Answer:
Sessile animals compete for food, shelter (accommodation) and energy resources.
Step-by-step 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.