Captive Care of the Mexican Axolotl Ambystoma mexicanum – Part 2

Check out: Captive Care of the Mexican Axolotl Ambystoma mexicanum – Part 1, for the first part of this article.

Feeding

Repto-min, trout chow or salmon chow serves well as a mainstay; alternate this with Hikari Massivore Delight or a pelleted cichlid food, freeze dried prawn, live blackworms, earthworms, minnows, shiners and guppies.  Axolotls will also take frozen clams, mussels and similar foods, but marine-derived items should not be used as a major part of the diet.

Although normally bottom feeders, well-habituated axolotls will rise to the surface to eat, and take readily to hand- feeding.  A finger waved before one will be grabbed and “swallowed”.

Finely-chopped blackworms (use a razor) are the best food to start off with when raising larvae; brine shrimp are also accepted, but growth with be faster for those consuming blackworms (and each other!).  Be aware that blackworms, even chopped pieces, clump together; larvae may choke trying to take down a large ball.  Be sure to swish the worms about the tank, and watch that they do not “find each other” after awhile.  A surface worm feeder that releases the worms individually will help relieve this problem.  I’ve not been able to induce axolotls under 2 inches in length to accept Repto-min or other dry foods, but others report success with very small individuals.

Social Groups

While not overly aggressive toward each other when un-crowded, the feeding of live food seems to stimulate a near frenzy, during which animals may bite the gills and toes of their tank-mates. Generally these grow back without problems, but a treatment with Aquarium Pharmaceuticals Stresscoat is a useful safety measure.

Axolotls housed together should be nearly the same size – even a difference of 25% is too great, as the larger animal will eventually bite off the gills and limbs of the smaller, possibly killing it.  Feeding injuries among similarly-sized animals are less severe – the loss of a toe or gill tip.

Losses are usually high when young animals are reared together, but can be lessened somewhat by the provision of dense cover (please see “Physical Environment”, above).

Captive Longevity

Captive longevity approaches 25 years.  Animals in my collection are still breeding at age 17.

Handling

It is best to usher an axolotl into a plastic container, as they may damage their delicate skins when thrashing about in a nylon net.  Axolotls may also be picked up by hand, but use caution as they tend to lie very still and then suddenly explode, and can easily propel themselves to the floor.  Handle only when necessary to move or examine an animal, and use wet hands and great care as the skin is quite injury-prone.

Miscellaneous

The axolotl’s long history as a laboratory animal has given rise to a wide variety of attractive color phases, including leucistic, black, albino, piebald and others.  The genetics of color inheritance in this species is quite interesting, and seems not to follow the “normal” rules…at least not as I learned them!  Recently, bio-engineered axolotls that glow fluorescent green have appeared in the trade.

Rearing axolotls in the lab differs in some respects from home care, but much of value is contained in the protocols of institutions maintaining large research colonies.  You can read about how it’s done at laboratories and universities all over the world at:

http://www.ambystoma.org/AGSC/suppleguide.pdf