Hysterocrates gigas

Region: AfricaClass: ArachnidaOrder: AraneaeFamily: TheraphosidaeGenus: HysterocratesScientific Name: Hysterocrates gigas

Description: Tarantulas in this family are generally large and “hairy”. This tarantula has various color variations from post molt to pre molt, after a molt the tarantula may appear velvet black eventually lightening in coloration before the next molt. The colors also include rusty black to a dull dark brown and eventually even a rusty orange indicating possible pre molt. Its eyes are small and weak and used to judge light levels. This tarantula has no ears - instead the “hairs” on its body are sensitive to vibrations, especially the leg “hairs”. They can detect movement up to 2 feet distant.

The rear legs of this tarantula bend inward and have an enlarged “football shaped” tibia on leg pair IV which once the tarantula reaches maturity will no longer be there; its abdomen is oval in shape with a diameter up to 4”. Although it has “hairy” legs, this tarantula is an “Old World” species and it does not have urticating “hairs” on its abdomen. (Urticating “hairs” are irritating “hairs” that can be shed in defense, and are often found on “New World” species.)

It may also have a leg span up to 8”. This is a tarantula with downwards facing, parallel fangs, more comparable to pickaxes than pincers. Adult males have smaller abdomens than females. Male pedipalps are club shaped, but it may take up to 4 years for differences between male and female to become obvious, reason being that the average male lifespan is about 4 years and the leg span of the male is roughly 5”. These tarantulas spin very little silk - what silk they spin is used for egg sacs or to line their burrows - they do not make webs.

Distribution: The over 850 members of the Theraphosidae family live in tropical and sub-tropical

Environments. This one is a West African spider, found in Cameroon.

Habitat: They need temperatures of 70 - 95 degrees F. and the humidity in their environment must be high – around 60 - 90%. They are naturally found in tropical rain forests.

Food: These tarantulas will eat other invertebrates, such as crickets, cockroaches, moths, butterflies and other spiders or small vertebrates, such as lizards, frogs, mice, snakes and occasionally birds. They crush their prey with their fangs, instill digestive juices into the body of their prey and suck up the resulting liquid.

Skin/Color/Coat: Post molt the tarantula will appear Black with grey accents, after that color morph it will start to fade to a “tawny red” indicating pre molt.

Vocalization: Is produced when the tarantula is in a defensive stance by rubbing leg pairs I and II together producing a “velcro tearing” sound.

Reproduction and Development: Females lay eggs in an egg sac that may contain hundreds of eggs. Spiderlings live together for up to 6 months, though some tarantulas from the same sac are believed to co-habitate long after and even share burrows and tunnel systems. Spiderlings are very difficult to see. Their mother will kill prey for them. In their first year of life, spiderlings molt up to 8 times. Males will not molt again after reaching penultimate, although females will molt about once a year after maturity. And depending on how much the tarantula is fed will result in more frequent molts inevitably resulting in faster maturity time.

Adaptations: These tarantulas are opportunistic, nocturnal hunters and will take whatever prey they find. The venom of these tarantulas is rarely fatal to humans, although it may make you feel a little sick, unless you have an uncommon intolerance to LD50 proteins then you may need to seek medical attention. Spider venom is usually only harmful to its specific prey. They will attack a human only when provoked. There has never been a known fatality associated with any tarantula. (The only known fatality where a tarantula was concerned was in Central America and the person died of a secondary infection. This was before antibiotics).

To defend themselves, they rear up aggressively on their hind legs in a threatening posture, smack their front legs on the ground and use the “hairs” on their legs to produce a hissing sound that sounds a bit like velcro being separated. (Only New World tarantulas have adapted the defence of urticating hairs.) Their alternate defence is to run away. The name "tarantula" is commonly given to spiders in this family. It is a misnomer - it was originally given to a smaller wolf spider from Taranto, Italy, where, in the Middle Ages, people danced themselves into a trance - called the tarantella - in an attempt to purge the effects of the spider's bite.

These tarantulas molt by splitting open their old exoskeleton and wriggling out of it. They pull their legs out of their old skeletons as we pull our fingers out of gloves. A new exoskeleton has grown underneath and remains soft for about a week. The tarantula stretches his new skeleton to allow for growth space and the new skeleton hardens. During and after the molt, the tarantula is weak and dehydrated. It may take hours to complete a molt. During this time the tarantula is lying on its back with its legs in the air, very vulnerable to other creatures - even some that would normally be its prey.

Fangs are part of the exoskeleton and are shed as well. The tarantula should not eat for a week to be sure that its new fangs have hardened. A lost limb may be fully or partially regenerated during a molt. Many spiders live only a year, but tarantulas can live up to 25+ years. The local name of Baboon tarantula may be because baboons like to eat them, or because they have a similar coloration. In West African folk stories, the spider is a link between man and the Supreme Being. Ananasi became the messenger between gods and people and negotiated such things as day and night, wind and rain.

Threats: This is a rare tarantula. Its natural enemies are mammals (i.e. baboons). Birds, reptiles, wasp, ants and amphibians will prey on tarantulas. They are also collected as pets.

Status: Rare

[References: Animal, Ed. David Burnie & Don E. Wilson, Smithsonian Institute, 2001 Tarantulas in the Vivarium, P.Klaas, Krieger Pub. Co., 2001 The Encyclopedia of Insects, Ed. C. O'Toole, Equinox, 1987 http://www.amonline.net http://www.nhm.ac.uk/entomology http://arachnophiliac.co.uk, http://www.torontozoo.com/Animals/details.asp?AnimalId=667]