# Parasites in Isopods



## Engeli (Oct 3, 2014)

Some months ago I noticed nematodes in my Azureus. The lab result was "Aplectana sp.", a roundworm. Aplectana seems to be pretty aggressive and I had to destroy the whole inventory of my viv, including plants.
The frogs had to go through several weeks of treatment and finally had a negative fecal result. I got a new viv, bought everything new from scratch and desinfected everything that went in there. I also started another new viv with more Tincs that came from a different source and they also tested negative.

Today I made a fecal on my microscope and ALL frogs were positive for Aplectana in different vivs. Believe me, I was shocked as I was very careful not to transmit anything from one viv to the other.

So I made some thoughts where it could come from and the only thing I did not desinfect or renew are my feeder cultures. Just out of fun I put springtails, flies and isopods under the microscope and with horror, I found my isopods were FULL of Aplectana. I guess I found the source of all my troubles!

That means I have to rip down AGAIN everything and the frogs need another treatment. Extremely annoying!

Did somebody else make the same experience that Isopods are potential parasite carriers?


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## Judy S (Aug 29, 2010)

THAT is interesting...I will be subscribing to this thread...hopefully you will get some good answers...hopefully Ed will chime in, although he is not the only "expert"--DB has a lot of experienced "bug" people. Perhaps you can mine the forum to look at the members who seem to be proficient in this area....and PM them if you don't get good answers...good luck


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## xm41907 (Nov 26, 2007)

Did you identify Aplectana yourself or did you send it out to a lab? If I read it right, your initial identification was from a lab, but now you self-diagnosed? I'm no expert on nematodes, but I would ensure your ID is correct before making any drastic destruction of your new set up. 

From a brief google search, it appears valid that isopods could have been the reservoir for them. Many parasites can persist on arthropod feeders. If I had a parasite issue, I would first isolate the infected frogs, then switch feeders and attempt to sanitize the tank as best possible and hope for the best.


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## MWAInverts (Oct 7, 2014)

Also keep in mind that one negative test doesn't mean 100% negative.


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## Engeli (Oct 3, 2014)

xm41907 said:


> Did you identify Aplectana yourself or did you send it out to a lab? If I read it right, your initial identification was from a lab, but now you self-diagnosed? QUOTE]
> 
> Yes, Aplectana was diagnosed by the lab. They have a very specific shape with a sharp needle-like end. Clearly visible also now under the microscope.


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## Engeli (Oct 3, 2014)

MWAInverts said:


> Also keep in mind that one negative test doesn't mean 100% negative.


Right, I checked multiple times over 2 weeks and then sent to the lab in addition to have a second opinion which also confirmed the negative result.


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## Ed (Sep 19, 2004)

so how did you determine that the nematodes weren't Neoaplectana in the isopods as opposed to Aplectana.... 
Or how did you determine that the nematodes in the isopods aren't Steinernema ssp? 

I have significant doubts that the isopod cultures contain Aplectana as while (as far as is known) have a free living larval stage they do not have a free living reproductive stage (like Rhabdias ssp.) so the isopod cultures should not be able to sustain the population of the nematodes. If you are seeing larvae and adults in the isopods then this is not a parasite that infects frogs.... 
This could also result in a false positive test in the frogs if the techs are expecting a vertebrate parasite as opposed to contamination by a similar arthropod parasite. Aplectana do not parasitize arthropods while Neoaplectana and Steinernema do. 

Some comments 

Ed


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## Engeli (Oct 3, 2014)

Ed said:


> so how did you determine that the nematodes weren't Neoaplectana in the isopods as opposed to Aplectana....
> Or how did you determine that the nematodes in the isopods aren't Steinernema ssp?
> 
> Aplectana do not parasitize arthropods while Neoaplectana and Steinernema do.
> ...


Ed, I will send further fecal samples again as well as Isopods to the lab. They are specialized on exotic's fecals. 
So if Aplectana do not parasitize arthropods, do Neoaplectana and Steinernema parasitize frogs?
One frog had a small injury a week ago in the viv that's why I seperated him from the others and put him into QT where he still is. His fecals were also positive and I can completely exclude a crosscontamination in the QT viv as it never came in touch with Isopods, it clearly came from the frog. I am also very sure that what I see under the microscope is the same species from frogs and isopods. 
I could not discover free living stades within the isopod culture, only larvae. The culture is running since August last year.


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## a hill (Aug 4, 2007)

Just posting to subscribe and keep tabs. 

Keep us updated please. 




Smiling when unhappy makes you happier. 
Transcribed via Siri.


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## Ed (Sep 19, 2004)

Engeli said:


> Ed, I will send further fecal samples oagain as well as Isopods to the lab. They are specialized on exotic's fecals.


This does not mean that your not going to get a false positive result. Are they specialized in identifying parasitic nematodes that infect arthropods? 
If they are not, then you can get misidentified nematodes as a result. Why would they expect to find similar nematodes in the fecal that were not parasites in vertebrates? 
I've actually seen this happen in person with people who specialized in exotic animal fecals (vet techs who were employed at a zoo for years). The false positive was from feeding various animals earthworms and resulted in repeated attempts including quarantining and stripping down enclosures repeated time with treatment before they figured out it was from the nematodes in the earthworms. After that we had to notate on the fecal form that they were fed earthworms so they wouldn't make the same mistake. 




Engeli said:


> So if Aplectana do not parasitize arthropods, do Neoaplectana and Steinernema parasitize frogs?


No, but this does not mean that they can't be found in the fecals of the frogs. If the frog had consumed infected arthropods then the nematodes and the eggs can pass through the frog undigested resulting in the false positive. This can happen even in mammals like tenrecs that are fed earthworms that have a nematode burden. 




Engeli said:


> One frog had a small injury a week ago in the viv that's why I seperated him from the others and put him into QT where he still is. His fecals were also positive and I can completely exclude a crosscontamination in the QT viv as it never came in touch with Isopods, it clearly came from the frog. I am also very sure that what I see under the microscope is the same species from frogs and isopods.
> I could not discover free living stades within the isopod culture, only larvae. The culture is running since August last year.


See above why the frog could still be positive. As I asked how did you differentiate Aplectana from Neoaplectana and Steinernema since all three are similar in morphology? If you are making the identification based on the "sharp" point in the tail then you could misidentify them as you would then need to also examine the adult male, and the third stage infectious larvae and them measure various aspects and ratios to correctly identify the species. 
If you are only finding larvae in the culture it doesn't mean that it still can't be a species that parasitizes isopods as opposed to frogs. 

Some comments 

Ed


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## Ed (Sep 19, 2004)

I also have to ask why are you so concerned about an oxyurid infection? If the frogs are not showing signs of problems with the oxyurids what is the point of all of this repeated tearing down the enclosures and treatments? Not all oxyurid infections are a problem. They can actually assist with digestion and the availability of nutrients and this has been seen across a number of taxa as an example see 
Pryor. G.S. & Bjorndal, K.A. "Effects of the nematode Gyrinicola batrachiensis on development, gut morphology, and fermentation in bullfrog tadpoles (Rana catesbeiana): a novel mutualism". J. Exp. Zool. 2005. 303A: 704-712 

Some comments 

Ed


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## Judy S (Aug 29, 2010)

Props........


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## Engeli (Oct 3, 2014)

Ed said:


> I also have to ask why are you so concerned about an oxyurid infection? If the frogs are not showing signs of problems with the oxyurids what is the point of all of this repeated tearing down the enclosures and treatments? Not all oxyurid infections are a problem. They can actually assist with digestion and the availability of nutrients and this has been seen across a number of taxa as an example see
> Pryor. G.S. & Bjorndal, K.A. "Effects of the nematode Gyrinicola batrachiensis on development, gut morphology, and fermentation in bullfrog tadpoles (Rana catesbeiana): a novel mutualism". J. Exp. Zool. 2005. 303A: 704-712
> 
> Some comments
> ...


I had one frog that was skinny and had diarrhea and after the treatment he gained weight and had nice compact fecals. I did some research and in my opinion Aplectana belong to Cosmocercoidea and not to Oxyuroidea? The Neoaplactana and Steinernema belong to Rhabditoidea.


The first time they had the infection (and I strongly belive it came from the same isopod culture) they had adult nematodes in the fecal that was sent to the lab and diagnosed with Aplectana. Adult nematodes were approx. 5-7mm. How big do Neoaplectana/Steinernema get in the adult state?


The recent fecal samples have huge loads of larvae, the load is much, much higher than in the isopods. This makes me think reproduction took place within the frog and was not a by-product of undigested arthropod specific nematodes. All of them were moving.

But we will see what the results say from the lab this time when they have all sample material (including the isopods).


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## Ed (Sep 19, 2004)

Engeli said:


> I had one frog that was skinny and had diarrhea and after the treatment he gained weight and had nice compact fecals. I did some research and in my opinion Aplectana belong to Cosmocercoidea and not to Oxyuroidea? The Neoaplactana and Steinernema belong to Rhabditoidea.c


There is argument about the taxonomy. I am more versed in an older taxonomy in which the Oxyuridae were still under Rhabditida. Hence my reference. 




Engeli said:


> The first time they had the infection (and I strongly belive it came from the same isopod culture) they had adult nematodes in the fecal that was sent to the lab and diagnosed with Aplectana. Adult nematodes were approx. 5-7mm. How big do Neoaplectana/Steinernema get in the adult state?
> 
> 
> The recent fecal samples have huge loads of larvae, the load is much, much higher than in the isopods. This makes me think reproduction took place within the frog and was not a by-product of undigested arthropod specific nematodes. All of them were moving.
> ...


I can make a prediction... the lab is going to identify them as Aplectana again. Why do I expect that to be the result, simple they are going to use a key that is used with vertebrate parasites in mind and as such is not going to contain the information to include nematodes that infect arthropods. 

I'm not sure why you think that the nematodes from the isopods would have to me deceased after passage through the GI tract of the frog. 

Some comments 

Ed


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## Engeli (Oct 3, 2014)

Ed said:


> I'm not sure why you think that the nematodes from the isopods would have to me deceased after passage through the GI tract of the frog.


...Drosophila come out dead as well


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## Engeli (Oct 3, 2014)

So in the meantime I received the laboratory results. 

They found nematode larvae in frog feces and Isopods. But the biggest load of larvae (plus bigger states) have been found in the Isopod substrate. Their assumption is that these are soil nematodes but they can't be morphologically distinguished from pathogenic nematodes.

I also frequently checked feces under my microscope and the larvae load was getting less and less until they seemed to fully disappear, at least in one Tinc pair. The problem seems to have been solved on it's own.

Everything will stay now as it is in the vivs and the disgusting Isopods have been thrown away 

The good news is that my Azureus laid their first clutch yesterday!


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## Engeli (Oct 3, 2014)

Last year in early autumn I bought a bag of commercial seet soil (bio) as I used it for the pea aphid cultures. I stopped those during the winter time and wanted to start again today.

From now on everything will be checked under the microscope before it goes into the viv 

Guess what I found in that soil today? Some very well known faces!
Amazing! This is the source of the nematodes. The bag was outside on the balcony during the whole winter with minus degrees and it seems that had no impact at all. Must have mixed some of it into the Isopod cultures as well in autumn but couldn't remember.

Well, very clear now that they are harmless for the frogs. Anyway, I will use that bag for flowers on the balcony rather than for cultures ;-)


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