2 This study was made from 1932 on aboard the Fuji Maru, guide vessel 

 of the Shizuoka Prefecture Fisheries Ifcrperi ment Station, at Mito Beach 

 in Shizuoka Prefecture;, at the Kanagawa Prefecture Misaki Marine 

 Laboratory , end at several other places „ 



So The fish used in the experiments were Sardinia melano sticta and 

 g2graulj-s j aponicus of sizes suitable for use as baito 



4, By keeping a school of bait fish in a tightly closed vessel and 

 studying the rate of speed at which they consumed oxygen by abnormal 

 breathing it was demonstrated that since the average lethal concentration 

 of oxygen for bait fish is roughly fixed, the more fish (total body 

 weight) there are, the faster the oxygen will be used up and the quicker 

 the fish will die« 



So By shutting up a single sardine or anchovy in a small tightly closed 

 vessel and measuring the lethal concentration of oxygen it was found that 

 sardines die when the free oxygen falls below about 2 cc per liter and 

 that the figure for anchovies varies only slightly from this,. 



So With the old=fashioned type of bait tank with natural water circula- 

 tion the danger was always present that the fish would begin to show 

 signs of oxygen deficiency, not only right after they had been placed in 

 the tanks and in their ement were using up large quantities of free 

 oxygen but also whenever the vessel was not rolling very much, however, 

 with the present style of tanks with pumped water circulation, if only 

 a little care is taken for a short while after the fish are put into the 

 tank, there is thereafter no danger at all of oxygen deficiency., This 

 has been shown by citing actual experience 



7„ Minute quantities of ac=>tetrahydro A naphthylamin hydrochloride 5$ 

 solution, which causes fever centrally by exciting the temperature center 

 and other sympathetic nerve ganglia, a xlOOO solution of adrenalin, which 

 causes fever by central and peripheral . and pituitrin, which 

 causes the body temperature to drop by acting centrally, were injected 

 subcutaneously and were found t o cause no reaction,, Thus it was learned 

 that sardines appear to have no center for regulating body temperature 

 and that their body temperature changes with the temperature of the 

 surrounding water c 



8c A controlled=temperature tank was used to study the resistance of 

 bait fish to sudden rises and drops in the water temperature* With the 

 sea~water at approximately 22° = 25°C at the time of the experiment,, it 

 was found that sardines could endure a temperature range of 7° = 2& 

 while anchovies could live in a range of 11° = 51 C o This demonstrated 

 that sardines have resistance to low temperatures (sudden drops in 

 temperatures) while anchovies are more resistant to high temperatures 

 (sudden rises in temperature). 



53 



