Possibly some of the ugliest fish in sea, the Scorpaenidae are masters of camouflage. Here’s some video.
I shot this very short piece in October in the southern Red Sea. It features two devil scorpionfish (Scorpaenopsis diabolus). As you can see, they blend into their surroundings very easily. I’ve never seen two together though, could they be getting better acquainted?
Scorpionfish are related to lionfish and stonefish and share one of the characteristic traits of the family: they are not strong swimmers and when spooked will barely swim more than a meter or two before settling again. Lionfish have developed elaborate defensive capabilities in the shape of venomous spines, and the even more sedate scorpionfish have evolved themselves to near invisibility, which they demonstrate above.
Both types of fish rely on large mouths which when opened create a lot of inward water movement, helping them to engulf slow moving prey, which in the case of scorpionfish will be crustaceans and unwary fish.