significant at the 1 -percent level. This indi- 

 cates that the various samples were not all 

 drawn from the same population. This hetero- 

 geneity of samples was further analyzed with 

 meaningful comparisons between individual 

 areas. 



The samples secured in the Hudson Riv- 

 er were compared, on the basis of body depth, 

 with those taken in the Delaware River (table 2), 

 the nearest geographic area studied. The co- 

 variance procedure testing the slopes resulted 

 in nonsignificance . The intercepts when sub- 

 jected to analysis yielded a value significant at 

 the 1 -percent level. It is therefore assumed 

 that the body depth - standard length relation of 

 the Hudson and Delaware populations increases 

 at different rates from embryonic stage until 

 approximately 32 mm., the minimum size 

 studied (table 13); the two populations increase 

 at the same rate from 32 mm . until at least 227 

 mm. Because of the existing linear relation be- 

 tween the two variables, this similarity undoubt- 

 edly holds true for larger size fish. 



Raney (1957) studying meristic charact- 

 ers, found similarities between the James and 

 Hudson populations. They were significantly 

 different but, approached one another in high 

 first dorsal spine counts, low second dorsal soft 

 ray counts, and low anal soft ray counts. Thus, 

 the Hudson River samples were compared with 

 those collected in the James . The body depth - 

 standard length relation of samples from these 

 two river systems were compared for homo- 

 geneity and an "F' value significant at the 1 -per- 

 cent level resulted (table 3) . 



marie Sound (table 7) , the nearest area to the 

 south. The other collections from Chesapeake 

 Bay differed in body depth - standard length re - 

 lation. The York samples were significantly 

 different from the Rappahannock's (table 9) and 

 the latter were significant from specimens col- 

 lected in the Potomac (table 8) . 



The upstream Santee- Cooper, S.C., 

 samples were compared with those taken below 

 the dam. The covariance test for the homogeneity 

 of regression coefficients, for the regression of 

 body depth on standard length, resulted in an "F" 

 value that was significant at the 1 -percent level 

 (table 10). This indicates that the collections 

 were not taken from the same population, unless 

 an unusual sample was encountered. On the basis 

 of body depth, the downstream Santee-Cooper 

 samples were compared with those from Albe- 

 marle Sound, the nearest area to the north, and 

 a highly significant "F" value resulted (table 11). 



A north -south cline is noted in the column 

 of body depths found in table 12. The northern 

 samples (Hudson and Delaware) are seen to have 

 the least body depth while those from the southern- 

 most area Santee-Cooper, have the greatest body 

 depth. The Chesapeake samples are intermedi- 

 ate and, with the exception of York River, there 

 is an indication of a reverse trend within the Bay. 

 The more southern Albemarle Sound specimens 

 have a greater body depth than the collections 

 within Chesapeake Bay, with the York River 

 population once again proving to be an exception . 

 The Santee-Cooper samples taken below the dam 

 were deeper bodied than those taken above the 

 dam. 



Within the Chesapeake Bay, when using 

 the body depth - standard length relation as an 

 index, most samples used in this study appear 

 to have been drawn from different populations . 

 The only populations found homogeneous in body 

 depth were the James and Rappahannock. These 

 twcf collections yielded nonsignificant results in 

 both slope and intercept (table 4) . The latter 

 two tests proved that the samples were drawn 

 from the same population or, and undoubtedly 

 the case, that body depth caimot be used in 

 separating the two populations . The James 

 specimens were significantly different in body 

 depth from the York (table 5) and Potomac 

 samples (table 6), as well as those from Albe- 



Caudal -Peduncle Depth -- The overall "F" 

 test for the homogeneity of the regression co- 

 efficients, for the regression of caudal peduncle 

 on body depth, yielded a value that was significant 

 at the 1-percent level (table 1). This indicates 

 that the samples used for the test were not drawn 

 from a homogeneous population. 



Table 12 reveals that there is some cor- 

 relation between caudal peduncle depth and body 

 depth. There is only one marked divergence, 

 that of the Potomac having a thicker peduncle than 

 the downstream Santee-Cooper population. The 

 Hudson and Delaware once again harbor the slim- 

 mest fish, with the James next in order. 



