Fish Ventilation Most fish use gills for respiration in water
and researchers can observe how fast a fish’s gill cover beats to
study ventilation, much like we might observe breathing rate for a
person. Professor Brad Baldwin is interested in how water chemistry
might affect gill beat rates. In one experiment he randomly
assigned fish to tanks with different levels of calcium. One tank
was low in calcium (0.71 mg/L), the second tank had a medium amount
(5.24 mg/L), and...