Answer:
Connell conducted this experiment to learn more about the competitive exclusion and distribution of barnacle species
Step-by-step explanation:
The competitive exclusion principle establishes that two or more species that share the same niche requirements, in the same habitat, and are in biological competition for the same resources, won´t be able to coexist indefinitely in the same space if the other ecological factors are constant. This is because species with identical niches have the same necessities, which means that they will compete for the same resources. If these species have the same requirements, they can not coexist. When the superior competitor occupies the inferior competitor´s fundamental niche, the first species has advantages over the second species and monopolizes all the resources. From that moment, the inferior species is displaced and must adapt to use other resources changing its behavior, or must migrate to another area where it can get access to its needs or get extinct.
Connell saw that Chthalamus live in the upper intertidal zone, where Balanus can not live because they can not tolerate desiccation. Balanus live in the lower intertidal zone, where Chthalamus can not live because of its vulnerability to predation. But these two species compete for the middle intertidal zone, where they can both live.
The example of Balanus and Chthalamus is a case of competitive exclusion, which refers to the exclusion of the inferior competitor -Chthalamus- by the superior competitor -Balanus- when there is not habitat differentiation, and both species can not share the same niche. In this case, the dominant species occupies part of the fundamental niche of the inferior competitor -medium to low tides-. Balanus excludes Chthalamus because the first species is much bigger and grows faster than the second one. So the middle intertidal zone is only inhabited by Balanus. The area occupied by Chthalamus is smaller in the presence of Balanus. In the absence of Balanus, Chthalamus can live in a broader area occupying the middle intertidal zone.
The fundamental niche is considered all the physical conditions in which a species can live, reproduce, and survive, as long as there is no interaction with other species. The Chthalamus´fundamental niches include the upper intertidal zones, the middle, and the lower intertidal zone.
The realized niche refers to the restricted conditions in which a species can live and survive regarding environmental physic characteristics and the interaction with other species. Chthalamus ´ realized niche is the shallow waters. It can not live in the middle intertidal zone because it competes with Balanus, and this last species is the dominant one and occupies that area. Chthalamus can neither live in deep water because of the predation pressures acting on them.