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

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

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.

 

 

As is true for tarantulas, reptile enthusiasts (myself included) are often interested in scorpions.  Today I would like to provide an overview of these most ancient of animals (they were likely the first creatures to leave the sea for a terrestrial existence), with specifics concerning some readily available species to follow next time.

Please Note:  All scorpions manufacture venom and are capable of delivering a painful sting. Human fatalities are rare but not unknown, and the venoms of many are relatively unstudied.  Also, an allergic reaction is always possible…during my years at the Bronx Zoo I was often in contact with scorpion researchers….some reported relatively severe reactions from species not known to be dangerously venomous.

Unfortunately, the trade in scorpions is not well-regulated, and highly venomous species do appear from time to time (I’ll relate a personal experience in Part II of this article).  Purchase scorpions only from reliable sources, and be sure you can identify the species you are considering.  That being said, some of those best-suited to captivity are not dangerous, and make fascinating terrarium subjects.  Please check the legalities of scorpion ownership before acquiring one, as such is regulated in some areas.

Do not grab scorpions by hand, despite what you may see others do.  To move a scorpion, use a long handled stainless steel hemostat to gently grasp the telson (“tail”).  A bit of foam rubber should be secured to the tips to prevent the scorpion from being injured. 

Classification

Scorpions are classified in the order Scorpionidae, and, along with spiders, ticks and mites, in the Class Arachnida.  Nearly 2,000 species have been described (as opposed to 40,000+ spiders), ranging in size from .3 to 8.5 inches in length.  The 4 inch long Cetrruroides gracilis is the largest species in the USA, while the South African flat rock scorpion (Hadogenes troglodytes) is the world’s longest and heaviest.

Range and Habitat

Scorpions are found in tropical, sub-tropical and (less commonly) temperate regions of all continents except Antarctica, and are absent from New Zealand.  Various species are adapted to live in deserts, open forests, grasslands, caves and rainforests.  Some are quite at home around people, and may be found in overgrown fields, agricultural areas, gardens, parks and even within homes.

A surprising number thrive in quite cold climates, ranging as far north as Canada and southern Illinois in North America.  A feral colony of a small African species, introduced in produce shipments, is established in southern England.  In the USA, scorpions reach their greatest diversity in the southwest, where 60+ species may be found.

Diet

All are predacious, with most consuming soft-bodied insects but some specializing in land snails, sowbugs and other scorpions.  Larger species may take frogs, lizards, shrews and other sizable animals on occasion.

Reproduction

All scorpions thus far studied give birth to live young, and a number are parthenogenic.  Females typically carry the soft, relatively defenseless young on their backs for a time.  Many species feed their offspring with shredded insects…in some the young are totally dependant upon their mothers for food and will perish if separated too quickly.

In contrast to most of their spider relatives, certain species, including the popularly kept emperor scorpion, are quite social and may be housed in colonies.

Venom

Scorpion venoms are not well-studied, but thought to be quite complex.  Some that have been analyzed have yielded compounds with potential medicinal value.  Most seem to be neurotoxic in nature, but cytotoxic varieties are known as well.

The larger scorpion species are generally not dangerous to people, while some of the very small ones have caused fatalities.  Most of the 25-30 species thought to be capable of delivering serious stings are classified within the Genera Centruroides, Androctonus and Tityus.  However, as we have limited knowledge of scorpions in general, all should be treated with caution.  As mentioned, the possibility of allergic reactions to even weak venoms is always a possibility.  In all cases, small, straw-colored scorpions from the Middle East and North Africa should be avoided.

Scorpions in Captivity

At least 15 species are well-established in captive breeding populations, and many others are regularly available.  Fortunately, one of the largest and most interesting, the emperor scorpion, is also quite benign.  It lives well in groups, and females are surprisingly attentive to their young.  Next time I’ll write about the care of this and other popular species.

A short introduction to scorpion ecology, along with a diagram of their body parts and photos of common species of the American Southwest, is posted at:

http://wc.pima.edu/~bfiero/tucsonecology/animals/arth_scorpions.htm

Note: Please see Tarantulas in Captivity: An Overview of Popular Species for information on other species and an overview of tarantula-keeping.

 

Sri Lankan Ornamental Tarantula, Poecilotheria fasciata

Beautifully colored in gray and greenish-brown with an overlying pattern of light gray, these striking, arboreal tarantulas hail from Sri Lanka and neighboring southern India.  The undersides of the first 2 pairs of legs are bright yellow, adding greatly to the effect of their threat display.

Although they do well in captivity, it must be remembered that these spiders are fast-moving and high strung, with possibly the most powerful tarantula venoms known (such has not proven dangerous to people, but, as with all venoms, the potential for severe allergic reactions exists).  They should not be handled.

 

Ornamental tarantulas should be housed in a tall terrarium with ample climbing surfaces.  A hollow branch or bamboo stick should be provided as a hiding spot – unlike pink-toed and other arboreal spiders, ornamental tarantulas do not construct substantial silken retreats.  They occur in habitats subjected to a prolonged dry season – in captivity, a daily misting of water will satisfy their needs. Ornamentals are one of the few tarantulas that can sometimes be kept in groups (the pink toed tarantulas, Avicularia spp., are the other; please see Part I of this article for cautions) – several spiderlings have even been observed feeding upon the same insect!  Their diet should consist of roaches, crickets, waxworms and wild-caught insects such as moths.

 

Suntiger Tarantula, Psalmopoeus irminia

Venezuela’s suntiger is quite large for an arboreal tarantula, and strikingly marked in black and red.  These qualities, and its relative hardiness, have added to its popularity in recent years – in fact, this species has even been hybridized with the closely related Trinidad chevron tarantula,

P. cambridgei (the offspring are sterile and not brightly-marked). 

 

Suntigers require high humidity and should be kept in a tall terrarium over a moist substrate  and sprayed with water daily.  Clumps of damp sphagnum moss  wedged among the branches and other climbing surfaces will also help in maintaining moisture levels.

Ravenous predators (feed them crickets, roaches, waxworms, moths and other insects) and quick to “take offense”, these beauties live up to the “tiger” portion of their name quite well!

 

Haitian Brown Tarantula, Phormictopus cancerides

This species was formerly imported in large numbers, and was relatively inexpensive for such a large spider.  The state of Florida now prohibits its sale, and importations have fallen off, but captive-hatched animals are regularly available.

 

Native to Hispaniola (Haiti and the Dominican Republic) and Puerto Rico, with close relatives in Cuba, this large, ground-dwelling spider is dark brown in color.  The males are infused with an attractive purple iridescence.  Field reports indicate that they are less likely than other tarantulas to use a specific shelter, and may wander about in search of prey in the manner of wolf spiders.

 

Haitian browns should be kept on a moist substrate  and provided with a cave  in which to hide.  Females are long-lived, easily reaching the 20 year mark in captivity, but their size and willingness to bite and shed urticating hairs renders them unsuitable for those new to tarantula-keeping.  In common with tarantulas from similar habitats, Haitian browns relish earthworms (worms are usually rejected by arboreal and desert-dwelling spiders).  They will also take crickets, roaches, wild-caught insects and dead pink mice.

 

Mexican or Arizona Blond Tarantula, Aphonopelma chalcodes

This is one of the few North American tarantulas to have become popular in the pet trade, and with good reason – adapted to the harsh conditions of their Sonoran Desert (southern Arizona and northern Mexico) home, females can reach ages of 20 years or more in captivity.  It is also a beautifully-marked spider that exhibits an unusual degree of sexual dimorphism – females are tawny brown with dark basal (close to body) leg segments, while males are slate blue with orange to reddish abdomens.

 

Mexican blond tarantulas construct burrows of up to 2 feet in length, the entrances of which are covered with silk by day, apparently to conserve moisture.  This species’ life history is strongly influenced by environmental conditions and its activity levels are cyclical in nature.  The spiders may remain sealed within their burrows for 6 months at a time, while in July and August the males wander about en masse in search of females.

 

Mexican blonds should be housed in a terrarium with a deep (they do best if allowed to construct burrows), dry substrate of gravel and sand.  They are quite docile, but this should not be taken to mean that they can be carelessly handled (please see Part I of this article).  Like all desert-adapted spiders, they require but a light misting of water every few days, and are prone to fungal infections if kept under damp conditions.  Captive-born Mexican blond tarantulas, even those several generations removed from the wild, seem tuned to an “internal clock” and may go off-feed for extended periods.  As they store a great deal of food in the abdomen, and have experimentally gone without feeding for up to 2 years, this is not a concern for healthy individuals.

 

Oklahoma Brown Tarantula, Aphonopelma hentzi

This native of the American Midwest is only rarely encountered in the trade, and its care is similar to that of the Mexican blond tarantula (see above).

 

I mention it here due to an interesting peculiarity in its natural history.  The burrows of this spider are often inhabited by the 1 ½ inch long Great Plains narrow-mouthed toad, Gastrophryne olivacea.  Despite the amphibian-eating propensities of most tarantulas, the toad remains unmolested by its huge host.  Possibly, it is protected by skin toxins or, it is theorized, the toad performs a service by consuming tiny flies, ants and other insects that might parasitize the tarantula or consume its eggs.  The toad, in return, receives a safe, moist home and the protection of an aggressive predator.

 

Scores of other tarantulas and spiders, as well as scorpions, millipedes, pill bugs, centipedes, mantids, roaches and other invertebrates, make fascinating terrarium subjects.  It has been my good fortune to have studied a number of species in the wild, and to have helped establish the Bronx Zoo’s invertebrate collection.  I will post addition invertebrate-oriented articles from time to time. 

 

A comprehensive, well-illustrated article on tarantula biology and natural history is posted at:

http://www.thebts.co.uk/old_articles/natural.htm

Although only 906 of the world’s 40,024 spider species are tarantulas (Family Theraphosidae), these interesting creatures are the best known of the group and among the most sought-after of invertebrate pets. Reptile enthusiasts, myself included, seem particularly drawn to them, hence their inclusion in this blog. Today I would like to provide an overview of the group and specifics concerning some readily available species. Future articles will cover care and breeding in detail.

Please Note: Tarantulas, like all spiders, manufacture venom and are capable of delivering a painful bite. Human fatalities from bites are unknown, but their venoms are relatively unstudied, and an allergic reaction is always possible. New World species also possess urticating (irritating) hairs, which are shed when the spider is disturbed. A colleague of mine required surgery to remove hairs shed by a Mexican Red Knee Tarantula (a relatively docile species) from his eye. Do not handle tarantulas, despite what you may see others do – move the spiders, if at all, by urging them into a plastic container, and wear goggles where appropriate. Please also check the legalities of tarantula ownership – several species are protected by law; others are prohibited in some states.

Tarantulas in General
Tarantulas range in size from those that mature at 1 inch in length to behemoths with 12 inch leg spans, and may be ground-dwelling, fossorial (burrowing) or arboreal. Females of several species can reach 30 years of age (most males live but 1 or 2 years).

They are found in tropical, sub-tropical and (less commonly) temperate regions of Africa, the Middle East, southern Asia, Australia, New Zealand, the Indo-Pacific, Micronesia, Central and South America, the southern half of the USA and throughout the Caribbean. Various species are adapted to live in deserts, open forests, grasslands and rainforests. A number also thrive around people, and may be found in overgrown fields, agricultural areas, gardens and even within homes.

Although considered to be “primitive” spiders, tarantulas are quite successful as a group, and are the dominant invertebrate predators in many environments. They take any animal that can be overcome, including spiders, centipedes and other invertebrates as well as snakes, frogs, lizards, mice and other small rodents. The name “bird-eating spider” was first applied to the group in 1705 when Swiss naturalist Maria Sibylla Merian included, in a book on the insects of Suriname, a painting of a pink-toed tarantula consuming a hummingbird.

Tarantulas are distinguished from other spiders by their book lungs (unique respiratory organs), the presence of 2 claws and adhesive pads on the tips of the legs and by the fact that they use their fangs in an “up and down” as opposed to “side to side” motion.

Goliath Bird-eating Tarantula, Theraphosa blondi
This rich-brown spider is the undisputed king of the trade and, with a leg-span approaching 12 inches, of the spider world as well. Relatively unknown here until the early 1980’s (please look for my future note concerning my early experiences with them), captive born goliaths are now readily available. This animal is not, however, for the beginner – they are extremely aggressive and fairly demanding as captives.

Native to the rainforests of northeastern South America, goliath birdeaters require high humidity in captivity and a terrarium of at least 20 gallons in size. They should be provided with deep, moist substrate in which to burrow, or an artificial cave . Adults are fully capable of overcoming an adult mouse, but such is not recommended as food (dead mice are accepted). They fare well on roaches, earthworms, crickets and wild-caught insects such as grasshoppers and katydids.

Mexican Red Knee Tarantula, Brachypelma smithi
Quite different from the goliath in color, temperament and captive needs, the red knee is responsible for the advent of tarantula keeping in this country. Jet-black with bright red-orange leg joints, this spider is quite calm in temperament (but can bite and shed urticating hairs, see above) and hardy. One that I received as an adult lived for 18 years, putting its total age at over 23, and similar records are common.

The red knee hails from western Mexico, and is tolerant of quite dry conditions (recent hatchlings need a fairly moist environment, however). It does well on a sand-gravel substrate and readily accepts crickets, roaches, newly-molted super mealworms and wild-caught insects. This species is now protected by the Mexican government, but captive-born specimens are commonly available.

Pink-toed Tarantula, Avicularia avicularia
Unlike the previous 2 spiders, the pink-toed tarantula (named for its pink-tipped “toes”, or tarsi) is strictly arboreal. It is also unique in that it is encouraged, rather than displaced, by human activities. Various species range from the Caribbean south to Peru, and readily colonize homes, gardens and parks.

Pink-toed tarantulas construct a thick, silken retreat on tree trunks, roof eves and among plants (where they will often bind 2 leaves together to form sturdy walls for their homes). They prefer moderate humidity, but are fairly tolerant in that regard. Oddly for a spider, pink toed tarantulas get along fairly well in groups, with 2-3 individuals usually co-existing in a tank of 20 gallons or so in size. They should be kept in a vertically-oriented terrarium (an aquarium turned on end works well) furnished with cork bark, bamboo and other climbing surfaces. Pink toes relish moths and other wild-caught insects, but also fare well on crickets, roaches and waxworms.

Thailand Black Tarantula, Haplopelma minax
This Southeast Asian native is the first of the Old World species that we will cover. Like all, it lacks urticating hairs, but more than compensates for this with its extremely aggressive nature and willingness to bite. They are also quite fast, and should not be handled. Threatened individuals rear up on their back legs to expose the large fangs – which, highlighted against a red-colored patch and often tipped by a drop of venom, are intimidating in the extreme. I have observed several to fall right over onto their backs during the threat display – a position from which, it would seem, an enemy could not approach without being bitten (I have not tried, nor will I!).

This species requires a moist substrate into which it can burrow and, being high-strung, does best with minimal disturbance. A night-viewing bulb will enhance your ability to watch the spider go about its nightly activities. Thailand black tarantulas should be fed earthworms, roaches, crickets and wild caught insects such as moths and grasshoppers.

The photo accompanying this article shows a Thailand black tarantula in typical tarantula hunting position – poised at the burrow’s entrance, ready to pounce upon prey or retreat from an enemy. The silk that you see is used to provide stability to the burrow’s walls and most likely alerts the spider, via vibrations, of approaching animals. It is not, and this hold true for all tarantulas, used to ensnare prey.

 

You can access a wealth of tarantula-related resources at:
http://www.exoticfauna.com/