Minnow is a general term for freshwater and saltwater fish, especially those used as bait fish or for fishing bait. More specifically, it refers to small freshwater fish of the family Cyprinidae. They are also known in Ireland as .
Smaller fish in the subfamily Leuciscinae are considered to be "true" minnows.
Bluntnose minnow (Pimephales notatus): The bluntnose minnow is a primary bait fish for Northern America (more specifically Ohio) and has a very high tolerance for variable water qualities, which helps its distribution throughout many regions. The snout of the bluntnose minnow overhangs the mouth, giving it the bluntnose. There is a dark lateral line which stretches from the opercle to the base of the tail, where a large black spot is located. The average size of the adult is approximately 5 cm (2 in). 'Pimephales
Common shiner (Notropis cornutus): These fish are one of the most common type of bait fish and are almost exclusively stream dwellers. The common shiner can be identified by the nine rays on its anal fin and terminal mouth. This minnow is typically bluish silver on the sides and greenish blue on the back., save for breeding season in which case the male gains a rose colored tail and anal fin. The shiner grows about 5–10 cm (2–4 in) within one year and reach a size of 13 cm (5 in) at adulthood. Another common "shiner" bait fish is the young version of the European chub (Leuciscus cephalus or Squalius cephaloides) which is quite easy to catch. Notropis potteri is known as the chub shiner.
Common emerald shiner (Notropis atherinoides atherinoides): Common shiners are most abundant in the Great Lakes of North America, primarily Lake Erie. The name of the emerald shiner comes from the greenish emerald band that expands from the back of the gill cover to the tail. This type of minnow has a short, rounded snout, the only difference between the common emerald shiner and the silver shiner is that the silver shiner has a longer snout and a larger eye. These fish grow to an average length of about 6 cm. This is one of the most common bait fish used in the Lake Erie region of Ohio and many fisherman hold it over all other bait.