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

Please see Part I and II of this article for information on scorpion natural history and further details on emperor scorpion care.

The captive reproduction of emperor scorpions is a most interesting endeavor (for hobbyists and, I imagine, the scorpions themselves!).  When properly housed and cared for, emperor scorpions are relatively easy to breed.  This is surprising, given that they are such unique and highly specialized creatures, and is an opportunity that should not be missed.  Many prominent invertebrate specialists started out with this species…keeping them is a wonderful way of becoming involved in invertebrate husbandry, and will almost certainly “hook” you for good.

Distinguishing the Sexes

In captivity, as within certain parts of the natural range, mating may occur during any month.  Adult females are longer and stouter than males, but this is not a reliable means of distinguishing the sexes.

There are some slight differences in the shape of the genital openings.  View the scorpions from below, in a clear plastic box, when attempting to sex in this manner – do not restrain them via hand or tongs.  Photos of the undersides of male and female emperor scorpions are posted at http://www.pandinusimperator.nl/EN/biology_EN.htm.

Courtship and Mating

Reproduction is most likely to occur if your scorpions are housed in a large terrarium that provides ample burrowing opportunities.  All species studied thus far perform a “mating dance”, with the pair locking claws and moving about.  It is theorized that this helps to clear a patch of ground for the deposition of the males’ sperm packet.  I imagine, but have not been able to determine for sure, that the specific dance “moves” also aid in species’ recognition among these nearly blind creatures (this is the case in “dancing” scorpion relatives, such as jumping spiders).

The male deposits a sperm packet on the ground and pulls the female over it (it is tempting here to draw analogies to salamander reproduction).  Hooks along the edges of the sperm packet latch onto the female’s genital opening, and the eggs are then fertilized internally.

Gestation and Birth

Gestation is highly variable, ranging from 7-10 months on average but sometimes exceeding 1 year.  It is likely that stress, temperature and other factors play a role in determining the length of the gestation period.

Females continue to feed while gravid, and may swell noticeably…when viewed from above, the carapace segments appear widely spaced, and seem ready to split apart (heavily-fed scorpions of either sex, however, may also appear gravid).

The young (sometimes called “scorplings”), 8-30 in number, are born alive and measure about 5/8 of an inch in length.  They are white in color and remain on the female’s back until their first moult, at which time they darken and begin to venture off on their own.  Once this occurs, they will readily accept ½ inch crickets, small waxworms, newly molted mealworms, wild-caught insects and canned silkworms.

Maternal Care of the Young

Female emperor scorpions feed their young with finely-shredded insects – this really is something to see.  By all means, try to do so by viewing yours at night with the aid of an incandescent “nocturnal” bulb.  The degree of care they provide to their young is extraordinary, and is far greater than one might expect from such supposedly “primitive” creatures.  Even among those scorpions that exhibit social behavior, emperors stand out as being very advanced in this regard.

Caring for the Mother and Her Brood

Once the female has given birth, all other scorpions should be removed from the terrarium, as she will become highly aggressive and defensive.  Do not relocate the mother…this inevitably stresses her and may cause her to consume her young.

Females with young react aggressively to any disturbance, even occasionally grabbing and eating scorplings that become dislodged from their backs.  This is not an uncommon occurrence – do not remove the remaining young unless she begins eating them regularly, as the overall survival rate is improved when clutches are reared with their mother.  I have raised several clutches to adulthood with the mother present – the key lies in disturbing her as little as possible and in providing a deep, secure burrow.

I usually raise the terrarium’s temperature to 85-90 F when rearing young emperor scorpions – this may not be essential, but I have found it to work well.

Sexual maturity in the wild is reportedly reached in 4-7 years, but captives may breed when only 12-14 months of age.  Emperor scorpions under my care have reproduced at age 3 and 4 years.

The Woodland Park Zoo provides interesting information on emperor and other scorpions in nature and captivity at:

http://www.zoo.org/factsheets/scorpion/scorpion.html

Those who keep reptiles, especially turtles and lizards, are often of the opinion that amphibians make rather unresponsive pets.  True, a number of frogs and toads “come to life” at feeding time, but by and large amphibians are somewhat more retiring than are most reptiles.  This is especially true of the salamanders, many of which spend the vast majority of their lives in hiding.

A Beautifully-Colored and Responsive Salamander

The strikingly beautiful fire salamander is, however, a notable exception.  Native to cool, mossy woodlands in southwest Asia, much of Europe, and a small portion of northwestern Africa (a continent noted for its lack of salamanders), fire salamanders are as visually oriented as any turtle and eagerly anticipate regular feeding times.  Typically colored jet-black and mottled with bright orange or yellow, one subspecies, Salamandra salamandra fastuosa is largely bright yellow with bold black lines going down the body, legs, and tail (please see photo).

The many fire salamanders I have kept would, without exception, leave their retreats in anticipation of food when I approached their terrarium.  Most feed from the fingers or forceps and are not shy about moving about in broad daylight once they are acclimatized to captivity.  They even move differently than most salamanders – holding their bodies high off the group and “stomping about” in a very determined (and most “un-salamander-like”) manner. And, as you can see from the photo, their bold personalities also suit them well as “amphibian ambassadors” to budding herpetologists!

A Caution Concerning Temperature

Fire salamanders could very well be the ideal amphibian pet for reptile enthusiasts.  Their one drawback is a distinct sensitivity to warm temperatures…a cool basement or similar situation is pretty much a necessity for success with this species.  Although individuals hailing from certain populations are a bit more heat-tolerant than others, nearly all become stressed at temperatures over 72°F.

Breeding and Longevity in My Collection and Elsewhere

However, when properly cared for, fire salamanders are among the most long-lived of all amphibians, with the captive longevity record being just over 50 years.

I received the 2 individuals pictured together here as larvae 14 years ago – they have bred several times and show no signs of slowing down.  They do not lay eggs, but rather give birth to live larvae. Some populations, particularly those living at high elevations, give birth to fully formed little salamanders, skipping the larval stage completely.

How I Keep and Feed Fire Salamanders

I keep my fire salamanders in a basement where yearly temperatures range from 55-68F.

As you can see from the accompanying photo, they feed readily from plastic tongs.  This allows me to increase dietary variety through the use of canned invertebrates – snails are particularly favored.  Field research has shown land snails to be an important part of the natural diet in many regions, so I rely heavily upon these, especially during the winter when other foods are scarce.

I also use canned silkworms, live earthworms (50% of the diet), blackworms, crickets, mealworm beetles, waxworms, sow bugs and wild-caught insects (i.e. moths gathered with the aid of a Zoo Med Bug Napper).

Further Reading

You can learn more about this salamander’s natural history and the threats facing wild populations at http://amphibiaweb.org/cgi/amphib_query?where-genus=Salamandra&where-species=salamandra

The robust African bullfrog shares with the fire salamander and Chinese/Japanese giant salamanders the distinction of being the longest lived of all captive amphibians. I personally know of 2 specimens that lived for 21 years in captivity, both owned by the same person (interestingly, although housed separately, they died within a few days of one other). The unpublished longevity record for the species is 50 years.

Ammonia – an Ever-Present Threat
However, one easily-overlooked point – terrarium hygiene – can very quickly end their potentially long lives. In my experience, a lack of attention to this critical point is the most common cause of African bullfrog deaths in captivity. Despite their burly, somewhat tank-like exteriors, African bullfrogs are extremely sensitive to ammonia toxicity…tiny metamorphs and huge, decades-old adults are equally vulnerable.

These frogs usually (but absolutely not “always”!) defecate in their water bowl. The bowl should be cleaned at least once daily, even if it does not appear fouled. Frogs soaking in fouled water will absorb ammonia through their skin and can die in short order.

Daily care while you are on vacation or otherwise absent from home is a must…a day or so of missed cleanings can easily kill a treasured old pet (think of how you’d feel then!).

Useful Products and Techniques
R-Zilla Terrarium Cleaner is safe to use on water bowls and terrariums, but wherever amphibians are concerned it is essential that all surfaces are rinsed thoroughly after being disinfected. Be sure to use a water conditioner  to de-chlorinate water used in the bowl and in spraying the substrate.

A very useful product of which I was made aware recently is Hagen Cycle. It is contains huge populations of live beneficial aerobic bacteria, is being increasingly used in laboratory frog colonies, both for aquatic species and in the water bowls of others. I believe it is an important product to consider when keeping large frogs, which produce copious amounts of nitrogenous wastes (it is not, however, a substitute for water changes).

As your frog may also defecate outside of the water bowl, it is important that the entire terrarium can be easily cleaned. Simple set-ups are therefore preferable for African bullfrogs (when designing planted zoo exhibits, I always allow for a floor drain and false bottom, so that the substrate can be hosed down without removing the frog). Washable terrarium liners are very useful in African bullfrog enclosures.

Further Reading
You can read more about African bullfrog natural history and captive husbandry in the following articles on this blog: The African Bullfrog – Devoted Parent, An Appetite for Cobras , and Feeding African Bullfrogs.

Note: For further information on red eared sliders in the wild and captivity, please see The Red Eared Slider in Outdoor Ponds  and Typical and Atypical Habitats of the Red Eared Slider

The red eared slider is familiar to herp enthusiasts the world over, but many of its relatives are not.  As one of the many subspecies of the common slider, the red-ear is cousin to a surprising variety of rare and poorly studied turtles.

Widely-ranging Subspecies

The red-eared slider is one of 15 described subspecies of the common slider, Trachemys scripta.  The common slider is considered to be the most variable, in terms of physical appearance, of all turtles, and has a huge natural range.  Common sliders of one variety or another may be found from southeastern Virginia to northern Florida, west to Kansas and New Mexico and south through Mexico to northern Columbia and Venezuela.

A Slider among Sea Turtles

The most “exotic” slider subspecies that I have handled are the Nicaraguan slider, Trachemys s. emolli, which was shown to me by a friend in Costa Rica, and the Meso-American slider, Trachemys s. venusta.  I encountered the Meso-American slider at Tortuguero, Costa Rica, where it nests on ocean beaches amidst green and leatherback turtles.

It is said that Meso-American sliders wash out to the sea from the mouths of nearby rivers, then make their way to the beaches to nest…but I have not heard an explanation of  how they negotiate the return trip.  In any event, I have observed them in large rivers and can attest to the fact that at least some individuals nest on ocean beaches, right along with sea turtles.

Sliders in the Desert and Box Turtles in Water

Perhaps the rarest of all slider subspecies is the Cuatro Cienegas slider, Trachemys s. taylori, found only in the Cuatro Cienegas Basin of Coahuila, Mexico.  Smack in the middle of the Chihuahuan Desert, this 500 square mile oasis is also home to another very rare and unusual turtle – Coahuilan box turtle, Terrapene coahuila.  Long isolated from related species, the 75+ animal species endemic to Cuatro Cienegas have developed a host of unusual survival strategies.  The Coahuilan box turtle, for example, is unique among all box turtles in spending most of its life in water.

I’ve worked with Coahuilan box turtles in captivity…its hard to describe how strange it is to see them bobbing about in deep water.  With their highly-domed shells, they seem completely unsuited for a watery existence, yet get along quite well.  Their future in the wild is tenuous at best, but they breed very well in captivity.

Further Reading

An interesting article on the unique reptiles and amphibians of the Cuatro Cienegas Basin is posted at http://www.desertfishes.org/cuatroc/literature/cc_symp1/4/j4.html.

Click: Emperor Scorpion, Pandinus imperator, Care – Part 1, to read the first part of this article.

Heat, Humidity and Light

Temperature should be maintained at 78-86 F, and humidity at 70-85%.  Do not cover the terrarium’s top with plastic in order to increase humidity, as air circulation is desirable.  Rather, use a moisture-retaining substrate (please see above) and spray frequently with de-chlorinated water (the substrate should be slightly moist to the touch).

In order not to disturb your scorpions at night, heat should be provided by an incandescent “nocturnal” bulb; this will also allow you to observe your pets when they are most active.  A ceramic heater may also be used.

Due to peculiarities in molecular structure of the exoskeleton, scorpions fluoresce under UVB light.  Despite having discovered this in the 1940’s, scientists cannot as yet determine why such a facility should exist. The fluorescent sheen they exhibit is quite unearthly…a UVB-lit scorpion exhibit that I maintained at the Bronx Zoo has long been a favorite of visitors.  Try lighting your scorpions with a UVB bulb at night…and while you’re at it, please see if you can find out what is going on with their fluorescence!

Feeding

Scorpions should be offered a wide range of soft-bodied invertebrates, including crickets, roaches, waxworms, silkworms and butterworms; some individuals will accept earthworms as well.  Do not rely on crickets as a dietary mainstay; rather, provide as much variety as possible.  In the warmer months, I feed mine mainly on wild caught moths, earwigs, caterpillars, katydids, crickets and soft-bodied beetles (Zoo Med’s Bug Napper is an excellent insect trap).

Emperor scorpions take readily to tong feeding , and should be provided with canned grasshoppers and silkworms as a means of increasing dietary variety.  We know nothing of their vitamin/mineral needs…I powder my scorpions’ food once weekly with a reptile dietary supplement  as “insurance”.

Emperor scorpions may on occasion take small frogs, lizards and even nestling rodents in the wild.  This is almost certainly a rare event…vertebrate food is not required in captivity.

Water should be provided in a shallow, easily-exited water bowl.

Social Grouping/Compatible Species

Emperor scorpions present the opportunity for fascinating studies in the evolution of social behavior.  Despite being as close to “living dinosaurs” as we are likely to see, these ancient animals exhibit complex social behaviors.  In the wild, they often live in discreet groups that occupy a single, extensive system of burrows.  We know little about the functioning of these groups.  The young of emperor and other highly social scorpions remain dependent upon their mothers for longer than do other species, but other than that, specific details are lacking.

As emperor scorpions readily exhibit natural behaviors when properly housed in captivity, the research potential for interested hobbyists is enormous.  I urge you to seriously consider working with this fascinating creature.

Captive groups almost always co-exist peaceably, provided they are given ample space and hiding/burrowing areas.  Females that breed in group situations require special attention…I’ll address this in an article on reproduction shortly.  Emperor scorpions will attack and/or consume other types of scorpions.

Further information and references to papers on emperor scorpions is posted at

http://www.ub.ntnu.no/scorpion-files/p_imperator.php