Figure 1. — The fish tagging equipment in use. 



plates are washed and dried, and tag numbers and 

 length measurements are recorded. Fisli lengths 

 are read oti' the tagging plates with a T-square 

 ruler. 



With ex{)erience in judging the time required 

 to immobilize akule, two men (a tagger and an 

 anesthetist) have tagged about 100 fish per hour. 

 The rapidity and I'elative ease of tagging by this 

 method also atl'ord time for additional care in 



handling the fish. Use of the X-ray-film tagging 

 plate has three other advantages over the usual 

 tagging procedure: it (1) eliminates reading and 

 recording tlie tag niunbers and fish-length meas- 

 urements during the tagging; (2) minimizes errors 

 (misreading, misrecording, and digit bias) during 

 the tagging; and (3) provides permanent length 

 records that can be rechecked later. 



LITERATURE CITED 



JoERis, Leonard S. 



19.59. Rapid measurement of fish. I'rogr. Fish-Cult. 

 21(4) : 190-191. 

 Sakuda, Henry M. 



1966. A modified plastic internal anchor tag. 

 Progr. Fish-Cult. 28(3) : 132. 



Thompson, D'Arcy W. 



1929. Apparatus for measuring fish. ,T. Cons. 

 4(1) :10-1. 



WOLLASTON, H. J. B. 



1928. New apparatus for measuring fish. J. Cons. 

 3(3) : 380-381. 



574 



U.S. FISH AND WILDLIFE SERVICE 



