IOWA (Cont. ) 



Leader; reports available. 



Address inquiries to: Kenneth D. Carlander, as in No. 1 above. 



4. Life History and Ecology of Carpsuckers, Carpiodes , spp. 



The role of carpsuckers is little known, even though these fish are abun- 

 dant in many Iowa catfish streams. The present study is an exploratory one to 

 determine relative abundance, habitat selection, growth, and food habits of 

 the species in the Des Moines River. 



Iowa State Conservation Commission and the U. S. Fish and Wildlife 

 Service cooperating; Des Moines River, Boone County; began October 1955, 

 to close July 1957; $2100; Kenneth D. Carlander and Marvin Buchholz, Leaders; 

 reports available. 



Address inquiries to: Kenneth D. Carlander, as in No. 1 above. 



5. Survival and Growth of Young-of-the-year Fish 



In an attempt to determine the factors which affect the abundance of year 

 classes, the early life history of Clear Lake fishes is being investigated. 

 Weekly collections are made at several portions of the lake, with emphasis 

 on relative abundance, seasonal changes, growth, and food relationships. 



Iowa State Conservation Commission, U. S. Fish and Wildlife Service, and 

 Sport Fishing Institute cooperating; Clear Lake; began May 1956, to close 

 March 1958; $2200; Kenneth D. Carlander and Richard L. Ridenhour, Leaders; 

 reports available. 



Address inquiries to: Kenneth D. Carlander, as in No. 1 above. 



6. Life History and Ecology of Clear Lake Minnows 



Although several species of minnows are present in Clear Lake, none of 

 them are very abundant, possibly due to predation by the game fish popula- 

 tions. The present study on the minnows includes weekly collections at several 

 points to determine relative abvmdance, seasonal changes, growth, and food 

 relationships. 



Iowa State Conservation Commission, U. S. Fish and Wildlife Service, 

 and Sport Fishing Institute cooperating; Clear Lake; began July 1956, to close 

 July 1959; $2200; Kenneth D. Carlander and James McCann, Leaders; reports 

 available. 



Address inquiries to: Kenneth D. Carlander, as in No. 1 above. 



7. Walleye Fry Stocking in Clear Lake 



Plantings of over 5, 000 walleye fry per acre have been made in Clear 

 Lake in the even numbered years since 1948 with no fry stockings in the odd 

 numbered years, to test the effectiveness of annual fry stockings such as 

 have been made since 1915. Scales are taken each year from adult fish to 

 deternnine year class abundance and to see whether there is a corresponding 

 alternation of abundant year classes. 



Iowa State Conservation Commission and U. S. Fish and Wildlife Service 

 cooperating; Clear Lake; began 1948, to close 1959; $300; Kenneth D. Carlander, 

 Leader; reports available. 



Address inquiries to: Kenneth D. Carlander, as in No. 1 above. 



8. Fish Population Changes in Clear Lake, Iowa 



Annual Collections of scales, length-weight data, life history information, 

 and gill net catch records have been made at Clear Lake each summer since 

 1947. 



Iowa State Conservation Commission, U. S. Fish and Wildlife Service and 

 Sport Fishing Institute cooperatiiig; Clear Lake; began June 1947, indefinite; 



35 



