(1978) found concentrations of mature sauger along substrate of 

 shale bedrock and sand-gravel in the Sandusky River and in riffles 

 of cobble-boulder in the Maumee River. 



To better identify the location of spawning areas for sauger 

 a 32 km reach of the Tongue River from Twelve Mile Dam to the mouth 

 was electrofished on May 9 and 10, 1979. A total of 165 and 37 

 mature male and female sauger were captured; a catch rate of 5.2 

 and 1.2 fish per kilometer, respectively. The sex ratio was 4.5 

 males to one female. Of the 37 females, 2 6 were gravid, 2 ripe and 

 9 spent. Males and females were generally caught together with 

 concentrations evident at two locations; 1) near the mouth (river 

 km 0-6) and 2) half-way between the mouth and Twelve Mile Dam 

 (river km 17-22) (Figure 28) . Concentrations of sauger were 

 smallest from river km 22 upstream to Twelve Mile Dam (river km 

 32) . 

 Temperature 



The mean water temperatures at which sauger first entered the 

 Tongue River in large numbers was 10 to 12°C. Peak spawning (as 

 indicated by peak numbers of males) occurred at 13.2 to 14.0°C 

 during 1977-1979 (Table 22) . During 1980, however, numbers 

 increased when temperatures first exceeded 10°C and then declined 

 after temperatures reached the favorable 13 to 14°C range (Figure 

 A-22) . 



92 



