The Pop-eye Catalufa (Pristigenys serrula) is an interesting and unique fish. They have the red coloration common to many soldierfish and squirrelfish with black on the fins but this fish has a stout, compact body dominated by very large eyes and a big mouth.
Squirrelfish and Soldierfish are brightly colored, usually red with pearly white, silver, black or yellow accents – but unlike most other reef fish, their color is not used to get them noticed. These fish, belonging to separate subfamilies of the family Holocentridae, use their red color to help them disappear in the dark depths and caves where they live and hunt. These fish are nocturnal, meaning they are active mostly at night, and many live in deeper waters than the sunlight can penetrate. The all have very large eyes, too, which helps them to see prey in their dark environment.
Squirrelfish and Soldierfish spend most of their time during daylight hours hiding in rocks, caves, or other dim areas of the aquarium. They can be kept as individuals, but are more secure in groups, and should be kept that way if the tank is large enough. They will not bother corals, but will eat small fish, shrimp, and other invertebrates they come across. Feed them a variety of meaty foods and provide a space for them to hide, whether with live rock or ornaments with caves.