In the hypothesis that C. stellatus (a species of barnacle) is competitively excluded from the lower intertidal zone by B. balanoides (another species of barnacle), what could be concluded about the two species? The fundamental and realized niches of B. balanoides and C. stellatus are both identical. The fundamental and realized niches of B. balanoides and C. stellatus are both different. The fundamental and realized niches of B. balanoides are different, but the fundamental and realized niches of C. stellatus are identical. The fundamental and realized niches of B. balanoides are identical, but the fundamental and realized niches of C. stellatus are different.

Competitive exclusion principle.

Explanation:

The fundamental and realized niches of B. balanoides are identical, but the fundamental and realized niches of C. stellatus are different.

All the possible combination of resources and condition under which a species can grow, survive and reproduce is called its fundamental niche. Whereas, the more limited set of resources and condition under which a species can grow, survive and reproduce in the presence of competitors and predators is termed as its realized niche.

Competitive exclusion principle states that if two competing species coexist in a stable, homogeneous environment, then they do so as a result of differentiation in their realized niche.

B. balanoides can use a wider range of resources than C. stellatus because its fundamental and realized niches are identical. Hence thrives to exclude C. stellatus.