My money is on the maroons clicking away.........
"Hi folks,
I've been trying to find out exactly how my Clarki clown makes that clicking sound. I've found plenty of web sites that affirm, "Yes, they make noises.", but none that explain how they do it. Special click organ? Grinding teeth? Biological proton acceleration? As you can see, I'm really scrounging for answers.
Happy Holidays,
Craig
<Hee hee! It's... their teeth grinding... using their gas bladder to add volume (as a resonator)... other fishes generate sound with articulated bony body parts (e.g. triggers), stretching muscles along their bladder (e.g. croakers)... Bob Fenner>