Which factors contribute to lower aquatic heart rates?

Lower aquatic heart rates are influenced by various physiological and environmental factors. The choice highlighting water temperature and reduced body mass is significant because both factors can impact an organism's metabolic rate and overall activity.

In aquatics, temperature plays a crucial role in affecting heart rates. Generally, as water temperature decreases, metabolic rates slow, leading to lower heart rates. This is particularly relevant for ectothermic animals, which cannot regulate their internal body temperatures. A cooler aquatic environment reduces the demands on the heart, often resulting in a slower heart rate.

Similarly, reduced body mass also contributes to lower heart rates due to the decreased demand for blood circulation. Smaller-bodied organisms often encounter lower metabolic demands, meaning their hearts do not need to pump as vigorously or as often as those of larger organisms. This relationship emphasizes the efficiency of metabolic processes in smaller bodies, leading to lower heart function requirements.

In contrast, other factors mentioned in the incorrect options, such as buoyancy, oxygen levels, gravity, body temperature, pressure, and resistance, do not have the same direct correlation with heart rate in aquatic environments. Buoyancy can influence how easily organisms move but doesn't necessarily lower heart rates. Gravity's impact is different underwater compared to terrestrial environments, and the interplay of pressure and resistance