Two barnacles, Balanus and Chthamalus, can both survive on the lower rocks just above the low-tide line on the Scottish coast, but only Balanus actually does so, with Chthamalus adopting a higher zone. Which of the following best accounts for this niche separation?
A)competitive exclusion
B)predation of Chthamalus by Balanus
C)cooperative displacement
D)primary succession
E)mutualism

Question

Quizplus · Accepted Answer

Competitive exclusion is the most likely reason for the niche separation between Balanus and Chthamalus. This means that Balanus outcompetes Chthamalus for resources in the lower rock zone, forcing Chthamalus to occupy a higher zone where it is better able to survive. The other options, such as predation or mutualism, are less likely to explain the observed niche separation.

Two Barnacles, Balanus and Chthamalus, Can Both Survive on the Lower