Problem: From a proximate perspective, this behavior can be attributed to the Betta fish's need for oxygen. Bettas are labyrinth fish equipped with a specialized organ known as the labyrinth organ, which allows them to breathe atmospheric air. When a Betta swims to the surface and opens its mouth, it is likely trying to gulp air. From an ultimate perspective, this behavior relates to evolutionary adaptations that increase the fish's chances of survival. By developing the ability to breathe air, Betta fish can inhabit various environments, including shallow waters that may not contain enough dissolved oxygen for other fish species. This adaptation allows them to exploit ecological niches where food resources may be available. Need Assignment Help?