I believe the term for an observable trait of an organism would be called or noted as the organism's phenotype.
The warmer the water, the larger the water depths must be to form the hydrate. Deep inside he sea floor, however, the temperature is too high for the formation of methane hydrates because of the Earth's internal heat. Oxidation Many bacteria use methane to provide energy for their metabolism.
-worldoceanreview.com
Delta can also be an easy answer plus it is easy to remember
