Percopsidae is a family of fish in the order

Percopsiformes The Percopsiformes are a small order of ray-finned fishes, comprising the trout-perch and its allies. It contains just ten extant species, grouped into seven genera and three families. Five of these genera are monotypic In biology, a mono ...

, with one extant

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

with two species, both

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to North America, and two known fossil genera. They are small fish with weak fin spines, and an

adipose fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

similar to those of

trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', '' Salmo'' and '' Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salm ...

. They feed on insects and small

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

References

Trout-perch article by Robert G. BramblettSpecies summary ''Percopsis transmontana'' sand roller
Percopsiformes Fish of North America Ray-finned fish families {{Percopsiformes-stub