Phytoplankton are typically eaten by zooplankton - tiny marine animals - which themselves are prey for small fish and other animals.

浮游动物（微小的海洋生物）通常吃浮游植物，而其本身又是小鱼和其它动物的捕食对象。

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Phytoplankton are the microscopic plant life that zooplankton and other Marine animals eat, essentially the grain crop of the world's oceans.

浮游植物是浮游动物和其它海洋动物的食物，可以说是海洋的庄稼。

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The other source is the native lagoon species, such as periodical outbreak zooplankton (e. g. larvae of macrura, brachyura and anomura) and some endemic planktonic species;

另一部分是周期性爆发的浮游动物（如长尾类、歪尾类的幼体）和一些潟湖本地种类。

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But the analysis by Kruta and her colleagues indicates their ammonites would have dined on small organisms floating in the water, such as zooplankton, tiny crustaceans, and even other petite ammonites.

BBC: Ammonite diet revealed in X-rays