endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Red River drainage (Hudson Bay basin) and Mississippi River basin from central Minnesota to the Gulf, and from southwestern Pennsylvania west to eastern South Dakota, Nebraska, Kansas, Oklahoma, and Texas; Gulf Slope drainages from the Ochlockonee River, Florida, to San Antonio Bay, Texas (Page and Burr 2011). In the late 1980s and early 1990s, a few specimens were caught by commercial fishermen in Lake Michigan (Fago 1993). Extirpated from most of upper Mississippi system; common in much of the remainder of the range.
Length: 46 cm
Habitat Type: Freshwater
Comments: Habitat includes clear to moderately turbid medium to large rivers and large reservoirs; usually in current over sand and gravel; occasionally occurs in coastal brackish or marine waters (Robins and Ray 1986, Page and Burr 2011).
Spawning occurs probably in deep water of main channels over bars of coarse sand or gravel (Lee et al. 1980).
Depth range (m): 1 - 1
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Migrates upstream for spawning.
Comments: Eats zooplankton, small insect larvae, and small fishes.
Based on studies in:
USA: Maryland, Chesapeake Bay (Estuarine)
This list may not be complete but is based on published studies.
Known prey organisms
Other suspension feeders
Based on studies in:
USA: Maryland, Chesapeake Bay (Estuarine)
This list may not be complete but is based on published studies.
100,000 to >1,000,000 individuals
Comments: Total adult population size is unknown but certainly exceeds 100,000.
A schooling species.
Life History and Behavior
Spawns from early March to late April in Florida, early May to early July in upper Mississippi drainage.
Molecular Biology and Genetics
Statistics of barcoding coverage: Alosa chrysochloris
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Large range and population size in central North America; has declined in abundance in upper Mississippi River basin as a result of dams; no major threats in most of range.
Global Short Term Trend: Unknown
Global Long Term Trend: Relatively stable to decline of 30%
Comments: Abundance in the lower Missouri River has increased as a result of human-caused changes in the river (e.g., reservoir construction) (Cross, Copeia 1975:382-385; Pflieger and Grace 1987).
Comments: Extirpated from most of upper Mississippi system, apparently due to presence of dams (but see trend comments).
Relevance to Humans and Ecosystems
The skipjack shad (Alosa chrysochloris) is a North American, migratory, fresh- and brackiswater fish species in the herring family Clupeidae. The name skipjack shad comes from the fact that it is commonly seen leaping out of the water while feeding. Other common names include blue herring, golden shad, river shad, Tennessee tarpon, and McKinley shad. The skipjack shad is restricted to the Gulf of Mexico drainage basins. Skipjack shad are found in clear to moderately turbid water in areas with flow. Because they are a migratory species, dams often impede their reproduction. Records suggest that this species was much more abundant in the Upper Mississippi River basin before it was impounded. Currently, the skipjack shad is most abundant in the Upper Mississippi River below the mouth of the Ohio River. They are known as an “early-run” species as they migrate to spawn in the early spring.
The skipjack shad is restricted to the Gulf of Mexico and its drainage, in the United States. The Gulf of Mexico drainage includes the ACF (Apalachicola/Chattahoochee/Flint River) basin, the Mississippi basin, and the Rio Grande basin. Records indicate that this species was more abundant in the upper Mississippi River before it was impounded, and currently skipjack shad are most abundant in the upper Mississippi River below the mouth of the Ohio River. In recent years, human modifications to the middle Missouri River have made conditions more favorable for skipjack shad and their distribution has expanded upstream to the Nebraska-South Dakota border. Skipjack shad were historically found in the northern upper Mississippi River and the St. Croix River; however, there have only been four records of skipjack shad in Wisconsin waters since the 1950s. Because this fish is a migratory species, dams have diminished its distribution. It cannot continue to migrate northward over dams; therefore it is rare to see a skipjack shad in the upper reaches of the Gulf of Mexico drainages.
Skipjack shad are a migratory schooling species. They are a euryhaline species that can enter brackish and freshwater bodies. They can be anadromous but are not obligated to be because they can complete their life cycle in freshwater. Skipjack shad are strongly migratory within rivers and prefer fast flowing water where they are renowned for leaping. They are found in clear to moderately turbid waters in large rivers and reservoirs usually within the current over sand or gravel. In one study, skipjack shad have been found to feed on other shad/herring species such as the threadfin shad, the gizzard shad and young of the year herring species. In some extreme cases, it was shown that they could rely on cannibalism to survive. They are also known to feed on small fishes, mostly shad, while the juveniles feed on insects. The maximum size of the shad/herring utilized by skipjack shad was found to be about 30-35% of the skipjack’s body length. There is not much data on the predators of the skipjack shad. Larger fish species, seabirds, and humans prey upon them. In fact, it is shown that fish species in the family Clupeidae including the skipjack shad comprise up to 45% of the diet of these avian species.
The spawning season for skipjack shad is from early March to late April in the southern extent of its range. In the upper Mississippi river drainage spawning time is from early May to early July. Females produce about 100,000 to 300,000 eggs per year, presumably after 2 to 3 years of growth with an average size being 11.8 inches (30 cm) Spawning is thought to occur in the depths of main channel over coarse sand-gravel bars. Spawning temperature range is between 16 and 21 °C (61 and 70 °F). Eggs are broadcast over the substrate. Skipjack shad young may reach total lengths of 75–150 millimetres (3.0–5.9 in) during their first year. The maximum length in adults is 20 inches, but they are most commonly found to be between 12 and 18 inches (300–460 mm). The oldest specimen of skipjack shad reported was four years old. High population rates and the fact that there it has little to no interest to fisheries tells us that humans do not have much influence on life history. Impoundments have changed their distribution slightly, but they have no trouble spawning as a result.
Human impacts on skipjack shad populations seem to be minimal in the southern parts of their distribution. Dams have limited the natural distribution of the species. Skipjacks are no longer found in high numbers in the northern reaches of their distribution because of their inability to migrate over large impoundments. The Minnesota Department of Natural Resources (DNR) webpage tells us that "Further research into the species' life history and ecological requirements is needed. It is known that lock and dam structures hinder migration of skipjack shads during the early spring. If the skipjack shad is to be reestablished in Minnesota and Wisconsin, where they are nearly extirpated, fish passage features such as ladders or lifts will be required on Mississippi River lock and dams." In Minnesota, the construction of a fish passage facility is being considered at U.S. Lock and Dam 3 near Red Wing and could help skipjack shad migration in the Mississippi River drainage. The Minnesota DNR Division of Ecological Services received a State Wildlife Grant to conduct surveys for rare fish species in the Mississippi River from the Twin Cities to the Iowa border. These surveys were conducted from 2006-2008, and while the skipjack shad was a targeted species, none were found. In addition to the extirpation of the skipjack shad from Minnesota and Wisconsin, the ebony shell (Fusconaia ebena) and elephant ear (Elliptio crassidens), both state endangered mussels for which the skipjack is the sole host during their larval stages, are threatened to be extirpated as well.
In order to keep their distribution from shrinking further, humans need to decrease the number of dams that are constructed, or construct dams that skipjack shads are able to migrate through. In addition to hindering their migration, dams reduce flow. Skipjacks prefer areas with fast flowing water. In addition, it is necessary to keep turbidity and siltation levels down, as this species will only live in waters that are clear to moderately turbid. Sampling of skipjack shad has been performed through the use of gillnetting and electro fishing. These methods are best utilized beneath impoundments over sand or gravel substrates around spawning time each spring, where they are most abundant. Sampling should be done across the entire native range to document its abundance in different locations and human induced changes. For now, skipjack shad have a stable abundance in the southern part of its distribution, and need more management plans put into place in the northernmost reaches of its distribution.
While the skipjack shad has been attributed to the subgenus Potomolobius of the genus Alosa along with other North American shad species, it has been found to be phylogenetically the most basal of the Alosa species, which are also found in Europe and Western Asia.
- Faria, R.; Weiss, S. & Alexandrino, P. (2006): A molecular phylogenetic perspective on the evolutionary history of Alosa spp. (Clupeidae). Molecular Phylogenetics and Evolution 40(1): 298–304.doi:10.1016/j.ympev.2006.02.008.
- Whitehead, P.J.P. 1985 FAO Species Catalogue. Vol. 7. Clupeoid fishes of the world (suborder Clupeioidei). An annotated and illustrated catalogue of the herrings sardines, pilchards, sprats, shads, anchovies and wolf-herrings. Part 1-Chirocentridae, Clupeidae and Pristigasteridae. FAO Fish. Synop. 125(7/1):1-303. http://books.google.com/books?id=yRHGc1kL9QEC&pg=PR3&lpg=PR3
- Neebling, Travis E., and Quist, Michael C. (2008): on the Distribution and Status of Western Sand Darter, Spotted Gar, and Skipjack Herring in Iowa Rivers. Journal of the Iowa Academy of Science. 115(1-4):24-27 http://web.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=13832a69-a983-4fb8-9e6a-e53905ec4654%40sessionmgr4&vid=8&hid=12
- Bowen, BR (2008):Phylogenetic Relationships Among North American Alosa species (Clupeidae) Journal of Fish Biology 72:1188-1201 http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.2007.01785.x/full
- Etnier, D. A. and W. C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press, Knoxville, 681 pp.
- Page, Lawrence M., and Brooks M. Burr. 1991. A Field Guide to Freshwater Fishes of North America, north of Mexico. Houghton Mifflin Company, Boston.
- McLean, R. B., J. S. Griffith, and M. V. McGee (2006) Threadfin shad, Dorosoma petenense Günther, mortality: causes and ecological implications in a South-eastern United States reservoir. Journal of Fish Biology. 27(1):1-12 http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.1985.tb04004.x/pdf
- Tibbs, J., and Galat, D. (1998) The influence of river stage on endangered least terns and their fish prey in the Mississippi River. Regulated Rivers and Research Management. 14(3): pp. 257–266 http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291099-1646%28199805/06%2914:3%3C257::AID-RRR500%3E3.0.CO;2-9/pdf
- Wolfe, J. C. 1969. Biological studies of the skipjack herring, Alosa chrysochloris, in the Apalachicola River, Florida. M.S. Thesis. Florida State University, Tallahassee. pp. 68
- Coker, R. E. 1930. Studies of common fishes of the Mississippi River at Keokuk. Bull. U. S. Bureau Fish, 45:141-225.
- Galat, David L., and Clark, Sandra J., 2002, Fish spawning and discharge-temperature coupling along the Missouri River: 6th Annual Missouri River Natural Resources Conference, Missouri River Science, p. 40.
- Minnesota Department of Natural Resources. 2011. Species Profile: Skipjack Herring, The state of Minnesota http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=AFCFA01030
Names and Taxonomy
Comments: Formerly placed in genus Pomolobus. Forms a geographically separated species pair with A. mediocris. Original description may have been based on A. alabamae or both A. alabamae and A. chrysochloris. See Lee et al. (1980) for pertinent literature citations.
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