FISHERY BULLETIN: VOL. 78, NO. 2 



The impression of "patches" of larvae in poor 

 condition indicated by the histological samples 

 from the Newport Beach area was further 

 strengthened by subsequent examination of the 

 unsectioned larvae remaining from all net tows. 

 Figure 15 shows a random portion of tow 23, which 

 contained over 300 larvae and produced only 

 healthy larvae in the histological sampling. The 

 specimens are full-bodied with good symmetry 

 and are straight, or at worst gently curved. Figure 

 16 shows a random portion of tow 9, which pro- 

 duced a high proportion of emaciated larvae in the 

 histological sampling. Several of these larvae 

 have angular body bends, trunks and digestive 

 tracts that are lumpy and sinuous, and heads often 

 misshapen with loose or missing eyes. They also 

 appeared to be less intensely colored by the fixing 

 solution than the others. When viewed in toto, this 

 and the other three tow collections of larvae that 

 produced histologically poor samples were readily 

 distinguishable from all others. 



The emaciated larvae consititute a percentage 

 of the number of larvae examined, but the mag- 

 nitude of this percentage depends on the portion of 



the total samples that are considered (Table 3). 

 The four tows with a high incidence of emaciation, 

 considered by themselves, indicate 60% 

 emaciated larvae within local patches. This drops 

 sharply to 12% when coverage is expanded to a few 

 dozen tows in approximately 200 mi^ off Newport 

 Beach, and to 10% when an additional 10 tows, 

 rather widely scattered over the San Pedro Channel 

 area are included (inshore set). By comparison, the 

 pooled offshore samples (offshore set) which repre- 

 sent perhaps 6,000 mi^, indicate 5% emaciated, and 

 samples pooled for the entire cruise show an inter- 

 mediate value of 8% emaciated. 



Day and night subsets of the inshore and 

 offshore sets show differences in both the available 

 population and the percentage of emaciated lar- 

 vae. The lower daytime catches imply that the 

 population was less available during this period, 

 probably because much of it migrated below the 20 

 m depth of the tows during the day and probably 

 also because larvae have some success in visually 

 avoiding the net during the day. As a simple 

 binomial function, the 15% emaciated larvae for 

 the inshore night group is significantly higher 



Figure 15. — A random portion of the northern anchovy larvae from tow 23, in which the larvae show generally good body form. 



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