What freshwater animal eats green river grass?

There isn't a specific freshwater animal that is known to eat "green river grass" as a primary food source. Here's why:

* "Green river grass" isn't a specific plant: There is no widely recognized plant called "green river grass."

* Freshwater animals have different diets: Freshwater animals have varied diets depending on their species. Some are omnivores (eat plants and animals), some are herbivores (eat plants only), and some are carnivores (eat meat only).

* Grasses are typically terrestrial: Most grasses are land-based plants. While some aquatic plants might resemble grasses, they have different nutritional profiles.

Possible candidates:

* Herbivorous fish: Some fish species like grass carp are known to eat aquatic plants, but they're more likely to consume algae and submerged vegetation rather than land-based grasses.

* Aquatic invertebrates: Some invertebrates like snails and water beetles might nibble on submerged grasses, but they are not specialized for consuming grasses.

To identify an animal that might eat a specific plant, you need to know the plant's scientific name and location. You can then research the local fauna and see if any species have dietary habits that include that plant.