Last updated March 18, 2000
Here I mix what documented information I
have read with things I've picked up through my own experience with axolotls.
In situations where my personal experience differs from what I've read,
I say so.
- The recommended temperature for keeping an axolotl is from 14 to 18
degrees Celsius, which is between 57 and 64 degrees Fahrenheit. Since the
axolotl is a cold-blooded animal, its metabolic rate is proportional to
its body temperature. When the water is unusually cool, it may take an
extra long time for the axolotl to digest its food. If it takes too
long, the food in the axolotl's stomach may begin to spoil before it's
fully processed- not a pretty thought. To avoid this sort of poisoning,
the axolotl will regurgitate its food at the first indication that spoiling
may occur. If your axolotl spits his food back up, first make sure that
what you're feeding it is fresh. Next, check the water temperature and
make sure it's not too cold. If adjusting the temperature doesn't seem
to help, check the chemical composition of the water. Too many chemicals
floating around in the water may affect not only the axolotl's ability
to determine the quality of his food but could also be directly harmful.
See the next topic for more info about chemicals.
- Warmer water temperatures will increase the axolotl's metabolism; it
may need to eat more often. Also, algae, fungi, and bacteria flourish as
water temperature increases. If you are unable to keep the water below
80 degrees F, be prepared to make regular water changes and be sure to
keep the tank extra clean.
- Unless you live in an unusually cool climate, you will not need water
heaters at all. A good way to reduce temperature in the room where you
keep the tank is to make sure it is well ventilated and keep the blinds
only partially open most of the time.
According to the Wardley Corporation brochure, Why Test Water?,
pH stands for "power of hydrogen" and is a measure for determining
the amount of hydrogen ions in water. (I have received email from at least
one person who says that pH stands for something else- "parts hydronium,"
if I remember correctly.)
The pH scale goes from 0.0 to 14.0, where 7.0 is said to be neutral,
less than 7.0 is acidic, and more than 7.0 is basic. Usually
you hear only the term "acidic" when referring to low pH values
and "alkaline" in reference to pH values that are high. It's
actually a little more complex than that, because water of a given pH can
have a number of different properties:
When the pH is:
Low (< 7.0)
medium to high
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 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
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 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
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
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.
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
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. And I personally recommend regular
nitrite tests. Here are some kits that I've used, with success.
|Freshwater Nitrite Test Kit, by Aquarium Pharmaceuticals, Inc.
|Freshwater Deluxe pH Test Kit, by Aquarium Pharmaceuticals,
|Chlorine & Chloramine Test Kit, by Aquarium Pharmaceuticals,
Inc. This kit also contains a separate test for ammonia.
|pH Water Test Lab, by The Wardley Corporation. This kit has
a cool "acid/base demand test" that helps you determine how much
pH raising/lowering additives to add to your tank to reach a neutral pH.
Use this feature for minor adjustments only. Major pH discrepancies should
be addressed with water changes and other measures.
|Hardness Professional Water Test Lab, by The Wardley Corporation.
I have never actually used this product, since I've never had the need
to. I have been impressed by some of Wardley's other products, though.
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.
|Aqua Plus, by Fin Care (Distributed by Rolf C. Hagen Corp.).
This product also "neutralizes heavy metals" and protects the
skin and promotes healing with its P.H.E. (Pure Herbal Extract).
|Start Right, by Jungle Laboratories Corporation. Also "stimulates
natural slime coat."
|Stress Coat, by Aquarium Pharmaceuticals, Inc. Also contains
aloe vera, to protect skin and aid healing.
You can add these products directly to the tank.
|ACE (Ammonia and Chloramine Eliminator), by Jungle Laboratories
|Ammo Lock 2, by Aquarium Pharmaceuticals, Inc.
Biological filter additives
|Stress Zyme, by Aquarium Pharmaceuticals, Inc.
Products to increase water hardness
I have never used any water hardness products, because I simply haven't
had the need. I know of these products, however:
|Wardley Raise Hardness, by The Wardley Corporation.
|Wardley Raise Calcium, by The Wardley Corporation.
- Axolotls can get pretty big (Puck's 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 Puckles, 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.
- 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.
- 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
- 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
- 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."
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
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
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 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
- 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.
My philosophy of filtration has changed in recent months, due to some
things I'd noticed in my own tanks, some emails from experienced readers,
and the alt.aquaria FAQ on filters. I highly
recommend this FAQ, as it is comprehensive and informative. You can find
at the Aquaria FAQ site.
I ended up ditching my under gravel filter and above-board cartridge
filter for a Marineland Products Penguin 125. The $25 device uses a combination
of "wet-dry" and cartridge techniques to provide adequate filtration
and aeration for a ten-gallon tank.
The cartridge is important, as it catches larger bits of waste, and
the activated carbon inside neutralizes ammonia. The "wet-dry"
mechanism is a little waterwheel that is moved by the water that flows
underneath it. Helpful bacteria collect on the wheel as it spins. It is
called wet-dry because most of the wheel actually comes out of the water;
capturing fresh air molecules which it pulls into the water down below.
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.
- 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.
Here's a safe way to hold an axolotl.
Remember: firm but gentle!
- 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 til
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.
- 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
|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.
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.
A fully metamorphosed
axolotl. Cool, huh?
of oddities, my band, Loaf, does a song about Puckles.
You can hear the whole thing at the Songs About
- 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. Please e-mail me
if you've got anything to add.
- 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.
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
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.
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
|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 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.).
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."
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.
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
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
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.
For more detailed information, check out my bibliography.
Also, consult Susan Duhon's Short Guide to Axolotl
Husbandry, courtesy of the Indiana
University Axolotl Colony.
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. There's a little bit more on this topic on the Introduction page.
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.
A note about pet shops
Understand that the life span of an axolotl in the average pet store is probably about
a week or two unless it's fed properly and given a tank of its own. Pet stores generally
throw axolotls into catch-all tanks that only have a couple of inches of water, which they
must share with a bunch of frogs, newts, and sometimes even crabs! Other times they'll be
placed in aquariums with tons of fish and snails which continually nibble at their gills
and skin. No matter how old an axolotl lives to be while under your care, it's going to be
a lot happier and safer with you than it would be at the store.
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.).
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
Important: Please read and follow the directions that come with all
pet supplies that you purchase.
|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
|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
|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.|
There is a lot more helpful information on these topics in the Frequently Axed Questions page.
|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.|
place? Go back to the index.
All About Axolotls: Table of Contents
Inky's Linkies: Front Page