Which term describes organisms that thrive under high pressure?

The term that describes organisms that thrive under high pressure is "barophilic." These organisms are specifically adapted to live and reproduce in environments with elevated pressure levels, such as those found deep in the ocean or underground. Barophilic organisms have unique biochemical and structural adaptations that enable them to survive and function effectively in these extreme conditions.

Understanding the distinctions among the other terms can clarify why barophilic is the correct choice. "Mesophilic" refers to organisms that thrive at moderate temperatures, typically between 20°C and 45°C. "Thermophilic" pertains to organisms that prefer high temperatures, often above 45°C. "Halophilic" describes organisms that thrive in high-salinity environments, such as salt lakes or salt mines. Each of these terms pertains to specific environmental adaptations related to temperature or salinity rather than pressure, emphasizing why "barophilic" is the term that accurately captures organisms thriving under high pressure.