# Isopods Possibly Dangerous to Tarantulas



## Derivative (Mar 25, 2019)

First I want to preface this by saying I am not even close to an expert by any means and that you should take this with 20 grains of salt. My speculation is that Isopods aren't harmless and that under certain circumstances can be dangerous towards tarantulas and that people should be more mindful of isopods populations in their tarantula enclosures.
    On Tom Moran's most recent podcast he mentions finding a few of his Tityus Stigmurus scorpion adults dead and being eaten by isopods. He said that he suspects that what may have happened is that the isopod population got out of control and due to there not being enough food for the isopods they resorted to swarming some adult scorpions who were on the ground. He speculates that the reason the baby scorpions weren't eaten is because they live up on the cork bark and not on the ground. It is important to note that this was his speculation he does not know for sure if maybe the scorpions died and than the isopods ate them or if the isopods attacked them. Although he doesnt know what else could have happened to those scorpions. So this may be a possible piece of evidence towards Isopods not being as harmless as previously thought.
  Another piece of evidence I found of Isopods not being harmless and even being potentially dangerous is an old thread here on arachnoboards called "anoles under attack" it was posted by the user auroboros. On this thread auroboros says "I just bought a mating pair of brown anoles for a terrarium I already had set up for a while. It had a plant or 2, a few sticks poking out of the ground, a giant land snail and about 100 or so isopods that were originally used to keep the tank clean until there numbers got too high. I introduced the anoles to keep the isopod population down but it seems they wont give up there supremacy without a fight.Despite the lizards gobbling up countless isopods, they made a counter attack upon the alpha male and devoured over an inch from his tail (nothing but bone left) he still has lots of tail left but I really don't like the idea of my lizard being eaten alive. Its a ten gallon fish tank I keep them in, so theres not a lot of space for a fancy set up. Any suggestions on keeping my lizards on top of the food chain instead of a spiraling cycle of Predator vs Pseudo-predator? " Later in the post he says "well, the problem sort of fixed its self. The Isopods only were attacking the male, its been less than a week since I bought them and the male just died today  . Im gonna go bring it back to the store and get a new one. 
I think the Isopods could sense he was weak and took advantage."I personally think that this could be a case of an overabundance of isopods with not enough food and I cant help but imagine what would have happened had it been a molting tarantula in the cage .
   A third piece of evidence I found is a thread titled " MEAT EATING isopods" on the website chameleonforums.com where the user little leaf tested if Isopods would eat animal meat by putting red meat with isopods and observing them eat it. This is not what I consider as evidence though due to the fact that isopods are known to eat dead and decaying organic matter. What I consider evidence in this post is when the user says " because the HOLE in my cham is not pretty". Later on in the thread when asked if maybe the flesh was dead or decaying before the isopod attacked the chameleon the user little leaf responds with "no, he had nothing on him before it bit him- I had to pick the isopod off , and then the mark was there in the am - and grew to the scab -".
  It is also important to note that the giant isopods of the oceans are carnivores and that it wouldn't be far fetched for the commonly used isopods to be carnivorous and dangerous towards tarantulas in certain circumstances.
  I am not saying to stop using Isopods. What I am saying is to be careful with them and monitor there populations while making sure they have enough food so that they don't revert to swarming and eating your tarantulas. There are many instances of Isopods being extremely helpful at keeping moist enclosures mold free and healthy. It is only when there is an overabundance of isopods and an underabundance of food in which they could be potentially harmful to your tarantulas.
Here are the links to the webpages on isopod attacks.
anoles under attack
http://arachnoboards.com/threads/anoles-under-attack.214189/
Toms Big spiders Podcast
https://www.buzzsprout.com/148967 
MEAT EATING isopods
https://www.chameleonforums.com/threads/meat-eating-isopods.135733/

Reactions: Informative 1


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## Teal (Mar 25, 2019)

Certain species of isopods (Porcellio scabers come to mind) are said to be a threat to other animals.

However, without solid evidence of isopods attacking a LIVING animal... I just don't by it. I have fed my isopods all sorts of things, including recently deceased adult male dubia roaches and raw meat which they are quick to devour.

Reactions: Like 1


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## Derivative (Mar 25, 2019)

Teal said:


> Certain species of isopods (Porcellio scabers come to mind) are said to be a threat to other animals.
> 
> However, without solid evidence of isopods attacking a LIVING animal... I just don't by it. I have fed my isopods all sorts of things, including recently deceased adult male dubia roaches and raw meat which they are quick to devour.


My evidence is anecdotal so it is not certain but I do think that there is nothing wrong with taking precautions with isopods. Monitoring their populations in your T enclosures and making sure the isopods have sufficient resources to survive does not hurt anything to my knowledge and that is all I am suggesting.

Reactions: Agree 1


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## Teal (Mar 25, 2019)

Derivative said:


> My evidence is anecdotal so it is not certain but I do think that there is nothing wrong with taking precautions with isopods. Monitoring their populations in your T enclosures and making sure the isopods have sufficient resources to survive does not hurt anything to my knowledge and that is all I am suggesting.


Oh, absolutely precautions should be taken! Any enclosure with multiple animals should be under careful observation to make sure they all have their needs being met without competition for resources that could lead to any sort of predation.

Reactions: Agree 3


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## The Grym Reaper (Mar 25, 2019)

I did try using them once and found they just annoyed the shit out of the tarantula (large enough to trigger a feeding response but too small to actually eat) so I got rid of them in the end. 

I'll just stick to springtails tbh.

Reactions: Agree 2


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## Teal (Mar 25, 2019)

The Grym Reaper said:


> I did try using them once and found they just annoyed the shit out of the tarantula (large enough to trigger a feeding response but too small to actually eat) so I got rid of them in the end.
> 
> I'll just stick to springtails tbh.


Some of my roach colonies on moist sub have springtails and they seem incredibly annoying! 

The only time I have founf any of my Ts noticed isopods was a C. versi juvie who was quite excited about all the snacks roaming her enclosure

Reactions: Funny 4


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## Derivative (Mar 25, 2019)

Teal said:


> Some of my roach colonies on moist sub have springtails and they seem incredibly annoying!
> 
> The only time I have founf any of my Ts noticed isopods was a C. versi juvie who was quite excited about all the snacks roaming her enclosure


I bet you wound up with one extremely overweight C. Versicolor. lol


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## Teal (Mar 25, 2019)

Derivative said:


> I bet you wound up with one extremely overweight C. Versicolor. lol


I put 6 adult A. vulgare in there... They didn't last the first night LOL

Reactions: Funny 4


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## SonsofArachne (Mar 25, 2019)

Teal said:


> Some of my roach colonies on moist sub have springtails and they seem incredibly annoying!


I keep them with T's, centipedes, roaches, and scorpions. I've never seen any of these animals pay any attention to springtails.

Edit: exception - small T and true spider slings and also centipede plings will eat them.


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## The Grym Reaper (Mar 25, 2019)

Teal said:


> Some of my roach colonies on moist sub have springtails and they seem incredibly annoying!


I use them in any enclosure they'll survive in and they're also in my roach colonies to deter mites from setting up shop in them, never had an issue, even the slings don't seem to notice them.


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## MikeyD (Mar 25, 2019)

Not all isopods are created equal.  The dwarf tropical (white or Costa Rican purple) are the most harmless but I wouldn’t trust the larger species.  I used to keep juvenile P scaber in with my whip scorpions until the day I dropped in some pinhead crickets and saw an isopod grab a living cricket and start eating it.    If they are hungry they are a danger to a molting Tarantula.    I’ve since stopped using isopods and have switched to springtails for moist enclosures and I just keep isopods in my snake vivariums.


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## Johjie (Mar 25, 2019)

I was recently given some 1st or 2nd instar C. elegans with isopods included in the enclosure as feeders. If isopods were to eat a T, I'd imagine such a small sling would be an optimal meal. Haven't had any problems so far but it is also very difficult to check on them as they have burrowed pretty deep. I will try to observe them more closely to see if there are any problems but so far, none I can tell.

We also have isopods in a enclosure with our H. Minax, they stay below the T's webbing that covers all of the substrate and don't venture elsewhere. The substrate showed signs of mold but the isopods have demolished it. There are so many isopods now I have had concerns however I have been closely monitoring them. My only thoughts have been if their population gets out of control I will just remove the T and use their populations in other enclosures.


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## Dandrobates (Mar 25, 2019)

The term “bioactive” and the controversies it causes always make me laugh. I’ve kept springtails and isopods as cleanup crews in frog vivariums for the past twenty years. In fact I started with native springtails by accident long before this ridiculous buzzword came into fashion. Now it’s in vogue in the tarantula community and to be honest I don’t understand why people bother obsessing over it. With the exception of moisture dependent species I don’t see any benefit for T’s. I keep my frog vivariums stocked with with microfauna for one reason...because they eat crap and the fungus that grows on crap. Frogs crap a lot (much more than tarantulas) and a miniature ecosystem that can sustain itself makes for easier maintenance. I’ve never had swarms of rogue isopods or springtails gang up on my dart frogs, give them black eyes and then devour them. HOWEVER, I do not keep my Tarantula or invert enclosures stocked with microfauna. Why? Because it serves no practical purpose to them. I can spot clean a T enclosure much easier than a dart frog enclosure. If you are concerned about swarms of isopods killing healthy animals yes! There is anecdotal evidence of it. However people don’t seem to get the fact that you don’t need them in the first place. 

End of rant

Reactions: Agree 1


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## SonsofArachne (Mar 25, 2019)

Dandrobates said:


> With the exception of moisture dependent species I don’t see any benefit for T’s.





Dandrobates said:


> However people don’t seem to get the fact that you don’t need them in the first place.


You kind of contradict yourself there. And I'm really not sure where else besides with moisture dependent species you would bother using springtails. In drier enclosures all they do is hang out in the water dish until they die off. But in moist enclosures I find them invaluable in keeping mold in check.


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## Dandrobates (Mar 25, 2019)

Also regarding the OP’s mention of brown anoles, anoles are and have been wild caught almost exclusively. They are frequently loaded with parasites, treated as disposable pets given their abundance and and are easily stressed by breeding. All these factors equal unhealthy animals. I find it much more likely that the anole in question had significant health issues that lead to it giving up the ghost. The isopods Anoles are also semi to fully arboreal so why was it on the ground where the isopods were in the first place?

Reactions: Agree 1


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## Dandrobates (Mar 25, 2019)

SonsofArachne said:


> You kind of contradict yourself there. And I'm really not sure where else besides with moisture dependent species you would bother using springtails. In drier enclosures all they do is hang out in the water dish until they die off. But in moist enclosures I find them invaluable in keeping mold in check.


To clarify I meant isopods are not a necessity. Springtails do the job fine by themselves

Reactions: Like 1


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## Vanessa (Mar 25, 2019)

I have heard of two cases where scorpions have died without an obvious cause and they have suspected the isopods. I have never repeated that, because it was always just speculation with no real proof.
Since doing some isopod research myself, I have set up a bioactive enclosure for my crested gecko recently, it occurred to me that the isopods could have killed those scorpions. I only have dwarf whites in with my gecko, but there are many species that are lean more towards being omnivorous. I was even told that I could put my snake's skin, dead tarantulas and tarantula exuvia into the enclosure for those isopods to eat (not that I would ever do that, because the urticating hairs would be dangerous to my gecko), which strengthened the death by isopod theory even further.
Either way, I only have some native springtails in with my scorpion and that is how I am going to leave it.


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## Derivative (Mar 25, 2019)

Dandrobates said:


> The term “bioactive” and the controversies it causes always make me laugh. I’ve kept springtails and isopods as cleanup crews in frog vivariums for the past twenty years. In fact I started with native springtails by accident long before this ridiculous buzzword came into fashion. Now it’s in vogue in the tarantula community and to be honest I don’t understand why people bother obsessing over it. With the exception of moisture dependent species I don’t see any benefit for T’s. I keep my frog vivariums stocked with with microfauna for one reason...because they eat crap and the fungus that grows on crap. Frogs crap a lot (much more than tarantulas) and a miniature ecosystem that can sustain itself makes for easier maintenance. I’ve never had swarms of rogue isopods or springtails gang up on my dart frogs, give them black eyes and then devour them. HOWEVER, I do not keep my Tarantula or invert enclosures stocked with microfauna. Why? Because it serves no practical purpose to them. I can spot clean a T enclosure much easier than a dart frog enclosure. If you are concerned about swarms of isopods killing healthy animals yes! There is anecdotal evidence of it. However people don’t seem to get the fact that you don’t need them in the first place.
> 
> End of rant


    I think most people obsess over them based on their asthetics . Personally I would use them if I could because they look cool and as long as it is set up correctly the tarantula shouldn't suffer any negative consequences. 
   Although I do think that one day some random begginer is going to set up their new G. Rosea with tall plants so they can have a bioactive enclosure and end up with a tarantula splat on the cage floor because they wanted a bioactive enclosure but did zero research.


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## Gaherp (Mar 25, 2019)

I've kept dwarf purples since the very first ones came into the country. Dwarf  whites maybe a year after they became available. I've bred tons of dartfrogs, and the volume of tarantulas I have with isopods in the enclosure is alot to say the least. Now in all that time,  20 plus years, I have yet to see a dwarf isopod(be it a few or tons) feed or predate upon a dartfrog, spiderling , or scorpion. I am not saying this very anomalous event could not happen I am just saying with thousands of these animals interacting over the years I have never witnessed it. Maybe the food was not present for these pods to feed and something did happen to trigger this. Either way maybe pay better attention to isopod numbers in your setups and feeding them occasionally probably would not be a bad thing if the absence of food for the pods was to blame.

Reactions: Like 3


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## Johjie (Mar 25, 2019)

SonsofArachne said:


> You kind of contradict yourself there. And I'm really not sure where else besides with moisture dependent species you would bother using springtails. In drier enclosures all they do is hang out in the water dish until they die off. But in moist enclosures I find them invaluable in keeping mold in check.


This is exactly why I don't really use springtails much. In the water dish etc. (Edit: spelling)


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## Rittdk01 (Mar 26, 2019)

I keep dwarf white isopods in with my H gigas and T stirmi enclosures.  They  don’t bother my tarantulas at all.  They also don’t get out of control in population, but I don’t think they would be a threat.  

^^The scorpions probably died and then were eaten and the female anole was probably chewing on the males tail.


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## Zevil (Mar 26, 2019)

I kept dwarf whites and grays in my chameleon enclosure for a while now. I have never seen them climbing up for food or trying to eat the chameleon when he goes down to catch a few isopods for food. I believe a bioactive setup has been around for ages and no solid evidence has suggest that isopods will eat live healthy animals for food.


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## Rhino1 (Mar 26, 2019)

Ive had those little pale dwarf isopods in tropical scorpion enclosures on and off for years, I can't honestly say that I even see a difference in quality whether they are there or not to begin with. I had cannibalism twice in communal set ups but isopods had nothing to do with it, other than that hardly see them until I pull a terrarium down


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## chanda (Mar 26, 2019)

Go big or go home, right? I didn't bother with those itty-bitty dwarf isopods. I have the big (locally caught) canyon isopods (some flavor of _Porcellio_) and I've put them in with roaches (_Blaberus giganteus_), millipedes, assassin bugs, and my _T. stirmi_. For the most part they don't seem to cause any problems - though the assassins (_P. biguttatus_) did not feed on the isopods as much as I'd hoped they would - but in the millipede cage, I suspect that they were killing and eating my millipedes and also eating their eggs. It is possible that the millipedes died first and the roaches were just playing clean-up crew, but  I rehoused the millipedes to an isopod-free cage and they seem to be doing much better without their little crustacean roommates. I suspect that the isopods were also eating the eggs of the assassin bugs - but given how prolific those guys are, there were still plenty of nymphs hatching out!


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## Dandrobates (Mar 26, 2019)

Derivative said:


> I think most people obsess over them based on their asthetics . Personally I would use them if I could because they look cool and as long as it is set up correctly the tarantula shouldn't suffer any negative consequences.
> Although I do think that one day some random begginer is going to set up their new G. Rosea with tall plants so they can have a bioactive enclosure and end up with a tarantula splat on the cage floor because they wanted a bioactive enclosure but did zero research.


What irks me the most is the misrepresentation of the concept. Creating a naturalistic terrarium or enclosure is not a difficult task in and of itself. The object of the game though is in fact creating a closed system that can manage it’s own waste effectively while maintaining the captive needs of it’s inhabitants. This is the premise people seem to miss.

I take issue with the way certain companies market and label their products as “bioactive” and how they target species and biomes where the premise as they define it just won’t work.(see my example at the end)  “If your enclosure doesn’t contain X, Y and Z then it’s not “bioactive.”  And “Any environment and species can be maintained bioactivly” That’s a load of nonsense. There is a lot of misinformation out there and the novice keeper of any animal can easily be led astray.

Vendors use the term bioactive as a buzzword to sell products that in some situations work very well but in others are pointless. There is much more involved in creating a closed biome than throwing in isopods and springtails. Enclosure size, moisture and humidity, lighting and biomass all come into play. Hell, an aquarium filter is essentially “bioactive” because it utilizes bacteria to manage waste. But if you overload it with waste it’s ineffective. Anyone who’s overloaded an aquarium with too many fish knows that, once the biomass of the fish exceeds the clean up crew’s ability to manage the waste, the water quality goes out the window and the system is no longer effective.

Now here’s my example of bad bioactive advice. I found a video on you tube of a certain person who sells bioactive products and here is what I took away from it. He had a 40 breeder set up as a bioactive bearded dragon enclosure. His contention was that the system would maintain itself with little to no maintenance. Well the reality is the enclosure looked great but there is no way in balls that it’s going to work. He’s keeping a semi arid to arid species on moist cocofiber which is a big no no for several reasons ( beardy keepers back me up), and he’s relying on springtails to clear out the animals waste. Ok in a 400 gallon enclosure I’d buy it. But there is no way a 40 breeder can hold enough microfauna to manage all that fecal matter. But it looks pretty so people buy his product.


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## Sandland (Apr 1, 2019)

I have been keeping isopods with some tarantula's, scorpions. millies, etc. Never have I even suspected they have killed or even harassed an animal before. that being said the reason I keep them in the more display type cages is to clean up waste that would be harder to clean up or even find in a larger planted type display. If I were to throw a dead cricket in one of the cages with them it would not take long before a surprising amount of them would be swarming and eating the cricket but id rather have that then mites on a forgotten cricket. I also feed isopods in the same cages because if just left with what the tarantula leaves behind the isopods would starve in short order.


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