And he found that he could differentiate individual piranha species by analyzing factors like pitch and harmonics and number of barks.

他发现，他能通过分析音高、和声以及咆哮次数等因素来区分个体水虎鱼的种类。

Differences in the numbers, sizes and shapes of bones, help us to differentiate one species from another.

骨骼的数量、大小和形状的差异有助于我们将一个物种与另一个物种区分开来。

He could differentiate the innumerable species of the herbivora by scent, and he could tell, too, whether an animal was approaching or departing merely by the waxing or waning strength of its effluvium.

他可以通过气味区分无数种类的食草动物，他也可以仅仅通过动物散发出的气味的强弱来判断动物是接近还是离开。