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

The African spurred tortoise (Geochelone sulcata) is at once a highly desirable and problematical pet. One of the most engaging of all tortoises, with long-term pets exhibiting a degree of responsiveness more commonly associated with dogs, hatchlings are available for modest prices.

Size

Spurred tortoises are, however, the largest of all mainland tortoises, and may attain weights in excess of 200 pounds. Only one other mainland species, the yellow-footed tortoise (G. denticulata), gives the spurred any serious competition. A friend wrote me that he recently examined a 60 year old captive that weighed 190 pounds.

A harsh natural habitat – the southern fringe of the Sahara Desert – has equipped spurred tortoises with a remarkable ability to grow rapidly when food is plentiful. I weighed 2 individuals that topped 60 pounds by age 5!

Space

Few hobbyists are equipped to properly care for a spurred tortoise. They require a great deal of room, with males being particularly active during the breeding season. Indeed, a ½ acre outdoor exhibit I over-saw proved too small for a pair of 80 pounders.

A determined spurred tortoise is also difficult to confine, and will dig under or plow through seemingly impenetrable barriers. Males may become territorial, and treat people and other pets as threats.

Stopping Traffic in Manhattan

I took in the tortoise pictured here when its owner could no longer provide for it. He is currently at Social Tees, New York City’s premier animal rescue facility, awaiting transport to a new outdoor home in Florida.

It takes some doing to raise eyebrows in Manhattan’s East Village, but as you can see from the photo this stout fellow does so admirably. In fact, Social Tees reptile expert Robert Shapiro has dubbed him “Speed Bump” because of his traffic-stopping abilities! When not meeting new neighbors, “Speed Bump” has the run of a large outdoor yard – not easy to arrange at today’s rents!

Island Giants

The African spurred tortoise is exceeded in size only by 2 island-dwelling species, the Aldabra (G. gigantea) and Galapagos tortoises (G. elephantopus). Those on the Aldabra Islands (between Kenya and Madagascar) are the only survivors of a host of giant species that once inhabited the Seychelles and other islands in the Indian Ocean. Sadly, all were hunted to extinction by the early 1800’s.

Aldabra tortoises exceed the better-known “Galaps” in size. What may be the world’s largest terrestrial turtle was an Aldabra that resided at the London Zoo and is now preserved in the British Museum. This fellow weighed 560 pounds at the time of his death, by which point he had lost weight; he may have topped 600 pounds in his prime.

I have worked with both species, and found them to be unbelievably intelligent…Aldabra tortoises cover their food trays, backing up to expose only a bit of food at a time, so as not to draw the attention of hungry exhibit mates!

Please Plan Ahead

Despite my enthusiasm, I must advise you to think carefully before taking on even a small spurred tortoise. Please think long-term, and write in for advice.

Further Reading

I’ve recounted some interesting giant tortoise stories in the following articles:

Feisty Terrier Proves no Match for African Spurred Tortoise

How Reptiles Adjust to Novel Situations

Legendary turtle biologist Peter Prichard gives a wonderful account of living and extinct giant tortoises in the classic Encyclopedia of Turtles (TFH, 1979).

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

Mantids (a/k/a praying mantis) are growing in popularity among invertebrate keepers, with a number of species now being regularly bred in captivity. Ranging in size from minute stick-mimics to 10-inch-long behemoths capable of capturing mice and lizards, the world’s 2,400+ mantid species are among the insect world’s most fascinating members, and many are well suited to terrarium life.

Sociable Mantids?

Praying mantids vie with weasels and shrews as the most rapacious of all predators…I once saw a female Chinese mantid (Tenodera aridifolia sinensis) catch and consume a hornet while she was copulating! Females of many species eat their mates, often during the act of mating.

However, some species, including the popularly-kept dead leaf mantid (Tenodera aridifolia), get along quite well together. I have raised clutches of dead leaf mantids with very few losses….perhaps several hanging upside down from a branch, as is their habit, are better camouflaged than would be a single individual.

Camouflage Artists

All mantids studied thus far are supremely well-camouflaged, mimicking, among other things, leaves, sticks, bark and lichen. Orchid mantids so closely resemble their namesakes that insects often alight directly upon them, mistaking the spectacularly-colored predators for flowers.

Farmer’s Friend

Insatiable appetites have long endeared mantids to farmers the world over. The Chinese mantid was imported into the USA in 1896 to battle agricultural pests. Exceeding the nation’s 20 native species in size, the Chinese mantid may consume upwards of 2,000 insects during its lifetime. Millions of its egg cases, or oothecum, are still sold annually for use in gardens, greenhouses and farms.

The European or praying mantid (Mantis religiosa) appeared in the USA in 1899, as a stowaway. Armed with a taste for the tree-killing gypsy moth (also a European introduction), the new insect predator quickly found favor in its adopted home. Today both mantids are widely distributed throughout the USA.

My own introduction to mantid rearing, at age 7, involved a famous entomologist and chop meat waved about on toothpicks. I’ll cover that story and mantid care in the future.

Further Reading

To learn more about mantid natural history and biology, please visit

http://www.discoverlife.org/mp/20o?search=Mantodea.

Image referenced from Wikipedia and originally posted by GRBerry.

After shedding, leopard geckos (Eublepharis macularius) sometimes exhibit a condition that superficially resembles what snake owners know as “retained eye caps”. However, the structure of a leopard gecko’s eye, and that of the closely related banded and fat-tailed geckos, is nothing like that of a snake’s, and problems following shedding must be addressed in a very different manner.

Leopard Gecko Eye Structure

Leopard, banded and fat-tailed geckos are classified in the gecko subfamily Eublepharinae, and differ from all other geckos in having movable eyelids. In fact, the genus name, Eublepharis, means “true eye lids”. The eyes of all other species in the family Gekkonidae are covered by a transparent cap, or spectacle, which is fused to the eyelids (like snakes, they cannot blink their eyes).

The eyelids of leopard geckos and their relatives are lined with a thin layer of skin. This eyelid liner is replaced along with the rest of the gecko’s skin when shedding occurs. However, if conditions are too dry in the terrarium, the eyelid lining may stick to the lid and be retained after shedding. This will lead to an irritation. Eventually, an infection will set in and cause the eye to swell.

Diagnosis and Treatment

The retained skin is thin but visible, so check your gecko carefully after it sheds. Geckos so affected will also blink a great deal, and may rub the area.

While experienced hobbyists may be able to remove retained eye caps (brille) from pet snakes, retained eyelid liners are an entirely different matter. This problem must be attended to by an experienced veterinarian only.

Avoiding Problems: Humidity and Diet

An overly-dry environment seems to be the main factor leading to retained eyelid liners. Although geckos are native to quite arid habitats, like all desert animals they are able to find moist retreats, usually below ground, when necessary. It is easy to overlook this when keeping desert animals. For years zoos kept Gila monsters, native to one of the driest places on earth, in bone-dry exhibits. Field research showed, however, that these lizards actually spend 90% of their time in burrows where humidity levels are quite high.

Shedding aids are useful for lizards of all types, especially desert-adapted species.

Low Vitamin A levels have also been implicated in gecko shedding problems. Be sure to provide your lizard with a varied diet and appropriate vitamin/mineral supplements. Please write in if you need detailed advice on feeding your gecko.

While most people acknowledge that spiders perform a valuable service by consuming harmful insects, there remains the lingering belief that the vast majorities are dangerously venomous, and do more harm than good. Today I’d like to pass along some facts and figures that you may find interesting.

Venom

All spiders produce venom, but in most cases it is only potent enough to overcome the invertebrates upon which they feed. Less than 1% of the world’s 40,000+ spider species are capable of delivering a dangerously venomous bite to humans.

The Real Killers

Dogs, horses, pigs and other domestic animals, although enjoying a far more favorable reputation than spiders, actually kill and maim many more people than do our 8-legged neighbors. In fact, far more people are killed yearly in the USA by falling vending machines (I’m guessing in bars?) than by spiders or snakes!

Potentially Deadly Spiders

The most highly venomous Arachnid, Australia’s funnel-web spider (Atrax robustus), has not caused a fatality since the introduction of antivenin in 1981. In the USA, widows (Latrodectus spp.) and the brown recluse spider (Loxosceles reclusa) are potentially dangerous, but antivenin is available. The bite of the world’s largest spider, South America’s 12-inch goliath bird-eater (Theraphosa blondi), is very painful but otherwise harmless.

Other Spider-Associated Risks

The foregoing should not be taken as a license to ignore caution when dealing with spiders. Just as with bees and other venomous animals, allergic persons can be killed by the bites of relatively benign species, and dangerous infections can be associated with the bite of any animal. Many tarantulas shed urticating hairs when disturbed or even when just moving about. A colleague of mine underwent major surgery to remove such hairs, deposited on his hand by a “tame” red-kneed tarantula, from his eye.

I have kept native and exotic spiders since childhood, and have never been bitten because I do not pick up spiders with my hands. I urge you to handle spiders, if at all, with a plastic tongs or by ushering them into a container.

Further Reading

An excellent resource for those interested in spiders, the American Museum of Natural History’s World Spider Catalog is published at http://research.amnh.org/entomology/spiders/catalog/.

Please see my article Tarantulas in Captivity for information on keeping these fascinating creatures at home.

Funnel Web spider image referenced from Wikipedia and originally posted by Zinnmann

Goliath Bird Eating Spider image referenced from Wikipedia and originally posted by Dcoetzee

Aeromonas hydrophila is a common species of gram negative bacteria that often infects captive frogs and salamanders. It is particularly prevalent during the warmer months, when high temperatures stress amphibian immune systems (even tropical species often spend much of their time in cool micro-habitats) and leave them vulnerable to microorganisms that might otherwise have been resisted. Aeromonas infections are usually referred to as “red leg” or “Septicemia”.

Symptoms

Red leg, so named because the red lesions associated with it often first appear on the skin where the rear legs meet the body, is contagious and can be transmitted by contact with infected water, animals, wood, etc. The skin hemorrhages that typically occur become progressively deeper and the skin eventually sloughs off. Afflicted animals may also twitch, convulse, and become comatose. If not treated in its early stages, the condition is almost always fatal.

Improved sanitation is an immediate first step to take. Hands must be washed after handling animals and enclosures, for your own and your collection’s benefit. Environmental conditions such as poor hygiene will contribute to Aeromonas outbreaks, as will overcrowding.

Refrigeration as Treatment

Red leg is sometimes cured or by refrigeration at 39 to 41°F for two weeks. This treatment, pioneered in laboratory colonies of leopard frogs, has also been successfully used with Mexican axolotls. It appears that the immune systems of some amphibians function more effectively at low temperatures, while Aeromonas bacteria does best under warmer conditions.

The beneficial effects of low temperatures are not limited to red leg alone…while working at the Bronx Zoo I twice submitted “dead” salamanders (a mudpuppy and a hellbender) for necropsy, only to find them alive and well after a night in the animal hospital’s refrigerator!

Medical Treatment

When working with animals afflicted by any type of infection, it is very important that you contact your personal physician for advice concerning possible health risks to you and other members of your household.

While lacerated skin would lead one to believe that Aeromonas is the culprit, a definite diagnosis can only be made by blood culture performed by a veterinarian. This is important because a number of other species of bacteria, including Pseudomonas and Salmonella, may cause similar lesions, and the treatment of each will likely vary. Opportunistic bacteria and fungi, which commonly colonize the open wounds, must also be addressed.

Further Reading

An interesting early case history of a red leg outbreak among captive frogs is posted at https://kb.osu.edu/dspace/bitstream/1811/5136/1/V66N01_087.pdf.