The Challenger's Deep bestiary has nine fish, each with unique icy patterns. They’re totally different from the ones found in Mariana’s Veil’s first layer, ...

There are a total of 10 fish that you must catch to 100% complete the Challenger's Deep Bestiary. Once you get the Heat upgrade for your submarine, use it to reach deeper areas.

More than 80% of the Earth’s ocean has yet to be mapped. This is due, in part, to the challenges associated with deep-sea exploration, including intense pressure, zero visibility and extremely ...

The Challenger Deep, which is named after the British Royal Navy survey vessel HMS Challenger, ... deep-sea fish, and microorganisms that can live in lightless environments and high pressure.

In addition to the nine fish that are included in the Challenger's Deep bestiary, you can also catch the secret Frozen Leviathan there, which is very difficult to obtain.