There are 16 major families of freshwater fish in the United States. Knowing which family a fish is from will help you to identify it easier. It is important to already know the parts of a fish before reading this post, you can find this information here.

• Lepisosteidae: gar family
  • these fish have a long cylindrical body
  • they have long jaws and snouts with sharp teeth
  • notable species: spotted gar (Lepisosteus oculatus), longnose gar (Lepisosteus osseus), and alligator gar (Lepisosteus spatula)

• Clupeidae: herring family
  • thin silvery fish
  • have no lateral line
  • have a saw like pectoral fin
  • notable species: gizzard shad (Dorosoma cepedianum) and the threadfin shad (Dorosoma pentenense)

• Cyprinidae: carp and minnow family
  • mouthparts are not sucker-like
  • the largest family of freshwater fish
  • notable species: central stoneroller (Campostoma anomalum), red shiner (Cyprinella lutrensis), blacktail shiner (Cyprinella venusta), common carp (Cyprinus carpio), golden shiner (Notemigonus crysoleucas), bullhead minnow (Pimephales vigilax)

• Catostomidae: sucker family
  • sucker-like mouth and think lips
  • large body with smooth scales
  • notable species: river carpsucker (Carpiodes carpio), smallmouth buffalo (Ictiobus bubalus), and gray redhorse (Moxostoma congestum)

• Ictaluridae: North American Catfish Family
  • no scales
  • barbels present around the mouth
  • have an adipose fin
  • notable species: yellow bullhead (Ameiurus natalis), blue catfish (Ictalurus furcatus), channel catfish (Ictalurus punctatus), flathead catfish (Pylodictis olivaris)

• Esocidae: pike family
  • long and cylinder shaped body
  • duckbill-like mouth with long jaws
  • notable species: chain pickerel (Esox niger), redfin pickerel (Esox americanus)

• Aphredoderidae: pirate perch family
  • only has one species in the family: pirate perch (Aphredoderus sayanus)
  • dark olive colored with some speckles
  • anus under throat
  • largemouth

 

 

• Atherinopsidae: New World silverside family
  • thin fish with silvery bands on the sides
  • has flat snout
  • lower jaws extend before the upper jaw
  • notable species: brook silverside (Labidesthes sicculus), inland silverside (Menidia beryllina)

 

 

• Fundulidae: topminnow family
  • flat head and top the of back
  • mouth upturned
  • long body
  • no lateral line
  • notable species: blackstripe topminnow (Fundulus notatus)

 

 

• Poeciliidae: livebearer family
  • similar looking to the topminnows
  • notable species: western mosquitofish (Gambusia affinis), sailfin molly (Poecilia latipinna)

 

 

• Cyprinodontidae: pupfish family
  • very rounded body
  • mouth upturned
  • the head is flat but the back has an arch
  • no lateral line
  • notable species: sheepshead minnow (Cyprinodon variegatus)

 

 

• Moronidae: temperate bass family
  • has strips
  • opercle has well-developed spines
  • the dorsal fin is almost completely divided into two parts
  • notable species: white bass (Morone chrysops), yellow bass (Morone mississippiensis), striped bass (Morone saxatilis)

 

 

• Centrarchidae: sunfish family
  • the dorsal fin is united
  • the anal fin has between 3 to 8 spines
  • has thoracic pelvic fins
  • notable species: green sunfish (Lepomis cyanellus), bluegill (Lepomis macrochirus), longear sunfish (Lepomis megalotis), spotted bass (Micropterus punctulatus), largemouth bass (Micropterus salmoides), white crappie  (Pomoxis annularis)

 

 

• Percidae: perch family
  • dorsal fin completely divided
  • anal fin has 1 or 2 spines
  • notable species: orangethroat darter (Etheostoma spectabile), bigscale logperch (Percina macrolepida), dusky darter (Percina sciera)

 

 

• Sciaenidae: drum and croaker family
  • silvery fish
  • high back a
  • long dorsal fin
  • notable species: freshwater drum (Aplodinotus grunniens)

 

 

• Cichlidae: chilid family
  • lateral line broken under dorsal fin
  • one nostril on each side of the head
  • notable species: Rio Grande cichlid (Cichlasoma cyanoguttatum) blue tilapia (Oreochromis aurea)