What does fish eat that are producers?

Fish that are herbivores (plant-eaters) eat producers. Producers are organisms like:

* Algae: This is the most common food source for many fish, especially in freshwater and saltwater environments.

* Aquatic plants: Some fish eat the leaves, stems, and roots of plants like water lilies, pondweeds, and cattails.

* Phytoplankton: These are microscopic algae that drift in the water column, providing a vital food source for many fish.

It's important to note that some fish are omnivores, meaning they eat both plants and animals. However, they still rely on producers as a significant part of their diet.