Erdington Aquatics

AXOLOTL

By Josh Mayfield, an American author (Last update 1999) at: http://inky.50megs.com/axolotlfaq.html

Sentences in red have been added by me. All images are of stock taken over the past few months. References to one or two companies are obviously US based.

These are the questions that I hear the most often from people who've never seen or heard of axolotls before.

What the heck is that thing?

An axolotl, of course! More specifically, it's Ambystoma mexicanum, a salamander unique to some areas of Mexico. My axolotl is white, with fluffy, red gills. Most axolotls are a darkish gray, though, and some have brown and white splotches.

What kind of name is axolotl?

Nahuatl, the language of the ancient Aztecs. Literally, it means "water dog," although it can apparently be translated a number of ways. "Water sprite" and "water player" are just a couple. The axolotl takes its name from Xolotl, the rather diverse Aztec god of games, monstrosities, and the dead and resurrected.

What are those things on his head?

His gills. Unlike most salamanders, the axolotl never leaves the water... as long as he has gills, at least (more on that later). Axolotls are said to be neotenous; they can live and breed in what is really a larval, more or less undeveloped form. Many salamanders have gills when they are very young, but as they mature and develop lungs, their gills shrink and eventually disappear. Axolotls are thought to have evolved from Ambystoma tigrinum, the tiger salamander- pretty convincing when you consider that larval tiger salamanders look so much like baby axolotls that it's nearly impossible to tell them apart!

How long do they live?

The average lifespan seems to be ten to fifteen years, although there was at least one that reportedly lived twenty-five years in a French laboratory. If the latter is true, I'd tend to think that the average age is a bit higher- I mean, how many people live to be a hundred forty?

Most amphibians can survive in fresh water with a pH between 6.5 and 8.5, although I shoot specifically for a range of 7.0-7.2. Most municipal water supplies are supplemented with chlorine, ammonia, and various other chemicals and minerals to fortify the water and inhibit contamination. Because of this chemical treatment, the pH of water straight from your faucet is usually over 7.0. For example, the chlorine content in my city's water is so high that I can smell it when I turn on the faucet. Sometimes I can smell the ammonia, too. The pH of water straight from my tap is 7.8.

Note that while regular pH checks on your pet's water are important, pH readings alone are not enough. It is possible to have deadly amounts of ammonia, nitrite, or chlorine in water with a 7.0 pH. Changes in your water's pH are an indication that the water's chemistry has changed. Too far in either direction is a bad thing.

Chlorine

Chlorine increases a water's pH. Water that comes from your faucet almost always has some chlorine in it. While the relatively small amounts of the chemical in your tap water are safe for people to ingest, they can be harmful to sensitive animals like axolotls. They can also kill the good bacteria in your aquarium that consume and convert deadly ammonia, protecting your pet. Chlorine eventually leaves water as a gas over a short time. This is why water in a glass left on your nightstand tastes different in the morning that it did before you went to sleep. Any amount of chlorine in your aquarium is likely to dissipate within 24 hours. However you will never be able to develop an effective biological filter unless you rid all chlorine from your water before you add it to the tank. Some people do this by filling a bucket with water and letting it sit for a day or two before using the water. Others (like me) put some chlorine remover in the bucket when we fill it up and mix the water up really good before adding it to the tank. All chlorine-removing products that I've used work pretty much immediately, according to my own before-and-after tests with pH and chlorine test kits.

Ammonia

Ammonia is a waste product given off by most water dwelling organisms, including axolotls. While ammonia itself has a low pH, the type of ammonia that exists in water with a high pH is usually more dangerous than in water where the pH is low. Increased water temperature can also increase the harmful effects of ammonia. You should test your water for ammonia often. Once a week is probably adequate. Some reasons for high ammonia content are decomposing food or waste (accelerated by high water temperature) and tank overpopulation. There aren't any products you can buy that eliminate ammonia from the water. Rather, you can get things that will convert the ammonia into less harmful substances called nitrates and nitrites. You can also purchase additives for your tank that contain helpful Nitrobacter and Nitrosomonas bacteria that consume the ammonia and break it down into more tolerable compounds. The only way to remove ammonia is to change your water. It's normally not a good idea to change all of your water at one time except in extreme cases of contamination. Ways to prevent ammonia build up are increasing water aeration with air stones or above-the-tank filters, maintaining a healthy biological filter, maintaining a low water temperature, using a filter whose media contains activated charcoal, and regular collection of uneaten food and waste products.

Nitrite

Nitrite is one of the compounds produced by ammonia-detoxifying products and ammonia-eating bacteria. While it's generally safer than ammonia, it can build up if you're not careful and cause serious problems.Somewhat recently, I was quite perplexed because both of my axolotls had stopped eating, lost their energy and appetites, and were developing small sores that weren't healing. I found no ammonia or chlorine in the water, there was adequate aeration, the temperature was low, and the water was generally clean. In desperation I purchased a nitrite testing kit and was shocked to find deadly amounts of the chemical in my tank. I had to replace 90% of the water to get back down to safe levels. After boosting my biological filter with good bacteria and making sure to always treat the water for chlorine before adding it to the tank I have not found detectable levels of nitrite since.

The biological filter

Nature has its own ways for keeping water clean. While many natural filtration and purification methods happen on far too large a scale to help your aquarium, one very effective method is the biological filter. Some bacteria eat harmful chemicals like ammonia and convert them into things that are less dangerous, and sometimes even good for us. The chlorine that is probably added to your home's water supply is intended to kill bad bacteria that can harm you, but it also kills the good ones that could help you and your pet. If you treat your water for chlorine before adding it to your tank, some good bacteria will eventually develop that can help keep the water clean and safe for your axolotl. Things that help ensure a healthy biological filter are adequate aeration, plenty of porous surfaces for the bacteria to hold onto (this may be the best argument for aquarium gravel), and circulation. I have what's called a wet-dry filter for my tank. It uses a cartridge that contains activated charcoal for controlling ammonia and collecting large bits of waste, plus a water wheel that increases aeration and maintains a healthy colony of good bacteria year-round. You see, every time you change your filter cartridge, you're getting rid of a bunch of those helpful bacteria... the dual-barreled approach of the wet-dry filter ensures that some of the little guys are always there while the new cartridge builds up a colony of its own. The bacteria need an ample supply of oxygen to do their job. Without adequate oxygen in the water, the bacteria and your axolotl will suffer, and ammonia will flourish. Refer to the Filtration and Aeration section for more on this topic.

Since this article was written in 1999, the upgrade in technology has obviously changed. Please call the shop for up to date information on the filtration needs of his lovely creature.

Hardness

I live in a hard water town. Hardness is a measure of the amounts of calcium and magnesium in water. Some municipalities don't supplement their water with these things, resulting in soft water. Soft water might not be so bad for the people who drink it, as long as their diets include appropriate amounts of those chemicals. But your aquatic pets need some calcium and magnesium too! If you don't know what kind of water you have, you can call your local water authority and ask, or you can purchase a water hardness testing kit at a pet shop. If you find that you have soft water, you must supplement it with minerals. Some laboratories make their own concoctions. One of these is called Holtfreter's solution, and it contains different forms and amounts of sodium, calcium, magnesium, and potassium. You can also find products to increase water hardness at some pet stores.

Water testing kits

Water test kits are essential to the proper care of your pet. As long as you make a habit of removing all chlorine from your water before putting it in your tank, you don't have to test for that. You should always check the water's pH and test for ammonia. These products instantly remove chlorine from the water, and sometimes do other things. Remember to remove chlorine from the water before pouring it into the tank. If chlorine's in your tank for even a few seconds it can kill your biological filter. Contact the shop for items on sale.

Integration

Axolotls can get pretty big (Puckles, one of the authors, is about ten inches long) and they are great swimmers. While a small tank (3-5 gallons) may be fine for an axolotl when it's young (less than 8 months), an adult axolotl should have a lot of room to move around. I suggest at least a 10 gallon tank for 1-2 adult axolotls, and an extra 5 gallons for every two axolotls there after (like you'll ever be able to find that many!) If you're a real herp/fish freak like me, you probably have a ton of other fun and friendly animals that you would love to have your axolotl harmoniously share the same tank with. Don't give in to the temptation. There are many reasons:

First off, axolotl gills are incredibly tempting bait to fish and other water-dwellers. The gills are very fragile and sensitive- even a little nibbling could be harmful.
Next, not only are fish a danger, but even SNAILS can be very harmful to an axolotl. I have seen numerous very unfortunate pet-store arrangements where they threw axolotls in tanks with fish, snails, and even freshwater crabs! Even though axolotls do not have eyelids, they do go to sleep, and when they do, they really zonk out! It's during these times that snails can overcome the axolotl and suck away its flesh, leaving severe wounds if not killing it.
Also, the axolotl has a big mouth, and he's not afraid to use it. (The first part of the axolotl's scientific name, ambystoma, means "cup-mouth.") When I first got my, he was only about three inches long- just a little bigger than the fire-bellied newts that I put him in the same tank with. Two days after I got him, I caught Puckles trying to eat Henry, one of the newts; Puck had Henry's whole head inside his mouth and was shaking him like crazy. Soon after that first incident, I witnessed a couple more close calls, and decided to move Puckles elsewhere.

I thus cannot recommend keeping axolotls in an aquarium with any creatures other than other axolotls.

Lighting

Axolotls are more mostly nocturnal; they do not like a lot of sunlight, and should have a place to hide when it gets too bright. I have seen pictures of tanks with half a flower pot inside, which the axolotl used as a little tent. I bought a little castle for Earthy. It's about ten inches tall and hollow inside. There's a big, rounded door in front, which Earthy has no trouble passing through. Often, Earthy curls up inside his castle and pokes his head out, waiting for someone to bring him some food. Sometimes, when he wants to "get away," he'll just walk in, head first, and let his tail hang out the front door. I keep Earthy in a side room, so I can keep the blinds down most of the time without causing myself or my wife any inconvenience. If your axolotl's in a room where sunlight is not so easy to block, keep the tank away from the window and make sure that it is at least partially out of any direct sunlight.

Scenery

Aside from a good shelter, I don't recommend putting in any other plants or tank decorations. For one thing, axolotls are powerful swimmers, and they can get so riled up that they shoot around the tank like pinballs, and the more obstacles there are in the tank the more difficult it gets for the little guys to navigate. Also, if you put plants in, your axolotl will pull them up looking for food. Even plastic plants are not safe; eventually, you'll walk in to find all the foliage floating around the top of the tank. One cosmetic improvement that I do recommend, however, is getting a nice background for the tank. You can make your own or get one from a pet store, shaped to fit your tank. Such backdrops are good because they not only make the tank more appealing to your eye, but they'll make things a little easier on your axolotl's eyes by blocking out sunlight from the back of the tank.

Substrate

Substrate, the stuff at the bottom of the tank, serves two purposes. First, it physically traps some waste particles, keeping them from floating around the tank endlessly. Second, all the nooks and crannies provide the right environment for a colony of good bacteria which consume the waste and some of the bad chemicals in the water. My first problem with Puckles was his dangerous habit of eating the aquarium gravel. I used to have him in a tank with my newts, Henry and Sven. I fed them all at the same time, in the same way. I'd drop a couple of chunks in the water, and the newts would come swimming for it and eat their stuff before it even started to sink. Puck would wait til his food fell to the bottom and then suck it up.

When he was very young, Puck's skin was translucent; you could see his insides. One afternoon, when I came in to feed him and the newts, I noticed that Puckles was having some trouble swimming. He was flailing his arms and swishing his tail, but he couldn't get off the aquarium floor. Then I noticed his belly, unusually bloated, had spots of purple and green. He had stuffed himself with gravel! Axolotls use the force of opening their huge mouths like a vacuum rather than sucking in with their lungs. Food (and anything in its vicinity) shoots into the mouth with the current caused by the axolotl's violent gulps. He wasn't intentionally eating the gravel; he just couldn't help it, because of the way his food was being supplied to him. I hadn't quite put this together yet, though...

That night, I put him in a big bowl with no gravel, and I ran a hose from a small air pump into it. I was very scared, as Puckles just stood still in the bowl and appeared to be in pain. The next morning, however, I saw three rocks sitting in the bowl beneath him. I soon got him his own tank with the big pink marbles for substrate, and every day for the next couple of weeks I'd find another green or purple rock in the bottom of his tank, which I quickly removed. Strangely, about three months after his recovery, I found a couple of tiny white rocks in his tank when I was cleaning it out. Apparently, they were bits of gravel that he didn't pass right away, and the green and purple paint had been eaten away inside him! Although he sometimes got a marble in his mouth, it wouldn't fit down his throat, allowing him to realize his mistake and spit it out. I used the same kind of marbles with my later axolotls, and one of them, Earthy, actually managed to swallow one, which stayed in his stomach for about nine months! A few months ago, he spat it out though, and he's been fine ever since.

Earlier this year I got an email from someone who said that my marbles may not be sufficient to support a bacterial colony in the tank, and that regular aquarium gravel was really the best thing for it. Since I had been feeding my axolotls by hand for almost two years, I was confident that their swallowing gravel was no longer going to be an issue. I now have regular aquarium gravel, with an above-board filter, and the aquarium's cleaner than ever, and I haven't had to change the water for weeks.

Food and Feeding

In laboratories, axolotls are usually fed strips of beef or liver. Peter Scott suggests cutting the meat into strips of 3 or 4 cm long and .5 cm thick. Small to medium-sized worms, like red worms, are good, too. I tried worms with Puckles, and although he eagerly sucked them into his mouth, they were apparently to wiggly for him to swallow; they inevitably escaped. (I should also note that live worms can carry parasites.) He seemed rather more content with little chunks of frozen brine shrimp and occasional cubes of freeze-dried tubifex worms. Although the shrimp provided enough nutrition for Puck to survive and grow, he liked variety, so I threw the tubifex worms in for a treat. If your axolotl suddenly stops eating his regular meal and your water is clean and chemical-free, try offering him something new. Sometimes even a brief change in diet will be enough to get him back on track. I used to use a big pair of tongs to lower food down to Puck for him to grab. Sometimes I'd have to wiggle his food in front of him, which can be difficult to do carefully with tongs, so I just started feeding him by hand. Usually, all I had to do is touch the food to his lips and he'd gulp it in. Occasionally, he'd get my finger (I swear he did it on purpose sometimes!), and although he had tiny little teeth, the nips didn't really hurt. If you ever find yourself with an axolotl clamped onto your finger, just calm down and let him figure out that he's not going to be able to swallow your finger without a fair amount of trouble. He'll get the picture and back off. Usually.

What I feed my pets

I feed my axolotls frozen brine shrimp and freeze-dried tubifex worm cubes. The shrimp has most if not all of the nutrients that the axolotl needs, and the tubifex worms provide substance and protein. I have tried beef strips, frozen beef heart, feeder guppies, and earthworms with little to no success; my guys simply aren't interested. Tip: If you use freeze-dried tubifex worm cubes, get the cubes out and close the container before your fingers are wet. The moisture that gets into the container if your fingers are moist can spoil the other cubes in the container and cause them to go stale.

Feeder goldfish and guppies

I have gotten numerous emails from folks who use small guppies or goldfish and say they work pretty well. But I have gotten many more emails from people whose axolotls were seriously injured by the gill-nibbling "feeders."

Pellet food

The Indiana Axolotl Colony uses these things called soft-wet salmon pellets that they get from a certain fish food distributor. Another axolotl owner I know uses the same pellets.

When to feed your pet

The amount and frequency of what you feed your axolotl will vary depending on the axolotl's age, size, and the climate. Some need to be fed every day, others do better when fed every other day. Metabolism rises with temperature, so they may eat more on warmer days.

How to feed your pet

How you feed your pet often depends on the food. Pellet foods can be just dropped into the water (make sure to collect any uneaten pellets as soon as you can). You can use forceps, tongs, or your fingers to offer meat strips to your axolotl. I prefer hand-feeding for a few reasons:

It's fun!
It trains the axolotl to look up for food rather than down, where it may accidentally gulp up some gravel.
By placing the food directly in the axolotl's mouth, you know exactly what the animal's consuming, and minimize the amount of waste left in the tank.

When I feed them the tubifex worm cubes, I first immerse the cube in the tank and squeeze most of the air out. This makes the cube smaller and softer, and also decreases the chance that the axolotl will float to the top like a balloon and flow around with the current until it burps. (While I admit it is very funny to see, it clearly annoys the axolotl.)

Housekeeping

Axolotls are messy. Their waste has a high ammonia content, and if left unchecked, can produce a rather nasty environment for the little guys- to say nothing of the smell! Replace at least 20% of the water every two weeks or so, making sure that you also balance the pH and rid the water of harmful substances. I recommend siphoning the water out, because you can pull out whatever uneaten food and other junk that the filter doesn't get while you change the water. I use a sort of hand-operated siphon to do this- the thought of using a traditional mouth-primed siphon unnerves me. The gadget I use is a long plastic shaft connected to a few feet of rubber tubing. I drop the tube in a bucket and shake the shaft up and down in water until the siphon action kicks in and starts filling the bucket. You should change your filter media when you change your water. The carbon chunks in most filters help remove ammonia and aid aeration.

Filtration and Aeration

Good filtration is a must for almost any aquatic arrangement that's bigger than a fish bowl. Mother Nature regularly supplies our water with lots of helpful bacteria which eat waste products and nasty chemicals like ammonia. These little guys are very effective. They are so effective, in fact, that if you have only one or two small critters like guppies alone in a fish bowl or a tank, you may not need any auxiliary filtration at all. Axolotls are rather messy, though, and you need to aid the bacteria with adequate filtration and aeration.

Aeration is important for both the bacteria in the water and the axolotl. If there isn't enough oxygen in the water, the bacteria die, and waste products contaminate the water. Also, the axolotl will not be able to "breathe" with its gills, and may be forced to make frequent trips to the top for gulps of air. If you notice that your axolotl's gills are shrinking and it's spending a lot of time swimming to the top and gulping for air, you should check the water's chemistry and make sure you're cycling enough oxygen into it.

A really cool thing about this dual-action system is that when you're replacing the cartridge, you're not removing all of the good bacteria from your tank, as there's still plenty of it on the wheel that's spinning around. And unless something goes wrong with the filter, you never have to replace the wheel. See, if you're simply using a cartridge to filter the water, you actually sort of hinder the biological filtration action each time you replace the cartridge, because a lot of the little buggers tend to collect on each cartridge over time.

My choice is not the only effective way to filter a tank. There are many options, and much of the determining factors when making your purchase may simply be your own preference, or practical matters like how many electrical outlets you have available or whether a particular device will work with your existing aquarium hood. See Shop for up to date equipment.

Handling

First off, please do not handle your axolotl unless you have to. Axolotl skin is very sensitive and soft, and even brief contact can be damaging if you're not careful. About the only time you should have to handle you axolotl is when you are moving it from one tank to another. Take a good look at the picture provided here. The person is shown using both hands, with one behind the head and another holding both legs and the tail. Axolotls are very wiggly and slimy and strong. You will be surprised how firm (but gentle!) you have to be when transporting them. I once had a terrible scare when Puck literally jumped from my hand and landed on my desk. He looked very surprised when he hit the desk and didn't fight when I scooped him up to put him back in the water, but he nicked himself up a bit, especially in the tail, and it took about three weeks for the wounds to heal.

Behavior

Axolotls exhibit a measurable amount of intelligence. They are very curious, relatively brave, and can easily be taught tricks through classical conditioning (a trait which has made them the subject of some bizarre medical experiments). For instance, every time I feed my axolotl, I have to open the lid to his tank. Since he has to look up to get the food that I bring down to him, the moment I open the tank his head shoots straight up. If I open the lid and linger for a while, he swims to the top and doesn't settle down till I feed him. Sometimes, when I'm just in the room playing on the computer, I'll look over at his tank and he'll be there with his nose against the glass, waiting for me to notice him.

Oddities

If you've been paying attention, you've probably noticed that I've left some things out... occasional implications that axolotl gills are temporary, the fact that they have noses, etc. Well, yes, there is more. Although the axolotl can live its whole life in what is basically an undeveloped state, some axolotls do actually lose their gills and leave the water. This tendency, or rather the ability, to develop further seems to be passed on genetically. Not all axolotls can do it, and of those who can, some do it more easily than others. While it seems to be pretty rare in the wild, scientists can elicit metamorphosis successfully through a number of methods, like gradually reducing the amount of water in the tank and changing the chemistry of the water.

NOTE: I do not encourage the intentional morphing of axolotls for a number of reasons:

First, you can't tell just by looking at an axolotl whether it's capable of changing; you have to know its heritage. If you keep trying to morph an axolotl that just can't do it, you're only going to cause him unnecessary stress and confusion.
Second, some of the methods used, although effective, come at a high price. Just because an axolotl is capable of changing doesn't mean that the process won't be tough on him (imagine going through puberty again, only this time you lose all your hair and your eyes bug out to twice their size!), and the stress caused by some methods causes death before change even begins.
My third reason is the fact that the axolotl's life span is cut significantly once it morphs, due to an increased metabolism.
Also, morphing seems to rob the axolotl of another of its fascinating traits- the ability to regenerate.

Please do not email me asking how to make your pets change. I have seen it happen, and it can by very stressful for the axolotl, and possibly fatal. If you want to observe the metamorphosis for scientific reasons, please consult the experts. This is a link to an American site.

As long as an axolotl is in its neotenous form, it can easily heal wounds and regrow limbs and even eyes! It's one of the most highly developed regenerative animals in Nature. It sounds horrible, but Puckles recently injured himself pretty severely. I don't know exactly what happened, but I think he banged his arm into one of the under-gravel filter's vents (to keep fishies from swimming down the tubes) during one of his occasional pinball-swims. He had a huge gash under his shoulder and the bones of his fingers were sticking out of the skin. He started to get a fungal infection, so I treated the water with an anti-fungal agent (see below). The treatment stopped the infection, but it was too late for his arm. It fell off the next day, and he eventually grew another one.

Sickness

Please note: For some people who come here, this may be the most important part of The Axolotl Page. Any input from owners or experts here is certainly welcome. I will add any new information on diseases and injury that I find.

Okay... Aside from visible damage due to infections or injuries, one way to determine if your axolotl is sick is to monitor its eating habits. If he swallows his food but spits it back up (sometimes in little soft pellets), he's probably healthy but having a hard time from the temperature or composition of the water.

If he refuses to eat one day, don't panic, but keep an eye out for certain things. See if he'll eat something different. If not, try the next day, and the day after that. It's not unusual for an axolotl to simply not be hungry for a couple of days. If he goes for more then three days without eating anything, though, then you should really examine the situation. First, check the pH, the chlorine, ammonia, and chloramine levels of the water. Neutralize the pH if it's off-balance and rid the water of any harmful chemicals immediately. Also, check the temperature of the water. If the water's too cold, sometimes he knows not to even try to eat; he'll never get it digested in time.

If you notice any injuries, examine them every day. If you see any discoloration or a cottony-white substance forming on the wound, treat the water for fungal infections immediately. I used freshwater MarOxy (Mardel Laboratories, Inc.) when Puck hurt his arm and it fully healed the infection within two days. I noticed that it also increased the pH significantly, too, so watch out, and stick to the directions.

Bumps and lumps on the skin

Axolotls can sometimes develop small (pinhead to pea-sized) bumps in their skin. While you should take note whenever something like this appears, it's not always a problem. The lumps are often the result of some fluid build-up beneath the skin. Sometimes they go away over time, and sometimes they remain for the rest of the pet's life without changing.

Occasionally scar tissue will form around an injury, causing a lifelong lump. These as well are nothing to worry about.

One bump here or there is generally not cause for concern. But if you notice numerous bumps developing over a short time, the axolotl could be experiencing heart or kidney failure or a parasitic infestation.

If you suspect that the bumps are the result of healed injuries you may consider increasing the size of the tank you keep your axolotl in or reduce clutter within the existing tank to minimize future trauma.

Swelling

While some axolotls are finicky eaters, others will keep eating as long as you offer them food. Overeating can cause them to plump up like a balloon at the Macy's Thanksgiving Day Parade. Reducing the amount of food per sitting, or feeding less often will allow them to slim back down.

As eggs form within the female axolotl's body, they cause her abdomen to swell. If you notice growth just in that area and nowhere else, this may be what you're seeing.

More serious is gross swelling of other areas like the head or cloacal region. These indicate failure of a major organ like the heart or kidney and are not, to my knowledge, treatable. Your best bet is to find a veterinarian immediately and prepare for the worst

Shrinking gills, frequent trips to the surface

Normally, an axolotl's primary source of oxygen is that which its gills can extract from the water. But if the gills are damaged or if there is not enough oxygen in the water, the axolotl will swim to the surface and inhale some fresh air. Fish nibbling the gills is the most frequent cause of gill damage that I hear of from people who write me. Take the fish out of the tank. Other reasons for shrinkage are water toxicity, contamination, lack of aeration, and metamorphosis. Fix the water toxicity problem by replacing most (or all- in severe cases only) of the water with clean, treated water. Also consider getting a filter with replaceable media that contains activated charcoal for keeping down ammonia levels.

If your pet is eating regularly and appears healthy, but the gills continually shrink, it may be starting to metamorphose. Animals in this stage will gradually spend more time at the surface, eventually breathing air using their nostrils and lungs. Remember that this change is natural in Tiger salamanders, but is usually a defense mechanism in axolotls. If you know your pet is an axolotl and it is beginning to metamorphose, check your water for excess food, waste, chlorine, ammonia, and nitrite immediately and take appropriate steps, if necessary.

Fungal infections

The most common symptom of a fungal problem is a white, cottony substance that forms on the gills and healing wounds. Fungi can also kill baby axolotls and fertilized eggs- especially when dead eggs are not regularly removed from the tank.

Treatments are relatively easy to administer and available at most pet shops. Mercurochrome, malachite green ("zinc-free" according to Scott), and chloramine are commonly used. All of these chemicals should be used sparingly and very carefully, because each of them can harm the axolotl in excessive doses.

Fungal problems are more likely when the water is dirty or too warm. Prevention measures include:

Regularly siphon or net excess food and waste.
Slightly reduce the portions at feeding time.
Keep the tank out of direct sunlight to inhibit fungal growth and keep the water cool.
Pull down the shade during the day to keep the temperature down.
Change your filter media regularly.

Bacterial problems

Bacterial infection is hard to diagnose because the symptoms vary widely and many also occur due to unrelated problems. You might see any of the following:

Reddish areas develop on the skin, usually on the legs or belly.
The axolotl stops eating.
The axolotl eats, but coughs the food back up.
A seemingly healthy axolotl dies unexpectedly.
The axolotl seems to lose coordination. Injuries from bumping into things can result.
Excessive swelling- sometimes in a specific area, sometimes all over- occurs.
Small lumps begin to develop on the skin.

Veterinarians can sometimes treat these problems by injecting or feeding the axolotl antibiotics. Pet shop antibiotics are not recommended, because the recommended dosage is probably not enough for a large aquarium creature like an axolotl (although they might be effective with very young axolotls.)

I have seen mention of tetracyclines as a treatment for bacterial problems, but these chemicals can be very harmful to an axolotl's skin. If you suspect a bacterial outbreak, consult a vet if you can. If you have more than one axolotl in the same aquarium it is likely that all will be affected, even if only one starts to display symptoms. Once the problem is brought under control, you should completely clean out and disinfect the tank before using it again. If any of your pets survive a bacterial outbreak like this, you might not want to add any new pets to the tank with them. Even though the survivors may appear cured, they could still be carrying the organism that caused the problem and could pass it on to any pet that joins them. You can prevent these problems by limiting the number of creatures you add to the tank and avoiding live foods (worms, brine shrimp, feeder guppies, etc.).

Genetic disorders

There are some problems that can arise even if you take excellent care of your pet. These are inherited traits; problems that were passed on from earlier generations. They are most commonly found in axolotl colonies where there has been excessive inbreeding. Scott lists the following as common symptoms of genetic disorders:

"...small or completely absent eyes, blood disorders such as anemia or cardiac irregularities and arrested or deformed limb development. Gills may be reduced, twisted, or excessively fragile."

Parasites

Although rare, parasitic infestations cannot be ruled out if your axolotl is new or you use live food like worms or feeder fish. Some parasites known to bother amphibians are Trichodina, Vorticella, Glaucoma, roundworms, and flatworms.

The only visible symptom I've heard of is excess mucus on the skin and gills, which can cause your axolotl to spend a lot of time at the top of the water so it can breathe the air. (Axolotls do this any time the gills are under stress or shrinking due to metamorphosis.) Note that this symptom is only associated with certain kinds of parasites. Others cause different problems.

Roundworms and flatworms may be present in the animal's stool, but they may be too small to see with the naked eye.

Treatments for parasites that attack amphibians are drastic and not always effective. Contact a good vet immediately if you suspect parasites are causing problems.

Breeding

Axolotls become sexually mature once they are about a year old. Males will have a pronounced bump in the cloacal region (that's underneath, between the hind legs, in case you're wondering). Males will also tend to be skinnier and have longer tails than females. Females usually have shorter, wider heads than males. Also, the female's belly will appear to "get fat" as she begins producing eggs.

In the wild, axolotls breed from December to June, but in the lab or at home, it's more likely to occur from March to June- and animals who just reach sexual maturity in spring might produce eggs after this period, as well. In artificial conditions, mating is usually prompted by some kind of environmental change, like a drop or an increase in average water temperature. The axolotls must first be exposed to "normal" conditions for at least a few weeks before any environmental changes you make can have a significant impact.

For best results, you should have some plants in the tank where the female can deposit her eggs. Elodea are the most widely recommended, but you could probably use Sagitarria or Vallisneria, too. Additionally, the male is going to need some kind of flat surface- a rock or a plate of some kind- to deposit his spermatophores. The female will eventually position herself over a spermatophore and pick it up with her cloaca. She may pick up more than one. About a day after this happens, she will begin depositing her eggs, usually on the plants you have provided. There may be anywhere from 300 to 1100 eggs altogether.

The eggs should be removed and placed into another, well-aerated tank. Simply transplant any plants that have eggs attached to them. Plentiful oxygen is very important to the successful development of the young axolotl- even before it hatches. Use as big a tank as is feasible for your situation, as overcrowding can result in reduced oxygen and excessive metabolic waste. Keep the eggs away from direct sunlight and keep the tank relatively cool.

As the eggs develop you will be able to distinguish dead eggs from live ones. The dead ones will have a grayish color and won't grow or move. Remove dead eggs regularly, as they attract bacteria and fungi which can infect otherwise healthy eggs. Hatching normally takes placed within about two weeks. The hatched larva will not have limbs; these will develop over the next four to five weeks.

It is important for the larvae to have a lot of room to grow and keep out of each others' hair. The more space they have, the quicker they'll grow and the less likely and attack each other. Apparently, reducing the amount of light in the tank can curb some of this aggressive behavior.

A good food for these tiny axolotls is Artemia (brine shrimp, "sea monkeys")- not frozen, but live. To reduce the risk of introducing too much salt to the axolotls' tank, gently rinse a net full of Artemia under cool water before dropping them in the tank. They will survive long enough in fresh water to attract the axolotls' attention. Very small daphnia and tubifex worms can also be used (but only if brine shrimp are not feasible). As the young axolotls grow, try introducing them to chopped earthworms or small bits of beef.

Age

Average life span of the axolotl

If free of illness, genetic abnormalities, and if cared for properly, it is said that an axolotl can live from ten to fifteen years. I have actually gotten emails from people whose axolotls were eight and ten years old. Things like poor water condition, metamorphosis, disease, serious injury, and inherited weakness of the heart or kidney can all take a toll on the axolotl's life.

Determining the age of your pet

If you're trying to determine how old your axolotl is, good luck! After the first year and a half, the size and shape of the axolotl's body will remain pretty much the same. Very old axolotls may be identifiable by numerous benign bumps (edema; pockets of fluid under the skin), "battle scars", and malformed limbs (due to the not-quite-perfect regeneration of a lost limb.) These are not infallible indicators, though. Young axolotls can exhibit some degree of all of these traits, as well.

New Pet Owner Checklist

Here's a list of everything you'll need in order to take care of your axolotl. The list is broken into two sections. The first sections lists things that you must have, while the second lists things that are not necessary for your pet's survival, but will make your life easier in maintaining a healthy environment. You should be able to buy all of the items listed below for around $100 (U.S.). Copy List then ring the shop at 0800 0121679 for details.

I recommend against going to grocery stores or department stores for pet supplies. They usually don't have a good selection, and their prices for pet supplies are often highly inflated- even if their non-pet items are reasonably priced. Go to a pet store for your pet's needs. They'll have a better selection, are more likely to offer better deals, and almost always provide better service.

Important: Please read and follow the directions that come with all pet supplies that you purchase.

Essential items

Aquarium with hood: The tank should be 10 to 20 gallons with a hood that allows easy access to the water for feeding and cleaning, but closes to cover the tank when you're done. There should also be enough open area in the back of the hood for your water filter to fit, but not so much that one of your inmates can escape.

Filter: Get a water filtration system that's matched for the right size of tank. One that's too weak won't properly aerate or circulate the water. One that's too strong will blow your animals around and cause great stress. Look for filters that use activated carbon in their filter media, as this is a good way to control ammonia. Also see Filtration and Aeration.

Gravel: You need gravel to provide a surface for your pet to walk on and grow a colony of good bacteria to keep the water clean. Always rinse aquarium gravel thoroughly before putting it in your tank. This will remove any chemicals, dirt, or tiny dangerous particles that might harm your pet. Note: Do not rinse off gravel in your bathtub! Some very small shards of gravel inevitably fall out and can scratch the tub and poke your feet the next time you use it. Rinse the gravel outside or in a utility sink instead. Also see Substrate.

Thermometer: You can get nice little thermometers that stick to the surface of the tank for a very good price. Place the thermometer somewhere that it's easy to see so you can check it regularly. Also see Temperature.

Water testing kits: Get a pH test kit, plus one that checks for ammonia, and one that tests for nitrite. Check your pH every week, ammonia every two weeks, and nitrite every month. Also see Chemistry.

Chlorine remover: No water that contains chlorine should ever enter your tank. It kills the good bacteria, and burns your pet's skin. See Chemistry for more.

A big bucket: Get a new, sturdy bucket that you can use when adding new water and siphoning out old water. Don't use the bucket for anything but your pets- plastic absorbs chemicals (like household cleaning agents) that can come back out in water that you add later. If you keep the bucket clean, you can even store your pet supplies in there when you're not using them, like I do.

Food: I recommend freeze-dried tubifex worm cubes and frozen brine shrimp as starter foods for axolotls. There are plenty of other things you can try, too. See Food and Feeding for details.

Gravel siphon: Even if you only use it during seasonal cleanings and when emptying the tank, a gravel siphon is one of the most important tools you can have.

Net: A small, fine net is a necessity for scooping up loose bits of food and waste after feedings.

Nice-to-have items

Extra filter media: Most filters come with one replaceable cartridge that's good for about two weeks. It's good to have some extra cartridges on hand so you can change them when you need to.

Other water treatments: You can get chemicals that raise and lower water pH and "detoxify" ammonia in the water. Things like this are great for emergencies and times when you can't do your regular maintenance. But please note: If you use these kinds of chemicals, understand that high levels of ammonia in any form are never safe, and drastic changes in the water's pH indicate serious problems. If you just keep pouring these chemicals in without doing anything to find out what the real problem is, you're not helping your pet.

Tank scrubber: Every couple of months I use a tank scrubber to keep the insides of the glass clean. It's got a long, white handle and a scratchy blue pad at the end. It does a great job, but I have to be careful when I use it, because Earthy keeps trying to eat it!

Tube scrubber: You can do wonders for your tank by cleaning out the tubes on your water filter every few months. Tube scrubbers are these long, springy, metal wands with little bristly brushes at each end. They are very flexible, so they wiggle right through your tubes and clean out all sorts of horrid stuff. Run some warm water through the tubes before and after you scrub them. Also do this outside or at a utility sink, and don't wear your good clothes! You are likely to get splattered if you're not careful. Your pets will appreciate your effort though, I promise.

Hiding place: This is actually a must-have item if the room where your axolotl lives is very sunny. Axolotls don't like bright light, and they like having a little dark place to relax in. (Remember, no eyelids, so the darker the better for dreamless sleep.) It's tough to find a good place, though. It should be big enough for your pet to enter unobstructed, and heavy enough that your pet cannot easily knock it around. Some people use modified ceramic flower pots. You should be very careful to remove any sharp edges or loose pieces if you do this.

Reproduced by kind permission of Josh Mayfield at:

http://inky.50megs.com/axolotlfaq.html

Images are from stock in the shop taken at the time of producing the article

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