There are over 600 recognised species of tarantula though typically only a tiny percentage of these are seen regularly in the pet trade.
This huge reservoir of tarantulas can be divided up in a wide variety of different ways based on habitat, size, colouration and more so an article discussing the different types of tarantula could never be totally exhaustive.
I would here, though, to offer a few distinctions which I hope will help you to understand tarantulas better and keep them more successfully if you know how to differentiate the different types of theraphosid spider available as exotic pets.
Broadly speaking some tarantula live on the ground whilst others prefer to live up high. For example many Brachypelma tarantulas from central and north America like to dig burrows or find rocks to hide under whilst Pink Toe tarantulas from south America prefer to hide up in banana plants or under lose tree bark.
Typically the arboreal tarantulas are much faster moving and faster growing than their ground-dwelling counterparts and of course require a different environment in captivity.
Ground dwelling tarantulas should ideally be given the opportunity to dig burrows or at least hide under a piece of cork bark. In the other hand, arboreal tarantulas should be given some vertical cork bark behind which they can hide.
New World/Old World
New World tarantulas – those that hail from the Americas – can be quite different from those coming from the Old World (typically Africa and Asia).
For example it is only New World tarantulas which possess the urticating hairs which cause irritation to some keepers, but they are also typically more docile than their Old World cousins.
Tarantulas from Africa and Asia typically are more aggressive (though of focurse there are exceptions) and reputedly have more potent venom.
If you want a tarantula to hold, then one from the New World is typically a better idea so long as you are careful to wash your hands thoroughly after handling and keep your spider a safe distance from your eyes.
Tarantulas vary widely in their final size. There are dwarf tarantula species from Chile that only grow to a legspan of a few inches while the Goliath Bird Eater from south America can reach the size of a dinner plate.
Obviously the smaller tarantulas don’t require as much space to house, but equally may not make such an impressive captive. Most tarantulas in the trade tend to fall within a reasonable scale of around 5-6 inches in legspan when mature though due to the variety of species available at different times final sizes should be checked in a book before a purchase is made.
Fast Growing/Slow Growing
Some tarantulas grow very quickly indeed and can go from a spiderling to a mature adult in only 18 months to 2 years. Examples of these may be the Salmon Pink (Lasiodora parahybana) and many Poecilotheria species. Others may take 5 years or more to mature.
The faster growing species can therefore be bought as youngsters and will quickly grow into an impressive specimen whilst you may want to opt to buy a larger specimen of a slow growing species.
Also, be aware that the faster growing species normally require proportionately more food. Whilst a Mexican Red Knee (Brachypelma smithi) may only eat once or twice a week, a Salmon Pink (L. parahybana) may eat virtually every day if given the chance.
Lastly, the fast growing a tarantula is, typically the shorter the lifespan. A fast growing Pink Toe (Aviculariaspp.) may be mature in only a few years but may only have a lifespan of 8 years at most. In contrast some slow growing Brachypelma have reportedly lived for 30 years or more.
Fast Moving/Slow Moving
Slow moving tarantulas are obviously easier to both handle and maintain. If a slow moving spider tries to escape while you are feeding it this is unlikely to be a problem. On the other hand a fast-moving spider might be out and gone before you have a chance to realize what is going on so again a slower moving species is likely to be better for the beginner.
Once mature, a male tarantula is a very short lived animal. If it sees it’s next birthday this is something to celebrate. In contrast females may go on for years. Males are still necessary to further captive breeding but if you are buying a tarantula simply as a pet, rather than as a breeding project, then it is wise to try and seek out a female if at all possible.