Posted by Hermit on March 26, 2002 at 11:32:52:
I have an undulated trigger in a 150 w/ a niger. Both are about 3 inches long. I noticed a dark spot on the tail end of my undulate, right before his tail fin. This dark spot seems to come and go, and vary in darkness, almost like a mood ring (without color). It seems to me that when the fish is agitated, or hungry, etc, the dot gets darker. I have seen the spot on other undulates, and I know of the 'gravid spot' in fancy guppies (and some other fish). I was wondering, what is this spot? Does it have a significance as per my fish's age, sex, temperment, or maturity? I have also witnesses it 'playing dead', when it lays on it's side in a clearing somewhere and just sits there on his side. Is this normal behavior? My tank levels are legit...
