Secondary consumers form the third trophic level in a food chain or food web. They eat primary consumers which in turn eat the producers. An organism can have a different consumer level according to its position in the given good chain.
In the given food web; rattle snake, kit fox, coyote and raven eat many things simultaneously. However all of them also eat desert woodrat. Desert woodrat is a primary consumer since it consumes producer plants like creosote bush and beavertail cactus. Rattle snake, kit fox, coyote and raven are secondary consumers since they eat the primary consumer (desert woodrat). Desert iguana is not a secondary consumer. It directly feeds on creosote bush so it is a primary consumer.
The interaction between the biosphere and hydrosphere is that the hydrosphere provides water for the biosphere to function, grow, and live. Animals (biosphere), fish (biosphere) need water (hydrosphere) to live and swim.
