Elizabeth Bishop's poem "The Fish" seems at first the telling of a "big catch," but as the poem progresses the reader discerns that the speaker has a growing respect for this big fish that is "venerable."  The speaker says that she "admire[s] his sullen face" and the "mechanism of his jaw."  Upon closer inspection, the speaker of the poem notices five pieces of old fish line with hooks that have "grown firmly in his mouth.

These hooks and lines are

Like medals with their ribbons

frayed and wavering,

a five-haired beard of wisdom

trailing from his aching jaw.

At this point the speaker senses that "victory" fills up the boat as she recognizes the five times that the old fish has defeated other fishermen.  Like ribbons won for this victory, a rainbow caused from the mixing of oil in the bilge of the boat spreads its colors.  When the speaker says "everything was rainbow, rainbow, rainbow!" she feels that the old winner deserves to be let go.  Thus, the rainbow reminds the speaker of winning awards, and, in her release of the old fish, the rainbow comes to symbolize the renewal of life as it does in nature.

Critics Lloyd Scwartz and Sybil P. Estes write,

Bishop's poetry is pictorial not only in the sense of giving vivid description of natural phenomena, but also in it use of artificial object to relect on the self-referential aspect of art.  Nature is like art...nature speaks.

Nature, the old walleyed pike, and art, the creation of a rainbow in the bottom of the boat, speaks to the person holding the fish and he/she understands the venerableness of this fish; out of respect for its having defeated five others who have caught it, the fish is released.