Rolly Poly?

[Mihai]

I have lots of rolly pollies in my tank. They look like a regular rolly polly except that they live in the tank and have two things like look like horns at their backs.

They even curl up when you pick them up (I picked one up by mistake when I was cleaning some bubble algae).

They seem to eat algae, and prefer the night, although I can see them during the day as well. They come in several colors and patterns (only white pictured here though).

What's the scoop with them? They don't seem to be amphipods, copepods or amphipods. So? Good guys I assume (I hope! as I have at least 100 of them).

Thanks,
Mihai

 

[John_Brandt]

Those look like isopods.

 

[Mihai]

And that would be... good? For some reason I thought that isopods are only parasitic on fishes. I need to brush up.
Thanks a lot,
Mihai

 

[John_Brandt]

Some of them are parasitic. I don't know if yours are, but they could be scavengers instead.

 

[Fishdude]

Hey Mihai,

Do yours have two big black eyes. I have some from Floriday liverock that look kinda like yours. Mine have big black eyes. I'm restarting my tank after a crash so no fish in there yet. My critters seemed to be digging in the sand. I sure hope they're not parasitic. Anyone have any info?

 

[Mihai]

Nope, they have very small eyes (if at all). I'm also afraid that they might be parasitic (no fish in here either).
I'm almost afraid to put the first fish in as I have a big population. If you want to hear scary stories about isopods look in Fenner's book about invertebrates.

Mihai