This Fish’s Eyes Turn Black When It Gets Mad Guppies have silver eyes, but when they’re ready for a fight, their irises go dark. An experiment with robots shows why.

This Marine Biologist Explained Why Deep Sea Fish Tend To Be Darker, So Y'all Can Shut Up About "The Little Mermaid" Being Black Now BuzzFeed Tue, September 13, 2022 at 8:34 PM UTC ...

The Invisible Man isn’t the only expert in making himself imperceptible with optics science. Species of ultra-black fish also have that tactic down pat, according to a study published Thursday ...

The discovery was made 100 miles northwest of Tallahassee by the state’s Fish and Wildlife Research Institute, and photos show the eel-like fish had black eyes and black teeth.