RECORD OF THE LARVAE OF THE PACIFIC MACKEREL 

 (PNEUMATOPHORUS DIEGO ), 1957 



The distribution and abundance of Pacific mackerel larvae in 1957 are 

 illustrated in figure 6. For uniformity, the same categories of abundance are 

 used in the distribution of Pacific mackerel larvae as In the other larval charts 

 Included In this report. The values at an individual station represent the cumu- 

 lative standard haul total for all occupancies during the year. 



The larvae of Pacific mackerel are reported by size in table VI; the size 

 categories are identical to those used for jack mackerel (see p. 59 for midpoints 

 and ranges). The data are summarized by month and area in text table 10. 



Pacific mackerel larvae ranked eighteenth in abundance during 1957; thus 

 it is one of the less abundant kinds in the CCOFI area. The number of larvae 

 taken during a season has been fairly constant during the past three years, as is 

 shown in the following tabulation: 



1955 1956 1957 



Total 92 1,950 99.9 40 1,519 100.0 76 1,865 100.0 



In the regular CCOFI survey area most Pacific mackerel larvae are taken off 

 central Baja California, especially between lines 110 and 120. During 1957, less 

 than 7 percent of the larvae were taken to the north of this area, a lesser percen- 

 tage than in 1955 or 1956. Over three-fourths of the larvae were obtained in 

 Sebastian Viscaino Bay, mainly during July through October. 



Four cruises were made into the Gulf of California during 1957. Paciflc 

 mackerel larvae taken on these cruises will be dealt with in a separate report, 

 but it should be noted that larvae of this species were much more abimdant in the 

 Gulf than on the outer coast. 



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