Who is it? Pests or not?

[m.petrov]

In the aquarium of my friend there were such "beetles"! Who is it? Pests or not?

 

[cloak]

Isopod of some sort.

http://reefkeeping.com/issues/2002-05/rs/index.htm

 

[m.petrov]

Isopod of some sort.

http://reefkeeping.com/issues/2002-05/rs/index.htm

Thank you!

 

[reef lover]

Yup and look to be the harmless kind.