within two weeks. Floy cinch-up tags (FT-4) were also placed around the 

 caudal peduncle, assuming less irritation would occur. Test fish held at 

 the hatchery showed similar irritation to the extreme that the caudal fin 

 was lost. Finally, the Floy cinch-up tag was inserted through the flesh 

 immediately ventral to the dorsal fin and tightened. Observations on recap- 

 tured fish suggested good tag retention and little irritation. 



SAUGER 



Sauger (Stizostedion oanadense) samples were collected primarily by 

 electrofishing. The boat was adapted, however, to provide an efficient two- 

 man operation. The negative electrode remained on the bottom of the boat, 

 but the positives were supported by a boom system. One man dipped fish while 

 the other retained control of the boat. Sampling was conducted an average 

 of four days a week. Sauger were measured, weighed, and tagged, and a scale 

 sample was collected prior to release. The Floy anchor tag was inserted 

 immediately posterior to the dorsal fin. Drift samples were taken in an 

 attempt to collect sauger fry and eggs. 



CHANNEL CATFISH 



Channel catfish (Ictalurus punatatus) populations in the Tongue River 

 were monitored by sampling with baited traps constructed from reinforcing 

 bar material and chicken wire in three reaches of the river. Using rotten 

 cheese as bait produced the most fish per trap night. Catfish were tagged 

 with Floy anchor tags in 1974 and 1975, but high incidence of anchor tag 

 loss reported in other studies prompted a change to other tagging methods. 

 A numbered plastic disc attached to the fish with 0.81-mm (0.032-in) 

 stainless steel wire immediately ventral to the dorsal fin was used in 

 1975 and 1976. Irritation associated with this tag resulted in the use of 

 the Floy cinch-up tag. Preliminary results suggest good retention and minor 

 irritation. 



AGE AND GROWTH 



Attempts to determine the age of shovelnose sturgeon by sectioning a pectoral 

 fin ray as described by Priegel and Wirth (1975) for lake sturgeon were 

 unsuccessful. The cross section was opaque and no annulus formation could be 

 detected. An attempt to determine growth by comparing weights and lengths 

 at marking and recapture was also unsuccessful, as is explained on page 47. 



Age and growth of sauger were investigated by analysis of scales. 



Pectoral spines taken from channel catfish were sectioned as described by 

 Marzolf (1955) and Sneed (1951) using an instrument similar to the one described 

 by Witt (1961). With this instrument, the spines were sectioned thin enough to 

 eliminate further grinding. The sections were coated with glycerin and aged 

 with the aid of a binocular microscope. The translucent rings were considered 

 to be year marks when they were distinct and continuous in all areas of the 

 section (Marzolf 1955). 



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