PART I 



RESPONSE OF TUNA TO CHEMICAL STIMULI 



BY 



Albert L„ Testerp P., Bo van Weelj and 

 John Jo Naughton 

 University of Hawaii 



In 1951„ exploratory studies of the response of tuna and 

 other fish to chemicalj, visual^ auditory, and electrical stimuli were 

 conducted by Po Bo van Weel„ So Co HsiaO;, !„ Miyake„ and Ao Lo 

 Tester (Special Scientific Reports Fisheries Noo 9l> of the faculty of 

 the University of Hawaii under contract (Nool^fw-.l 3 33 1) with the 

 U„ So Department of the luteTior, Fish and Wildlife Service^ Pacific 

 Oceanic Fishery InvestigationSo It was hoped that these studies not 

 only would contribute to an understanding of tuna behavior but also 

 would provide an indication of ways of attracting tuna to within the 

 reach of a fishing vessel at seao 



Of the various 1951 studies;, the most promising was in 

 the field of chemoreceptiono Van Weel fl952) found that little tunny 

 (Euthynnus yaitoll and yellowfin (Neothunnus macropterus) held in cap- 

 tivity responded to cleaXj, almost colorless extracts of tuna fleshy 



A new l=.year contract (Noo I6fw.= 18564) for a further study 

 of the reactions of tuna to chem.ic;al stimuli became effective June 1, 

 1952a Efforts were to be made to duplicate and extend van Weel's ob- 

 servations „ to identify chennicilly the attractive 8ubstance(8), and to 

 make observations on the reaction of the fish to combined chemical 

 and visual stimulio 



This report deals with the 1952-53 results in the field of 

 chemoreception and includes a brief account of the success attained in 

 fishing and establishing the tuhas in captivityo 



Notes Contribution No. 47 of the Hawaii Marine Laboratory, 

 University of Hawaii, 



