Fish have a circulatory system with a two-chambered heart, and fish are backboned aquatic animals. Given these facts, the two-chambered heart of some backboned aquatic animals is part of their: among the following options:
- aerobic capacity
 - three-chambered heart
 - biological diversity
 - it keeps an organism warm
 - the body's largest organ
 - circulatory system
 - salmon
 - swimming system


 

      circulatory system   