and the dolphin have body temperatures 0.6'^ higher than the surrounding 

 water. Studies in this field must be made more accurate through the 

 addition of more measurement data. 



In measuring the body temperature of saury, as in the case of sardines, 

 the fish are small and therefore a rod-shaped thermometer is unsuitable. 

 It is necessary to use a thermo-electric pile or an electrical resistance 

 thermometer. 



Form and body wei^^ht of fish . The form and locomotion of fish vary 

 depending on the species, and they also differ according to the size and 

 age of the fish. The pattern and speed of the movements of fish, and the 

 resistance to their movements differ markedly depending on form, density, 

 propulsive power, and the operation of the fins. The study of these 

 problems probably will require mathematical researches based on aerodynamic 

 experiments in a wind-tunnel or in a tank using models and real fish as 

 well as actual measurements, 7?hat I wish to do here is to attempt an 

 elementary examination of thr essentials of the form and vreight of the 

 body of the fish from the records of actual measurements of skipjack and 

 saury. Now when we make iV the reight of the fish, I the body length, 

 and p the density of all parts of the body 



u 



= ^jjjp^Kdycl:L „U) 



/'differs in each part of the body and should be determined separately for 

 each cross-section, however, considering the state of equilibrium of the 

 body of the fish in tho water, it is assumed that it has a roughly uniform 

 value p which is approximately the density of the surrounding water. Then- 

 with the ratios of body height (A) and body mdth {d ) to body length 

 (/ ) expressed as 5. and Q { ^^^l,o~Bl), it is possible to make the 

 substitutions dyC^dl > d^^Bdi, and o^ sdidl ^ov any part of the body, 

 giving roughly ^ 



W^ fj.gp'0i/3l'^ (5) 



Accordingly yf 3 /. f^\ 



K--J3 X 10 ^u-'pap (6) ^^^ 



As for the circumfei'-'ence 3 , if we take it as the circumference of a 

 circle whose diameter is ^fd 



s.s'=n ^^ ....(7) 



If the cross-section is taken as an ellipse of which^isthe long axis and d 

 is the short axis, c = ^~" will be too small, so 



5=-S'+A,^i=^*C*- (8) 



(3) Kimura, Kinosuke: The Fatness and Density of Fish. In Bulletin of 

 the Japanese Society of Scientific Fisheries, Vol.6, N0o2, pp. 69-72. 

 1937. In this article Kimura defined the above-mentioned /fas the condi- 

 tion factor, determined ^ , A/^, and/ for the sardine, and discussed 

 K. in detail. 



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