Moser and Pommeranz: Distribution of eggs and larvae of Engraulis mordax 



937 



-r- 



25 



30 10 20 30 40 50 60 70 80 



Larvae/ 1000m3 



I I I I I I I I I I 



28 31 34 37 40 43 46 49 52 55 58 61 

 30 33 36 39 42 45 48 51 54 57 60 63 



Tow number 



^ 40-80 



E 



2 80-120 



,^.S\^.S^,^.\^^.\..^.\^^SSSSN^ 



-1— 



10 



1^ 



25 



30 20 40 60 80 100 120 140 



Larvae/ 1000m3 



Figure 17 



Peprilus simUUmus larvae (no./lOOO niM in MESSHAI tows. Average from ( Al deep and (B) shal- 

 low tows at inshore (solid) and offshore (shaded! stations; (C) densities in 0-40 m stratum from 

 sequential deep tows at inshore station; (D) densities in 0-40 m stratum (average of pooled 10-m 

 strata) from sequential shallow tows at inshore station; average from lE) deep and (F) shallow 

 tows at inshore station before storm (cross-hatching) and after storm (hatching). 



most abundant shelf species in the samples, typically 

 spawns from late spring to summer; however, spawn- 

 ing began unusually early in 1980 since larvae were 

 abundant as early as March off San Onofre (Walker 

 et al., 1987). Peprilus simillimus, Par-alichthys cali- 

 fornicus, and Cithanchthys spp. have broad spawn- 

 ing seasons with high larval abundance in late win- 

 ter to early spring. This was particularly evident in 

 .1980 (Walker et al., 1987; Moser et al., 1993). 



The vertical distribution of larval fishes is closely 

 related to the temperature profile of the water column. 



Ahlstrom ( 1959) described two general categories: those 

 taxa whose larvae occur almost entirely within the 

 upper mixed layer and in the upper part of the ther- 

 mocline; and those that occur within or below the ther- 

 mocline. Larvae of shorefishes, including most 

 clupeoids, typically fall within the first category. Gen- 

 erally, slope and offshore taxa produce deeper-living 

 larvae, although many oceanic taxa also have shallow- 

 living larvae. Northern anchovy had similar vertical 

 profiles at the slope and offshore stations although den- 

 sities were much higher at the slope station, where the 



