FISHERY BULLETIN: VOL. 71, NO. 2 



Table 6. — CV^ values by year of hatch in the 100.0-199.9 mm size class of barred 



sand bass from southern California. 



' The 1960, 1961, and 1962 year of fiatch class of fish were not included in this analysis since 

 N = 4. 



en 9 



6 



-I 9 



_l 



<-> I 



< 



-1.8 _| 



< 



1.0 Q 



I- 

 o 



0.8 LU 



I69.4±20.6 20I.6±I43 2')2.0±9.l 180.5+5 5 II78±7.7 



1980 



1 1 — \ 



1988 1960 1963 



MEAN YEAR OF HATCH 





Figure 1. — CK^ values for southern California barred 

 sand bass grouped by probable year of hatch. Closed 

 circles, gill rakers; open circles, pectoral fin rays. Numbers 

 on upper abscissa indicate mean length of specimens in 

 samples ± SE. To increase sample sizes fish from several 

 consecutive years of hatch were pooled as follows: up to 

 and including 1956; 1957 through 1959; 1960 through 

 1962; 1963 through 1965; 1966 and later. 



Figure 2 graphically demonstrates how asym- 

 metry values vary with increasing size, both 

 in our Mexican fish and in fish from our 

 southern California cohorts analysis. 



Grunion 



Only two bilateral meristic counts were made 

 on grunion, the number of pectoral fin rays 

 and total gill rakers. Most gioinion were 

 probably not over 2 years old and, hence, were 

 not grouped into classes based on dates of 

 hatch but rather only by dates of collection 

 (Table 7). Our Turtle Bay sample is not large 

 enough to determine asymmetry trends with 

 body size. 



The Turtle Bay collection has the lowest 

 CV"^ values. Contemporary San Quintin and 

 San Diego collections have statistically increas- 



ing CV^ values with time. We employed Ken- 

 dalls' coefficient of concordance (Snedecor, 

 1956) on the data in Table 7 to test for asym- 

 metry trends with date of capture for both 

 characters in grunion from Belmont Shore. 

 The results are significant, 0.05 < P < 0.01, 

 indicating a significant association between 

 year of collection and asymmetry for both 

 characters. 



•6 > 

 .2 



.o2 



Ll 

 .8 



.6 -I 



-^ 

 .2 O 



H 

 O 



.8 Q_ 



.6 



.4%.0 



.2 " 



STANDARD LENGTH mm 



Figure 2. — CV^ values for Mexican and California 

 barred sand bass, by standard length. Mexican fish 

 grouped by 50-mm size classes, all years of hatch 

 combined. California fish grouped by 100-mm size 

 classes, only fish hatched in the period 1957-59 included. 

 Dots, gill rakers; open circles, pectoral fin rays. Numbers 

 by data points indicate sample sizes. 



Barred Surfperch 



For this species, as for grunion, only pectoral 

 fin rays and gill rakers were used in our analy- 

 ses. From the data presented in Table 8 it 

 can be seen that the barred surfperch data 



362 



