Isopod (sow/pill bugs) Armadillidium nasatum

After collecting many ispods (sow bugs, pill bugs, roly polys, etc) to act as tank cleaners I wanted to know what species I have.

So searching for local isopods I found a document from the local college, IU (Indiana University), here is the document for Indiana isopods. To tell them apart I learned about antenna flagellum, segments, spike protrusions on the rear, and such. Some of the most telling areas are the number of segments, color, and length.

Looking through the document at some of the odd isopods it became clear, I have the standard everyday isopod, Armadillidium vulgare - or at least a identical strain called Armadillidium nasatum. The only difference I can find, is a squarish lobe that protrudes from the head. You can see the lobe in my photo of one of my isopods right behind the antennas.

If anyone is an expert on isopods and think it is a different species let me know, as I am curious to what I have.

The photo is of a dead dried out isopod, so the color has lighten significantly - as they are typically dark gray with banded spots of reddish brown. My photo was taken using 45 images setup using focus stacking.

So far I am using a CHDK script that will adjust focus slightly and take a photo - repeating until the camera has hit the manual focusing limit. Of course I could simply zoom in slightly afterwards to add more focus ability, but that will make it out of alignment - one reason I am looking to get a macro rail sooner or later.

Interesting enough you can see the "face" and it's eyes are the honeycomb looking things under the antennas, in the middle of the horizontal length.

Looks a little odd in shape and color but judging by the face it should be A. nasatum.

Orin said:

Looks a little odd in shape and color but judging by the face it should be A. nasatum.

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Thank you very much for confirming the isopod species

There is a face there? I believe you...but it must be one only a mother or father can love...hehe

Thanks for sharing...

dmina said:

There is a face there? I believe you...but it must be one only a mother or father can love...hehe

Thanks for sharing...

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Yeah I would have to agree with you it isn't much of a face as we know it. Motherly love allows any face to be beautiful doesn't it?

Cool!

Thanks. I think what I like most is I now know what species is in my area (or backyard mostly at least).

I have 3 species in my back garden, they are so cool.

#Day50 of #100DaysofNature by mattd85, on Flickr

My isopods have been thriving well in their habitat. I got a photo of one molting, which is strange as they molt in two stages (once for the rear half, and again for the front). The freshly molted area is quite white for a few hours, until it dries and hardens.

You can read on how to make your own DIY isopod habitat at my topic here.

Here is the photo...

This isopod is almost twice the size of a football. I took this picture at the local aquarium last week.

Sweet find Orin

Never would have thought a aquarium would have such a species as Bathynomus giganteus on display. That alone would have made the trip worthwhile for me. I'll have to see if any nearby aquariums have them so I can see one myself.

It was at the Greater Cleveland Aquarium. Strange thing was I never would have seen it if we didn't walk through the kids area upstairs. It was in a tank in the play room. I've never seen one alive before, just a pickled, much smaller one, twenty-five years ago.
This one has red filamentous algae growing on it because it has been alive a long time. In nature they're too deep for light needed for algae growth.

Aw, 6 hour drive one way for me, so not going to happen anytime soon. That is a strange place, I guess they figure kids will get the most enjoyment from a giant "pillbug". Awesome find though, sounds like it was a highlight for you too.

Orin said:

This isopod is almost twice the size of a football. I took this picture at the local aquarium last week.

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That's awesome.

CosbyArt said:

After collecting many ispods (sow bugs, pill bugs, roly polys, etc) to act as tank cleaners I wanted to know what species I have.

So searching for local isopods I found a document from the local college, IU (Indiana University), here is the document for Indiana isopods. To tell them apart I learned about antenna flagellum, segments, spike protrusions on the rear, and such. Some of the most telling areas are the number of segments, color, and length.

Looking through the document at some of the odd isopods it became clear, I have the standard everyday isopod, Armadillidium vulgare - or at least a identical strain called Armadillidium nasatum. The only difference I can find, is a squarish lobe that protrudes from the head. You can see the lobe in my photo of one of my isopods right behind the antennas.

If anyone is an expert on isopods and think it is a different species let me know, as I am curious to what I have.

The photo is of a dead dried out isopod, so the color has lighten significantly - as they are typically dark gray with banded spots of reddish brown. My photo was taken using 45 images setup using focus stacking.

So far I am using a CHDK script that will adjust focus slightly and take a photo - repeating until the camera has hit the manual focusing limit. Of course I could simply zoom in slightly afterwards to add more focus ability, but that will make it out of alignment - one reason I am looking to get a macro rail sooner or later.

Interesting enough you can see the "face" and it's eyes are the honeycomb looking things under the antennas, in the middle of the horizontal length.

...

Click to expand...

Great shot!

I have been reading my new book, "Isopods in captivity: Terrarium Clean-up crews" and have been learning some rather interesting things about the creatures. I've also discovered with the majority of isopods found in the wild, their basic look and coloring/patterning can tell the species without having to do close-ups with them all.

It seems I have at least three species found in my backyard. The largest population is Armadillidium nasatum, then some Armadillidium vulgare, and a tiny amount of a unknown species (unknown to me at least). I assume the unknown species is more commonly referred to as sowbugs as they are much flatter, do not roll into balls (volvation), and run much faster. I have yet to get a decent shot of them due to their speed, and there are a few that have a orange coloration to them too.

Here are a couple decent shots of a few isopods in my colony culture showing their coloration/patterning...

The unknown species might be Porcellio scaber. When I caught some many were orange.

All About Insects said:

The unknown species might be Porcellio scaber. When I caught some many were orange.

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You very likely right, but I'll have to track them down for a photo. I'll transfer them to another tiny container for a photo to see.

All About Insects said:

The unknown species might be Porcellio scaber. When I caught some many were orange.

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I got two out of my culture, however the really bright orange one was nowhere to be found (likely hiding in the substrate and I did not want to crush any isopods there trying to find it).

They appear more brown than orange in my photos due to my interior lighting, and I was unable to adjust it to be more lifelike - although hopefully they are good enough for identification. Also I noticed several other isopods in my culture that appear the same as the ones below, but were almost the typical Armadillidium vulgare gray. So perhaps some are just a color morph of their species.