Axolotls, Salamanders, and Newts
by: David Starkey   
    Greater Detroit Aquarium Society
    Dec. 1988 monthly meeting presentation 

Every spare tank even a leaky one can be used as a terrarium
for amphibians. A half full ten gallon aquarium is all that
is required. Add rocks piled above the surface to provide a
dry spot so salamanders can be on land or in the water.
The ornaments depend on the type of salamander. It's wise
to determine what kind of salamander you want before you set up
the tank. Of the 350 different species of salamanders it is
easy to see how hard it is to get information on all of them.
 
I'd like to share some information on the most popular newts,
salamanders, and axolotls, which are the notophthalmus
viridescens or red spotted newt, ambystoma tigrinum
or tiger salamander, cynops pyirhaster or red bellied newt,
tarichalorea or california, nexerus maculous common mud
puppy, and the ambystoma mexicanum axolotl. 
I'd like to talk about the axolotl now because they are salamanders
but fully aquatic. Axolotls come from Lake Schalco and Lake
Xochimilco near Mexico City. Other than always being under water
they are pretty much the same as other salamander in the larvae
state. that's all they really are, they are unmetamorphosised
salamanders that can reproduce in the larvae state. They eat the
same things and are kept at the same temperatures other salamanders.
The only major difference in raising them is that they require no land,
but there are some interesting facts about them. In 1865 at the
Jardin des Plantes in France, one of the brood of large axolotls which
a keeper had successful bred showed some with different colors.
Nothing was thought of this until the ones that were a different
color grew up and turned into normal salamanders. From a stock
which rarely metamorphosed. 
So now we have two groups axolotls and salamanders.
There really no special difference in care except for
raising fry of different salamanders. The name axolotl is that
of an ancient Aztec god Xolotl, the god of
monstrosities like deformities and twins. Xolotl was
also the Aztec god of the dead. There was a myth that the
god Xolotl was trying to escape banishment from earth by
changing forms, each form was ugly or parred. When he assumed
the form of an axolotl he was captured and condemned to live
forever in the form of the axolotl.  Axolotl also means watersprite.
The true meaning was lost over time. It roughly translates water-dog.
  
Axolotls have large mouths a feature responsible for their
scientific name ambystoma, ambyx meaning cup and stoma meaning
mouth. While they have fine teeth, they do not chew
their food rather they gulp their food in stages. 
The feathery gills in both salamander larvae and axolotls
are filled with small blood vessels. By fanning their gills
oxygen is absorbed directly into the bloodstream. While they
have two small kidneys the larval axolotl excretes 50% of
it nitrogenous waste as ammonia. Much of it is lost through
the gills. Gas exchange through the skin is important in
amphibians in general. In fact some small salamanders have no
lungs and rely solely on skin absorption for respiration. 

In the category of salamanders the tiger salamander could be
called a salamander, undire, newt, or eft; what ever they are
called they all mean the same except an eft is a salamander
in it's terrestrial form. 

The axolotl has neoteny or stays in the water all it's life.
This helps against predators but prevents colonization of the
land. However the salamander is a perfect example of the true
definition of a amphibian, amphi meaning double and bios meaning life.
This double life represents it's early life in
water and it's adult life on land or water. Most amphibians adult
life helps it escape land predators by going into the water and
escape water borne enemies by going
on land. Almost all amphibians go through this double life.
The axolotl doesn't because of an iodine deficiency.
Nexerus or mud puppy doesn't go through this double life
because they are very primitive salamanders.
 
In the case of mud puppies they live a long time. It takes
four to six years to reach maturity. It's also safer for the
mud puppy to stay in the water. They rely on camouflage to
protect them. With few exceptions, all other salamanders live in
water in their larvae stage, breathing trough feather like gills.
As they reach metamorphoses they develop lungs and loose
their gills. While on land many would be predators have learned to leave
them alone. Toxins are a big protector for many newts and
salamanders. The skin of the California newt is very toxic. That's
the main reason you should wash your hands after
handling them. There are an average of 1380 poisonous glands
on the back skin of a salamander. The poison from just one
gland is enough to kill a mouse.

There are several things to consider in the care of
salamanders. The first is light. Most salamanders don't
require light. They are nocturnal and come out at night.
This also helps protect against predators. Although a little
light should be provided. If your terrarium does have a light
so much the better. The main reason for having a light on a
terrarium is to create humidity. Amphibians thrive in humidity
and that's why you need a hood.
 
The hood serves many purposes. The first is to prevent
your pets from climbing out, and the second is to keep in
heat and humidity from the light.

Food:  mealworms, earthworms, tubifex, white worms, tadpoles, 
frog eggs, small fish, beef heart, and even scraps of
hamburger. Personally I feed my axolotls, turtles, salamanders, and
frogs beef kidneys from farmer jack. It's good to vary the
diet to assure proper nutrition. A good combination of these
foods is always good. Use caution as some wild caught foods
carry parasites. Also don't get worms from off the sidewalk
or driveway. Gas, oil, and antifreeze on worms are not good
for food. Also lawn worms may contain traces of weed killer. 
They really don't need to be feed every day although small
amounts every day are ok. I feed larger  amounts about every
two days. 

Spawning is reasonably simple according to most books. I've
spawned my axolotls a couple days ago and have the triumphant
amount of one egg.  Before I talk about spawning let's talk
about getting mature animals first. Maturity in salamanders is
reached anywhere from one year after they come out of the
water to three years. In axolotls maturity is reached between
six months and one year. In the male this is shown by an increase
in size of cloca. The males are more slender with long tails.
 
The female axolotl is stout bodied with a wide belly due to the
presence of eggs. The sex in salamanders is hard to
judge, but in some species crests and colors intensify in the
spring. In the spring mountain snow melts and cool water is carried
many miles to the lakes where axolotls live. This change in
temperature seems to make axolotls spawn. In some species of
salamanders the males grab the female  and mates
while other species like the axolotl the male will place
his spermatophore packets in water, on gravel. 
The female picks up this packet and begins to lay between
300 and 600 eggs. All eggs are laid under water everywhere
they can.
 
If elodea or similar plants are provided the eggs laid on them
would produce good fry. That's because as eggs develop the more
air that can get around the eggs the
better. Amphibian eggs swell up for better air circulation. Eggs
deposited on plants develop better because there is better
air circulation on the plant than on the bottom of the tank. 
Eggs are the fastest developing stage of life of amphibians. As
the embryo develops they look more and more like miniature 
axolotls. After two weeks front legs develop, they help
stabilize the larvae. Five weeks later the back legs appear. They
grow fast and have a high metabolic rate. Baby brine
shrimp should be fed to them a couple days after hatching.
 
As they grow they can be fed tubifex or white worms chopped
up to suit the size of the larvae. Tubifex worms should not
be the sole diet. As they grow they can be fed beef heart or
liver also cut in chunks to suit the larvae. After 6 months
to a year the salamander larvae metamorphosis and becomes
an adult salamander. 

In summing up id' like to offer a few suggestions.
1. don't eat newts.
2. don't put them in your mouth.
3. handle specimens carefully. Carl Kraniak taught me a
   trick. wet your hand before handling a salamander to keep
   their protective slime coat from being ruined.
4. wash hands thoroughly after handling any amphibian.
5. sickness and diseases: lost digits or fingers or injured tail
   will regenerate.  Big problems  come from overfeeding,
   overcrowding, not cleaning the tank.
6. avoid crowding and mixing species and sizes unless you
   are sure they can tolerate each other.
7. vary the diet to assure nutrition.
8. keep salamanders cool 75 degrees or cooler.
9. keep containers covered.
10. keep live food cultures handy to assure a constant and
    varied supply.
11. handle large specimens only when necessary.
12. join a society to share experiences with others.
13. avoid plastic plants with newts. they may uproot
    them in their eternal search for food.
14. don't collect endangered species there are plenty
    common ones.
15. avoid smaller species that are hard to feed and
    are more susceptible to disease.