deBuen, F. 1957. Pelagic fishes and oceanog r aph ic 

 conditions along the northern and central coast of 

 Chile, [Fr. summ.] UNESCO Symposium on Physical 

 Oceanography 1955 Tokyo, UNESCO, Tokyo, p. 153- 

 155. 



A general overview of tuna and billfish biol- 

 ogy and related oceanographic observations 

 for the central Chile coast. 



KEY WORDS: tuna, billfishes, feed, water 

 color, maturation, sea surface temperatures. 



Dizon, A.E. 1977. Effect of dissolved oxygen concen- 

 tration and salinity on swimming speed of two 

 species of tuna. Fish. Bull., U.S. 75:649-653. 



Yellowfin and skipjack held in tanks were 

 tested against decreasing oxygen and sali- 

 nity. No consistent swimming speed changes 

 were observed when salinity was decreased 

 from 34 to 29°/oo. For oxygen decreases: a) 

 at about 4 ppm skipjack abruptly increased 

 swimming speed; b) yellowfin did not alter 

 speed; c) some skipjack died at about 2.5 

 ppm. Hypothesized that increased swimming 

 speed at low oxygen levels is a behavioral 

 response to remove an animal from suboptimal 

 areas . 



KEY WORDS: tuna, yellowfin, skipjack, oxy- 

 gen, salinity, habitat, behavior, distribu- 

 tion, depth. 



Dizon, A.E., R.W. Brill, and H.S.N. Yuen. 1978. 

 Correlations between environment, physiology, and 

 activity and the effects on thermoregulation in 

 skipjack tuna. In G.D. Sharp and A.E. Dizon 

 (editors). The physiological ecology of tunas, p. 

 233-259. Acad. Press., N.Y. 



Reviewed the physiological limitations im- 

 posed by the habitat on the fish. Discussed 

 energetics of swimming and thermal regula- 

 tion, and physiology of skipjack in relation 

 to habitat occupied. 



KEY WORDS: tuna, skipjack, yellowfin, be- 

 havior, habitat, temperature, oxygen, depth, 

 thermocline, light. 



21 



