Question

In the hypothesis that Chthamalus stellatus (a species of barnacle) is competitively excluded from the lower intertidal zone by Semibalanus balanoides (another species of barnacle), what could be concluded about the two species?

Answer 1

Competitive exclusion

Explanation:

Competitive exclusion principle states that if two species compete for same resources then they cannot coexist together that is why Chthamalus is excluded by zones from Semibalanus balanoides

Zonation of barnacles is influenced by competition

Chthamalus not only occupy the mid-shore but survive and grow better than in its normal high-shore zone

Chthamalus is more tolerant of physical stresses than Semibalanus, and can therefore survive in the high-shore, where it has a ‘spatial refuge’ beyond the limits of Semibalanus

In the mid-shore, however, Semibalanus thrives and competitively excludes Chthamalus by undercutting or overgrowing it