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

One of the world’s largest scorpions, the emperor is also the most widely kept, and captive born specimens are readily available.  Other than females with young on their back, emperor scorpions are rather mild-mannered.  The sting may be painful, but is not considered dangerous to healthy adults.

Physical Description

Females may reach 7 inches in length and, when gravid, exceed 50 grams in weight (by way of comparison, the average house mouse weighs 20 grams); males are slightly smaller.  Both sexes are jet black in color.

Range and Habitat

Emperor scorpions thrive in areas of high humidity, and are generally associated with rainforests.  There are some reports of populations living in wet savannas and human-influenced habitats as well.  They are native to northwest and north-central Africa, with their range extending from Mauritania south and east to Zaire.

Status in the Wild

Wild populations have been little-studied, but concern over huge exports in the early 1990’s led to the listing of this species on CITES II.  Those in the US trade are largely captive bred, although animals “ranched” in Togo and Benin are sometimes imported.  The closely related P. dictator and P. gambiensis, uncommon in the pet trade, are also listed on CITES II.

CAPTIVE HUSBANDRY

The Enclosure

Provide your scorpions with as much space as possible.  A pair can be kept in a 10 gallon aquarium, but larger is always better; a 20 gallon can support 4-6 animals.  The screen cover should be secured with cage clamps.

Physical Environment – Habitat Type and Terrarium Decorations

Emperor scorpions inhabit extensive burrow systems in the wild, and should be given the opportunity to burrow in captivity.  Under such conditions, they will exhibit a wide range of interesting behaviors – far more so than if kept in a simple terrarium.  When able to construct secure burrows, captive scorpions become quite confident and therefore more likely to show themselves.

Emperors also take readily to artificial caves  and hideouts excavated below driftwood and other structures.  I once created a very interesting exhibit by partially burying a number of artificial caves at different levels within the substrate of a 55 gallon aquarium.  The resident colony of emperor scorpions dug pathways between the various cave entrances and established a complicated maze of “avenues” – more reminiscent of rodent runways than anything one might associate with an invertebrate.  I highly recommend this type of set up for your scorpions.

Substrate

Excavator Clay Burrowing Substrate  is specifically designed for fossorial animals and is a great choice for burrowing scorpions.   A few handfuls of Jungle Earth Reptile Bedding  should be mixed in to help retain moisture.

Click: Emperor Scorpion, Pandinus imperator, Care – Part 2, to read the second part of this article.

Writing in the current issue of the journal Animal Behavior, researchers from the University of Grenada report that female Mexican lance-headed rattlesnakes frequently consume infertile eggs and non-living young after giving birth.  This is said to be the first documented case of cannibalism among rattlesnakes (please see below for my observations, however).  Interestingly, with a sole exception, the females did not consume young that were born alive, even though these remain inactive for several hours after birth, and appear (to us, at least!) to be dead.

Rattlesnakes bear live young, and females use up a great deal of energy and body mass during gestation (they do not feed while gravid).  It is theorized that consuming those young which are dead upon birth helps them to recover their strength.

Rattlesnake Cannibalism in another Species

While working with the comprehensive rattlesnake collection at NYC’s Staten Island Zoo, I had the opportunity to participate in breeding efforts for a number of species.  Most births occurred at night and were not filmed, so I cannot say if females of other species ever consumed non-living young.  However, newly born Neo-tropical rattlesnakes (Crotalus durissus) did consume litter-mates on two occasions.

Hog Fat and other Unusual Snake Foods

Contrary to popular belief, many snakes consume non-living prey (i.e. carrion) in the wild.  The most unusual incident I recall was a note published in the journal Herpetologica…a water moccasin (Agkistrodon piscivorous) was observed stripping fat from a road-killed feral hog!

Of the snakes I have worked with in the field and captivity, moccasins, indigo snakes, black racers and anacondas stand out as taking the widest variety of prey species, and each engages in cannibalism.  One particularly large moccasin I cared for consumed a northern water snake that shared its exhibit (not my idea – I had moved on by then!!).  I’m sure the same occurs in the wild, in areas where moccasins and various water snakes co-exist.

A Collection for Rattlesnake Aficionados

I had the wonderful opportunity of participating in the renovation of the Staten Island Zoo’s reptile house, former stomping ground of legendary snakeman Carl Kauffeld (known to all snake keepers as the author of Snakes, the Keeper and the Kept and Snakes and Snake Hunting).

As in former times, the zoo now boasts an impressive rattlesnake collection…please visit if you have the opportunity.  Pictured here are a few exhibits that I set up for the opening – Neo-tropical rattlesnakes, banded rock rattlesnakes and desert Massasaugas.

Further Reading

Lance-headed rattlesnake photos and natural history information are posted at:

http://www.ratelslangen.nl/gallery/Crotalus_polystictus_Mexican_lance-headed/

Breeding Leopard Geckos (Eublepharis macularius) at Home: Determining the Sex of Your Pets

The ever popular leopard gecko is a good choice as an introduction to the breeding of lizards in captivity. Success, while not assured, is common…yet, these little fellows are so captivating that even zoos and well-experienced breeders continue to work with them.

Spring’s Effect
Leopard geckos are often brought into breeding readiness by the slight changes in temperature and day length that are evident even indoors. With the imminent arrival of spring (writing from southern NY I am happy to report hearing a song sparrow singing for the first time today!), I thought it a good time to discuss how female from male leopard geckos differ in appearance.

The Pores
Take a look at your pet’s vent, which is an opening, used for copulation and defecation, at the base of the lizard’s tail. Directly above the vent, between the rear legs, you will see a series of “V” shaped little bumps, which are known as pre-anal pores. These are large and readily visible in males and tiny and less-evident in females. The pores produce waxy secretions that are used by males to mark territories and, possibly, to attract females.

Hemipenes
Between the vent and the base of the tail, mature male geckos exhibit a pair of bulges. These bulges conceal the hemipenes, which are used during copulation to achieve internal fertilization. Male lizards and snakes have 2 hemipenes, and can use either, but only one at a time, when mating.

Practice!
You may need to look at a number of geckos, or reliable photographs, before being able to reliably distinguish males from females…but once you get the right “search image” the process becomes quite easy. Please remember that only mature animals – males of age 1 year or more, females generally of age 18 months or so – will exhibit noticeable sexual dimorphism (differences in appearance).

Further Reading
Please check out the book I’ve written on leopard gecko care and natural history at http://www.thatpetplace.com/pet/prod/240453/product.web.

See Feeding Pet African Bullfrogs Pyxicephalus adspersus – Part 1 for the first part of this article.

How does one satisfy a 9 pound amphibian!?

Wild-Caught Insects
Native invertebrates, collected from pesticide-free areas, should be offered whenever possible. In my work with frogs of all types, I’ve found very little that approaches the beneficial effects of a varied diet. Zoo Med’s Bug Napper is an excellent insect trap.

Sweeping a net through tall grass and searching around outdoor lights will also yield a number of useful species. Avoid using spiders, stinging and brightly-colored insects and fireflies, and do not collect during times when your collecting site is being sprayed with insecticides as part of mosquito control programs.

African bullfrogs under my care have enthusiastically accepted (“enthusiastically” goes without saying where these stout fellows are concerned!) cicadas, katydids, grasshoppers, beetles and their grubs, moths, tree crickets, hover flies, caterpillars, and most everything else I could come up with. I rely heavily upon wild-caught invertebrates throughout the spring, summer and early fall, but even a few beetles plucked from a screen door every night or so will go a long way in keeping your pet in the peak of health.

The Importance of Canned Insects
African bullfrogs can be easily trained to accept non-living food items from a plastic feeding tongs (well, to be honest, no actual “training” is involved…they generally just swallow whatever moves within range!). They have a very vigorous feeding response, and hit food quite hard. Accordingly, I avoid using metal feeding implements, as the risk of a mouth injury is fairly high.

This frog’s willingness to tong-feed is quite fortunate, because it enables us to use canned insects as a source of important dietary variety. The canned grasshoppers are quite large, and are suitable even for adult African bullfrogs. Large canned grasshoppers, silkworms and other insects can be broken into smaller pieces for juvenile frogs.

Meal Frequency and Nutritional Supplements
Juvenile frogs can be fed 3-4 times weekly, while adults do fine with a meal each 4-7 days (fast them for 10 days or so after a “heavy” meal of large shiners or pink mice). Smaller, more frequent meals can also be offered…I personally find this preferable, but it is not as critical for with this species as it seems to be for certain others.

The food of juveniles should be powdered with Reptocal at every other feeding, that of adults once weekly. During periods when you are unable to offer a varied diet, alternate Reptocal with Reptivite.

The African bullfrog pictured here may be seen in the wonderful amphibian exhibit area at Norwalk Connecticut’s Maritime Aquarium. I was involved in the project’s development as a consultant, and am pleased to say that the staff has done an excellent job of keeping and breeding a wide variety of amphibians in beautiful, naturalistic exhibits. The accompanying photographs show some of the aquarium’s other residents – albino American bullfrogs with pumpkinseed sunfishes, poison frogs and tiger salamanders. Also exhibited are barking treefrogs, Surinam toads, bronze frogs, mudpuppies, fire salamanders, red-eyed treefrogs and many other toads, salamanders and frogs from both the USA and abroad – please visit if you have the opportunity.

Further Reading
For a startling account of African bullfrog predation upon red spitting cobras and of the amazing degree of parental care these frogs provide to their tadpoles, please see my articles “An Appetite for Cobras” and “The African Bullfrog (South African Burrowing Frog, Giant Bullfrog), Pyxicephalus adspersus: The World’s Heaviest Frog is also a Devoted Parent”.

African bullfrogs seem to give rise to all sorts of interesting stories.

How does one satisfy a 9 pound amphibian!?”

Although African bullfrogs are among the most popular and long-lived (to 50 years) of amphibian pets, there remains some confusion as to their proper diet in captivity. Prompted by recent blog inquiries, I thought I’d set down a few thoughts on the subject.

Calcium Through Cannibalism
African bullfrogs, especially growing animals, seem to require a great deal of calcium. Perhaps this is due to their naturally fast growth rate – in their native southern Africa, breeding ponds dry quickly and tadpoles must transform quickly if they are to survive. The froglets then have but a short time to gorge upon enough food to sustain themselves through aestivation periods (dry weather dormancy) that may reach a year in length.

Often, the main source of food for the small metamorphs (transforming frogs) is other African bullfrogs. There is evidence that frogs will preferentially prey upon unrelated individuals, but in any case a diet so high in vertebrates is quite unusual for amphibians.

The Perils of a Rodent-Based Diet
Captive amphibians that are fed vertebrate-rich diets, usually in the form of mice, often develop eye (lipid deposits), kidney and liver problems. Although African bullfrogs do feed heavily upon other frogs in the wild, the practice of feeding captives largely upon mice, while a convenient way of sating these huge fellows, is not advisable.

Outside of the breeding season, the diet in the wild consists mainly of locusts, spiders, beetles, scorpions and other invertebrates…the vertebrates that are taken are more likely to be lizards, snakes and frogs than mammals. In some cases, rodent-based captive diets have not led to problems, but hair impactions and obesity-related health complications have resulted in others.

Providing a Healthful, Varied Diet

Fish and Crayfish
I prefer using goldfish, minnows and shiners for the vertebrate portion of African bullfrog diets, (the bones are an excellent calcium source), with only an occasional pink (un-furred mouse) being provided. Crayfishes, if available, are a fine food item and good calcium source. Neither of these food items is likely encountered by African bullfrogs in their native habitat – crayfish are not native to Africa, although 1 North American species is introduced, and the frogs tend to breed in fishless, temporary pools – but both have proven very useful in the long-term maintenance of this species.

Earthworms and Nightcrawlers
Earthworms, including nightcrawlers for adult frogs, are an excellent source of nutrition, and can comprise a majority of the food offered. The earthworm’s calcium: phosphorus ratio has been shown to generally hover around 2:1, which is ideal as regards frog diets. I believe that earthworms from different habitats may vary in this regard, but have none-the-less had very good results with earthworm-based diets over many years.

Commercially Available Insects
The balance of the diet can consist of crickets, roaches, super mealworms, waxworms, tomato hornworms and other commercially available insects. Large roaches (as well as nightcrawlers) present an excellent means of keeping your frog sated without resorting to rodents. For information on keeping and breeding the orange-spotted roach, please see my article “The Orange (or Guyana) Spotted Roach, Blaptica dubia.

Read Feeding Pet African Bullfrogs Pyxicephalus adspersus – Part 2