from marginal sloughs and lakes: Umbra limi, Esox 
americanus, Notropis anogenus, Aphredoderus sayanus, 
Fundulus notti, Centrarchus macropterus, Lepomis mi- 
crolophus, and Etheostoma exile. The origins of the 
specimens of Jctalurus catus and Ctenopharyngodon idel- 
la are unknown. A long list of stragglers from tributary 
streams includes: Dionda nubila, Nocomis biguttatus, 
Notropis boops, Notropis chrysocephalus, Notropis rubel- 
lus, Notropis venustus, Phoxinus erythrogaster, Semo- 
tilus atromaculatus, Semotilus margarita, Fundulus oliva- 
ceus, Culaea inconstans, Micropterus punctulatus, Etheo- 
stoma caeruleum, Etheostoma flabellare, Etheostoma 
spectabile, Etheostoma zonale, Percina maculata, Percina 
sciera, and Cottus carolinae. 
Six other species of small fishes, although never re- 
corded from the Mississippi River, are common in some 
of the small tributaries and may eventually be found as 
stragglers in the river. They are the ribbon shiner, 
Notropis fumeus; telescope shiner, Notropis telescopus: 
bleeding shiner, Notropis zonatus; creek chubsucker, 
Erimyzon oblongus; slender madtom, Noturus extlis; and 
northern studfish, Fundulus catenatus. 
The most dramatic contribution of a tributary to the 
regular fauna is made by the Missouri River, having 
introduced into the Mississippi the silt-tolerant Scaphir- 
hynchus albus, Hybognathus argyritis, Hybognathus pla- 
citus, Hybopsis gelida, Hybopsis gracilis, and Hybopsis 
meekt. The Ohio River has a diluting effect upon the 
Mississippi's silty water. Near the mouth of the Ohio 
there is a sharp increase in the abundance of Alosa 
chrysochloris, Dorosoma petenense, Notropis shumardi, 
Votropis volucellus, and Menidia audens. Medium-sized 
11 
rivers appear to contribute little or nothing to the river 
fauna and to have assemblages of typical Mississippi 
River fishes near their mouths, 
PRESENT STATE OF THE MISSISSIPPI RIVER 
Despite the steady decline in the number of commer- 
cial fishermen and despite highly publicized references 
to the Mississippi River as a sewer, the evidence avail- 
able indicates that the Mississippi has a rich fish fauna 
and that it supports good populations of most of its 
native species. With the exception of the muskellunge, 
no indigenous species of fishes are known to have been 
extirpated in historic times. 
Several species appear to be less generally distributed 
and less common than formerly, but their decline can- 
not be attributed with certainty to increased pollution. 
Species such as the lake sturgeon were said to be deci- 
mated in the Mississippi River 60 or more years ago 
(Forbes & Richardson 1908:25). It is probable that 
drainage of marginal lakes and sloughs, erection of flood- 
control dams, destruction or modification of habitats 
through efforts to maintain a navigable channel, and 
excessive siltation have been the major causes of the ob- 
servable changes in the numbers and distribution of 
fishes. However, such current threats as pesticide resi- 
dues, mercury accumulations, industrial and domestic 
wastes, oil spills, accidental discharge of toxicants, ther- 
mal pollution, the proposed creation of a 12-foot navj- 
gation channel, and loss of marginal refuges make the 
need for constant surveillance of the Mississippi River 
ever more acute. 
LITERATURE CITED 
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Conservationist 21(6) : 44. 
AILEY, REEVE M., Chairman. 1970. A list of common and 
scientific names of fishes from the United States and Canada. 
3rd ed. American Fisheries Society Special Publication 6. 
150 p. 
ARNICKOL, Pau G., and WILLIAM C. STARRETT. 1951. Com- 
mercial and sport fishes of the Mississippi River between 
Caruthersville, Missouri, and Dubuque, Iowa. Illinois Nat- 
ural History Survey Bulletin 201526 1-350) 
ECKER, GEorGE C. 1966. Fishes of southwestern Wisconsin. 
Wisconsin Academy of Sciences, Arts and Letters Transac- 
tions 55:87-117. 
ARLANDER, Harriet BELL. 1954. A history of fish and 
fishing in the upper Mississippi River. Upper Mississippi 
River Conservation Committee. 96 p. 
OKER, Ropert E. 1930. Studies of common fishes of the 
Mississippi River at Keokuk. U. S. Bureau of Fisheries 
Bulletin for 1929, 45:141-225. 
ORBES, STEPHEN ALFRED, and Ropert Eart RICHARDSON. 
1908. The fishes of Illinois. Illinois State Laboratory of 
Natural History, Urbana. cxxxi + 357 p. + atlas of 102 
maps. 
See WILLARD. 1935. The distribution of Wisconsin 
fishes. State of Wisconsin Conservation Commission, Madi- 
son. 235 p. 
REENWOop, P. Humpury, Donn E. Rosen, STANLEY H. 
Weitzman, and Grorce S. Myers. 1966. Phyletic studies 
of teleostean fishes, with a provisional classification of living 
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131(4) :339-456. 
UBBS, Cart L., and Kart F. Lacter. 1941. Guide to the 
fishes of the Great Lakes and tributary waters. Cranbrook 
Institute of Science Bulletin No. 18. 100 p. + 118 fig. 
EEK, SeTH Eucenr. 1892. A report upon the fishes of Iowa, 
based upon observations and collections made during 1889, 
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10:217-248. 
Norp, Rosert C. 1967. A compendium of fishery information 
on the upper Mississippi River. Upper Mississippi River 
Conservation Committee [La Crosse, Wisconsin]. 238 p. 
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souri fishes. University of Kansas Publications, Museum of 
Natural History 20(3) : 225570. 
Puitups, Gary L., and James C. UNDERHILL. 1967. Revised 
distribution records of some Minnesota fishes, with addition 
of two species to the faunal list. Minnesota Academy of 
Science Journal 34(2) : 177-180. 
Rock, Leo F. 1963. 1962 Mississippi River sport fishing creel 
census. Illinois Department of Conservation Division of 
Fisheries, Springfield. Mimeographed, 92 p. 
SMITH, Puitip W. 1965. A preliminary annotated list of the 
lampreys and fishes of Illinois. Illinois Natural History 
Survey Biological Notes No. 54. 12 p. 
STARRETT, WILLIAM C., and Paut G. Barnicxou. 1955. Effi- 
ciency and selectivity of commercial fishing devices used on 
the Mississippi River. Illinois Natural History Survey Bul- 
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, WituiAM J. Hartu, and Pure W. Smitu. 1960. Par- 
asitic lampreys of the genus Ichthyomyzon in the rivers of 
Illinois. Copeia 1960(4) :337-346. 
Taytor, Wituiam Rarpw. 1969. A revision of the catfish 
genus Noturus Rafinesque, with an analysis of higher groups 
in the Ictaluridae. U. S. National Museum Bulletin 282. 
315 p. + 21 plates. 
Upper Mississipp1 River CONSERVATION CoMMITTEE. 1945- 
1968. Proceedings of Annual Meetings 4-24. Mimeographed. 
UNDERHILL, James C. 1957. The distribution of Minnesota 
minnows and darters in relation to Pleistocene glaciation. 
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