Question

For what resource might sessile animals compete?

Answer 1

If you look at different sessile aniimals, you'll notice that they are generally filter feeders- they suck in nutrients from their surroundings. Those that are larger and can "pull in" more nutrients than others. Holometabolus insects do it because the larvae can eat and inhabit a different place than the adults so there is no competition for resources, like food. Lepidopterans are a good example, caterpillars eat leaves and plants while the adults pollinate flowers and drink nectar.

Answer 2

Answer:

Sessile animals compete for food, shelter (accommodation) and energy resources.

Explanation:

Sessile animals are stagnant animals (unable to loco mote) that fix to a place, object or other living species and take their nourishment form the surrounding or from the base to which they are attached.  

Competition arises when resources are limited. In such scenarios, a sessile animal compete for space, food, energy resources such as light etc. In case of sessile animals living in water, the major competition is for space and food only.