Benthopelagic is a term used to describe aquatic organisms that live in the deep waters of the ocean. This term is derived from two words: benthic, which means bottom-dwelling, and pelagic, which means living in the open ocean. There are several synonyms for benthopelagic, including abyssal, bathypelagic, and mesopelagic. Abyssal refers to organisms living in the deepest parts of the ocean, while bathypelagic refers to those living in the mid-level depths. Mesopelagic refers to creatures that live in the lower zone of the open ocean and are often referred to as the twilight zone. These synonyms help to describe the diverse range of aquatic organisms living in the deep waters of the ocean.