Axolotl—Forever Young

In addition to caring for over 200 animals at the Ark
Encounter and Creation Museum zoos, I care for
my own creatures at home. I have a dog and a ball
python, but I recently decided to add another pet to my
menagerie. I chose to adopt a truly unique creature—an
axolotl. If you’re like most people, you’re probably wondering,
“An axo-what?”

Axolotls (ax-oh-LOT-els) are aquatic salamanders that
grow to about a foot long and are found only in the cool,
dark waters of Lake Xochimilco (so-chee-MEEL-koh) and its
surrounding canals near Mexico City. I’ve always been fascinated
by these amphibians, and mine delights me every
day with her goofy antics. With an array of unique, God-given
features, axolotls make not only endearing exotic
pets but also fascinating subjects of medical research.

Coat of Many Colors

Axolotls are normally mottled green
and brown to camouflage underwater, but
they also come in a stunning array of colors
called morphs. My axolotl is black, but
axolotls can also be copper, golden, lavender,
gray, white, multicolored, pied, or
albino. Many axolotls, mine included, have
varying degrees of freckling on their bodies.
Scientists have even created a morph
called GFP (green fluorescent protein) that
glows under blue or UV lighting.

Baby Face

Though people may have difficulty
recalling its name, they rarely forget
seeing an axolotl’s “smiling” face surrounded
by fluffy gills. The reason for
that lovable appearance is a characteristic
known as neoteny (nee-OT-oh-nee),
meaning axolotls retain some juvenile
characteristics as adults. In a way, they
never grow up.

Most amphibians begin their lives as
aquatic tadpoles and go through metamorphosis
as they age, often growing
legs and transforming into air-breathing,
land-dwelling adults. However, axolotls
appear to have gotten “stuck” halfway
through the process. While they
develop legs and lungs, can breathe air,
and can sexually reproduce, they keep
their feathery gills and tadpole tails and
continue to live underwater.

Their neoteny stems from their lack
of a thyroid-stimulating hormone. However,
when given this missing hormone
under human care, axolotls will complete
their metamorphosis into fully
terrestrial salamanders. In fact, axolotl
neoteny helped scientists discover thyroid
hormones.

Darling But Deadly

Despite being adorable, axolotls are
far from innocent—they are formidable
hunters. Before Adam and Eve sinned
and creation was cursed (Genesis 3),
all animals ate vegetation (Genesis
1:29–30). In today’s fallen world, axolotls
consume worms, larvae, mollusks,
crustaceans, and fish, using suction to
vacuum prey into their mouths. My
axolotl has terrible aim, but her mighty
slurps are still powerful enough to
catch her dinner.

Medical Marvels

Axolotls’ incredible regenerative abilities
make them valuable research subjects
in laboratories worldwide. They’re
capable of regenerating not only limbs,
but also jaws, spinal cords, tails, eyes,
organs, and sections of their brains
with no scarring. They can regenerate
the same body part multiple times with
no imperfections. Scientists have even
successfully transplanted organs from
one axolotl to another.

How do axolotls heal? When
wounded, axolotls transform nearby
cells into stem cells and recruit other
stem cells in their body to come remedy
whatever was injured. Studying
axolotl regeneration has increased our
knowledge of everything from embryonic
development to organ transplants
to amputations. Additionally, axolotls
are over 1,000 times more resistant
to cancer than mammals, so they’ve
contributed to the research of curing
cancer. In fact, an extract derived from
axolotl egg cells successfully halts the
spread of breast cancer. Their neoteny
plus their healing abilities makes these
animals the closest thing to the fountain
of youth found in nature.

Tiger Hybrids

The majority of axolotls under
human care are descended from just
34 specimens taken out of Lake Xochimilco
during a French expedition
in 1863 that sparked the worldwide
interest in axolotls. Unfortunately,
this has led to substantial inbreeding,
so captive axolotls were crossed with
tiger salamanders to broaden the gene
pool. These hybridization efforts were
successful because the two species belong to the same created kind (Genesis
1:24–25). Consequently, most axolotls
under human care are actually
part tiger salamander.

Salamanders in Danger

Sadly, wild axolotls are on the brink of
extinction. A study in Lake Xochimilco
in 1998 found 6,000 axolotls per square
kilometer, but the most recent census
in 2015 found just 35 axolotls per square
kilometer.1 Scientists estimate there are
fewer than 1,000 left in their natural
habitat. Many of their original lakes
have been drained, and populations
are plummeting due to heavy pollution.
Additionally, humans have introduced
invasive fish into Lake Xochimilco that
eat axolotls.

We can be thankful that biologists are
working to inspire the Mexican people
to save these amphibians before they
go extinct. Researchers and locals have
begun building axolotl shelters, growing
water-filtering plants, and starting
chemical-free floating crop fields in
Lake Xochimilco as attempts to combat
the pollution and invasive predators.

God calls us to be good stewards of
his creation (Genesis 1:28), and we can
obey that dominion mandate by working
to save certain critically endangered
species like axolotls. These creatures
are incredible representations of God’s
creativity and design, and contribute
a great deal to advancing medical
research. If these conservation efforts
continue, I am hopeful that the amazing
axolotl will live on to fascinate future
researchers and pet owners like me.

Did You Know . . .

Art by DAVE MOTTRAM

Found exclusively in the lakes
of Xochimilco near Mexico City,
axolotls are sometimes called
Mexican walking fish (although
they’re not fish at all—they’re amphibians).

The name axolotl means “water dog” in the Nahuatl language of the
Aztecs. It’s a nod to Xolotl, an Aztec god who, according to mythology,
is said to have taken the form of a dog.

During courtship, male and female
axolotls “waltz” with each other.

Art by DAVE MOTTRAM

Like all amphibians, axolotls’ skin is
covered in a protective slime coat.

As amphibians, axolotls can
breathe through their skin.

At 32 billion base pairs, the
axolotl’s genome is 10 times
the length of a human’s.

Karina Altman is the animal presenter for Answers in
Genesis. She has a BS in marine biology from Texas A&M
University at Galveston. She has worked in zoos and
aquariums around the US since 2007 and has worked for the
Answers in Genesis zoos since 2015.