How to tell the difference between "good" and "bad" Isopods (CIROLANID VERSES SPHAEROMATID ISOPODS)

[Lionfish Lair]

CIROLANID VERSES SPHAEROMATID ISOPODS.

When you know what your looking for, telling the difference between a Cirolanid (bad) versus a Sphaeromatid (good) becomes a lot easier. It's all in the eyes.....
The eyes of the Cirolanid are generally closer together and towards the front of the head. They always look angry because of the slant of their eyes. Think of them as needing to look forward to "capture" it's prey.
The Sphaeromatid eyes are generally more to the side of the head. They always remind me of baby seals with their big black harmless looking eyes. Looking at the side by side pictures I've included of both isopods may help with this "visualization". smile emoticon
Sphaeromatids also have the common name "Roly Poly" as they, unlike the Cirolanid, roll up in a defensive position when they feel threatened. The Ciralonids cannot do this. Think of it like this: the Ciralonid is mean and will never back down from a fight. The innocent little Sphaeromatid rolls up in a tiny little ball saying "Please, don't hurt me!".
Where you find them may also help decipher which is which. If it's attached to your fish, it's probably pretty safe to say it's a Cirolanid. If there are a few scurrying around when you lift up a rock, lean towards it being a Sphaeromatid.

This is the Sphaeromatid, all curled up. Ciralanids can "curve", but they don't ball up like the Sphaeromatid.

I'm sorry about my big ole watermark on there. I had these pics posted on facebook and have had a lot of trouble with people snagging them. I'm going to make that a little smaller.

 

[GHsaltie]

I have to say I greatly enjoy reading your threads on all these fascinating critters. I'm pretty sure I go to the hitchhikers section of your site at least once a day and it has helped me so much in identifying many diverse creatures in my tank. So, hats off to you Lionfish, I love your work!

 

[Lionfish Lair]

That's sweet to say. It'll be fun to fill this section of the forum up with cool critters.

 

[saltyfilmfolks]

Excellent work Renee! As always. Just saw the thread starting the new forum, and yes, love your work!

And keep the watermark. Looks good from here

 

[meir]

I've had bad Isopoda I think called fish louse got them in WC percs

 

[Lionfish Lair]

And keep the watermark. Looks good from here

On my big ole widescreen it looks embarrassing huge because it's a wrong DPI. Someone snagged a pic and actually labelled it incorrectly. I was like Dude, change the label to a correct one. He told me "na-na na-na boo boo". Say wahhhhhhh! We have him to thank for this.

This forum section has nothing to do with me! I just saw it and pounced to be the first thread started! LOL!

The timing is great on this new forum though. Where I'm redoing my guide, I have gobs of new material and information to bring here to share. Now I can keep it all organized

 

[twreefer]

That's sweet to say. It'll be fun to fill this section of the forum up with cool critters.

Gosh, you have the cutest isopods!

 

[Giraffe0621]

CIROLANID VERSES SPHAEROMATID ISOPODS.

This is the Sphaeromatid, all curled up. Ciralanids can "curve", but they don't ball up like the Sphaeromatid.

@Lionfish Lair -- any idea if the good guys (Sphaeromatid) could be found in Live Rock from TBS? I see they have the bad guys (Ciralanids) listed on the list of possible things to find in your rocks... but trying to figure out if both are a possibility. I've only seen the ones in my tank very briefly & it's tough to decide which it is based on the eyes. I haven't seen them curl up at all, but they more just swim away when I try to get close. No fish in the tank yet, so no attaching to fish as a clue! Thanks

 

[seahorsebill]

Where can I get some?