming and laborious task so we're using a filter.
This type of filter is simply placed in the bottom of the tank directly onto the glass and the pipes attached.
Aquarium GravelOnce the filter is in place you can top this with 1 inch of standard tank gravel, this is where the Nitrosomonas and Nitrobacter bacteria will breed, these are useful bacteria that break down the waste from the Axolotl which is mostly in the form of ammonia.
The Nitrosomonas bacteria convert the ammonia in the droppings into nitrite which is, in turn, converted to safe nitrate by the Nitrobacter bacteria, a process known as nitrification.
It is important that this process takes place as the ammonia in the water if left will build up and your Axolotl will begin to get sick and eventually die.
An inexpensive testing kit is available for you to check the levels of nitrite in the water (the effects of Nitrosomonas).
If you have too many nitrites in the water then you may not have enough of the Nitrobacter bacteria present yet and you must remove some of the water and replace it with fresh ones until the levels have balanced themselves out.
You should replace 20% of the water which has been treated in the way mentioned below.
The tank gravel layer should be topped by a further layer (1 to 2 inches deep) of large (1/2 inch+) pebbles, this is because the Axolotl may swallow the small tank gravel as it feeds, this could cause problems as it may cut the gut of the Axolotl.
Heating ElementAxolotl like all amphibians are cold-blooded creatures, this means that their body is at the same temperature as the surrounding environment.
Ideally, they should be kept at a temperature of 18°C - 20°C all year round.
If the Axolotls are kept too cold then they may stop feeding as their metabolic rate reduces, this also means that any food consumed may not be fully digested in the gut before it begins to decompose and make your Axolotl ill.
If the temperature is too warm then their metabolic rate is speeded up and the Axolotl will feed more but it will be stressed by the high temperature.
The simplest safe method is to use an under-tank heating mat which has a thermostatic control to maintain the correct water temperature.
Water QualityThis is an important factor in keeping Axolotl in good health. Tap water is perfectly good but as it contains chlorine to kill off any unwanted bacteria (and our good ones) so it must be stood for at least 24 hours before being added to the tank, this will allow the chlorine to dissipate.
When first setting up your tank you will have non of the good bacteria mentioned above present in the gravel and filter so you must allow them to develop before adding your Axolotl.
The tank should be filled to the appropriate level with water and the filter pump turned on as if it has Axolotls in for at least two weeks, preferably three.
This will allow the bacteria to begin to develop. If you already have an Axolotl then you could add this to the tank and replace 10% of the water daily in order to speed up the process and get the natural bacteria off to a good start.
In either event, once you have got your tank established you will need to remove 20% of the water each week and replace it with fresh water that has been 'treated' using the method above, this will keep your Axolotls in good health.
PH LevelThe PH level of a given substance is the acidity or alkalinity of it, PH 7 is generally considered to be neutral. The PH scale is from 0 to 14 with PH 0 being the most acidic and PH 14 being the most alkaline.
What you should be aiming for is a PH level of around 7 (6.5 to 7.5 being acceptable).
The PH level of the water will have an effect on the nitrate and ammonia in the sense that the more alkaline the water the more toxic the effect of the ammonia or nitrate.
Simple inexpensive kits can be purchased to test the water PH level. If you find that your water is beyond the acceptable level (6.5 to 7.5) then you can remedy this quite easily with another kit designed for the purpose.
You should check the PH level of your Axolotl tank weekly until you can see a levelling out, from this point on you should test it every few weeks.
Temperature and Lighting
LightingAxolotls don't have any specific lighting requirements and the fluorescent light that comes with most aquariums is perfectly adequate.
They don't like bright lights and you shouldn't use any heat-generating lights or very bright ones as their eyes have no eyelids that can close to protect them.
HeatingHeating should take the form of either the ambient room temperature or if this is less than 18°C you should use some form of artificial heating.
This can take the form of an internal heating element which should be covered in some way to prevent the
Axolotl from being in direct contact or under tank heating which is probably the easiest and safest to use.
This takes the form of what is essentially a heated blanket with thermostatic control and a probe which is lowered into the water and switches off at a pre-determined temperature, in our case 18°C - 20°C.
If your Axolotl is kept at less than 18°C then its metabolic rate will slow, it may stop feeding and food will take longer to digest. If kept too warm it will feed more but become distressed.
Don't' keep your tank in direct sunlight as this will certainly cause the water to overheat and your Axolotl may die as a result.
CleanlinessAny food that the Axolotl doesn't eat should be removed after 24 hours otherwise it will begin to go rotten and spoil the water quality.
Similarly, any solid waste material should also be removed.
The easiest way to remove the waste and food remains is with a turkey basting syringe, inexpensive to buy and easy to use - just squeeze the end and release the pressure when over some waste.
Feeding RequirementsAxolotls are not fussy eaters, if it will fit in their wide mouth and go down their throat - they will eat it!
This doesn't mean that they should eat it however it just means that they will. Axolotls should have a balanced diet of carnivorous food as they are carnivores.
Worms, strips of meat, crickets, trout pellets, and daphnia all make good food for Axolotl but as with people - variety is the spice of life.
They require a balanced and varied diet which should include all of the above but none in excessive quantities, they should not be fed purely on worms for example as they would begin to show signs of malnutrition and will develop liver problems if fed on high-fat content food for prolonged periods of time.
You can either train your new Axolotl to feed from your hand at the surface of the tank or simply drop in sinking food, it's more fun if you train them to take from your hand though.
If you decide to feed with your fingers you should bear in mind that Axolotl have small basic teeth designed to hold food and if you wiggle your fingers too much they will try to grab them.
You won't be harmed though as the teeth are for holding wriggling worms and not for biting.
You should feed your pet Axolotl two or three times a day with a few worms, pellets etc and you will quickly find out what their appetite is like, as mentioned earlier you must remove any unused food the day after it is introduced to the tank or it will begin to sour and spoil the water quality.
Sex DifferencesThe male Axolotl when mature can be differentiated from the female by size, this depends on whether you have a greedy female or not of course!, but mostly by the swellings at the base of his rear legs (cloacal area).
The males develop quicker than the females and will be sexually mature by 12 months or so.
The female will also be a little fatter than the male as she carries a great number of eggs.
In the home, Axolotl breeding takes place between early spring and mid-summer but it must be induced by a drop in temperature of around 4°C.
There needs to be a little preparation on your part for successful mating to occur, firstly the male will need something like a flat slab of stone on to which he will deposit the sperm masses (spermatophore) and the female will want some aquatic plants on to which she can deposit her 300 - 900 eggs.
Egg LayingEventually (hopefully) the female will position her body over the spermatophore and pick them up with her cloaca (this can take a few days), around 24 hours later she will deposit her eggs on the plants you provided.
Egg CareThe newly laid eggs should be removed immediately to prevent them from being eaten and placed in a separate small tank which has a good air stone to add extra oxygen for the developing embryos and contains sterile distilled water.
It is advisable to move the eggs around with a soft stick on a daily basis to ensure that all the eggs get some oxygen.
From this point on the eggs should be kept in a cooler than normal water of around 15°C and kept away from strong light, you should if possible separate the eggs into small egg masses of around 40 eggs or so, this will allow more oxygen to get to the developing embryos.
The eggs will develop quickly and you will be able to differentiate the live ones from the dead ones by the greyish colour, any grey ones should be removed to prevent them from going bad and affecting the good ones.
Under normal circumstances, the good eggs will hatch after 14 to 18 days
Juvenile CareOnce the eggs have hatched the new Axolotl babies should be placed into a separate tank with plenty of room and a good air supply, if there is the insufficient room they will quickly begin to attack each other and heavy losses will occur.
Feeding baby Axolotl is a matter of introducing live brine shrimp (preferably) or daphnia and tubifex worms if shrimp aren't available.
As the young Axolotl develops you can start to feed small bits of liver, steak, chopped worms or other similarly small food sources.
Axolotls will grow rapidly and will reach maturity at around 7 to 12 months.
