Commensalism refers to the ecological relationship between two species in the biological world. One species will obtain survival benefits due to this relationship, but the other species does not obtain any benefits or harm in this relationship, but only drives the other to obtain benefits.
According to the above definition, which of the following phenomena belongs to commensalism?
Algae grow in the crevices of sloths' coarse hairs. In the rainy season, algae flourish and form a green camouflage, making sloths easier to survive in the trees. Algae use sloths as derivative work.