Iquique during the week of August 1 through the 8th, were unable to sight 

 any swordfish. 



Comparison of Chilean and Peruvian statistics show that the period of 

 greatest abundance (May, June) in northern Chile corresponds with the 

 period of least abundance in northern Peru, and that as abundance 

 decreases in Chile from late June on, it increases at the same time in north- 

 ern Peru, reaching its peak in September. On the other hand, the period of 

 least abundance in northern Chile (November through February) also 

 corresponds with another period of least abundance for northern Peru. 



It may be tentatively inferred from the above that perhaps the 

 Chilean and Peruvian swordfish may belong to the same population and 

 that they may move towards the north, from Chile to Peru, during late 

 June through September. It may be pointed out here, that commercial 

 fishermen operating in northern Chile state that the schools of swordfish 

 move from south to north (Tocopilla towards Iquique and Arica) during 

 late June and July and that the commercial fishermen operating out of 

 Mancora, northern Peru, have known for years that the September run 

 comes from the south. The fish arrive first ofl" Paita, about 65 miles south 

 of Mancora and a few days later they show up off the latter locality. The 

 coincidence of periods of least abundance for Chile and Peru during No- 

 vember through February may mean that the fish have moved into as yet 

 unknown spawning grounds during that time before returning south. This 

 period (November through February) comprises late spring and early sum- 

 mer in the southern hemisphere and it is interesting to note that Atlantic 

 swordfish spawn during that season of the year in the northern hemisphere. 

 .As already indicated, the gonads of the swordfish examined in northern 

 Chile during April through July, and in northern Peru during August, ap- 

 peared to be in a resting condition, thus indicating that spawning must take 

 place sometime between September and April. 



In addition to billfishes, yellowfin tuna, bonito, mackerel, and other 

 sconibrid fishes were studied in northern Chile, Peru and Ecuador. 



0Pther iiitfiaqU'al Ohserrations 



During the period of work in Chilean waters, arrangements were made 

 to cooperate with Dr. Francis O. Schmitt, head of the Department of Bi- 

 ology, Massachusetts Institute of Technology, in connection with studies 

 of the giant nerve fibers of the squid (Figure 6). These are among the 

 largest single nerve fibers in the animal kingdom and are being used in the 

 above institution in the investigation of the chemistry of the squid nerve 

 axoplasm. 



Since the giant squid (Figure 3) occurring in the Humboldt current ofT 

 Chile were expected to possess even larger nerve fibers, the expedition 



'25 



