For Jung, fish were symbols of some content from the unconscious, emotions, or life energy that is been stirring around in the unconscious from the beginning of our life. Therefore, fishing represents the search for, or process of becoming aware of, material from the unconscious. In this way fish can also symbolize the Self, or the inner Christ.
If the above does not seem to fit, consider a situation in which you or another have been acting like a cold fish or big fish in a little pond. You or another may have been fishing for compliments or other information; or behaving like a fish out of water. Is there something fishy about some situation; or is someone more of a queer fish than you have realized?

Perhaps it is time to get a little rest and hang up a gone fishing sign in your window. If you are fishing, it can symbolize a wish to relieve present stress; a need to get away and ponder some situation; delving into the waters of the unconscious for insight and wisdom. Eating fish would be incorporating new realizations or spiritual feelings or knowledge. If you are in the water, being eaten or swallowed by a large fish, this is the archetypal theme of night sea journey.

Fish may suggest you need to look to earlier situations for guidance in a present situation. Twin or double fishes can represent the astrological sign for Pisces, possibly someone born under that sign. Tiny fish in a bowl or container may represent sperm, a wish for sex or pregnancy. In many cultures, fish represent fertility and the preservation of life.