What is the role of the lamellae in fish gills?

The lamellae in fish gills play a crucial role in enhancing gas exchange, which is essential for the fish's respiration process. Lamellae are thin, flat structures that extend from the gill filaments and are richly supplied with blood vessels. Their large surface area increases the overall area available for oxygen absorption and carbon dioxide release. When water flows over the gill membranes, the oxygen dissolved in the water diffuses into the blood within the lamellae, while carbon dioxide diffuses out of the blood to be expelled into the surrounding water. This efficient design maximizes the rate of gas exchange, ensuring that fish can effectively extract the oxygen they need to survive while eliminating carbon dioxide efficiently.