I don't know how old the 2 were that I saw at the fish store but they looked exactly the same as the one in the picture I posted, white with brown highlights. They were both approx. 4 inches from end to end and about 2 inches wide. Both seemed to get around just fine in the 75 gallon(I believe) reef tank. They are very cool, kinda remind you of a submarine or something because they just kinda hang there and use their little "nozzle" to either pull water in or squirt it out causing motion.

Hope this helps.

Chris Riffey(forgot this last time :-)