DISTRIBUTION OF EGGS AND LARVAE OF JACK MACKEREL 



253 



The regional (north-south) distribution of 

 spawning fish was inferred from the regional dis- 

 tribution of eggs. The number of eggs found in a 

 region was expressed as a percent of the total for 

 all regions (i.e., annual total). These figures are 

 given in the last column in tables 2 through 5. 

 The lines comprising each region are as follows : 



Region 



1 

 2 

 3 

 4 

 5 

 6, 



Area 



Northern California.. 



Southern California 



Northern Baja California 



Upper central Baja C-.ilifornia. 

 Lower central Baja California, 

 Southern Baja California 



Lines 



40-77 

 80-93 

 97-107 

 110-120 

 123-137 

 140-157 



A slightly different approach was used to 

 elucidate the offshore-inshore distribution. Un- 

 like the preceding section, only selected stations 

 on selected lines were used, because the selected 

 data were more quickly and easily handled, and 

 because these particular selected stations had the 

 most regular coverage, having been occupied 

 almost every month throughout the 4 3-ears 

 studied. 



Only those lines and stations that are multiples 

 of 10 were used (e.g., lines 40, 50, and 60, but 

 not 63, 67, or 73, and stations 40, 50, and 60, but 

 not 45, 55, or 65), e.xcept for the most inshore 

 stations. The standardized nimibers of eggs 



Table 3. — Estimated number (in billions) of jack mackerel eggs in survey area, 1952 

 [Cruise numbers In parentheses. No eggs taken during cruises 5210 and 5211] 



1 Hundredths of a percent are used so that trace amounts of spawning may be indicated (see p. 252). 



