RECORD OF SARDINE EGGS, 1955 



The distribution and relative abundance of sardine eggs in 1955 are 

 shown in figure 2. This chart is comparable to the distributions for 1950 

 and 1951 in Ahlstrom (1954, figs. 7 and 8). Five categories of abundance 

 are used: zero spawning; light spawning, 1-30 eggs; moderate spawning, 

 31-300 eggs; moderately heavy spawning, 301-3000 eggs; and heavy spawning, 

 over 3000 eggs. The value plotted for each station is the cumulative 

 standard haul total for the year. 



A record of all hauls containing sardine eggs in 1955 is given in 

 table II. The eggs are grouped under two headings: "Number of normal eggs" 

 and 'Total number of eggs". The total number includes both normally develo- 

 ping sardine eggs, and eggs classified as abnormal. Abnormal eggs have 

 embryos that are stunted and misshapen; it is not known whether this is 

 due to a diseased condition of the eggs or to mechanical injury during col- 

 lection and preservation. 



Age categories of eggs are designated by the letters A through D, as 

 follows: 



A - Eggs spawned within 24 hours of collection 

 B - Eggs spawned within 24.1 to 48 hours of collection 

 C - Eggs spawned within 48.1 to 72 hours of collection 

 D - Eggs spawned within 72.1 to 96 hours of collection 

 Unclassified eggs (Unci.) includes deteriorating eggs that cannot 

 be classified with certainty. 



The occurrence and abundance of sardine eggs are summarized by month 

 and area in text table 2. No sardine eggs were obtained off central Cali- 

 fornia (station lines 60-77), consequently this area is omitted from the 

 table. 



The distribution of sardine spawning has changed quite markedly dur- 

 ing the time period covered by the surveys (1950 to date). In 1950 and 

 1951, spawning was separable into two centers: a northern center off 

 southern California and northern Baja California (lines 80-107), and a 

 southern center off central Baja California (lines 110-137). In recent 

 years the two centers are less well defined, and it may be misleading to 

 continue to use these designations, except as a convenient method of sub- 

 dividing the spawning area into an upper and a lower "half". In 1955, 

 there was approximately as much spawning in the upper center as in the 

 lower. There was also considerable spawning in the upper center in 1954. 

 As there was practically no spawning in this center in 1952 and 1953, 

 there must have been a marked shift in the spawning population between 

 1953 and 1954. 



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