Fish have good internal clocks

[happyhourhero]

Has anyone else observed their fish seemingly being able to tell time?

My sixline wrasse sleeps in its mucous cocoon each night and like clockwork will head into its sleeping hole about 2 minutes before my lights turn off. My lights cut off around 920pm and I usually stare at my tank while my wife rocks our baby to bed in the other room. The 6 line is never, ever out swimming when the lights turn off and it always retreats just before, careful not to waste a minute of time where it can bow up at its reflection.

 

[saltyhog]

I believe it.

I usually feed at about the same time and in the same part of the tank every day. They will start congregating abut 10 minutes before time.

Recently I changed ends of the tank.....it took them a whole 2 days to start congregating at the other end of the tank.

 

[revhtree Verified Admin]

Yes agreed!