FISH-FAUNA OF THE UPPER NEOSHO RIVER 405 Description of Study-areas 405 Methods 406 Changes in the Fauna at the Upper Neosho Station, 1957 through 1959 407 Local Variability of the Fauna in Different Areas at the Upper Neosho Station, 1959 409 Temporal Variability of Fauna in the Same Areas 411 Population-Estimation 412 Movement of Marked Fish 416 Similarity of the Fauna at the Upper Neosho Station to the Faunas of Nearby Streams 418 COMPARISON OF THE FISH-FAUNAS OF THE NEOSHO AND MARAIS DES CYGNES RIVERS 419 FAUNAL CHANGES, 1957 THROUGH 1959 420 CONCLUSIONS 423 ACKNOWLEDGMENTS 425 LITERATURE CITED 425 TABLES PAGE 1. Stream-flow in Cubic Feet per Second (C. F. S.), Neosho River near Council Grove, Kansas 364 2. Stream-flow in Cubic Feet per Second, Neosho River near Parsons, Kansas 364 3. Stream-flow in Cubic Feet per Second, Marais des Cygnes River near Ottawa, Kansas 364 4. Stream-flow in Cubic Feet per Second, Marais des Cygnes River at Trading Post, Kansas 365 5. Numbers and sizes of long-nosed gar 372 6. Numbers and sizes of short-nosed gar 374 7. Length-frequency of channel catfish from the Neosho River 388 8. Length-frequency of freshwater drum 402 9. Average number of individuals captured per hour 402 10. Numbers of fish seen or captured per hour 403 11. Numbers of occurrences and numbers counted 404 12. Percentage composition of the fish fauna at the Upper Neosho station in 1957, 1958 and 1959, as computed from results of rotenone collections 408 13. Relative abundance of fish 410 14. Changes in numbers of individuals 411 15. Data used in making direct proportion population-estimations 414 16. Data on movement of marked fish 416 INTRODUCTION