The sentence that puffer fish will lay eggs with the river during the breeding season reminds me of the poem I learned.

The beach is covered with wormwood, asparagus is beginning to sprout, and puffer fish are preparing to swim upstream from the sea back to the river. It means that the beach has been covered with Artemisia selengensis and asparagus has begun to sprout, which is the season when puffer fish return from the sea and lay eggs in the river. In Night Scene of Hui Chong Riverside II, "Artemisia selengensis has short reed buds all over the ground, which is the time when the puffer fish wants to go up". From Su Shi, a poet in the Northern Song Dynasty.