Samhain
Satin, Lace, and Sequins
As you may or may not know, I have a purple hairy pincushion urchin cruising around my tank. It likes to pick up my snails, frags, and anything else it can find and wear them as hats. My question is, how aware are these guys of their environment? I know they don't have eyes, nor do they have anything I can really equate to a nose or ears, but my urchin always rushes (as much as a urchin rushes anywhere) to check out something new in the tank. Right now he's sitting on top of my new Midas blenny's chosen hideout (no worries, there are multiple exits, so he isn't trapped). The urchin also always seems to know when I tie algae sheets to a rock, and he rushes over to be the first in line at the buffet, so to speak. It doesn't matter where I tie the algae. The urchin just cruises on over to it. And if I remove a frag hat and replace it where it was, he just goes right back over and picks it back up. Usually I have to place the frag somewhere else in the tank until he's away from its original home; then I put it back where it's supposed to be.
Is all that normal, and if so, how do these guys figure out what's going on?
Is all that normal, and if so, how do these guys figure out what's going on?