Lobefin fish are vertebrates that have bones rather than cartilage. They have lobe-shaped fins, hence their name. They contribute nutrients to their ecosystems. They're typically predatory fish that consume microorganisms, plants, and smaller marine animals. They take in nutrients then excrete them, recycling these nutrients into the ocean floor, providing a fertilizer for sea grass and algae to grow. Some examples of lobefin fish are the lungfish and the coelacanth.