Pet Axolotl Care

The Amazing Axolotl
Biology

Axolotls (Ambystoma mexicanum) are a very interesting aquatic salamander from Mexico. This amphibian has a very restricted natural range, living only in an isolated lake in Mexico City. This lake, named Xochimilco, has been reduced to polluted canals filled with introduced predatory fish. Axolotls are listed as endangered, however this species has been bred since the 1830s and all Axolotls in captivity today are captive bred. These salamanders do not go through the normal amphibian life cycle; they do not undergo metamorphosis and remain in the aquatic larval stage and reproduce without becoming adults. This ability is called neotony. Axolotls can be made to undergo metamorphosis by putting iodine into the water or adding a hormone called thyroxine into their diets. Individuals which have been made to undergo metamorphosis resemble and behave in a similar way to tiger salamanders to which they are related. Axolotls have been known to live for up to twenty years in captivity, their lifespan is somewhat shorter when kept in a warmer climate.

Appearance
Axolotls are very strange looking creatures and that is part of their appeal. They have feathery gills on each side of their head which take oxygen directly from the water to the blood stream. Axolotls have primitive lungs and will supplement their oxygen intake by gulping air from the surface of the water. Their natural colour is a dull brown; however they come in a variety of colour morphs including: albino, leusistic, golden, piebald, harlequin and melanistic. Scientist recently genetically engineered an Axolotl that has a small amount of jellyfish DNA; these animals possess a green fluorescent protein which gives them an emerald green body and green eyes. The gender of the animal can be identified by physical features, for example males have longer and narrower heads than females, their tails are longer and the swelling around their cloaca is bigger. There are certain species of salamanders which people could mistake for Axolotls. Tiger Salamander larvae look similar to the wild phase Axolotl and are often sold in their larval stage; they are called mudpuppies in the pet trade. Various species of cave salamander could be confused with albino Axolotls. Cave Salamanders are not albinos; they have lost their pigment due to living in dark caves and are very slender (Axolotls are quite chunky). Novice herpers could confuse Axolotls with other aquatic salamander species that have external gills like Lesser Sirens and Two-toed Amphiumas. In the pet trade Axolotls are sometimes referred to as Mexican Walking Fish, which is very misleading in a number of obvious ways.

Regeneration
Axolotls can regenerate lost limbs and other body parts such as bites taken out of their tails. It takes only 8 weeks for an Axolotl to regrow a damaged limb, the closet a human being can come to this is an expensive bionic limb designed by NASA. The regeneration abilities of these creatures are due to the fact that they stay in a larval state and therefore have a higher number of stem cells.
Behavior
Like other aquatic newts and salamanders Axolotls are not very active and spend most of the day on the bottom of the tank or floating about in the mid level water column. Axolotls hunt by scent and will search out suitable food. Sight also plays a part in hunting as movement is seen as a sign of a prey item. If you wiggle your fingers in front of your Axolotl it will often strike at your fingers. Dont worry an axolotls bite is harmless and does not hurt at all. Once an Axolotl has found its prey it will suck it up in a violent gulp, food is not chewed and prey items are limited to the size of the axolotls head. These amphibians can take surprisingly large prey for their size
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The Next Generation

Axolotls practice external reproduction as do all amphibians. They do not go into amplexis like frogs and toads; neither do they eject large amounts of sperm and eggs. The males drop a spermatophore onto the bottom of the lake, or tank. A spermatophore is a cluster of sperm incased in mucous. The male will then lead the female over the spermatophore which she will pick up in her cloaca. The female will lay between 300-600 eggs which will hatch after two weeks when kept at a temperature of 20 Celsius. If fed generous amounts of aquatic insects, these babies will reach sexual maturity within 1 year. Only a very small percentage of the young would reach breeding age in the wild due to predation and environmental factors. Captive bred specimens have a high survival rate as long as they are cared for properly. Do not breed your Axolotls if you are not able to take care of large numbers of fast growing salamanders that may be in your possession for longer than you may think.

Aquariums

Axolotls are one of the easiest amphibians to maintain in captivity, they are fully aquatic so some prior knowledge of aquariums is beneficial. They require an aquarium measuring 60cm x 30cm x 30cm, for a single adult. It is sometimes recommended to only fill the tank 2/3 full to allow your Axolotl to reach the surface in order to breathe air; however I kept my axolotl in a tank that was completely full for many years without problems. The water must be kept clean using a box filter or an internal power filter that has been modified by attaching a spay bard to the outflow of the filter to reduce the speed of water circulation in the aquarium. You will have to perform regular partial water changes to maintain water quality regardless of whether you have a filter or not. This task cannot be avoided as Axolotls produce a lot of waste for their size. When changing water always use a dechlorinator to get rid of chlorine and heavy metals which are present in tap water, these elements are harmful to aquatic animals. Use pea size gravel as a substrate, it comes in a large variety of different colours. Adding live plants and snails will create a balanced environment, plants that can be used include Java Moss and Oxygen Weed. Golden Apple Snails are widely available and thrive in Axolotl aquariums; they will help reduce the amount of algae on the sides of the tank. Lighting will be needed to maintain the plants; a standard fluorescent light designed for aquariums is more than adequate as Axolotls do not require exposure to UVB lighting. Do not keep fish with your Axolotl as it will eat small species such as guppies and larger species such as goldfish will be constantly harassed and will end up with severed fins. Fish will peck at your Axolotls gills causing damage. Keeping Axolotls together will result in bitten off limbs. Leg and fin biting is more prevalent in young animals. Adults will eat smaller specimens so keep similar sized animals together. Do not attempt to keep Axolotls in a garden pond; they will not survive due to warm water temperature and poor water quality.
Food and Feeding
Feed your Axolotl on the following: mealworms, frozen bloodworms, earthworms, crickets, guppies, cubed beef, chicken breast and turtle pellets. Out of all these foods earthworms and bloodworms are the best foods you can give, these food items are relished and will get the best feeding response. Mealworms are readily taken and can make up a part of a balanced diet, however giant mealworms are not recommended as a food item. Crickets and turtle pellets are generally disliked in my experience, crickets float on top of the water and try to climb out of the tank and my axolotl simply ignored the turtle pellets, which are expensive. Guppies are relished, but are very expensive to buy and Axolotls find them difficult to catch. Lean meat, such as chicken breasts and cubed beef are convenient foods but make the water very dirty. Feed your pet three to four prey items three times a week, the prey should not be larger than the length of your Axolotls head. Axolotls do not require calcium or vitamin supplements. Supplements in powder form would wash of food items. Do not over feed your Axolotl as they are enthusiastic feeders and will soon become obese. Remove uneaten food to prevent the water from becoming dirty.

Keep Them Cold
Axolotls do not tolerate warm temperatures. In fact, the water temperature in your tank should ideally be less than 20 degrees Celsius. If kept above this temperature for more than a day or two, your pet will suffer from anorexia, disease and eventually death. Wounded or sick individuals heal quicker at lower temperatures. An Axolotl that I owned, developed gill deformities which I am quite sure was related to high water temperatures. To keep the tank cool you can purchase a water chiller however they are expensive to purchase and use a lot of power. Alternatively during hot summer days you can place cool drink bottles filled with ice or cooler blocks in the tank to lower the water temperature. You will need to increase the amount of aeration in the tank during summer as there is less oxygen in warmer water. An Axolotls gills will grow longer in warm weather and shrink in colder weather, this has to do with the difference in oxygen levels in the water in relation to its temperature.

Health
Health problems are limited to injuries from fights with other Axolotls, fungal infections and on rare occasions bacterial infections. Axolotls will regenerate any injuries on their own but you should wipe the wound with an antiseptic such as Savlon. Fungal infections can be cured with anti fungal medication which you can find in the fish section of most pet shops. Bacterial infections most often occur in high temperatures and are treated with antibiotics which are added to the water, you can use the same antibiotic tonics that are designed to treat infections in ornamental fish. There is a possibility that youre pet can get infested with fish parasites such as ick or fish lice, add an anti-parasitic tonic to the water to get rid of these unwanted guests; these are available in the aquarium section of your local pet shop.

Yes Permits are Required
Axolotls are a black listed species and you will have to get a permit issued by Nature Conservation in order to keep them legally. Unfortunately the current laws do not favour the private keeper. Permits are not easy to get and you would have to come up with some justification for wanting to keep one. Reasons could include: scientific research, educational purposes and public display in a zoo or reptile park. CITES permits will be required to import or export these animals to and from foreign countries. Once you have successfully navigated your way through this legal maze and have finally got your permit, where do you get an Axolotl?

Acquiring an Axolotl
Due to the legal restrictions discussed above, Axolotls will not be seen for sale in a pet shop. The best place to look for one is the internet. Search online classifieds and place wanted adverts on reptile forums. Always include some kind of disclaimer stating that permits are required when posting wanted ads. I did a quick Google search and there are a lot of Axolotls for sale on free classified sites, mainly in Johannesburg. Finding a seller nearby is a must as Axolotls should not be transported in hot cars for hundreds of kilometers. Transport your Axolotl in a square plastic container filled with dechlorinated water. Keep your new pet cool during the journey to its new home. Make sure the tank is set up before you bring your new pet home. Give your new arrival a day or two to acclimatize to its new home before feeding it.
Are Axolotls Really an Invasive Species?
Due to the fact that Axolotls evolved in an isolated environment, originating from only two lakes, it is unlikely they have got the capacity to become a real threat in a totally different ecosystem. The fact that they have been bred in captivity for 180 years and have been kept in huge numbers by hundreds of scientific institutions and thousands of private keepers without any problems whatsoever proves that they are quite safe to keep in captivity. This species has not been successfully introduced into water systems in regions with cold water, let alone regions with warm water. Axolotls are not suited to our hot, oxygen starved, silt filled dams and lakes. These amphibians inhabit shallow water which is warmer and has lower oxygen content than deeper water zones. As we have seen on the news there is raw sewerage flowing into our river systems that harms not only indigenous species but alien species. Other forms of water pollution such as agricultural run off affects all aquatic animals. Amphibians are very sensitive to changes in water quality and there permeable skin allows toxins to enter the bloodstream easily. Captive bred specimens are unlikely to carry diseases. Wild Axolotl numbers have been decimated by introduced predatory fish. Here is a short list of freshwater predatory fish which live in South African lakes: Barbel, Small Mouth Bass, Large Mouthed Bass and Tilapia. Both species of bass are non native species. Egrets, Storks, Fish Eagles, Large Kingfishers, Terrapins and Hatchling Crocodiles would eagerly prey on Axolotls. Juvenile Axolotls and Axolotl eggs would satisfy the appetite of small fish and dragonfly larvae. Albino or other colour morphs would be picked off very easily as their unnatural colours make them more visible to predators. For a species to become invasive it must be able to maintain a long term breeding population. An Axolotl that is released into Zoo Lake and survives for 3 months and then dies from heat stress does not constitute an introduction in my eyes. I personally believe that Axolotls should be taken off the invasive species list or at least its status as an invasive species should be reviewed.

Conclusion
These rare and unusual salamanders are a popular pet in many countries and are of great scientific importance due to their regenerative abilities. It is a shame that they are labeled an invasive species and that they are generally unavailable to the private keeper. Since Axolotls are aquatic and are kept in aquariums they can get fish keepers interested in herps. Keeping one opens your eyes to a family of animals (salamanders) which do not occur anywhere in Africa. If you get the chance to keep an Axolotl it will amaze you and your friends for years to come.

By Timothy Zedi
www.timsreptiles.co.za