There is this treasure box that gives you treasures. Look out for it in your friend's tanks. There is only 1 per friend. It gives you stuff like cash, XP (experience), coins or even fish.
It will look like a Treasure box, with the words "Click Me!"
This is what it looks like after you open it up!
It will have a sign. It is not like the box that is on the left. That is the normal box.
Hunt your treasure, look out!