Is a fish a herbivore carnivore or decomposer?

Answer 1

Depends on what species. Some fish eat plant material, others eat other fish or sometimes insects, and possibly marine or terrestrial mammals. Some fish species may also eat and decompose decaying materials.

Answer 2

A fish can be herbivorous, carnivorous, or omnivorous depending on the species. Some fish primarily eat plants, some primarily eat other animals, and some eat a combination of both. There are no fish known to be decomposers as they do not play a significant role in breaking down dead organic matter.