the same locality as -0-group fish, it is necessary to compare samples of 

 the 0-group fish with samples of I-group fish taken one year later. Be- 

 cause such fish will be from the same year class, valid comparisons of the 

 circuli widths in the first growth zone can be made. Tables 26 and 27 

 show that the lIiO 0-group fish were sampled in 1931 at Montauk, N.Y,; in 

 1932 139 I"group fish were sampled. A comparison of the circuli widths 

 yields the following analysis of variance j 



Source 



Tbtal 

 Mean 

 Years 

 Within Years 



Degrees of 

 Freedom 



279 



1 



1 

 277 



F/vi 



Sum of 

 Squares 



2U8,81|8 

 2147,275 



1,568 

 P> 0,05 



Mean 

 Squares 



5 

 5.66 



The analysis of variance indicates no significant difference. From 

 this comparison, it can be concluded that the measurements are from the 

 same population of weakfish. Hence, northern I-group fish spent their 

 first summer in the same locality as 0-group fish. 



The latter observation suggests that all I-group weakfish in the 

 Northern area completed their first summer's growth there, so that data 

 drawn from the first growth zone of their scales is the equivalent of data 

 from the scales of Northern 0-group fish. The samples for the Northern 

 I-group were taken in the course of routine data collection from many 

 catches over extended periods of time. The 0-group samples were taken 

 over short periods of time at the end of the season. A few large samples, 

 especially c ollected when opportunities presented themselves, account for 

 a considerable part of the data. Since such large collections may over- 

 represent sub-groups, such as have frequently been observed among juven- 

 iles, it was concluded that the I-group data are probably more represen- 

 tative of the typical 0-group spacing in the northern area than are data 

 drawn directly from the 0-group samples. Consequently, in subsequent 

 analysis, normal distributions computed from the I-group data have been 

 used to represent the Northern area. 



Parenthetically, it may be noted that the differences in spacing 

 appear to be virtually independent of the differences in growth which 

 are also characteristic of the areas or of locality subdivisions within the 



Northern area. Within each area, the larger, hence presumably faster 

 ^^rowing individuals do not show materially coarser spacing. 



With the sole exception of the instance noted above, in which 

 Northern I-group and Northern 0-group fish agree with respect to circulus 

 spacing of the growth zone, adult distributions are significantly differ- 

 ent from the juvenile distributions characteristic of the areas in which 

 the adults were taken. The differences are such as to suggest that the 

 adults in each area repiesent a mixing of weakfish from two or more 

 nursery areas. 



7U 



