Figure 8 A scatter diagram of body height (A) (left vertical axis) 

 against body length ( / ) (horizontal axis) and total length (Z. ) 

 (inner right vertical axis) and head length (D ) (outer right vertical 

 axis). 



Figure 9 A scatter diagram of condition factor {K) against a: /3 . {kr ■ 

 dll ), 



Figure 10 A scatter diagram of body weight in gr (vertical axis) against 

 body length in cm (horizontal axis) for saury taken in November 194.0 

 (o) and August-September 1940 (x) plotted on logarithmic graph paper. 



Figure 11 A scatter dia^^ram of body height {^-), body circumference (-S), 

 body width ( o' ) j and condition factor (A) (all on the left vertical 

 axis) against body length in cm (horizontal axis) and total length 

 {L) in cm (right vertical axis). August-September fish are represented 

 by a circle for X. , an x for 5 , a circle with a dot for ^, and an 

 open triangle for d , and a circle with a dot for L . The November 

 fish are represented by a cross f or X , a circle with a dot for S, 

 a dot for K , a filled-in triangle fore/, and a dot f or Z . 



Figure 12 Four scatter diagrair.s cf K (verLical axes) plotted against 

 ^jL^i , 52.<X/3, and s/i „ 



Figure 13 Tvi'o scatter diagrams of condition factor ( ^) and bod> weight 

 [W) plotted against the ellipticity of the cross-section (c )._/ 



On the IVeight Composition of Skipjack Schools in the 

 Northeastern Sea Area 



/English title and synopsis_7 



On the Composition of Shoals of "Katuo," Euthynniis vagans (Lesson), 

 in the Northeastern Japanese Waters as Analysed by the 



Body- weight 



Gorozo Okamoto 



Based on the materials of the catch of "Katuo" landed at Kesennuma, 

 Miyagi Praf. in 1939, which are grouped according to their dominant body- 

 weights, an investigation was made on the composition of the fish. In 

 Fig. 2 four characteristic groups A, B, C, and D of the shoals are recog- 

 nizable, which are in the ratios of 75:10;3sll in the catch, and the in- 

 crease in the body-weight of each group during the fishing-season seems 

 to indicate the growth of the fish in the respective group. From the 

 point of view of forecasting the yearly catch, however, more detailed and 

 continual knowledge of the conditions such as migrations of the four 

 groups are wanted in the future, /"End of English synopsis_7 



In 1939 the total catch of skipjack from the Northeastern sea area, 

 that is the waters north of a line drarm east from Nojimasaki in Chiba 

 Prefecture and off the coasts of Tokiwa, Sanriku, and eastern Hokkaido, 



2U 



