Adverbs describe verbs, adjectives, or other adverbs, telling us how, when, where, or to what extent something happens.
To describe how a fish moves, you could use adverbs like:
* Swiftly: The fish swam swiftly through the water.
* Gracefully: The dolphin moved gracefully through the ocean.
* Rapidly: The salmon swam rapidly upstream.
You can also use adverbs to describe how a fish looks or acts:
* Silently: The fish moved silently through the tank.
* Curiously: The fish stared curiously at the new plant.
* Aggressively: The fish defended its territory aggressively.
So, instead of an adverb for "fish," you would use adverbs that describe the actions or characteristics of the fish itself.