Throughout the poem, the significance of the carp changes. In the first section, we learn about the 20 pound carp. This symbolizes luck, good fortune and hope. However, the carp turns into a negative symbol when we learn about Confucius's son. He was named "carp," but he died, representing bad luck.
The carp continues to be a negative symbol as the author tells us about how his father was betrayed. We see that those who loved the father but turned against him tasted the carp. Towards the end, the carp's meaning is one of negativity, representing pain and humiliation.