That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Please see Part I of this article for general information on some of earth’s most toxic amphibians (if not creatures in general) and for additional newt-keeping observations.

Tiny Newt vs. Giant Toad

The familiar red-spotted or Eastern newt (Notopthalmus viridescens) is at its most toxic in the immature eft (land) stage, but the aquatic adults are none-the-less well protected.

Decades ago, the mascot of an animal importer for whom I worked was a huge marine toad (Bufo marinus).  In those days, animals imported from then French Guyana were particularly massive, and this friendly, 4 pound+ specimen was no exception.  Imported animals which did not thrive following their long journey to the USA, ranging from giant Vietnamese centipedes to small rats and finches, all went to filling this amphibian behemoth’s huge appetite.

As a naïve 13 year old animal caretaker, I once tossed a nearly dead, 3-inch- long Eastern newt to the toad.  The newt was swallowed immediately and, right before my eyes, the toad flipped over…dead (along with my budding career!).  Years later, a co-worker reported a similar incident involving a Western painted turtle (Chrysemys picta bellii).

Interesting Means of Toxin Introduction

Several salamanders have quite unique ways of distributing their protective secretions – fire salamanders (Salamandra salamandra), for example, can squirt theirs for some distance.  Perhaps strangest of all, the Spanish ribbed newt (Pleurodeles waltl) actually drives toxin-tipped ribs through the skin of its back when confronted by a predator!

Cautions regarding Pet Newts and Salamanders

Highly toxic newts and salamanders, including all mentioned in this article, are widely available in the pet trade.  Many make interesting and long-lived pets.  However, please treat all newts and salamanders with caution…always wash well after handling them (most need not be handled, and none appreciate it) and, of course, do not trust them around children, mentally challenged persons, or pets.

Further Reading

Please check out my book Newts and Salamanders  for more information on the natural history and captive care of red-spotted newt, ribbed newts, fire salamanders and their relatives.

Image referenced from Wikipedia and originally posted by Peter Galaxy.

Reptile and amphibian keepers are fortunate to have at our disposal a huge array of substrates, many of which are formulated for specific animals (burrowing frogs, large snakes).  However, there are still a few situations, usually involving especially sensitive species, where we may need to improvise.  Today I’d like to relate my experiences using “alternative” substrates for desert-dwelling reptiles and hatchling tortoises.  I have long used both while working with animals in zoos, but have noticed that neither is well-known in the pet trade.

The Immune Systems of Desert Dwellers  

Reptiles hailing from desert and semi-desert habitats are often very sensitive to molds and fungi.  Having evolved in unique, relatively pathogen-free environments, their immune systems are usually unable to adapt to attack by microorganisms commonly encountered in captivity.

Potential Problems with Sand

Many of the substrates traditionally used for such creatures, including most types of sand, harbor molds and fungi when damp.  Although not a problem (in limited-contact situations) for all desert animals, some are especially sensitive and quickly succumb to skin and respiratory infections.

Chief among these in my experience are Egyptian tortoises (Testudo kleimanni), padloper tortoises (Homopus signatus, the world’s smallest tortoise) and several of the whip-tailed lizards (Cnemidophorus spp.).

Using Oyster Shell

Oyster shell (available at garden and poultry supply stores) does not support the growth of fungi or mold, is benign when swallowed in small amounts, and can be easily spot-cleaned and discarded when fouled.  I cannot recall any skin or respiratory problems in desert-dwelling reptiles maintained on oyster shell.

 

Further Reading

You can read more about fungal and other respiratory ailments in tortoises at: http://www.azeah.com/Care-Sheets.asp?id=125

Tortoise photo referenced from Wikipedia and originally posted by Stefano Alcini.

Having been chased by a Kodiak bear, confronted by an escaped king cobra and otherwise molested by scores of formidable animals, I felt relatively secure in accepting responsibility for a group of arboreal South American millipedes entrusted to me by colleague about to travel abroad. A primatologist, she had observed capuchin monkeys to rub millipedes over their bodies, and was investigating the situation (I, on the other hand, have always been far more interested in millipedes than monkeys!).

Deadly Millipedes?

A week after her departure, another coworker phoned me at 4 AM, frantically speaking in the rapid fire Spanish typical of her native Venezuela…and which I have great difficulty in grasping at 4 PM, much less 4 AM! Eventually I learned that 3 elderly millipede researchers had passed away recently, and that preliminary evidence indicated that cyanide poisoning, courtesy of the millipedes’ defensive chemicals, was suspected. I was warned against handling the millipedes (which I had been doing for weeks!) or putting them near my face (which I do not do with any creature).

The deaths turned out to be coincidental and unrelated to millipedes, but the incident led to a good deal of research into the defensive chemicals produced by these popular terrarium pets. It seems that millipede toxins are a very unique and complicated group of compounds.

Exploiting Millipede Toxins

Interestingly, a number of species of frogs and monkeys harness these chemical weapons for their own use. Although lagging behind such creatures by a few million years, humans are also getting into the act, and we may soon be putting millipede secretions to medicinal use.

An Amazing Coincidence!!!

The incident I related above, concerning myself and the millipedes, transpired approximately 8-10 years ago. I’m not sure why I decided to write about it today, but I’ve had millipede articles on my mind for some time, and thought this would make a nice introduction to the topic.

After writing this article I searched for a reference to add, for those readers who wished to learn more. You can imagine my shock when I discovered that today’s NY Times (28 June 2009) carries an article about the very same monkeys, people and millipedes involved in my story!!!

To read the entire article, please go to http://www.nytimes.com/2000/12/05/science/05MONK.html?pagewanted=print.

Next time I’ll explore the nature of these defensive weapons and the uses that monkeys, frogs and people are finding for them. Following that we’ll take a look at keeping and breeding millipedes in captivity.

Image referenced from Wikipedia and originally posted by Prashanthns.

 

I received my first “Uncle Milton’s Ant Farm” at about age 6, and instantly realized that therein lay the keys to a world previously closed to me (incidentally, Uncle Milton’s Ant Farms are still on the market, complete with decorative green plastic farmhouses and a coupon for live ants!).  My interest in subterranean creatures soared, and I soon had farms stocked not only ants but also earthworms, beetle grubs and even mole crickets.

From Ants to Gerbils

My introduction to using ant-farm type enclosures for other animals came a few years later.  Mongolian gerbils had just entered the US pet trade, and I became fascinated with these social, burrowing rodents.

In preparation for receiving my first pair of gerbils, I read all that I could get my hands on.  This amounted to a single care pamphlet – but within its pages I read about a burrow system designed by the author.  By inverting one aquarium (bottom side up) inside a larger tank, the author encouraged the rodents to burrow along the front glass.  When they emerged, the active little fellows had use of the entire large enclosure, since the bottom of the inverted tank, covered with soil, served as a substrate.

Fossorial Herps and Invertebrates

Starting with my own collection and refining the system while working at the Bronx and Staten Island Zoos, I found the basic premise widely applicable to fossorial (burrowing) creatures of all types.  The burrows are essentially sandwiched between 2 panes of glass, allowing for easy viewing through one side.

I especially like this set-up for eastern spadefoot toads, marbled salamanders, Australian water-holding frogs and fossorial tarantulas, scorpions and centipedes.  In the terrariums and zoo exhibits typically used for such creatures we are fortunate to get an occasional glimpse of anything approaching natural behavior.  However, displayed as described above, they reveal a great deal about their fascinating life histories.

Refinements

Tarantulas often line terrarium glass with silk, thwarting our efforts to observe them.  However, they are less likely to do this if you cover the outside of the glass (that portion that fronts along the burrow) with black paper or cardboard, hinged at the top with tape.  If you lift this gently, the spider may remain on view.

This technique is also useful for other high-strung creatures.  At Tokyo’s Ueno Zoo, I noticed that fossorial voles were very nicely displayed in an ant-farm type enclosure.  A hinged wooden door was used in place of the black paper described above, allowing visitors a peek at the rodents going about their business below-ground.  I have also successfully used the tank-within-a-tank system in zoo exhibits for dune mole rats and African pygmy mice.

Useful Products

Many burrowing animals are not only shy but nocturnal as well.  A night-viewing bulb  will help in observing them.

Substrate composition will vary, depending upon the species that you keep.  Two very useful products for burrowing animals are R Zilla Coconut Husk  and Zoo Med Repti Sand. Experiment with moisture levels until you have a composition that supports permanent burrow systems.

Further Reading

Some years ago I acquired a group of Australian water-holding frogs (Cyclorana platycephala) and found them to be among the amphibian world’s most accomplished burrowers.  To learn more about these amazing creatures, please see http://animals.jrank.org/pages/181/Amero-Australian-Treefrogs-Hylidae-WATER-HOLDING-FROG-Cyclorana-platycephala-SPECIES-ACCOUNTS.html.

 

Water holding Frog image referenced from Wikipedia and originally posted by Haplochromis

Tortoises are among the most highly-desired of reptile pets, but their care is fraught with difficulties, and captive death rates remain surprisingly high.  The plucky Russian, Horsefield’s or Central Asian tortoise (Testudo horsfieldi) is often promulgated as an ideal “first tortoise”.

A Cold Hearty Tortoise?

In many regards this is true.  Unlike most of its relatives, the little Russian tortoise is quite cold hearty.  Its range (three subspecies) extends from the southeastern coast of the Caspian Sea through Kazakhstan to western China and south to Iran, and encompasses some very cold regions.  Tortoises living in the north may be active for a mere three months each year.

Living on Little

The Russian tortoise’s adaptation to a Spartan diet also suits it to captivity. Generally, it subsists upon dry grasses, with only limited access to flowers, herbaceous plants and fruits.   Individuals in some populations rarely encounter standing water.

Size

Size also recommends the Russian tortoise as a pet…it tops out at 8.8 inches, and many are considerably smaller.

Nearly round in profile, the Russian tortoise is pleasantly colored in light to yellowish brown, and patterned with dark blotches.

Some Cautions

For all of the above reasons, it is a Russian tortoise that is often taken home by those new to tortoise-keeping.  Unfortunately, thousands perish each year, often because their owners were initially supplied with misleading advice.

Space and Cage Style

Despite their small size, Russian tortoises are far more active than other reptiles…even the largest of glass aquariums is inadequate.  You must think in terms of a 4-6’ x 4-6’ enclosure.

Glass aquariums, unless ventilated via fan, also do not provide sufficient air flow.  As humidity rises, respiratory problems are a near certainty.

Ideally, these tortoises should be housed outdoors throughout the warmer months.  Outdoor bird aviaries work well, although you may need to install an opaque, plastic barrier along the lower wall edge to prevent climbing. If you must keep your tortoise indoors, a custom-build enclosure is needed (please write in for details).

Environmental Conditions

Indoors or out, Russian tortoises require deep, dry substrates – grass and moist soil will not do.  A mix of sandy soil and oyster shell is ideal.  If unable to construct nighttime sleeping pallets (excavations), Russian tortoises become stressed and subject to dehydration-related disorders.

Pros and Cons

With proper care, the Russian tortoise can indeed be a most responsive and long-lived pet.  However, they are by no means animals to be purchased lightly.  Please consider your abilities carefully, and write in if you have any questions whatsoever.

I hesitate to discourage responsible people from keeping these fine animals…tortoises ranging from the tiny South African padloper to the massive giants of Aldabra and the Galapagos Islands have provided me with some of my most memorable herp-keeping experiences.  Yet I hesitate to paint too rosy a picture.  Please write in regarding your specific situation, and I’ll do my best to advise you appropriately.

The Russian tortoise owner must also take into consideration those other factors critical to the care of all tortoises – diet, UVA/UVB exposure, humidity levels, etc.. We’ll take a look at these and other subjects in future articles.

Further Reading

Please check out A Complete Guide to Russian Tortoises  in our Reptile Books Department.

An interesting article detailing the natural history of Russian tortoises in a harsh environment is published in the journal Ecography at

http://www.bio.usyd.edu.au/Shinelab/staff/xavier/ecography2003.pdf