The Dragon Fish comes in a few different species but is the original form of the Dragon Phenomenon.
To the world, a fish seems helpless, lost, and thoughtless. This is how those possessive of Wisdom should go throughout the world. This prevents the Ego and unnecessary attachments from arising.
The wise should swim deep into the Unconditioned State. By becoming one with Dao, the wise man become docile like a fish. Only to emerge from the depths of Dao as a Dragon when necessary.
Happiness is far from the man who thinks he knows everything.
Therefore, the Dragon Fish is used to act as a reminder to the user, of this docile-like phenomenon.