Since there are two HUGE bubbles beneath their eyes,
the head of Bubble-eyes Goldfish is extremely heavy.
Thus, you will see them moving thier tail so hard to move front.
In this case, thier two HUGE bubbles will keep vibrating.
To some people, it's a very cute movement.
To me, I am always afraid of that the bubbles will be broken...
But actually they sometimes BREAK!
(This kind of goldfish is strongly recommanded to keep separately.)
Surprisingly, those bubbles will grow back in a few weeks.
