An adaptation can be defined as a phenotypic trait that makes an organism and/or species better suited to its environment, thereby this organism/species will have more chances to survive and reproduce in such conditions. Rock-dwelling aquatic animals have different ecological, morphological and behavioral adaptations to survive in this type of environment. In this regard, it is well-known that these organisms show dorsally flattened bodies, since it is one fundamental morphological adaptation which helps them to dissipate the force of the waves.
When people have anemia, their body doesn't produce enough red blood cells. They don't get enough oxygen, which makes them feel fatigued and can also cause serious health complications.