prefer a river-type habitat (Bailey and Cross, 

 1954), their decline will probably continue. 



Paddlefish 



Only four paddlefish were collected during 

 the 7 years of study. Weight of these fish ranged 

 from 17.5 to 38.0 pounds. This catch was not 

 indicative of the abundance of this species, since 

 it is seldom taken by frame net or small -mesh 

 gill nets. Paddlefish were taken each year by 

 sport fishermen in the tailwaters of Fort Ran- 

 dall Dam, and individuals were observed surfac- 

 ing in Lewis and Clark Lake. Young-of-the-year 

 were not collected with the fishing gears reported 

 in this study; however, in 1962 a total of six, 

 ranging in length from 5.9 to 10.8 inches, were 

 taken in August and October by bottom trawl in 

 the old river channel in the central section of 

 the reservoir. Capture of these juveniles indi- 

 cates that this species was able to reproduce in 

 the reservoir or in the Missouri River below 

 Fort Randall Dam. 



Shortnose gar 



This species was common in the reservoir, 

 and most were collected from the relatively 

 shallow water of the old river flood plain. Fish 

 lengths ranged from 12.0 to 30.3 inches. In 

 1962, lengths of females averaged 24.5 inches 

 and weight 1.8 pounds, while length of males 

 averaged 22.5 inches and weight 1.4 pounds. All 

 fish over 20.0 inches in length were mature, and 

 spawning occurred during the last 2 weeks in 

 June. Young-of-the-year were taken only in 1956 

 (table 7). Abundance and length distribution of 

 gar collected each year suggests adequate repro- 

 duction to maintain the population at a rather 

 stable level (table 6). Most abundant year- 

 classes were produced in 1958 and 1959, and 

 growth rate after the first year (table 8) was sim- 

 ilar to that reported by Netsch and Witt (1962) 

 for the longnose gar in Missouri. This species 

 appears well adapted to conditions in the reser - 

 voir. 



Longnose gar 



Only one longnose gar was collected in the 

 reservoir, although this species was observed 

 in the dam tailwaters . Gavins Point Dam may be 



the upstream limit of this species in the 

 Missouri River, since none was collected by 

 South Dakota biologists in their studies on the 

 fish populations in Fort Randall and Oahe 

 Reservoirs . 



Gizzard shad 



There was a relatively small adult popu- 

 lation of gizzard shad in Lewis and Clark Lake. 

 According to Bailey and Allum (1962), south- 

 eastern South Dakota is on the northern edge 

 of the range of this species. Spawning usually 

 occurred during the last 2 weeks of June, and 

 since this species has a high reproductive po- 

 tential, young-of-the-year were typically abun- 

 dant (table 7). 



Survival of juneniles to their second summer 

 was very erratic because of winter mortality. 

 Reservoir water temperatures were not available 

 for the period 1956-62 for comparison with 

 juvenile shad survival. However, number of 

 days of ice cover in each of the seven winters 

 since impoundment was estimated from known 

 meteorological information in winters 1959-^60 

 through 1962-63. Estimated number of days of 

 reservoir ice cover for each winter, 1956-57 

 through 1962-63, was as follows: 



1956-57 

 1957-58 

 1958-59 

 1959-60 

 1960-61 

 1961-62 

 1962-63 



101 days 

 88 days 

 107 days 

 117 days 

 103 days 

 129 days 

 103 days 



There was no apparent over-winter survival of 

 young-of-the-year shad when reservoir ice 

 cover exceeded 103 days . Survival of shad to 

 age group 1 was attained in 1957, 1958, and 1961 

 (table 9). Preliminary analysis of 1963 col- 

 lections indicates good survival of the 1962 

 year-class to their second summer. 



Survival of the 1956 and 1957 year -classes 

 was good, but year -class survival after that 

 time was poor (table 9). All fish were sexually 

 mature at age group III. Young- of-the-year 

 shad was the dominant forage fish in Lewis and 

 Clark Lake. 



