The Mesopelagic Zone

The mesopelogic zone is a dark place and cold in the deep ocean in that place there's a lot of rare fish,
the scientist the CTD, remotely operated vehicles, submarines, nets and sonar to study the mesopelagic deep ocean.
The particular fish that live in the mesopelagic are the anglerfish, dragon fish, latern fish, hatechet fish, lightfish, they have a large eyes, the bigger the eyes the better can see in the dark,