TABLE 17. Average lengths and range of lengths for each age group of 132 

 channel catfish taken in the lower Tongue River in the fall of 1976. 



Average Length (mm) Range of Lengths (rmi) 



113 101-120 



211 186-230 



251 235-279 



276 254-301 



303 274-344 



340 335-344 



364 341-372 



388 362-404 



447 415-477 



468 452-489 



514 456-575 



547 492-665 



585 516-668 



600 374-745 



743 743-743 



CONVERSIONS: 1 mm = .0394 in 



Those catfish found in section lib were considered to be part of a 

 resident population since their movement is restricted by the T&Y and S-H 

 diversions. Since growth rates were constant between years in section lb, 

 it is suggested that channel catfish may spawn every other year in section lib. 

 Meyer (1960) found through examination of annuli on paddlefish maxillary 

 that the species spawned at intervals of 4-7 years. It is possible that the 

 irregular growth pattern exhibited in section lib by channel catfish is the 

 result of alternate-year spawning activity. 



DeRoth (1965) found smaller average lengths per age class in the channel 

 catfish of Lake Erie than those found in the Tongue. The same held true 

 with the catfish of the Lake of the Ozarks (Marzolf 1955). Witt (1966) 

 found greater average growth per annulus in the Little Nemaha River. A growth 

 rate similar to that shown in the Tongue River v;as found in the Des Moines 

 River of Iowa as reported by Carlander (1969). 



CATCH RATES 



In 1975, 472 channel catfish were captured in 106 trap sets for a catch 

 rate of 4.45 fish/trap. Catch rates for the three reaches were: section lb 



57 



