Table 3. — Experiment 3; effects on the mortality and shedding 

 of tagging with scalpel and forceps, tagging gun, and tagging 

 gun and forceps in groups of 50 adult fish. 



Tagging 



Dead 



Shed 



Total 



loss 



methods 













Numb 



er 



Number 



Percent 



Scalpel and forceps 



2 



1 



3 



6 



Tagging gun 



2 



10 



12 



24 



Gun and forceps 



1 







1 



2 



Control (not tagged) 



2 



- 



2 



4 



Experiment 4 



Objectives: (1) To determine if tags coated 

 with four types of tag lubricants which facili- 

 tated loading the guns affected the tag loss or 

 speed of incision healing in adult fish; (2) to 

 determine the rate of tag shedding with the 

 short -barreled tagging guns. 



Procedure: We tagged five groups of about 

 50 fish (mean length 160 mm) using short- 

 barreled tagging guns. The tags were uncoated 

 or were coated with Vaseline, Bacitracin, Baci- 

 tracin and Vaseline, or Tetracycline and Vase- 

 line. 



Results: Untreated tags had the lowest loss 

 (Table 4). The incision healing portion of the 

 experiment was conclusive. 



Discussion: Since the loss of tags coated with 

 the Tetracycline and Vaseline mixture was 

 slight, we decided to test both the mixture and 

 Vaseline again. The low shedding rate obtained 

 with untreated tags injected with the short- 

 barreled guns in this experiment substantiated 

 our belief that the high rate of tag shedding with 

 the long-barreled gun in Experiment 3 resulted 

 from poor tag penetration. 



Experiment 5 



Objective: To determine if the tag loss from 

 adult fish is affected by sticky tag coatings 

 which facilitate loading the guns, and if the tag 

 loss, as found by Janssen and Aplin (1945), 

 Aasen et al. (1961), and Bayliff and Klima 

 (1962), is affected by different taggers. 



Procedure: Three taggers each tagged three 

 groups of 20 fish (mean length 114 mm). One 

 group was tagged with clean dry tags, another 

 with tags coated with Vaseline, and a third 

 with tags coated with Tetracycline and Vaseline. 



Results: The differences among taggers were 

 as great as those among tag treatments (Ta- 

 ble 5). 



Discussion: A mechanical means of loading 

 tags into the guns eliminated the need to coat 

 the tags, and no further experiments on tag 

 coatings were conducted. We planned to reduce 

 tagger differences in field tagging studies by 

 further standardizing the tagging techniques. 



Experiment 6 



Table 4. — Experiment 4; effects of tag coatings on the mortality 

 and shedding from adult fish. 



Type tag 

 coating 



Number of 

 fish in 

 experiment 



Dead Shed 



Total loss 



Number- 



50 



Bacitracin and 

 Vaseline 



Tetracycline and 

 Vaseline 



Control (not tagged) 



50 



Number Percent 



30 



15 



13 



Objective: To determine the survival rate of 

 juvenile fish tagged with adult tags and micro- 

 wire tags (Jefferts, Bergman, and Fiscus, 1963). 



Procedure: Sixty-five fish from a group of 

 juveniles (mean length 90 mm) were tagged 

 with adult tags. An equal number of fish from 

 the same group were tagged with microwire 

 tags (1.02 by 0.25 mm) in the head, which is 

 the standard location for inserting them. 



Results: Only two fish with adult tags and 

 three with microwire tags survived. 



Discussion: Since microwire tags were too 

 small to be efficiently recovered with magnets 

 and since we also found that they could not be 

 recovered with electronic detector systems, we 

 discontinued experiments with them. Instead 

 we decided to conduct a series of experiments to 



