Answer:
Viperfish hunt by attracting prey to their glowing bellies. This adaptation is most useful for the open-ocean ecosystem.
Step-by-step explanation:
In the open ocean ecosystem, not much diversity of organisms is present. In order to survive in the open ocean, an organism must have certain adaptations which will allow it to get the basic resources needed for survival. If adaptations are not provided, organisms will nor be able to survive in the open ocean ecosystem.
The adaptation of glowing bellies in the viperfish allows it to attract its preys due to which it is able to get food and survive in the open ocean ecosystem.