Tarantula Care in Captivity
by Jody T. Barbeau and Martin J. Blasczyk
EDITOR'S NOTE: This article is reprinted from LORE magazine, a benefit of museum membership. ©1996 Milwaukee Public Museum, Inc.
In popular culture, the tarantula has often been portrayed as being both repulsive and something to be feared. Typical misconceptions have given them a bad reputation, one that is not justified. These private animals are usually quite harmless when treated with respect, and often exhibit interesting behaviors. As of late, these large spiders are acquiring a more common place in the pet trade. The number of available species is growing rapidly due both to importation and private captive breeding programs. Tarantulas are relatively easy to keep, provided a few basic guidelines are kept in mind.
Housing Your Spider
When purchasing a tarantula one of the primary things to consider is the type of environment in which the spider is going to be maintained. Because all spiders are quite cannibalistic, each should be housed in an individual container.
Aquariums work quite well as suitable containers. They are easy to obtain and allow a certain amount of creativity when establishing a habitat for the spider. Aquariums are available in a variety of sizes, but the 2-1/2, 5, and 10-gallon aquariums adequately suffice for most species. Larger species like the goliath bird eater (Theraphosa blondi (Latreille)) often require a more spacious enclosure. A cover should always be provided for each container. It should be noted that the standard aquarium cover, whether a full hood or versa-style hood, is unacceptable because they do not offer a secure fit. Arboreal tarantulas, in addition to many of the terrestrial forms, can easily climb glass and make use of any openings or hinged parts to affect an escape.
A secure-fitting cover should be used at all times. The appropriate choice of cover not only provides security but allows the humidity and temperature of the aquarium environment to be easily maintained. A locking screen top is the ideal choice of cover when accompanied by a custom cut piece of plexiglass. This combination not only provides security but prevents rapid evaporation of moisture and unnecessary heat loss. Plastic wrap can be substituted for the plexi glass to provide a similar effect at a more economical level.
Depending upon the current space availability and the number of spiders a person anticipates having, alternate means of storage should be explored. Plastic storage boxes commonly available at department stores provide an ideal alternate environment for tarantulas. Storage boxes are easy to secure and allow for compact storage. The commonly kept common Chilean (Grammastole spatulata (F.O.P.-Cambridge)) and Costa Rican zebra or striped knee (Aphonopelma seemani (F.O.P.-Cambridge)) often fare well in a shoe box. However, a good rule of thumb dictates that the container should be at least twice the length of the spider's leg span. Larger spiders can be maintained in a variety of box sizes. The arboreal tarantulas, such as the Trinidad chevron (Psalmopoeus cambridgei Pocock), have requirements that are different from the terrestrial spiders. For these tree-living spiders, tall one gallon plastic or glass containers are needed to provide a suitable environment.
The type of substrate, or ground cover, you use plays an important role for the well-being of the spider. Many popular books on the subject of keeping tarantulas advocate the use of aquarium gravel or sand as a ground medium. Unfortunately, this is not the best substrate to use. It may work for the Texas brown (Aphonopelma hentzi (Girard)) and similar scrub land type species when a water dish and a humidified shelter are also used, but for the tropical forest species the humidity level will not be high enough and desiccation could become a problem. The best overall ground medium for placement into glass aquariums or plastic shoe boxes is vermiculite.
Vermiculite is a light weight mica that has been heated to approximately 2,000 degrees Fahrenheit, is relatively sterile, absorbs water easily, and is commonly used for horticultural purposes. It can be obtained at local green houses or garden centers. Its light weight promotes the formation of burrows and its ability to retain moisture allows the humidity levels to remain relatively constant. When preparing the vermiculite for use, enough water should be added to the mixture to achieve a damp but not soggy consistency.
In addition to vermiculite, a shelter or retreat may be beneficial to the spider's well being, and also work to enhance the aesthetics of the container. Many of the plastic shelters for reptiles can be used for tarantulas. The use of cork bark in a spider set-up contributes to a more natural setting for your spider. Cork bark can be obtained from stores that specialize in reptile sales. It is light weight, cleans relatively easily, and can provide a retreat when the spider feels threatened. In enclosures using gravel as a substrate, a shelter with moistened vermiculite should be provided for the spider to assist in the molting process. Furthermore, when housing arboreal tarantulas in a one gallon jar, a vertical shelter should be provided such as a piece of cork bark, which offers adequate cover.
Temperature and Light
To have a healthy specimen it is important to monitor the temperature on a regular basis. Most tarantulas should be maintained between 70 and 85 degrees Fahrenheit, with 78 to 82 degrees being the optimum temperature for most species. The tropical forest spiders should be placed in an environment where a higher temperature range can be maintained. Spiders native to the scrub type areas can tolerate cooler temperatures for short periods of time. Most tarantulas can acclimate to accommodate moderate temperature fluctuations. However a severe drop in temperature could be hazardous to the spider's health. An example of a spider that is very susceptible to minor temperature fluctuations is the Asian bird eater (Haplopelma minax (Thorell)). This particular species of spider should be maintained in the upper temperature range if it is to do well.
Heating a tarantula's enclosure can prove to be a challenge. If the spider is housed in an aquarium, a heating pad should provide an adequate source of heat. Moreover, the under-the-tank heating pads commonly used for reptiles are available in a number of different sizes which makes finding the appropriate heating pad fairly easy. Stores specializing in reptiles will carry a wide variety of heating pads.
One item to avoid when heating your enclosure are the "hot rocks" used for reptiles. Often the temperature of the "hot rocks" will exceed 85 degrees Fahrenheit and will be too localized to adequately heat the entire container. You can run the risk of scorching the spider. If you try to diffuse the heat by covering the "hot rocks'" with natural rocks, the spiders may encounter the "hot rocks" when burrowing and potentially expose themselves to harm.
If more than a few spiders are being kept, it may be easier to house them in one location and monitor the area's temperature rather than monitoring each individual enclosure. Care should be taken to ensure that the room does not overheat, which could result in the loss of an entire collection.
When setting up the spider in a container, careful consideration also should be given to the light source. If incandescent bulbs are used, it is recommended that the wattage should not exceed 25 watts. The light source should be placed in a position that is high enough above the container to avoid overheating and dehydrating the tarantula. A red light bulb is the preferable method of illumination because it will not disturb the spider's nocturnal activities. Florescent light also works well since it gives off little heat, and the full spectrum bulbs that are available enhance the spider's iridescent coloring. Direct sunlight should be avoided due to the high probability of overheating the enclosure and killing the spider.
As emphasized above, the humidity levels are of significance. Without proper humidity the spider could have a problematic molt or suffer from dehydration. Both problems could prove fatal to the spider. Species from tropical rain forest areas need 75-90% humidity. To achieve this, simply keep the substrate moist and utilize a plexiglass lid for the aquarium or use a plastic storage box.
Feeding Your Spider
Once the tarantula's container has been set up, the next option to consider will be the spider's food source. Being primarily opportunistic in the wild, tarantulas are not particularly finicky eaters, preying upon arthropods and small vertebrates for their sustenance. In captivity they will fare well on a diet of crickets with other prey items occasionally introduced for variety. Domestic crickets (Acheta domestica) can be purchased from most pet stores and some bait stores. However, you should avoid field collecting crickets due to possible insecticide contamination that would be harmful to the spider.
Before the domestic crickets are fed to the spider, they should be nutrient loaded by offering the crickets a slice of orange for moisture and tropical fish flakes a few days prior to feeding. This should adequately enhance your crickets nutrient content. Meal worms (Tenebrio) and king meal worms (Zoophobas) can be used to supplement the spider's diet of domestic crickets when used in moderation.
With some of the larger species, vertebrate prey such as three day old mice, called "pinkies," and small lizards may be introduced into the enclosure. If the thought of feeding a spider "pinkies" makes you squeamish, you should note that even the larger species of spiders, such as the goliath pink foot (Psuedotheraphosa apophysis Tinter) can flourish solely on a diet of insects.
The number of prey items introduced into the tarantula's enclosure depends upon the frequency of its feeding schedule. Tarantulas can survive for months without feeding. However, adult spiders should have prey introduced into their enclosures once or twice a week. Non-adults may take prey as often as every two to three days. Generally, only a few prey items should be introduced into the container at a time. Any remains left should be removed the next day to prevent mold from developing on them. This will help to keep the habitat clean which in turn is better for the animal.
If for some reason the tarantula is refusing food it may either be already saturated or preparing to molt. Molting or ecdysis is a critical time for the spider. During this time the tarantula sheds it's old exoskeleton called the "exuviae," in order for the spider to grow in size. Often the spider will exhibit some tell-tale signs before it actually start the molting process. In many cases the spider will stop feeding, which may take place anywhere from a few days to a few weeks before its molt. It is not uncommon for some of the scrub area spiders to stop feeding months in advance.
The darkening of the exoskeleton is another sign of molting. If the spider has a "bald" patch on it's abdomen and it appears to be turning black, a molt is imminent. When the spider is ready to molt it will spin a web and then flip over on to it. The spider should not be flipped upright. After molting, the tarantula's new exoskeleton needs to harden in a process known as "tanning." This process usually takes a day or two. After a week, a few prey items can again be introduced.
Handling Your Spider
Inevitably, some owners have a "need" to hold their spider. Handling is not recommended for all but the most docile species, and even then caution is advised. The Mexican red rump (Brachypelma vagans (Ausserer)) as well as the common Chilean make likely candidates. However, these animals are new world species meaning that they originate from South America. New world tarantulas can cause a skin rash to develop if handled either frequently or improperly. The rash is due to the urticating hairs on the spider's abdomen. The hairs are frequently raked off by the hind legs of the spider as a defense mechanism against predators in the wild. In captivity the tarantula will "kick" them off when it is stressed or feels threatened. Handling is also risky for the spider because a drop from even a relatively low height may rupture the fragile abdomen and means almost certain death for the spider. Unless it is absolutely necessary, tarantulas should not be handled.
Tarantulas are fairly undemanding creatures to keep, provided that their basic requirements are met. A good suggestion in their captive husbandry is to find out the tarantula's native region and try to duplicate the environment found there. In effect, this will give almost all of the information required to maintain it and to have it flourish in captivity. When all preconceived notions are put aside, tarantulas can make fascinating display animals.