from the radius of the centrum and 

 the radii of the rings the calculated 

 body length at the time when each 

 ring was formed, so it appears that 

 further examination of these results 

 is necessary. 



a2 Comparison with the results of 

 Uno: 



Comparison with Uno's results 

 also shows differences of 1 to 1,5 

 cm. However, if we take into con- 

 sideration the great dispersion of the 

 lagged difference (table 3) and the 

 possibility that Uno's results were 

 greatly influenced by annual varia- 

 tions due to the fact that they con- 

 sisted of only a single value, it is 

 thought that there is apossibility that 

 the two sets of results are in agree- 

 ment. A rejection test of the two 

 separate results using the t-test was 

 made, and for the interval between 

 the 4th year and 5th year groups (11 

 group and HI group) a > 0. 3 and for 

 the interval between the 5th year and 

 6th year groups (III group and IV 

 group) a > 0. 6, so that it cannot be 

 said that they do not coincide. J.' 



7/ 



— Uno's age group 4, age group 5, and 



age group 6 are thought to correspond respec- 

 tively to group II, group III, and group IV. 



b. According to tables 1 to 4, the modal 

 lengths of the several groups are located at 

 approximately equal intervals, showing that 

 within this size range the growth of the albacore 

 is in a straight line or follows a curve which is 

 nearly a straight line. However, as already 

 mentioned, in this sea area albacore longer 

 then 120 cm. are very rarely taken. This is 

 not limited only to this sea area, for in other 

 sea areas also we find hardly any fish over 120 

 cm. in length. Consequently it is assumed that 

 the maximunn length which albacore reach is 

 between 120 and 125 cm. For group VI the 

 modal length is in the vicinity of 110 cm. and 

 the upper limit of the size range is at 115-118 

 cm. Accordingly this means that the growth of 

 albacore which are almost at the maximum size 

 which they can reach proceeds in a straight line. 

 Since the grdwth of most living organisms is 

 logistic, results of this sort may indicate that 

 it is unreasonable to postulate the various length 

 groups as age groups. 



On the other hand, some doubt also arises 

 as to the assumption that the maximum length 

 of albacore is between 120 and 125 cm. If w e 

 affirm that almost straight line growth is shown 

 up to the position of the modal length of group 

 VI, it means that the maximum length of alba- 

 core that we can anticipate must be much great- 

 er than 125 cm. However, on the basis of the 

 data collected up to the present, it is thought 

 that there is rather little room to establish a 

 hypothesis that the length which albacore can 

 reach is greater than 125 cm. 



Table 6, --Relation between age and body-length 

 a. According to Aikawa and Kato 



Age 







1 



Range of body-length < 35 



35 46 55 64 73 82 91 

 I I I I I I i 100 < 



46 55 64 73 82 91 100 



b. According to Uno 



M and S. D. indicate mean value and standard deviation 



12 



