1. Brachyurous crabs have a shorter tail compared to other crab species.
短尾类的蟹与其他螃蟹物种相比有较短的尾巴。

2. The brachyurous nature of these crabs allows them to move quickly in the water.
这些螃蟹短尾的特性使它们能够在水中快速移动。