Table 10. --Experiment 15; effects of adult and juvenile tags on the mor- 

 tality and shedding in juvenile fish when tags were inserted anterior- 

 ly at one angle (30°) and two angles (45° and 10°) either high or low 

 on the body cavity wall and when applied posteriorly from the base of 

 the pectoral fin. 







Number of 















fish in 











Type tag 



Method 



experiment 



Dead 



Shed 



Total 



loss 









1 



dumber 



Number 



Percent 



Juvenile 



1 angle-high 



40 



3 



11 



14 



35 





2 angle-high 



40 



11 



6 



17 



43 





1 angle-low 



39 



9 



20 



29 



74 





2 angle-low 



40 



10 



10 



20 



50 





Pectoral 



41 



2 



2 



4 



10 



Adult 



1 angle-high 



45 



21 



1 



22 



49 





2 angle-high 



45 



18 







18 



40 





1 angle-low 



40 



28 







28 



70 





2 angle-low 



30 



8 



1 



9 



30 





Pectoral 



40 



12 



4 



16 



40 



Control 



(not tagged) 



20 



2 



- 



2 



10 



Figure 4. — Juvenile tag being inserted with the modified 

 tagging gun in the pectoral position. The tag is in- 

 jected posteriorly from the origin of the left pectoral 

 fin. 



method used in experiments 7-13 is the poorest 

 of the tested methods for applying both adult 

 and juvenile tags in small menhaden. Tag 

 shedding, tagging mortality, and incision heal- 

 ing were prolonged as in Experiment 14, sug- 

 gesting again that these factors are slowed in 

 cool water. 



On the basis of results from Experiments 1-5, 

 we developed field tagging techniques for adult 

 menhaden. With tagging guns we injected clean 

 dry tags anteriorly at a point about 15 mm 

 above the origin of the right pelvic fin. Per- 

 sonnel were instructed to use the same method 

 of tag application to minimize tag loss differ- 

 ences among taggers. Experimental results in- 

 dicated the Type-1 tag loss for laboratory-tagged 

 fish (114 to 160 mm) ranged between 10 and 20% . 

 This is also our only indication of tag loss in 

 field-released tagged menhaden of this size. 



Experiments 6-15 were conducted to estab- 

 lish tagging techniques for juvenile menhaden. 

 Tags smaller than those used for adults, but 

 identical in other respects, were injected posteri- 

 orly into the fish from the origin of the left 

 pectoral fin with tagging guns which were mod- 



