Mississippi possesses one of the richest freshwater fish faunas in the United States, with a total of at least 292 species, of which 212 are native freshwater or diadromous (moving between freshwater and saltwater for purposes of spawning). In addition to native freshwater species, 66 species are primarily estuarine or marine but are capable of entering freshwater, 9 species have been introduced into Mississippi from regions outside North America, and 4 are native to North America but transplanted into Mississippi. Only four states support more native freshwater fish—Tennessee (297), Alabama (295), Kentucky (220), and Georgia (219).
The minnows (family Cyprinidae) contain the greatest number of species (59), followed by darters (family Percidae, 45), suckers (family Catostomidae, 20), catfish (family Ictaluridae, 18), and sunfish (family Centrarchidae, 18). Anglers and commercial fishers will be familiar with fish in some of these families, especially Centrarchidae (shadow bass, warmouth, bluegill, long-ear and red-ear sunfish, largemouth and spotted bass, white and black crappie), Ictaluridae (channel and blue catfish; black, yellow, and brown bullheads; flathead catfish), Catostomidae (smallmouth, bigmouth, and black buffalo; blacktail redhorse), and Percidae (walleye, sauger). Other sport or commercial fish include paddlefish (family Polyodontidae), grass and chain pickerel (family Esocidae), white, yellow, and striped bass (family Moronidae), freshwater drum (family Sciaenidae). The 28 or so native species that are sometimes harvested for sport or commercial purposes thus make up only a small portion of the total native freshwater fish fauna. Nongame fish comprise most of the diversity and are beautiful and fascinating in their own right. Along with sport fish, the nongame fish are vital to the health of Mississippi’s aquatic systems.
Three species (table 1A) are endemic to Mississippi, meaning that they are found nowhere else. The bayou darter (Etheostoma rubrum) occurs only in the Bayou Pierre system south of Vicksburg. The Yazoo shiner (Notropis rafinesquei) and the Yazoo darter (Etheostoma raneyi) are restricted to streams of the Yazoo drainage in northwestern Mississippi. Ten species are endemic to drainages that occur in Mississippi and one adjoining state (table 1B), further highlighting the unique elements of the Mississippi fauna. Seven of these species are endemic to the Mobile Basin (shared between Mississippi and Alabama). One species is endemic to the Mobile and Pascagoula drainages (shared with Alabama), one species is endemic to the Lake Pontchartrain drainage (shared with Louisiana), and one species is endemic to the Pearl River drainage (shared with Louisiana) and the Pascagoula River drainage. Unfortunately, this species, the pearl darter, has been extirpated from the Pearl River drainage and is now restricted solely to the Pascagoula River drainage. This river is unique in that it is the last large (mean annual discharge of more than 350 cubic meters per second) river system in the lower forty-eight states that is not seriously altered by mainstream dams or diversions. The natural flow regime of the Pascagoula River makes it an important refuge for fish that have been eliminated from other stream systems as a consequence of habitat modification or loss.
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Mississippi owes its rich fish fauna to its location adjoining upland areas to the north and east and to the Mississippi River along its western border. The Mississippi River Basin, which supports at least 31 families and 375 species of native fish, has had a major influence on the state’s fish fauna. The basin has variously functioned as a refuge for more northern clear-water fish during the Pleistocene glaciations (which ended approximately ten thousand years ago), as an area of speciation, as a conduit for dispersal for some species between stream systems, and as its character has changed since the last ice age, a barrier to clear-water, upland fish. The size, longevity, and positioning of the Mississippi River Basin have all contributed to the richness of the fish fauna. In particular, the north-south alignment allowed for a southward displacement of many species during the Pleistocene glacial advances, when what is now the northern United States was covered with ice sheets, with subsequent northward recolonization when the ice retreated. Most of Mississippi (with the exception of the extreme northeastern corner, including Tishomingo County) was inundated by shallow seas during various Cenozoic marine transgressions, whereas areas immediately to the east (northern Alabama) and north (Tennessee) were not. These areas are above the Fall Line, the boundary between the more upland Tertiary areas and the soft marine deposits of the Coastal Plain. Also, the Tennessee-Mississippi Basin of Alabama and Tennessee was south of the maximum penetration of the Pleistocene ice sheets. Thus, this area represents an ancient faunal region that, with its high topographic diversity, has provided ample opportunity for isolation and diversification of fish species. Tennessee’s Central Highlands region is considered a center of abundance and evolution for both darters and minnows, and Mississippi’s location near this area further explains the high diversity of its fish population.
Mississippi’s diverse fish fauna currently face some threats. Although the US Fish and Wildlife Service lists only two fish species from Mississippi as endangered (Alabama sturgeon and pallid sturgeon) and two as threatened (bayou darter, Gulf sturgeon), data compiled by the Mississippi Department of Wildlife, Fisheries, and Parks; the Mississippi Museum of Natural Science; and the Mississippi Wildlife Heritage program indicate that 70 species (35 percent of Mississippi’s native fish fauna) are to some degree imperiled. The primary reasons for imperilment include physical habitat loss or damage, chemical pollution, overexploitation, and introduction of nonnative (exotic) species. Thus, we must meet the challenge of maintaining this rich biological legacy for future generations.
- Herbert T. Boschung Jr. and Richard L. Mayden, Fishes of Alabama (2004)
- Brooks M. Burr and Richard L. Mayden, in Systematics, Historical Ecology, and North American Freshwater Fishes, ed. Richard L. Mayden (1992)
- Mats Dynesius and Christer Nilsson, Science (4 November 1994)
- David A. Etnier and Wayne C. Starnes, The Fishes of Tennessee (1993)
- Maurice F. Mettee, Patrick E. O’Neil, and J. Malcolm Pierson, Fishes of Alabama and the Mobile Basin (1996)
- Lawrence M. Page, Handbook of Darters (1983)
- Henry W. Robison, in Zoogeography of North American Freshwater Fishes, ed. C. H. Hocutt and E. O. Wiley (1986)
- Stephen T. Ross, Inland Fishes of Mississippi (2001)
- W. Todd Slack, Mississippi Museum of Natural Science, personal communication (November 2006)
- Melvin L. Warren Jr. and Brooks M. Burr, Fisheries (January 1994)