The video explores the myth that pouring soda on a bleeding fish can stop the bleeding by constricting blood vessels. A 2020 study tested this claim using different sodas and found no significant effect on bleeding duration or intensity. However, the study noted a temporary slowdown in bleeding due to bradycardia, a slow heart rate caused by CO2 in the drinks. This effect is linked to chemical receptors in the fish's gills. Despite this, the study concludes that soda does not benefit bleeding fish, and the reason for bradycardia remains unclear.

What is one hypothesis about why high carbon dioxide levels might lead to bradycardia in fish?

What conclusion can be drawn about the effectiveness of pouring carbonated drinks on bleeding fish?