The Nile catfish swims upside down, and therefore has developed a light back and a dark belly, the reverse of the usual fish color scheme.
英
美
- 尼罗河的鲇鱼在水中是反着身子游的,因此它们的背部是浅色的,而腹部却是深色的,和一般鱼的颜色布局相反。