Giant Isopods at Blackpool SeaLife Centre 09

Bathynomus giganteus.

These seem to be becoming more common in aquariums - good thing too, as they make a cracking exhibit.

How big are they?

I am appallingly bad at estimating size and I was viewing through curved glass but the largest one would have been about 20cm/8in in length.

Possibly a touch larger. Big, anyway!

I went today but unfortunately couldn't get a good look at them. One small specimen was right up by the glass and a larger one had its head in a cave and only the tail and part of the back was visible. I would say it was well over 8 inches long. They must have grown a lot.