Question

Connell performed a series of studies to understand what limits the distribution of barnacle species within an intertidal zone. The species were Balanus, adults of which are found along most of the intertidal zone except for the upper intertidal zone, and Chthamalus, adults of which are found above, but not below, the intertidal zone (see Figure). Which piece(s) of evidence enabled him to conclude that the location of Chthamalus adults represented its realized niche?

A. Balanus suffered from greater mortality than Chthamalus during a warm year with low tides that left them exposed to desiccation.

B. Chthamalus larvae occurred across a wider range in the tidal zone than the adults.

C. Chthamalus had low mortality during a warm year with low tides despite being exposed to desiccation.

D. Chthamalus was able to survive in lower tidal zones, but only when Balanus was removed.

Answer 1