The Red Shiner is a species of ray-finned fish in the Cyprinidae family. They are deep-bodied and laterally compressed and can grow to about three inches in length. For most of the year both males and females have silver sides and whitish abdomens. Males in breeding coloration, on the other hand, have iridescent pink-purple-blue sides and a red crown and fins (except the dorsal fin which remains dark).

Biology

Red shiners can live up to three years. They are omnivorous since they eat both aquatic and terrestrial invertebrates as well as algae. Red shiners have also been known to eat the eggs and larvae of native fish found in locations into which the red shiner has been introduced.

Reproduction

The spawning season for red shiners is generally from mid-April through September. As well as spawning in crevices like other members of the genus Cyprinella

Cyprinella

Cyprinella is the genus of satinfin shiners, ray-finned fish in the Cyprinidae family.It contains the following species:*Cyprinella alvarezdelvillari Contreras-Balderas & Lozano-Vilano, 1994...

, red shiners both broadcast their eggs and attach them to rocks and vegetation. Females can release up to 16 batches per day with up to 71 eggs per batch. The average clutch size, however, is 585 eggs and they may have anywhere from 5 to 19 clutches in one reproductive season. Red shiners are capable of generating viable hybrid offspring with closely related species such as the blue shiner

Blue Shiner

The Blue Shiner is a rare species of ray-finned fish in the family Cyprinidae.It is native to Alabama, Georgia, and Tennessee in the United States. It is a federally listed threatened species of the United States....

 and the blacktailed shiner.

Habitat

Red shiners are found naturally in a variety of aquatic habitats, including backwaters

Backwater (river)

A backwater is a part of a river in which there is little or no current. It refers either to a branch of a main river which lies alongside it and then rejoins it or to a body of water in a main river which is backed up by an obstruction such as the tide or a dam.-Alternative channel:If a river has...

, creek mouths, streams containing sand and silt substrates, riffle

Riffle

A Riffle is a short, relatively shallow and coarse-bedded length of stream over which the stream flows at higher velocity and higher turbulence than it normally does in comparison to a pool....

s, and pools. They are tolerant of areas of frequent high turbidity and siltation, but they tend to avoid waters with high acidity. Red shiner are habitat generalists in that they are adapted to favor a wide range of environmental conditions that most other fish species cannot tolerate. These include habitats that are degraded due to human disturbance, and those with poor water quality (such as polluted waterways), natural physiochemical extremes, and seasonally intermittent flows.

Range

The red shiner is naturally found in the Mississippi River basin from southern Wisconsin and eastern Indiana to South Dakota and Wyoming and south to Louisiana. It is also found as an introduced species in Arizona, Alabama, California, Colorado, Illinois, Georgia, Nebraska, the Carolinas, Wyoming, Massachusetts, Utah, Virginia, Nevada, and New Mexico.

Invasiveness

The red shiner is a common bait fish, and it is believed that the emptying of bait buckets containing them is the main cause of introduction of this species into new areas. It is also commonly used as an aquarium fish. It has become a species of special concern in the United States as it has been implicated in the decline of native fish populations in the areas into which it has been introduced. As previously mentioned, red shiners have been known to eat the eggs of native fish and in doing so hinder the growth of those populations. They are also adapted to thrive in a variety of environments, and as generalists, may be better able to persist in disturbed habitats than native species of those areas. Red shiners are capable of hybridizing with the blacktail shiner (Cyprinella venusta stigmatura), a native species found in the Coosa River

Coosa River

The Coosa River is a tributary of the Alabama River in the U.S. states of Alabama and Georgia. The river is about long altogether.The Coosa River is one of Alabama's most developed rivers...

, which serves to dilute the gene pool of this species.