CYPRINIDAE
Golden Shiner:
Diagnosis: The golden shiner is an extremely slab-sided golden, gray, or greenish cyprinid with a scaleless midventral keel extending from the bases of the pelvic fins to the anus, a strongly decurved lateral line, a falcate anal fin with 11-14 rays, and a small and sharply upturned mouth.
Ecology: The preferred habitat of the golden shiner is clear, well-vegetated waters f ponds and lakes and quiet pools of creeks and small rivers. The species has great ecological tolerance and can persist in badly polluted and highly turbid streams and in swamps where water temperatures are high in the summer months.
Distribution: The minnow is found statewide and is very common in low-gradient streams and in standing bodies of water in eastern and southern Illinois.
Creek Chub:
Diagnosis: The creek chub is a terete, stout-bodied minnow with a large head and very large mouth, a black spot on the anterior basal portion of the dorsal fin, 50-60 scales in the lateral line, and a small flaplike barbel on the upper lip anterior to the angle of the jaws.
Ecology: This minnow is well named, for it is abundant in creeks, especially in low-gradient streams with mud or clay substrates. It is sometimes common in headwaters over sand or gravel and in the vicinity of bank cutouts and tree roots, but it occurs there because it is a pioneer species in newly available watercourses.
Distribution: The creek chub is common in suitable habitats throughout Illinois, except in the Lake Michigan drainage, and it has increased in abundance in virtually all parts of the state as a result of the increase in silt, the temporary decrease in the size of many streams, and the elimination of competing species by human modification of streams and watersheds.
Horneyhead chub:
Diagnosis: The hornyhead chub is a terete stout-bodied minnow with a large head, a moderately large mouth, terminal barbels, 40-43 scales in the lateral line, the dorsal fin origin slightly behind the pelvic insertions, a yellowish or bronzy ground color, and usually an evident caudal spot.
Ecology: The hornyhead chub lives in clear, high-gradient creeks and small rivers with gravel or rubble bottoms. It avoids sluggish waters, silt bottoms, and large rivers.
Distribution: It is a common species in clear, moderately fast, gravelly streams throughout the northern half of Illinois.
Sliver chub:
Diagnosis: It is a whitish or silvery barbled minnow with rounded fin tips, a relatively large eye, a dorsal fin origin well in advance of the pelvic fin insertions, and 37-41 scales in the lateral line.
Ecology: The silver chub is a large-river fish that is poorly known. It also occurs in some lakes and some small rivers. It is usually found in pools or deep-flowing channels over sand or mixed silt-sand-gravel.
Distribution: Although primarily a fish of large rivers and lakes, the silver chub occurs commonly in the lower reaches of their major tributaries.
Emerald Shiner:
Diagnosis: The emerald shiner is a slender and slab-sided minnow, silvery in color, with 10-13 anal rays; the dorsal fin is situated well behind the pelvic bases; 35-40 lateral-line scales; a sharply pointed dorsal fin; usually 2, 4--4, 2 pharyngeal teeth; and a rounded snout.
Ecology: It is typically a large-river minnow and occurs in small streams only near their mouths. It is the most abundant fish species in large rivers.
Distribution: The emerald shiner is common in all large and medium-sized rivers. Like many other large-river species, it occurs in small streams only in southern Illinois and there its numbers fluctuate widely from year to year.
River Shiner:
Diagnosis: The river shiner is a robust and rather large-scaled minnow, straw colored above, with seven anal rays; a large oblique mouth; a rather broad middorsal stripe of uniform width, continuing along either side of the dorsal fin base.
Ecology: The river shiner is a large-river species that enters small streams of Illinois only in the south. It is extremely abundant in clear flowing water over a sand or gravelly bottom and is less tolerant of turbidity than the emerald shiner.
Distribution: It is restricted to large and medium-sized rivers but does not ascend the Illinois River a great distance.
Striped Shiner:
Diagnosis: The striped shiner is a large and much compressed shiner, bluish or greenish on the sides, with its dorsal fin situated far forward; distinctly elevated lateral-line scales; nine anal rays; rounded fins; a broad dusky middorsal stripe; 37040 lateral-line scales; sides frequently mottled with dark pigment; upper sides with many parallel dark lines that converge obliquely on the midline of the back.
Ecology: The striped shiner occurs in clear water of fast to moderately flowing small brooks and large creeks that have bottoms of gravel, rubble, or mixed sand and gravel. It avoids strong riffles and deep soft-bottomed pools, and it is sometimes present in large schools at the foot of riffles and in shallow hard-bottomed pools with some flow.
Distribution: The striped shiner is an abundant and generally distributed species in clear, gravelly creeks of eastern and central Illinois, but its range is sharply bounded on the north, west, and south.
Common Shiner:
Diagnosis: The common shiner is closely related and exceedingly similar to the striped shiner, differing from it in having smaller predorsal scales and the tip of the chin immaculate or with a few melanophores on the sides, and n lacking the parallel dark lines that converge obliquely at midback.
Ecology: it is similar to the striped shiner.
Distribution: It is extremely abundant in gravelly creeks in northern Illinois.
Bigmouth Shiner:
Diagnosis: The bigmouth shiner is a terete silvery to plumbeous shiner with eight anal rays; 34-37 lateral-line scales; unmarked fins; a large horizontal mouth; the dorsal fin origin almost over the pelvic fin insertions; a ventrally flattened head, triangular in cross section; eyes directed somewhat upward and forward as well as laterally; and a pair of distinct dusky crescent between the nostrils viewed from above.
Ecology: The bigmouth shiner is a plains species that is gradually expanding its range eastward. Essentially a fish of shallow water in creeks and small rivers, it is occasionally found in large rivers but seldom in small temporary streams.
Distribution: It is found throughout the state, except for the southern and extreme eastern parts.
Spottail Shiner:
Diagnosis: The spottail shiner is a somewhat slab-sided shiner, light olive above and silvery or white beneath, with a large black spot on the caudal peduncle, eight anal rays; 36-40 lateral-line scales, rather falcate dorsal and anal fins, the dorsal fin slightly in advance of the pelvic fin insertions, a nearly horizontal mouth, a rather large eye, the ventral edge of the caudal fin milky white, and variable pharyngeal teeth.
Ecology: The spottail shiner is a minnow of natural lakes and large rivers and is seldom found in other waters.
Distribution: It is abundant in shallow waters of Lake Michigan and in the Rock, Illinois, and Mississippi Rivers, but it is sporadic in the Mississippi below the mouth of the Missouri River.
Spotfin Shiner:
Diagnosis: The spotfin shiner is a compressed and bluish-silvery shiner with a dusky lateral band; a pointed snout; a small eye; a black blotch in the posterior rays of the dorsal fin; a dorsal fin situated slightly behind the pelvic fin insertions; scales on the sides of the body diamond shaped and sharply outlined with melanophores.
Ecology: It occurs chiefly in large creeks and small rivers but sometimes is found in smaller populations in large rivers and even lakes and reservoirs. the preferred habitat is clear raceways over gravel pools with some current and with a firm substrate of mixed gravel, sand, and silt.
Distribution: The spotfin shiner was once virtually statewide in Illinois although sporadic in occurrence in the western and southern parts of the state. It is now restricted to northern and eastern Illinois, but it follows the Mississippi and Wabash rivers southward.
Sand Shiner:
Diagnosis: The sand shiner is a terete straw-colored shiner with silvery sides and venter, a distinctly punctate and complete lateral line, usually seven anal rays, 34-38 lateral-line scales; a rather small mouth, a large eye, and a middorsal dark stripe that is expanded into a wedge-shaped blotch in front of the dorsal fin origin and that does not encircle the dorsal fin base.
Ecology: It occurs in permanent streams ranging in size from creeks to the Mississippi River and in clear natural and artificial lakes if they have bottoms of sand or gravel. However it reaches its greatest abundance in large, fast-flowing creeks with bottoms of mixed gravel and sand and is seldom, if ever, found in turbid streams flowing over clay or silt.
Distribution: It is abundant throughout the northern four-fifths of Illinois but is absent in the low-gradient streams of the south-central and in the streams of the Shawnee Hills and Coastal Plain Province.
Redfin Shiner:
Diagnosis: The redfin shiner is a deep-bodied, slab-sided, whitish shiner with small and closely crowded predorsal scales in 25 or more rows; a strongly decurved lateral line; lateral-line scales in 38 or more rows; the dorsal ray origin distinctly behind the pelvic fin insertions.
Ecology: It inhabits clear, low-gradient creeks, but it is tolerant of a considerable amount of turbidity and silt. In streams it is most abundant in pools habitats where there is little or no current.
Distribution: The redfin shiner is statewide in distribution and extremely abundant in eastern and southern Illinois. It is somewhat sporadic in western and extreme northwestern Illinois.
Steelcolor Shiner:
Diagnosis: The steelcolor shiner is a compressed and bluish-silvery shiner with a faint lateral band on the caudal peduncle; usually a well-developed scapular bar; a pointed snout; a small eye; a black blotch in the posterior rays of the dorsal fin; the dorsal fin situated slightly behind the pelvic fin insertions; scales on the sides of the body diamond shaped and sharply outlined with melanophores.
Ecology: It occurs in clear, gravelly, large creeks and small rivers in central and southern Illinois. It prefers large riffles and pools just below them or eddies besides raceways, especially in relatively unmodified.
Distribution: It once occurred throughout central Illinois, but has now retreated to streams toward in eastern side of the state.
Silverjaw Minnow:
Diagnosis: The silverjaw minnow is a terete and plain shiner-like minnow, palc tan above and silvery below, with highly distinctive pearl organs occurring on the lower cheeks and ventral surface of the head and having the appearance of mother-of-pearl, the ventral surface of head greatly flattened, the eyes directed upward, and a small and horizontal subterminal mouth.
Ecology: It live on the shifting sand bottom in riffles and raceways with moderate flow. It is common in many clear headwaters. It can tolerate some pollution and even mine wastes but not fine silt.
Distribution: The silverjaw minnow is an abundant species in much of eastern Illinois. It occurs in tributaries of the upper Illinois, those of the Wabash, and in many of those of the Kaskaskia River.
Bluntnose Minnow:
Diagnosis: The bluntnose minnow is a terete minnow, olivaceous above and whitish below, with a distinct black lateral band ending in a prominent caudal spot, a small black blotch in the anterior rays of the dorsal fin, and a bluntly rounded snout.
Ecology: It is the most abundant and widespread fish in Illinois. It prefers hard-bottomed pools in creeks and small rivers but occurs almost everywhere except in swamps and heavily silted ditches and ponds.
Distribution: The bluntnose minnow is abundant in all parts of the state except those regions that are principally swampy or have been so badly polluted that few fishes can survive in them.
Mississippi Silvery minnow :
Diagnosis: The silvery minnow is a terete and robust minnow, pale olivaceous above and silvery below, with a vague dusky band along each side, a small eye, and a basioccipital process wider than long and distinctly concave posteriorly.
Ecology: It is characteristic of clear rivers and large creeks that have sandy bottoms. Where it occurs, the species is usually abundant and obvious because of the large schools that flash silver when individuals turn on their sides.
Distribution: The silvery minnow is abundant in the Illinois, Kaskaskia, and Wabash and their larger tributaries. It is almost statewide in distribution, avoiding the northeastern corner of Illinois.
Fathead minnow:
Diagnosis: The fathead minnow is a stout and somewhat compressed minnow, dark olive above and yellowish olive below, with a long and coiled gut, a terminal and sharply oblique mouth, a brownish black peritoneum, and a dusky predorsal stripe.
Ecology: The fathead minnow occurs most commonly in sluggish creeks, ditches, and ponds with a mud bottom. In larger streams it occupies backwaters and muck-bottomed pools. It usually is abundant where the bluntnose minnow is absent, suggesting that it cannot compete successfully with species of similar habits.
Distribution: The fathead minnow is abundant and widespread in suitable habitat throughout northern and western Illinois.
Suckermouth minnow:
Diagnosis: The suckermouth minnow is a terete and olivaceous minnow with a horizontal mouth, fleshy lateral lobes on the lower jaw, and a small and intense black spot on the caudal peduncle.
Ecology: This minnow is a Great Plains species that is said to occur in relatively silt-free riffles and raceways that have turbid and organically rich water. It is also said to be most common in the absence of other riffle-inhabiting species and to be a pioneer species in streams of newly deforested areas.
Distribution: It is statewide in distribution except for the extreme northeastern corner of Illinois. It is common in sandy and gravelly streams throughout the state except in extreme southeastern Illinois.
Ozark Minnow:
Diagnosis: The ozark minnow is shinerlike but has a long and coiled gut. It is a dirty straw color above and whitish beneath with a prominent black lateral stripe that extends to the snout tip but not onto the chin.
Ecology: The ozark minnow lives in clear fast creeks with gravel bottoms. Is food probably consists of algae, ooze, and surface slime on pebbles in the stream bed. The spawning adult is a dirty yellow and the fins of the male are orange.
Distribution: This species occurs sporadically in clear gravelly streams of northwestern Illinois. It is also known from the Mississippi River of southwestern Illinois at three localities.
