Hydrothermal vent mussels and shrimps Most animals depend on biomass and bioenergy produced by crops and phytoplanktons (collectively known as producers) via photosynthesis. Herbivores, as Key individuals, eat the plant content directly to digest and soak up the nutrients, while carnivores together with other animals on bigger trophic levels indirectly https://nature29639.ageeksblog.com/33582547/the-smart-trick-of-wildlife-that-no-one-is-discussing