dorsal valve

例句：

1. 1. The dorsal valve of the fish is used for breathing.
   鱼的腹板阀用于呼吸。
2. 2. The dorsal valve is important for the survival of the animal.
   腹板阀对于动物的生存至关重要。
3. 3. During the breeding season, the dorsal valves of the male fish are exposed to attract females.
   在繁殖季节，雄性鱼类的腹板阀暴露出来吸引雌性。