Table 3. — Results of experiments to determine the suitability of checkwriter inks used with fast 



green FCF 



[Determination of the condition and location of secondary marks was made after death. Results 

 frcan shrimp that died within 10 days are not included] 



Table 4. — Summary of experiments involving fluorescent marks applied by the double-injection technique of marking 



[Determination of the location of the seoonlary marks was made after death. 

 Results do not include shrimp that died within 10 days of marking] 



pigments appear to provide marks that meet 

 the requirements of field mark- recapture 

 studies. 



Single-Injection Method of Marking 



This method consists of injecting a mixture 

 of primary and secondary marking materials 

 in a single operation. Various connbinations 

 of fast green and the fluorescent solvent. 



Fluorographic, were tested as combination 

 marks. The mixture of these materials ap- 

 peared green in color under white light and 

 chalk white under ultraviolet light. After in- 

 jection, the fast green concentrated in the gills 

 within 24 hours, whereas the fluorescent sol- 

 vent remained diffused throughout the body for 

 2 days and then began to concentrate in the 

 gills. Mixtures of 0.05 percent fast green and 

 Fluorographic in ratios of 7:1 or 8:1 produced 



