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.


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.


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.


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.

A pair of axolotls can provide a great introduction to amphibian breeding…I’ll include a short note about this next time. Until then, please write in with your questions and comments. Thanks, Frank Indiviglio.

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:

Captive Care of the Mexican Axolotl Ambystoma mexicanum – Part 1

Hello, Frank Indiviglio here.  Please see Natural History of the Axolotl for information on axolotls in their natural habitat.

I highly recommend the Mexican axolotl as an aquarium animal for both beginning and advanced hobbyists, and include them whenever possible in the zoo exhibits that I design.  Assuming that attention is paid to temperature and water quality (please see below), axolotls are hearty, long-lived and quite simple to breed.  They are also extremely responsive pets, taking readily to hand feeding and perfectly content to be out and about by day.


Axolotls are entirely aquatic, with an adult requiring an aquarium of approximately 10 gallons in size; 5-10 gallons more should be provided for each additional animal.

Axolotls also fare well in plastic terrariums or sweater boxes that are emptied and cleaned as opposed to filtered; this method is very useful when rearing large numbers of young.

Physical Environment

Axolotls are unusual among salamanders in not requiring a shelter, but the provision of such will help to alleviate aggression when groups are kept together.  They readily take up residence in plastic reptile caves, clay flower pots or PVC pipes.

The young enjoy consuming their brethren, and should be afforded as much opportunity to avoid each other as is possible.  Individual shelters are not effective in preventing this (among young animals) in group situations.  Rather, fill most of the aquarium’s water column with Penn Plax Baby Hideouts and other plastic aquarium plants.  Weight these down with plant ties to cover the base of the aquarium, and position tall plants so that they fill the vertical space as well. 

Axolotls can be kept in bare-bottomed or planted tanks.  If gravel is used, it should be of a size that cannot be swallowed.  Small rocks ingested during feeding are often passed, but impactions can occur.  Live aquarium plants, if used, should be sturdy and well-rooted, or floating.

Light and Heat

A florescent bulb is best used for illumination, as it will not add significantly to water temperature.  Axolotls do not need a source of UVB light.

Axolotls are native to cool, high-altitude lakes, and do best at water temperatures of 62-70 F, with a dip to 50-52 F in winter, if possible.  People do keep them at warmer temperatures, but such leaves the salamanders susceptible to illness and fungal problems.  At temperatures above 75 F, Saprolegnia infection is not infrequent (this and certain bacterial infections usually cause the animals to float to the surface).  A cool basement is ideal for year-round maintenance.

Water Quality and Filtration

Axolotls are fairly tolerant of a wide variety of conditions, but should ideally be kept in soft water with a pH of 6.9-7.6.  Hard or acidic water can damage the gills.

Adequate filtration and frequent water changes are essential.  Axolotls have large appetites and excrete copious amounts of nitrogenous wastes (which are largely dissolved in water and not visible), and can quickly succumb to ammonia toxicity.  An ammonia test kit should always be on hand. 


Canister, hanging or in-tank filters all have their place in axolotl aquariums, but each must be coupled with regular water changes.  Larvae are best kept in aquariums filtered with sponge or corner filters.  In all cases, filter outflow should be adjusted so as not to disturb the salamanders, as they are not strong swimmers and prefer still water.

Check out: Captive Care of the Mexican Axolotl Ambystoma mexicanum – Part 2, to read the rest of this article.

Frank Indiviglio

Turtle Docks and Basking Platforms in Professional and Private Collections – Product Review

Turtle dockHello, Frank Indiviglio here.

Plastic turtle docks and basking platforms are wonderful innovations that I have found very useful both at home and in public exhibits that I have designed.  The models I mention here look quite natural right out of the box, and when covered with some live algae and surrounded by live or artificial floating or emergent plants, the effect is quite good.

Commercial Exhibits and My Own Collection

Please see the photos below to see how I put a Basking Platform to use in exhibits at the Maritime Aquarium and in my own collection.  The brackets that secure the platform to the aquarium’s glass come in quite handy as live plant supports.  By placing the brackets over emergent plants such as peace lilies, you can create the effect of a plant-backed land area.

Debilitated Turtles and Frog Metamorphs

dockZoo Med’s Turtle Dock  slopes gently below the water’s surface to create a ramp for animals seeking to climb on board.  A debilitated Eastern painted turtle in my collection (it hatched with deformed rear legs, please see photo) makes great use of this and is easily able to leave the water. 

I also like this model for use with transforming tadpoles and small newts that might otherwise have difficulty in accessing land areas.  In shallow water, the area below the dock serves as a cave-like retreat as well.

Shoreline Terrariums

Shoreline terrariums housing fish, aquatic invertebrates and amphibians have always been a great favorite of mine.  I use both of the aforementioned models in creating these habitats.  Unlike rock piles, the suspended platforms leave plenty of space below for aquatic creatures. 

I’ve found that I can keep leopard and green frogs in quite deep water when their aquarium is furnished with a plastic platform.  This allows me to mix in a number of fish as well (in shallow water, the frogs prey upon the fish, but they cannot catch them in deep water).  As you can see from the accompanying photo, fiddler crabs use them as well. 

The Hagen Turtle Bank also holds great promise…I’ll check it out in the future and report back.

Please write in with your comments and questions.  Thanks, Frank Indiviglio.

Medications Based on the Immune System of the Mealworm or Darkling Beetle (Tenebrio molitor) may someday prevent the Emergence of Drug Resistant Microbes – Research Update

Hello, Frank Indiviglio here.

Mealworm BeetleThe mealworm has long been valued by pet keepers, but medical researchers are now giving it some respect as well.  A recent (December, 2008) article in the journal Science reveals that antimicrobial peptides manufactured by the mealworm beetle destroy any bacteria that happen to survive the original onslaught launched by the beetle’s immune system.


This is important because bacteria and other microbes that are not killed by drugs or immune system defenses often evolve into resistant strains, which are then very difficult to control.  This is currently a very serious human health concern, especially as regards hospital-based micro-organisms. 


It seems that insects are particularly effective at preventing the development of hard-to-kill microbes, and that most of the credit for this is due a unique group of chemicals known as antimicrobial peptides.  It is hoped that human medications modeled after these peptides may serve to limit the emergence of dangerous drug-resistant bacteria, fungi and other microbes.


Thanks, until next time, Frank Indiviglio.

Mealworms have a long history as important laboratory animals.  You can learn more by checking the forum at the following location:

Please also see my article on the proper use of mealworms as a pet food: Making the Most of the Mealworm: some tips on enhancing the nutritional value of this pet trade staple
Image referenced from Wikipedia and originally posted by

The Orange (or Guyana) Spotted Roach, Blaptica dubia: an Interesting Pet and Valuable Food for Reptiles, Amphibians, Invertebrates, Birds and Fishes – Part 3

Note: Please see Part I and Part 2 for further information on the captive care and natural history of this insect.

Hello, Frank Indiviglio here.

Social Grouping

The orange-spotted roach is sexually dimorphic – males have full wings (but rarely if ever fly), while females have only wing-stubs.  A ratio of 1 male per 3-5 females is ideal…excess males should be preferentially used as food for your collection.  Maintaining the roaches at this ratio will provide for a great deal of social interaction (please see Part I, Captive Habitat) and increased reproduction. 

Males attempt to bluff intruders onto their territories by rising up on their legs and fluttering the wings.  If this fails, a shoving match will ensue, with the loser retreating intact (well, except for his pride!).

Captive Longevity

The life cycle is 18 months to 2 years…but this is not well documented.  Please keep notes and pass along anything new you might learn.


Fertilization is internal, via a sperm packet deposited by the male.  Females produce the typical roach oothecum, or egg case, but retain it internally for a gestation period of approximately 1 month. 

The young, 20-30 in number, are born alive and reach sexual maturity in 3-4 months (this varies with temperature and stocking levels).


The reduced wing size in female orange-spotted roaches (and similar species) is attributed to paedomorphosis, or the retention of juvenile characteristics, rather than to wing growth inhibition. 

Flight muscle is, metabolically, one of the most active of animal tissues, and very “expensive” to support.  It is theorized that the resources put into maintaining the flight muscles may, in roaches, take away from reproductive potential.  In other words, female roaches are, in essence, “trading” flight for the ability to produce additional eggs.  Males of some species are though to retain the power of flight so as to be able to cover more ground when searching for mates.

I’ll cover additional types of roaches in the future.  Until then, please write in with your questions and comments. Thanks, Frank Indiviglio.

A description of the journal Cockroach Studies, along with photos of long-winged and wingless species, is posted at:

Image referenced from Wikipedia, here.

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