There are many ways that the Albacore tuna have adapted to their environment. First off, Albacore tuna are continuous swimmers which means they are always swimming at rapid speeds, especially during migration periods. They are able to reach speeds up to 80 kilometers per hour. Since they must always be swimming, they must possess many characteristics to help them do this. They have long skinny bodies which allows for speed in the ocean. They have tiny, cycloid scales as well, which allow for smooth skin. They also possess streamlined fins. The streamlined fins allow for extremely quick movements for the Albacore tuna. One reason for their long shape is due to their long pectoral fin.
Also, they must get a good kick to start their movement and then be able to maintain their speeds. To be able to do this, they have developed strong tail fins that seem to be fork shaped. Albacore tuna must also adapt to the loss of many structures that help with the uptake of oxygen. Most fish have some type of structure or structures that are used to pump water over their gills in order to obtain oxygen. However, Albacore tuna have lost these structures and also do not possess a swim bladder. Because of this, the tuna must have adaptations to avoid death. Albacore tuna swim with their mouths open to help receive oxygen-rich water. This helps to make the water go against their gills so they can receive the oxygen. Another adaptation that they have is a higher blood pressure. With this, they also have high hemoglobin concentrations which help with the absorption of oxygen. Another adaptation that they have to help with the absorption of oxygen is an extremely well developed circulatory system. This system helps to increase muscular activity and also helps to reduce heat loss. They tend to have a higher body temperature than the temperature of the water, which aides in a high metabolic rate. Further adaptations that the Albacore tuna possess is their coloration. They are dark blue on top and have a white underside that helps them blend into the surrounding water which hides themselves from the ocean's predators.
The final adaptation that the Albacore tuna possess is a process known as countercurrent exchange. This process helps increase the amount of oxygen intake to help them survive. In this process, water flows in opposite channels from the blood that is found in the capillaries. Low oxygen blood will flow down the capillaries and meet up with the water at the end. The blood runs into water with higher concentrations of oxygen as it runs down the capillaries. Thus, a diffusion gradient occurs where oxygen will flow into the blood, giving the fish more oxygen. As seen in the following image, countercurrent flow is far more effective in diffusion of oxygen than concurrent flow is.
The adaptations that the Albacore tuna have evolved have helped them to be able to survive and continue to strive in their habitats today.
You can find many other interesting aspects of the Albacore tuna by visiting the interactions page.