Tarantulas/Spiders

Phylum: Arthropoda
Class: Arachnida/Arachnidae
Order: Aranae
Family: Theraphosidae, various species
Natural Habitat/Distribution: Worldwide, all environments from arid to tropical
Size: Varies according to species, average is 1 1/4 – 12 inches (3-30 cm)
Life Span: 4-20 years of age, females can live up to 20 years, males average from 4-7 years.

Keeping these animals is not for everyone, but they have always been a popular pet in certain circles. They are in a category of animals where the extent of interaction is typically limited to observation through the window pane of an enclosure or habitat. With that being said, they can be a very interesting animal to keep due to their beauty and unique behaviors (e.g., versicolor-a.avicularia, an arboreal tarantula will build web nests/burrows in upper portions of the enclosure/foliage and use them to hide and hunt).

Enclosure/Habitat
This is possibly the most exciting and interesting part of keeping tarantulas and other invertebrates in general. The type of set up is mostly limited by the keepers imagination. Depending on the species there will be certain environmental needs that must be met. For the most part the enclosure can be anything from a small plastic container to a large elaborate terrarium with foliage (artificial plants preferable) and tunnel systems (created with pvc piping). Necessary considerations: Hide Box/Structure (i.e., log, cork bark, rocks, etc.), adequate substrate (minimum of 3-5 inches), temperature/humidity control, day/night cycle control (i.e., lighting), ventilation and a secure top. Be sure to clean and change on a frequent basis (full cleaning and changing every 2-3 months if possible, spot checks daily – every other day).

Substrate
Regardless of where the animal may come from an adequate substrate should consist of a mixture of an organic, fertilizer free, pesticide free potting soil and peat or sphagnum moss. This allows for an environment anywhere from dry to moist.

Climate/Humidity
This will vary depending on what region of the world the animal comes from. If unsure a good range is a ambient temperature gradient of 70-80 degrees. If you are providing a basking area it can be slightly warmer beneath the lamp. Be sure this is not overheating the entire enclosure. A digital thermometer with a temperature probe is a good investment. Humidity should range from 50-80% (even desert species require a low level of humidity). This can be achieved with a combination of, humidity boxes (plastic container with moist sphagnum moss – remember to change frequently as mold and bacteria will form), large water bowls (be sure to use a rock or some other apparatus in large bowls that will allow escape if the animal falls into the bowl) and frequent misting.

Diet
In their natural habitats they will consume a variety of insects and sometimes small mammals. In captivity the appropriate diet consists of crickets. If you would like to offer some variety from time to time, you can offer mealworms and other grubs. These should only be used as occasional food items. Crickets should be the primary food source. If they do not consume the crickets or other food item in a 24 hour period, be sure to remove them from the enclosure as this can contribute to stress and trauma (food items will begin to feed on your pet). They should be fed every 1-2 times per week. It is not uncommon for these animals to become anorexic. Their metabolism is very slow and allows for long periods without nutrition. Obviously if the animal goes without eating for more than 3-4 weeks, there might be an underlying problem (medical vs. environmental) and you should contact your veterinarian.

Handling
It is not recommended that they be handled. They are naturally nervous and defensive and will more often than not interpret your intentions as a threat. They have many built in natural defense mechanisms to deter predators (i.e., fangs). Tarantulas also have urticating hairs on their abdomen that can be flicked with their back legs in large clouds at a predator. They imbed in any tissue and cause irritation and can cause significant damage if they were to get into the eyes. Tarantulas have varying degrees of venom. Even the most potent tarantula venom is not fatal. A defensive posture for a tarantula includes the raising of the forelimbs. This usually indicates an eminent lunge or bite. Aside from these defense mechanisms there is also the danger of being dropped. They are rather fragile and cannot sustain much trauma. These animals do not have a skeletal system and all their internal structures on suspended in hemolymph (equivalent to blood in vertebrates) within the exoskeleton that we see. If you desire to handle your pet, please handle with care. Handle close to the ground. Be sure to use gloves, cups or other containers in order to pick them up. Scoop them up with the cup/container or gloved hand. You can also pick them up by gently placing an index finger and thumb on either side of the abdomen. Specifically where the cephalothorax meets the abdomen.

Molting
Like other arthropods/invertebrates Tarantulas have exoskeletons that must be shed or molted in order for them to grow. This can occur as often as every month, but will also depend on appetite and food consumption, as well as other environmental conditions. This is a very stressful time for these animals as they are in vulnerable state all throughout the process. Typically the actual “molting” process will take 12-24 hours from start to finish. During this period the animal basically crawls out of its old exoskeleton. Prior to this, some signs that indicate a molt are: Inappetence, color change and decreased activity. Maintaining adequate humidity is of vital importance to this entire process (never mist the animal directly, especially tarantulas). Problems typically occur as a result of decreased moisture and excessive stress. Be sure to keep your enclosure dark and quiet, especially when it is actively trying to crawl out. Do not offer food. NOTE: The animal will often be found on its back and side throughout the process. Do not panic as this is normal and any interference can be fatal. Think of this as a person trying to wiggle out of a straight jacket. If within 24 hours this has not resolved, then please contact your veterinarian. Be sure to not offer food or handle for at least one week after molting. The exoskeleton needs to harden prior to resuming normal activity.