The blue shiner (''Cyprinella caerulea'') is a species of

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% ...

in the carp family. It is native to the southeastern United States, where it is

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 els ...

to the Cahaba and

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.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 27, 2011 ...

systems of the Mobile River Basin. This is a federally listed threatened species under the

Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...

of the United States.

Geographic distribution

''C. caerulea'' is endemic to the basin of the

Mobile River The Mobile River is located in southern Alabama in the United States. Formed out of the confluence of the Tombigbee and Alabama rivers, the approximately river drains an area of of Alabama, with a watershed extending into Mississippi, Georgia ...

. Because of population declines, it is now restricted to the Coosa River system in four disjunct populations in northeast Alabama, northwest Georgia, and southeast Tennessee.Stephens, C.M. and Mayden, R.L., ''Threatened Fishes of the World: Cyprinella caerulea Jordan, 1877 (Cyprinidae).'' Environmental Biology of Fishes 55(3) (1999): 264. Within the Coosa River system, the fish was native to Choccolocco Creek, the Little River, Weogufka Creek, and Big Wills Creek in Alabama; the Coosawattee River the Oostanaula River in Georgia, and the

Conasauga River The Conasauga River is a river that runs through southeast Tennessee and northwest Georgia. The Conasauga River is longU.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 27, 2011 an ...

in Georgia and Tennessee. The causes of the population declines are not fully clear, but they are likely due to the degradation of habitat and water degradation caused by

urbanization Urbanization (or urbanisation) refers to the population shift from rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. It is predominantly t ...

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

, and

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to t ...

.George, A.L., Caldieraro, J.B., Chartrand, K.M., Mayden, R.L., ''Population Genetics of the Blue Shiner, Cyprinella caerulea.'' Southeastern Naturalist 7(4) (2008): 637-638. The extirpation from the Cahaba River in Alabama could be due to extensive urban development. Efforts are currently being made to reverse the effects of habitat and water degradation. If they are successful, the blue shiner may be delisted.

Biology

The blue shiner is a temperate, freshwater fish that occupies benthopelagic zones in streams. It occurs in second to fourth order streams with a moderate to low river currents, favoring sand and gravel substrates, and sometimes cobble. It generally remains at depths of 0.15 to 1 meter. It requires clear waters for feeding, because it is a visual drift feeder, taking invertebrates from the drift of the water column. Excess sedimentation in the habitat has an adverse effect on the fish, hindering its ability to feed.Blue Shiner (''Cyprinella caerulea'') 5-Year Review: Summary and Evaluation.
United States Fish and Wildlife Service. 14 October 2014. The spawning behavior of this species is similar to that of '' C. trichroistia'' and ''C. gibbsi''. A single male will protect a territory and females arrive to deposit eggs.Johnston, C. E. and J. R. Shute., ''Spawning behavior of the blue shiner (Cyprinella caerulea) and the holiday darter (Etheostoma brevirostrum), two rare fishes of the

, Georgia and Tennessee.'' Proc. Southeast. Fish. Count. 35 (1997): l-2. During spawning, the female forcefully sprays eggs into crevices. It does not engage in parental care. Adequate water flows are required to remove debris and sediment, keeping open the crevices that the fish requires for egg deposition. Clear waters are also required for the females to visualize the males, which perform displays to attract them.Stewart, J.H. and Larson, R., ''Blue shiner (Cyprinella caerulea) Recovery Plan.'' U.S. Fish and Wildlife Service (1999): 7. The spawning season of the blue shiner starts in early May and ends in late August. It may produce more than one clutch per season. The life span of the fish is about three years, with two-year-old individuals producing the most spawn.

Conservation

With water degradation being one of the main reasons for decline, conservation activities are focused on improving water quality. Construction near waterways should be reduced, as should dam-building and water pollution. Currently, the largest population of C. caerulea is in the Conasauga River. This has become the focus of conservation efforts and research. Estimations of abundance are made by assessing individual subpopulations. Research activities include sampling using

electrofishing Electrofishing is a fishing technique that uses direct current electricity flowing between a submerged cathode and anode. This affects the movements of nearby fish so that they swim toward the anode, where they can be caught or stunned.

and netting.Nuckols, D.R., and Roghair, C.N., ''Presence of Altamaha shiner (Cyprinella xaenura) and Ocmulgee shiner (Cyprinella callisema) within several Chattahoochee-Oconee National Forest streams''. U.S. Forest Service Southern Research Station, Center for Aquatic Technology Transfer (2003): 3

References

{{Taxonbar, from=Q308108 Cyprinella Taxa named by David Starr Jordan Fish described in 1877 Taxonomy articles created by Polbot ESA threatened species