banggai cardinal vibrating

I have two banggai cardinals (pterapogon kauderni) and today the larger of the two has been doing something I can best describe as vibrating. It seems like it's mostly his fins and tail that is easiest to see when it happens. He does it for about 2 seconds at a time, sometimes a few times in a row and sometimes just once or twice. The temperature is about 80F and water conditions good. The fish seems normal besides the vibrating, he doesn't seem sick or anything otherwise and he's eating normally. I've had him for a long time and never seen him do anything like this. What's going on??

 

i think the female shakes at the male before breeding. not sure but you could look up spawning behavior for the fish on google.

 

you are right! I started thinking the same thing and discovered that it's pretty normal. Last night we discovered that the male was holding eggs in his mouth! Today though I thought I saw him eat at feeding time, which normally he shouldn't if he still has the eggs. So I'm not sure but I think he may have eaten the eggs already...but I'm hoping I'm wrong!