SpeciesArea 1Area 3Area 634891015161820Golden Redhorse22...552......3Creek Chub4371......12...Sucker-mouthed Minnow.........5442253176Red-finned Shiner......1......431134Red Shiner44721111717043818620962Blunt-nosed Minnow.........410191089113Fat-headed Minnow1......12311215648Stoneroller6739498410755546722Black Bullhead5...121......37Yellow Bullhead11...21...1...3Channel Catfish147...3616...3123Channel Catfish(yy)[H]231617343422402328Flathead.........4812...1Flathead(yy)411211.........Stonecat25812775.........Green Sunfish271712131617626274Long-eared Sunfish13121633102231Logperch1......2...............Slender-headed Darter...125545231511Orange-throated Darter21291185...1Total233115316438480626661657347
Stoneroller, channel catfish (young-of-the-year), green sunfish, and long-eared sunfish formed the most stable element of the population, in that the numbers of these species varied less in successive collections than did numbers of other species.
The number of orange-throated darters remained constant at Areas 1 and 3, and the number of stonecats changed little in successive collections from Area 3. I suspect that an apparent decline in stonecats at Area 1 on September 4 was due to a slow rate of dispersal from the point of release (see pages 413, 414).
Some species (sucker-mouthed minnow, red-finned shiner, slender-headed darter, and fat-headed minnow) decreased significantly in successive samples from the same area because of mortality in handling or movement out of the area of initial capture.
The decrease in abundance of the sucker-mouthed minnow may have been due to some mobility of the species. Evidence for mortality caused by handling was obtained for the red-finned shiner and probably accounts for the reduction of this species in Area 6. The red-finned shiner is also probably a mobile species. The reduction in abundance of the slender-headed darter seems unexplainable because no evidence was obtained for either movement or mortality.
Fat-headed minnows also declined markedly in successive collections from Area 6, the only area in which the species was common. No marked fat-headed minnows were taken outside the area of release, indicating low mobility of the species. I cannot certainly account for their decline; possibly there was latent mortality due to shocking.
The numbers of red shiners, blunt-nosed minnows, and juvenile channel catfish varied erratically in successive collections, probably as a result of movement. This problem is discussed for all species in a later section.
The direct-proportion method was used to estimate fish populations in Areas 1, 3 and 6. Reliable results could not be obtained for all species because of scarcity, mortality in handling, mobility, or other factors.
A high rate of mortality due to handling was observed in Area 1 for the red shiner and in Area 6 for river carpsucker (young-of-the-year), sucker-mouthed minnows, red-finned shiner, red shiner, blunt-nosed minnow, and stoneroller. In Area 3, in contrast, there was little mortality in the same species during the twelve-hour interval that fish were held in traps prior to release as marked individuals.
The following species were common in at least one area, but probably are sufficiently mobile (see page 416) to invalidate estimates of static populations in small areas: red shiner, red-finned shiner, and channel catfish (yearlings and older). Other species were rare and are indicated as "T" in Table 13.
Those species for which population-estimates seem warranted include: golden redhorse, sucker-mouthed minnow, red shiner, sand shiner, fat-headed minnow, stoneroller, stonecat, channel catfish (young-of-the-year), green sunfish, long-eared sunfish, slender-headed darter, and orange-throated darter. I consider the estimate valid if a high percentage of the marked fish is recaptured. Results are presented in Table 15, and ordinarily will not be referred to in the following discussion of the population in each of the three areas.
Area 1The order of abundance at Area 1, in terms of the estimated population per 500 square feet, was as follows: stoneroller (47.6), stonecat (29.4), channel catfish (young-of-the-year) (20.6), green sunfish (19.4), red shiner (18.2), long-eared sunfish (9.4), channel catfish (yearlings and older) (6.5), golden redhorse (1.2). Insufficient data make inclusion of other species unreliable.A comparison of the order of abundance between the estimated total population and the percentage composition in the first collection from each area shows significant correlations. The percentage-composition of the fish fauna at Area 1 was calculated as follows: stoneroller (27.7%), red shiner (18.2%), green sunfish (11.2%), stonecat (10.3%), channel catfish (young-of-the-year) (9.5%), channel catfish (yearlings and older) (5.8%), long-eared sunfish (5.4%), golden redhorse (0.8%). It can be seen that the stoneroller, green sunfish, long-eared sunfish and golden redhorse follow each other in the same order in both calculations. The stonecat is shown to be more common than channel catfish (young-of-the-year) in both calculations, but both species appear to be more abundant than green sunfish and red shiner in calculations of the total population and less abundant in the percentage-composition in the first collection. I think that the order of abundance as shown by percentage-composition is the more accurate figure for Area 1. The abundance of the red shiner is known to have been affected by mortality in collecting. Furthermore, as will be shown later, the species is so mobile that its abundance often changes markedly in a short time. Therefore, it is not surprising to find the red shiner in widely varying positions of relative and absolute abundance. However, the green sunfish maintains stable populations and should remain in about the same position of abundance in relation to other species (such as the stonecat and channel catfish young-of-the-year) that also maintain stable populations. The differences in order of abundance obtained by the two methods for green sunfish and channel catfish young-of-the-year are not great. However, in the estimation of total population the abundance of the stonecat seems significantly greater, in relation to other species, than in the calculation of percentage-composition. I believe that this difference can be attributed to the relativelylow number of marked fish recaptured, which is probably due to a slow rate of dispersal from the point of release. Stonecats were released in relatively quiet water, and if they remained there they might be missed in subsequent collections, because they lack air-bladders and tend to remain on the bottom when shocked. Therefore, the calculated total population of the stonecat in Area 1 may be too high.
The order of abundance at Area 1, in terms of the estimated population per 500 square feet, was as follows: stoneroller (47.6), stonecat (29.4), channel catfish (young-of-the-year) (20.6), green sunfish (19.4), red shiner (18.2), long-eared sunfish (9.4), channel catfish (yearlings and older) (6.5), golden redhorse (1.2). Insufficient data make inclusion of other species unreliable.
A comparison of the order of abundance between the estimated total population and the percentage composition in the first collection from each area shows significant correlations. The percentage-composition of the fish fauna at Area 1 was calculated as follows: stoneroller (27.7%), red shiner (18.2%), green sunfish (11.2%), stonecat (10.3%), channel catfish (young-of-the-year) (9.5%), channel catfish (yearlings and older) (5.8%), long-eared sunfish (5.4%), golden redhorse (0.8%). It can be seen that the stoneroller, green sunfish, long-eared sunfish and golden redhorse follow each other in the same order in both calculations. The stonecat is shown to be more common than channel catfish (young-of-the-year) in both calculations, but both species appear to be more abundant than green sunfish and red shiner in calculations of the total population and less abundant in the percentage-composition in the first collection. I think that the order of abundance as shown by percentage-composition is the more accurate figure for Area 1. The abundance of the red shiner is known to have been affected by mortality in collecting. Furthermore, as will be shown later, the species is so mobile that its abundance often changes markedly in a short time. Therefore, it is not surprising to find the red shiner in widely varying positions of relative and absolute abundance. However, the green sunfish maintains stable populations and should remain in about the same position of abundance in relation to other species (such as the stonecat and channel catfish young-of-the-year) that also maintain stable populations. The differences in order of abundance obtained by the two methods for green sunfish and channel catfish young-of-the-year are not great. However, in the estimation of total population the abundance of the stonecat seems significantly greater, in relation to other species, than in the calculation of percentage-composition. I believe that this difference can be attributed to the relativelylow number of marked fish recaptured, which is probably due to a slow rate of dispersal from the point of release. Stonecats were released in relatively quiet water, and if they remained there they might be missed in subsequent collections, because they lack air-bladders and tend to remain on the bottom when shocked. Therefore, the calculated total population of the stonecat in Area 1 may be too high.
SpeciesNumber captured first collectionNumber marked and releasedNumber captured second collectionNumber of marked fish recapturedEstimated total populationPercent of marked fish recoveredNumber per 500 square feet136136136136136136136Golden Redhorse250250250250250100100—1.2.40Sucker-mouthed Minnow05431051150421201700126——330010.0—Red Shiner44116186221068671652025181431972128423171118.277.164Sand Shiner02510025703510—121073——48—05.8—Blunt-nosed Minnow041080328010910180—319—33280—16Fat-headed Minnow1111211101021560019——8300019——41.5Stoneroller6784545879333910767283588124227648442447.619.213.8Channel Catfish (j)[I]143739323716161301139—674106.53.1—Channel Catfish (yy)[J]334402233391634231011135102—4533320.68.1—Stonecat2570257087041—50—01614—29.4—0Green Sunfish27[K]—6227—6217—6214—2233—17552—3519.4—8.8Long-eared Sunfish1361013610123221036166377650609.4.51.9
Area 3The order of abundance of the species at Area 3, in terms of the estimated population per 500 square feet, was as follows: red shiner (77.1), stoneroller (19.2), sucker-mouthed minnow (10.0), channel catfish (young-of-the-year) (8.1), sand shiner (5.8), channel catfish (yearlings and older) (3.1), long-eared sunfish (0.5), golden redhorse (0.4). Insufficient data make inclusion of other species unreliable.For comparison with the estimates of total population, the percentage-composition in the first collection gives the following results: red shiner (24.0%), stoneroller (17.4%), sucker-mouthed minnow (11.2%), channel catfish (yearlings and older) (7.6%), channel catfish (young-of-the-year) (7.0%),long-eared sunfish (6.0%), sand shiner (5.2%), and golden redhorse (1.0%).For the most part, the species have the same order of abundance in both methods of analysis. Those that are apparently out of order are channel catfish (yearlings and older) and long-eared sunfish. The first species is mobile (excepting young-of-the-year) and commonly fluctuates widely in numbers in the same area; the second species was treated differently in that only adults were considered in the population-estimation whereas both young and adults were considered in calculating percentage-composition. (I found that I could not confidently distinguish between young-of-the-year of green sunfish, long-eared sunfish and orange-spotted sunfish after staining.)Area 6The order of abundance of the species at Area 6, in terms of the estimated population per 500 square feet, was as follows: red shiner (64.0), fat-headed minnow (41.5), blunt-nosed minnow (16.0), stoneroller (13.8), green sunfish (8.8), long-eared sunfish (1.9). Insufficient data make inclusion of other species unreliable.Calculations of percentage-composition give the following results: red shiner (20.1%), long-eared sunfish (14.6%), green sunfish (12.2%), fat-headed minnow (12.1%), blunt-nosed minnow (11.7%), stoneroller (5.8%). The two speciesof sunfish form a more significant part of the population in the latter analysis because young are included. Only adults were considered in the estimation of total population.The fact that estimates of the total population and the percentage-composition agree in most respects lends support to the validity of both methods of analysis. It should be re-emphasized that differences in the order of abundance in the various areas reflect the ability of each species to utilize each particular kind of habitat.
The order of abundance of the species at Area 3, in terms of the estimated population per 500 square feet, was as follows: red shiner (77.1), stoneroller (19.2), sucker-mouthed minnow (10.0), channel catfish (young-of-the-year) (8.1), sand shiner (5.8), channel catfish (yearlings and older) (3.1), long-eared sunfish (0.5), golden redhorse (0.4). Insufficient data make inclusion of other species unreliable.
For comparison with the estimates of total population, the percentage-composition in the first collection gives the following results: red shiner (24.0%), stoneroller (17.4%), sucker-mouthed minnow (11.2%), channel catfish (yearlings and older) (7.6%), channel catfish (young-of-the-year) (7.0%),long-eared sunfish (6.0%), sand shiner (5.2%), and golden redhorse (1.0%).
For the most part, the species have the same order of abundance in both methods of analysis. Those that are apparently out of order are channel catfish (yearlings and older) and long-eared sunfish. The first species is mobile (excepting young-of-the-year) and commonly fluctuates widely in numbers in the same area; the second species was treated differently in that only adults were considered in the population-estimation whereas both young and adults were considered in calculating percentage-composition. (I found that I could not confidently distinguish between young-of-the-year of green sunfish, long-eared sunfish and orange-spotted sunfish after staining.)
The order of abundance of the species at Area 6, in terms of the estimated population per 500 square feet, was as follows: red shiner (64.0), fat-headed minnow (41.5), blunt-nosed minnow (16.0), stoneroller (13.8), green sunfish (8.8), long-eared sunfish (1.9). Insufficient data make inclusion of other species unreliable.
Calculations of percentage-composition give the following results: red shiner (20.1%), long-eared sunfish (14.6%), green sunfish (12.2%), fat-headed minnow (12.1%), blunt-nosed minnow (11.7%), stoneroller (5.8%). The two speciesof sunfish form a more significant part of the population in the latter analysis because young are included. Only adults were considered in the estimation of total population.
The fact that estimates of the total population and the percentage-composition agree in most respects lends support to the validity of both methods of analysis. It should be re-emphasized that differences in the order of abundance in the various areas reflect the ability of each species to utilize each particular kind of habitat.
SpeciesNumber markedNumber recapturedNumber moved upstreamNumber moved downstreamGolden Redhorse241602Sucker-mouthed Minnow682770Red-finned Shiner74000Red Shiner13261524825Blunt-nosed Minnow13632110Fat-headed Minnow1514000Stoneroller1779010Black Bullhead25620Channel Catfish (j)[L]2943647Channel Catfish (yy)[M]1453420Stonecat33600Green Sunfish1246810Long-eared Sunfish332100Slender-headed Darter70100Orange-throated Darter13000
Some measure was gained of the amount of movement exhibited by several species of fish. Results are biased in favor of a conclusion that a species is sedentary because a large percentage of the recaptures were made in collections taken in the same immediate area three hours after release of marked fish, the total area checked was not large (one mile), and collecting was limited to an eleven-day period. Nevertheless, some species were shown to be definitely mobile and others exhibited pronounced sedentary tendencies. The results of experiments on movement are presented in Table 16. Marked fish (dyed and fin-clipped) were taken as long as seven days after being marked. Only those species in which more than ten individuals were marked are included.
Blunt-nosed minnow, red shiner, and channel catfish (yearlings and older) are more mobile than other species.
The mobility of channel catfish has been discussed by Muncy (1958) and Funk (1957). My records show that of 36 marked channel catfish that were recaptured, 11 were taken in areas other than the one into which they had been returned. A pronounced mobile tendency on the part of the red shiner and blunt-nosed minnow is shown by the fact that of 152 marked red shiners recaptured, 73 had moved from the area of release; and of 32 marked blunt-nosed minnows recaptured, 11 had moved from the area of release. The fact that the habitat occupied by these species is not precise (ranging from swift riffles to quiet pools) supports a conclusion that the species are mobile.
The fat-headed minnow, stoneroller, channel catfish (young-of-the-year), green sunfish and long-eared sunfish form a sedentary element of the population. With the exception of the fat-headed minnow, the sedentary group also maintained relatively stable numbers in Areas 1, 3 and 6 throughout the study (Table 14). It is interesting to note that, in contrast to the mobile group, the species forming the sedentary group have rather well-defined habitat preferences.
A third group of species, represented by the red-finned shiner, stonecat, slender-headed darter and orange-throated darter, was characterized by having a low rate of recapture. I suspect that mortality is a factor contributing to the failure to recapture red-finned shiners, because in one collection only four of 31 red-finned shiners captured were successfully marked and released, in another case 70 of 818. The red-finned shiner occurs most often in pools but is also taken in other areas, is pelagic, and probably is a mobile species.
The stonecat, slender-headed darter and orange-throated darter are generally restricted to riffle-habitats, and are probably sedentary. The low number of recaptures for these three species probably is due either to a slow rate of dispersal from the point of release or to latent mortality resulting from shock. Table 14 shows that these three species maintain comparatively stable populations, but there seems to be a tendency for a reduction in numbers with continued collecting, even though all fish captured were returned to the stream.
Golden redhorse showed a high rate of recapture. All individuals marked were recaptured three hours after release in Areas 1 (twofish) and 3 (five fish). Nine individuals were taken from Area 4 on 11 September; seven of these were marked and released in the next pool downstream (Area 3). On 15 September, two fish were retaken in Area 3 and two were retaken in Area 2, the next pool downstream. The species was common in Area 5 also where five of eight marked individuals were recaptured two days after release. It seems that the golden redhorse is somewhat restricted in movement, at least for short periods.
The sucker-mouthed minnow and black bullhead showed some movement—less than such mobile species as red shiners and channel catfish, but more than the sedentary group. Seven of 27 marked sucker-mouthed minnows were taken in areas adjacent to the one to which they had been returned. Two of six black bullheads that were recaptured had moved. The black bullhead moved the greater distance. The extent of short-term movement by several of the species in the Upper Neosho correlates well with redistribution subsequent to drought in the Wakarusa River, discussed by Deacon and Metcalf (1961).
The fauna that I found to be characteristic at the upper Neosho station has affinity with the upland tributary-fauna described by Metcalf (1959) for Chautauqua, Cowley and Elk Counties, Kansas. The primary difference is a nearly complete absence at my station of the Ozarkian element of the population. Some species (red-finned shiner, long-eared sunfish, and spotted bass) listed by Metcalf as characteristic of the mainstream of smaller rivers occur at the upper Neosho station in greater abundance then elsewhere in the Neosho. This difference is probably due to the fact that the upper Neosho station is somewhat larger and slightly more turbid than Metcalf's "upland tributaries."
Hall (1952) reported on the distribution of fishes in the vicinity of Fort Gibson Reservoir, an impoundment on the Grand (Neosho) River in Oklahoma. He separated the fishes into three groups according to habitat-preference: species restricted to upland tributaries on the east side of Grand (Neosho) River, species restricted to lowland tributaries on the west side of Grand (Neosho) River, and species occurring in the Grand River proper and/or tributaries on one or both sides.
Several species found in the upper Neosho River also occur in the area studied by Hall. Of these, only the creek chub was restricted to upland tributaries on the east side of Grand (Neosho) River. The sucker-mouthed minnow and red-finned shiner were restricted to the lowland tributaries on the west side of Grand (Neosho) River in the Fort Gibson Reservoir Area. Golden redhorse, stoneroller, yellow bullhead, spotted bass, green sunfish, long-eared sunfish, and orange-throated darter were present in collections from the Grand River proper and/or tributaries on both sides of the river, most commonly in tributaries.
Hall's data show that black bullhead, large-mouthed bass, white crappie, and logperch occurred most frequently in or near the quiet water of the reservoir. In my study these fish were most common in the larger, quiet pools at the upper Neosho station.
The Marais des Cygnes River has less gradient (especially in the upstream portions), fewer and shorter riffles, and more mud bottom than does the Neosho River. Stream-flow during drought was reduced to a proportionately greater degree in the Neosho River than it was in the Marais des Cygnes River. Average flow of the Neosho River near Parsons (drainage area: 4905 square miles), Kansas, was less than average flow of the Marais des Cygnes River at Trading Post (drainage area: 2880 square miles), Kansas, in 1953, 1955 and 1956. In normal times the Neosho River carries a larger volume of water than the Marais des Cygnes. The Neosho River has a greater variety of habitat-conditions and a more diversified fish-fauna than the Marais des Cygnes.
The following species were taken in the Neosho River but not in the Marais des Cygnes River: blue sucker, high-finned carpsucker, golden redhorse, gravel chub, mimic shiner, mountain minnow, parrot minnow, Neosho madtom (the only endemic in either river), mosquitofish, spotted bass, smallmouth, black crappie, logperch and fan-tailed darter. Most of the above species are usually found in association with gravel-bottom, which is prevalent in Neosho River. The blue sucker, high-finned carpsucker, gravel chub, mountain minnow, and parrot minnow normally occur in the larger streams in Kansas. The last three species became more abundant in the Neosho River following resumption of flow. The golden redhorse also increased in abundance from 1957 to 1959, but was most numerous at the upper Neosho station, whereas the other species occurred mainly at the lower stations.
The mimic shiner, spotted bass, smallmouth, and fan-tailed darterare characteristic of upstream habitats with clear water (tributaries, rather than the mainstream), and were taken in the Neosho River only in 1957 or became less abundant from 1957 to 1959.
The silver chub, slender madtom and tadpole madtom were taken in the Marais des Cygnes River only in 1957 and were not taken in the Neosho River.
The following species, common to both rivers, were more abundant in the Neosho: long-nosed gar, short-nosed gar, river carpsucker, creek chub, sucker-mouthed minnow, red-finned shiner, red shiner, ghost shiner, blunt-nosed minnow, fat-headed minnow, stoneroller, yellow bullhead, channel catfish, flathead, stonecat, largemouth, long-eared sunfish, slender-headed darter, and freshwater drum. These species, collectively, reflect the more diversified habitats (more gravel-bottom, more riffle-areas, more gradient, greater range of stream-size sampled) in the Neosho River.
The following species, common to both rivers, were more abundant in the Marais des Cygnes: gizzard shad, carp, sand shiner, black bullhead and white crappie. These species (with the exception of sand shiner) emphasize the fact that the Marais des Cygnes is a sluggish stream with large areas of mud bottom. Differences in the abundance of the sand shiner in the two rivers are part of taxonomic and distributional studies being conducted by Mr. Bernard C. Nelson.
The following species were not consistently more abundant in one river than the other: big-mouthed buffalo, black buffalo, small-mouthed buffalo, short-headed redhorse, green sunfish, orange-spotted sunfish and orange-throated darter. These species, excepting the orange-throated darter and short-headed redhorse, occurred in a wide variety of habitats.
The following species increased in abundance from 1957 to 1959 (Tables 10 and 11): long-nosed gar, short-nosed gar, river carpsucker, creek chub, gravel chub, sucker-mouthed minnow, mountain minnow, blunt-nosed minnow, parrot minnow, stoneroller, stonecat, Neosho madtom, green sunfish, slender-headed darter, and orange-throated darter.
These species can be separated into three groups, characteristic of different habitats but having in common a preference for permanent flow. One group, composed of long-nosed gar, short-nosed gar, river carpsucker, gravel chub, mountain minnow, parrot minnow, and Neosho madtom, prefers streams of moderate to large size.
A second group composed of creek chub, sucker-mouthed minnow, stoneroller, and orange-throated darter occurs most abundantly in small, permanent streams. The green sunfish may be included here on the basis of its abundance at the upper Neosho station; however, this is a pioneer species and does not require permanent flow.
The third group is characteristic of continuously flowing water, but in both upstream and downstream situations. The species in this group (blunt-nosed minnow, stonecat, and slender-headed darter), increased in response to a resumption of permanent flow, but did not respond as quickly as did channel catfish, flatheads and freshwater drum, which are discussed subsequently.
The fact that riffle-insects were abundant throughout my study convinces me that food was not a limiting factor in the re-establishment of the fish-fauna on riffles of the Neosho River.
The following species decreased in abundance during my study (Tables 10 and 11): gizzard shad, carp, rosy-faced shiner, blunt-faced shiner, red shiner, mimic shiner, black bullhead, yellow bullhead, channel catfish, flathead, slender madtom, tadpole madtom, freckled madtom, spotted bass, largemouth, black crappie, fan-tailed darter, and freshwater drum.
Among the species that decreased, three groups, characteristic of different habitats, can be distinguished. The first group occurs most commonly in ponded conditions or in slowly flowing streams. Species in this group are: shad, carp, black bullhead, tadpole madtom, largemouth, black crappie, and white crappie. Bullhead, bass and crappie commonly occur in farm ponds and lakes in Kansas and seem less well adapted to streams. It is therefore not surprising to find that these species decreased in abundance when flow was resumed.
A second group, composed of rosy-faced shiner, blunt-faced shiner, mimic shiner, slender madtom, freckled madtom, spotted bass, and fan-tailed darter, normally is characteristic of clear tributaries rather than the mainstream of rivers. These species probably used the mainstream as a refugium during drought; with the resumption of flow, conditions became unsuitable for these populations in the mainstream. At the same time, conditions probably became favorable to the re-establishment of these species in tributaries. Metcalf (1959:396) listed the rosy-faced shiner, blunt-facedshiner and mimic shiner as species that were characteristic of upland tributaries in the Flint Hills and Chautauqua Hills of Chautauqua, Cowley and Elk counties in Kansas. The slender madtom and fan-tailed darter are more common in clear streams of southeast Kansas than in other areas of the state (Cross, personal communication and data of the State Biological Survey of Kansas). Both species are recorded by Hall (1952:57-58) only in upland tributaries on the east side of Grand (Neosho) River in the Fort Gibson Reservoir area of Oklahoma. Neither species was taken in faunal studies of the Verdigris River in Oklahoma (Wallen, 1958), in the Verdigris and Fall rivers in Kansas (Schelske, 1957), or by Metcalf (1959).
The spotted bass is not so restricted in its distribution and its habitat-requirements as are other species in this group; but, in Kansas, spotted bass are most abundant in clear creeks in the southeast part of the state.
The freckled madtom was taken in most of the studies cited above and is most common in the smaller streams of the southeast one-fourth of Kansas and the northeast one-fourth of Oklahoma. Schelske (1957:47) reports that the freckled madtom was taken only in March, April, October and November in the Verdigris River, Kansas. My only record of this species was obtained in the Neosho River in April, 1958.
The third group is composed of channel catfish, flathead, and freshwater drum. This group represents that element of the population that responded most quickly to the resumption of continuous flow. The fact that adult channel catfish and flatheads live in pools and do not require flowing water to spawn gives these species a survival advantage as well as a reproductive advantage over obligatory riffle fishes (such as most darters) in the highly variable conditions found in Kansas streams. These factors resulted in unusually high reproductive success in 1957. Subsequent survival of fry was excellent; however, some mortality in the highly-dominant 1957 year-class became apparent in the 1958 and 1959 collections, accounting for a numerical decline in these species. The ability to respond immediately to increased flow is an adaptive feature that allows these species to maintain high levels of abundance in the highly fluctuating streams of Kansas.
The continuous flow that occurred in 1957 in the Neosho and Marais des Cygnes rivers, for the first time in four years, provided the necessary habitat for survival of young catfish hatched in thatyear. The nearly complete absence of other species on the riffles, and the abundant populations of riffle-insects that I observed in the summer of 1957, were undoubtedly factors contributing to the survival of young.
The decrease in abundance of the red shiner may be partially due to an increase in the numbers of other species that are well adapted to conditions of permanent flow. At the completion of my study, the red shiner was still the most abundant minnow in both rivers. In 1957 this species was common in many habitats, including swift riffles, that were later occupied by madtoms, darters, the gravel chub, mountain minnow and sucker-mouthed minnow.
The basic pattern of change was clearly an increase in the species that are characteristic of permanently flowing waters, and a decrease in the species that are characteristic of ponds or small, clear streams.
The fauna of the Neosho and Marais des Cygnes rivers is capable of a wide range of adjustment in response to marked environmental changes. As these rivers become low and clear they take on many of the faunal characteristics of smaller tributaries and ponds. Species such as black bullhead, spotted bass, largemouth, white crappie, red shiner, rosy-faced shiner, blunt-faced minnow, mimic shiner, and slender madtom assume a more prominent position in the total population. Other species such as channel catfish, flathead, freshwater drum, blue sucker, and such riffle-dwelling species as the gravel chub, Neosho madtom, and slender-headed darter hold a less prominent position in the total population.
When permanent flow is re-established the more mobile and the more generalized species (with respect to habitat) are able to utilize the available space immediately. As a result, these species increase rapidly in numbers. This increase occurs both by movement from more permanent waters and by reproduction. Channel catfish, flathead, freshwater drum, and river carpsucker are mobile species (Funk, 1957; Trautman, 1957) and long-nosed gar probably are mobile. Individuals that move supplement those that survive in residual pools, and provide brood stock adequate to produce a large year-class in the first year of permanent flow.
The five species last mentioned are found in diverse kinds of streams, indicating that they are adaptable to varying habitats. A sixth species, the red shiner, although probably less mobile, is able to utilize opportunistically nearly any kind of habitat inPlains streams. Although this species seldom is abundant in riffles, it was, in 1957, abundant in both pool and riffle situations at all my stations. These riffles were almost unoccupied by other species in 1957 until mid-summer, when hatches of channel catfish and flatheads occurred. Although adult channel catfish and flatheads live well in pools, the young occupy mainly riffles. This age- and size-segregation, in different habitats, was an advantage to the rapid re-establishment of these species in the Neosho and Marais des Cygnes rivers in 1957.
Species that occupy restricted habitats, especially riffle-dwellers such as the Neosho madtom, gravel chub, and slender-headed darter, were slowest to increase following drought. These species seem less capable of adapting to the variable conditions prevalent in the Neosho and Marais des Cygnes rivers than species that have more generalized habitat-requirements.
In the Neosho and Marais des Cygnes rivers nearly all species that were found in years just prior to the drought of 1952-1956 were again found in the last year of my survey; however, some species that live in a restricted habitat may eventually be extirpated in these two rivers. The high-finned carpsuckerCarpiodes velifer, common shinerNotropis cornutus, horny-headed chubHybopsis biguttata, and johnny darterEtheostoma nigrumall have specific habitat requirements and have disappeared or become restricted to one tributary in the Wakarusa River System (Deacon and Metcalf, 1961). The disappearance or reduction of these species implies long-term changes in the environment.
Suckers, minnows and catfishes constitute the main fauna of the Neosho and Marais des Cygnes rivers, because these families contain many species that have generalized habitat-requirements. Many of these fish are able to live successfully in either ponds or flowing waters and others are capable of long migrations. Because these fish predominate in the streams of Kansas, attempts should be made to utilize them more effectively.
In years such as 1957, large numbers of young channel catfish could be collected and used to stock new ponds and lakes. So doing would not affect the numbers ofadultsproduced in the stream, and, if enough young could be removed, those remaining in the streams might grow faster.
Suckers and carp are abundant in the two rivers and mostly are unused at present, because current regulations preclude the use of methods effective for the capture of these species.
The investigation here reported on was supported jointly by the Kansas Forestry, Fish and Game Commission and the State Biological Survey of Kansas.
I thank Messrs. W. L. Minckley, D. A. Distler, J. McMullen, A. L. Metcalf, L. J. Olund, M. Topping, B. Nelson and Claude Hastings for assistance in the field, and Mr. Ernest Craig, Game Protector, Erie, Kansas, for valuable suggestions and co-operation. I am especially grateful to Associate Professor Frank B. Cross for his pre-drought data, guidance, and criticism throughout the course of the work. I thank the many landowners who allowed me access to streams, and am especially indebted to Mr. and Mrs. Floyd Meats and Mr. and Mrs. Oliver Craig for their hospitality and assistance.
Assistant Professor Kenneth B. Armitage and Associate Professor Ronald L. McGregor read the manuscript and gave helpful advice. Mrs. Maxine Deacon typed the manuscript and assisted in other ways.