ack in the 90s when I was more into keeping snakes than tarantulas, my wife, Billie, and I attended a reptile expo in Massachusetts. While perusing the animals at the various tables, we saw a 10-gallon aquarium with about two inches of colorful aquarium gravel and a large black tarantula stood dead in the middle of it. It was easy to surmise that this spider was NOT happy, as it had its front legs raised high into the air and it would slap the ground every time a curious individual got too close to the tank. Although I did have two tarantulas at this time, I was still quite intimidated by them, and I found this threat display to be equally fascinating and terrifying. The cage was labeled simply, “Thailand Black Tarantula”, and I gave serious thought to purchasing the poor girl as she looked so stressed. I remember telling Billie, “their bites are no worse than a bee sting” so it wouldn’t really be dangerous to keep it.
What I didn’t know at the time was that this species was an Old World tarantula, and a bite from one would be a heck of a lot worse than a bee sting. I also had no idea that this was a shy, burrowing species, and the threat display was not due to the spider being “aggressive”, but because the setup was woefully inappropriate for it.
My experience was definitely not a unique one, as people first discovering the hobby are often confused to hear hobbyists discussing two different groups of tarantulas; New World and Old World. Luckily, a little research will reveal the main reason for the delineation between the two.
The simple explanation is that New World tarantulas are found in the western hemisphere and include Theraphosidae from North and South America and the surrounding islands. This includes species from the US, Mexico, all of South America, and the Caribbean islands.
Old World tarantulas, on the other hand, are found in the Eastern continents including Asia, Africa, Australia, and Europe.
Simple, right?
Now, being separated by an ocean isn’t the only difference in these two types of tarantulas. Anyone doing proper research will quickly hear New World spiders being described as calm, visible, and reluctant to bite. Even better, if they do happen to nip, their bites have been described as little more than “bee stings.”
Conversely, they will also discover that Old World spiders have been stigmatized for being potentially dangerous to the point where new hobbyists showing interest in these more “advanced” species are admonished by experienced keepers for even considering keeping them. For some, these more defensive spiders serve as a way to show off how brave one is for keeping such a fearsome creature. For others, stories about painful bites and aggressive behavior have completely turned them off to the idea of ever keeping one of these spiders.
Although there are absolutely key differences between New World and Old World species that all keepers need to be aware of, much that is made about these differences can be over exaggerated. With that in mind, let’s examine the major variances in these two types of spiders in terms of behavior and means of defense.
Defense
Possibly the most profound physiological difference between New World and Old World tarantulas is their means of defense. New World tarantulas lack the potent venom of their Old World cousins. Instead, they have evolved to possess a unique patch of “hairs” or setae on their abdomens or pedipalps that they use to defend themselves. These urticating hairs are barbed, irritating bristles that a tarantula can kick off or rub off its abdomen or palps as a deterrent to a predator. These barbs are not only irritating to the skin, but any animal that gets too close could find their eyes and respiratory tract filled with these torturous hairs.
Although potentially getting exposed to some itchy hairs seems much less threatening than a bite, urticating hairs are nothing to scoff at. Not only can some of the more potent hairs cause severe irritation and even blistering, but the effects can last for several days. Also, keepers report that continued exposure to these hairs over time creates an increased sensitivity to them. Veteran keepers have reported feeling itchy and irritated after entering a room containing New World spiders. In my years in the hobby, I’ve encountered a few longtime hobbyists who no longer keep New Worlds, as the hairs have become unbearable.
Old World tarantulas, on the other hand, lack these urticating hairs, meaning that they rely more on their speed and bites as a defense or deterrent. Old World venom is much more potent than New World venom, and bites are particularly nasty for primates and humans. One bitten by an Old World will not die from a bite, as the venom is not life-threatening. However, these bites are often considered to be “medically significant”, as they can cause excruciating pain, nausea, heart palpitations, full body cramping, and trouble breathing. In the case of envenomation, the afflicted individual may find a trip to the emergency room necessary in order to mitigate the pain and symptoms. In extreme cases, bite victims have continued to experience side effects from a bite months after envenomation.
Some joke that a bite from an Old World won’t kill you, but it will make you wish that you were dead for a bit.
Now, it should be mentioned that just because New World species don’t have potent venom does NOT mean that they won’t bite. New World spiders are just as capable of putting up a threat display and baring their fangs if provoked. In fact, many spiders, like the popular Phormictopus species, rarely use their hairs at all. These large 8”+ spiders are known for throwing up impressive threat displays as they expose their long fangs. Venom aside, a bite from ½” fangs could cause quite a bit of mechanical damage and would still be incredibly unpleasant.
Also, some New World species lack urticating hairs and have temperaments more akin to their Old World cousins. Common species in the genera Psalmopoeus, Catumiri, and Tapinauchenius don’t possess urticating hairs, meaning that they will be more likely to rely on bites as a deterrent. Ephebopus species, on the other hand, have urticating hairs on their pedipalps, or the smaller appendages outside of their fangs. Species in this genus are known to be more high-strung than your standard New Worlds. Folks unaware of this fact may find themselves surprised that their New World spider is less than cuddly.
Speed
Another variance between New World and Old World tarantulas often mentioned is a vast difference in speed. Many folks will point to most New World species being much slower and less prone to bolt overall, with some receiving the designation of “pet rock” due to their propensity to sit in one spot for days. Spiders in popular “beginner” genera like Grammostola, Brachypelma, or Aphonopelma have a reputation for being laid back, slow, and not easily spooked. This perceived lack of speed makes these species more desirable to new hobbyists who want a calmer animal or who are looking to handle their pets.
Old World species, on the other hand, are infamous for their speed and skittishness. Although Old Worlds are equipped with potent venom, many overlook the fact that their first line of defense when threatened is to run…not to stand their ground and fight. On the one hand, this is good news as it means these spiders will normally NOT resort to biting for a first line of defense. However, keepers used to calmer and slower New World spiders can be intimated by the sudden bursts of speed, especially during rehousings. A startled Old World can easily be out of its enclosure and loose in a home in the blink of an eye. The potential of the spider using its speed can definitely make a rehousing much more stressful without solid technique and planning.
It’s important to note, however, that speed isn’t exclusive to Old World spiders, and even a slower New World can boogie if motivated. Plenty of new keepers express that they are intimidated by the speed of their C. cyaneopubescens, or GBBs, and spiders in the arboreal genera Psalmopoeus and Tapinauchenius can be some of the fastest and most skittish spiders available, rivaling the speed of any Old World species. Even the mighty giants in the genus Theraphosa (which includes the Goliath Birdeater) can move startlingly fast for huge, heavy bodied spiders. Just imagine having a 10” spider scrambling out of its enclosure and onto your rehousing table!
Although the majority of Old World species run the table when it comes to speed, there are plenty of New World spiders that can give them a run for their money. And, it can’t be overstated that even “slow” species are capable of bursts of speed when motivated.
Behavior/temperament
So, now that we know the tools these two classes of tarantulas possess to defend themselves, we should discuss how likely they are to use these skills. When searching for “best beginner tarantulas,” one is bound to discover endless lists debating which of a gorgeous array of spiders is the best for the new hobbyist. Although these lists will include many different species from many genera, there will be one thing in common with all of them.
They will ALL feature New World tarantulas.
When constructing these lists, one of the most important factors keepers take into consideration is temperament. After all, most new keepers don’t want a giant, furry, unruly spider on their hands. With that in mind, most hobbyists recommend only New World tarantulas like Grammostolas, Brachypelmas, and Aphonopelmas to those looking to get their first spider. Many species in these genera have a reputation for being much more laid back and docile when adults and not prone to bolting or defensive behavior. Species like B. hamorii, G. pulchripes, T. albopilosum, and A. chalcodes are also coveted as pets because they are usually very visible. One looking for a calmer spider to admire and to show off to friends and family will definitely be wise to consider one of these species as a pet.
Then there is the fact that, if startled, these species are less likely to bolt or bite, instead resorting to using their urticating hairs as defense. For many, the idea of being exposed to some itchy bristles sounds much less threatening than being bitten and envenomated. Mistakes CAN happen, especially with those new to the hobby. Therefore, it’s definitely much more prudent for a keeper to learn the basics of husbandry and care with a species that is more likely to be calm and doesn’t possess potent venom.
Old Worlds
While researching tarantulas, a new keeper is bound to be bombarded with anecdotes about how “nasty” and “aggressive” Old World tarantulas are. YouTube is full of videos by keepers showing off their Old World spiders in a way to emphasize their more defensive tendencies as a way to get views from those who find angry spiders both terrifying and fascinating. The popular opinion about these spiders from people without a lot of experience is that they are frightening and dangerous.
Let’s get this out of the way: a frightened Old World tarantula can be incredibly defensive and will not hesitate to bite a perceived threat. Anyone who has seen an angry OBT, fangs bared and dripping venom as it violently slaps at the ground, can attest to how truly frightening this display can be. And, let’s not forget that a bite from one one of these spiders could easily result in a trip to the emergency room.
However, what is normally left out is that Old Worlds would rather run and hide than stand their ground. Most will quickly bolt to the safety of their burrows or, in the case of Poecilotheria species, flatten themselves out and use their natural camouflage to avoid detection. Unlike many of their New World counterparts, Old World species do NOT like to be caught out in the open. Many will dig deep burrows that they can bolt into with the slightest disturbance. Others will create ornate dens of webbing that serve as retreats. Arboreal species will often make opportunistic use of cork bark rounds and thick foliage as means of concealment and safety.
The fact is, if these species are set up correctly and given the correct requirements, then defensiveness under most circumstances can be completely avoided. The truth is that, if kept appropriately, most Old World species are quite shy and reclusive. In fact, the only downside about them is that, if given adequate space to burrow or hide, you might not see them much at all.
Let’s take the popular C. lividus or “Cobalt Blue” for example. A lot has been written about how “aggressive” and ornery this species is. I’ve read accounts of them slapping at the slightest movement and attacking keepers who are trying to change their water dishes or perform maintenance. However, this is a species that, if given the room to burrow, will rarely be seen. Those of use who keep them correctly report a shy spider that can only be caught outside of its burrow at night. Unfortunately, wild caught adult specimens are often available at pet stores where they are kept on shallow substrate and under bright lights. In other instances, the keepers have incorrectly provided their spiders with shallow, terrestrial enclosures that leave them feeling exposed and vulnerable. In both instances, this defensive behavior is caused by poor husbandry.
There is a big difference between an animal that is overly aggressive and one that is acting defensively because it’s stressed. Most Old Worlds, if housed correctly, will rarely be seen.
So, someone new to keeping tarantulas may be thinking, “if that’s the case, then why shouldn’t a beginner start with an Old World species?” Well, some can. However, if there is going to be friction between a keeper and her spider, it’s most likely going to occur during a rehousing. This is when the hobbyist has to move their spider from one enclosure to another. With burrowing species, this involves removing the animal from the security of its burrow, which can lead to defensive behavior. This is why many seasoned hobbyists encourage new keepers to practice their rehousings with more forgiving (and visible) New World species before moving into keeping Old Worlds.
Personally speaking, I have rehoused hundreds of Old World spiders over the years, and I’ve honestly never had much of an issue from any of them. The trick is to be respectful of the spider’s speed and mood, and to always maintain a calm approach when rehousing.
Impact on Keeping
In simplistic terms, New World Tarantulas are generally slower, more laid back, and lack venom that is potent for humans. Old World tarantulas are quite fast, have medically significant venom, and can use their speed and fangs to put a hurting on anyone who messes with them.
However, this oversimplification can be a bit misleading…
The fact is, ANY tarantula, both New World or Old World can be defensive or calm. There are plenty of stories out there about New World species throwing up threat postures and kicking up clouds of hair upon the slightest disturbance, or attacking water dishes or tongs during maintenance. Conversely, many folks report Old World spiders that are quite calm and laid back, even when caught out in the open. It’s always important to note that temperament can vary from spider to spider, and there are no guarantees when it comes to how one of these animals might behave.
Should this scare a new keeper? Absolutely not.
The trick is to treat ALL species of tarantulas with the utmost respect and to practice safe husbandry techniques no matter which spider you are working with.