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FIRST DIRECTION « - BUTANOL : METHYLETHYLKETONE AMMONIA WATER - 24 HOURS 



vation, the general similarity of adult and lar- 

 val chromatograms, was noted in the results 

 of the larval tests. 



As expected, adult samples developed 

 successfully in two-dinnensions yielded nnore 

 spots than those developed in only one-dimen- 

 sion, and differences in the positionof the spots 

 were more pronounced among most of the spe- 

 cies. Only two out of the six species tested 

 could not be distinguished, since chromatograms 

 of yellowfin and bigeye samples appeared iden- 

 tical. Perhaps the use of other solvents may 

 provide visible differences between these two 

 species. 



Results of larval samples of yellowfin 

 and skipjack were rather inconsistent. How- 

 ever, they do not preclude the usefulness of 

 this technique in taxonomic studies. Part of 

 the inconsistency could have been due to inade- 

 quate methods of application which can be reme- 

 died. There is some encouragement in the fact 

 that, of the better results obtained with skipjack 

 larvae, some sin-iilarity in the general distribu- 

 tional pattern of the more prominent amino 

 acids were evident. 



Figure 6. --Two-dimensional chromatogram of 

 adult yellowfin. 



DISCUSSION AND CONCLUSIONS 



These experiments provided valuable 

 infornnation concerning the use of chromatog- 

 raphic technique in the species identification 

 of some of the tunas. It was found that adult 

 samples of the same species of tuna developed 

 one-dimensionally in different solvents resulted 

 in dissimilar chromatograms. This was par- 

 ticularly noticeable of the albacore and bigeye 

 samples. Although yellowfin and skipjack sann- 

 ples developed in two different solvents showed 

 no difference in the chromatograms, it is be- 

 lieved that trials with other solvents would re- 

 veal a suitable solvent capable of producing dif- 

 ferent chromatograms between these two spe- 

 cies. Similarly, suitable solvents also could 

 be sought for the two frigate mackerels and 

 other species of tunas not mentioned. If suc- 

 cessful, one -dimensional chronnatography might 

 be a useful taxonomic tool for adult tunas. 



The same cannot be said with equal as- 

 surance about larval identification because lar- 

 vae of only two species (yellowfin and skipjack^ 

 were tested. However, one encouraging obser- 



FIRST DIRECTION :«- BUTANOL METHYLETHYLKETONE - AMMONIA WATER-24 HOURS 



Figure 7. --Two-dimensional chromatogrann of 

 adult skipjack. 



