10 



.' 



to 



10 



i 



to 2 

 10 



I 



5 / 



\ 



-J 



s 



VrlO 2 



CO 

 ^ 10 



IO 



MARCH 



i : i : ;«v : ' : 'i 



MMzmzszzL- 



APRIL 



Neuston 



MAY 



Midwater 



Epibenihic 



i bUd±CiUil^ 



_L 



JUNE 



J 6 9 12 15 18 21 24 27 3d O 3 6 9 12 15 18 21 24 27 30 3 6 9 12 15 18 21 24 27 30 O 3 6 9 12 15 18 21 24 27 30 



JULY 



AUGUST I SEPTEMBER 



Neuston 



ESsL 



Midwater 



cd r~ i 



Epibenthic 



OCTOBER 



NO 

 Senphus 



in 

 Samples 



L 



~»^" 



O 3 6 9 12 15 18 21 24 2730 3 6 9 12 15 18 21 24 27 30 O 3 6 9 12 15 18 21 24 27 30 O 3 6 9 12 15 18 21 24 27 30 



NOVEMBER 

 NO Senphus in Samples 



DECEMBER 



NO Senphus in Samples 



1 



Neuston 



JANUARY 

 NO Sen phus in Samples 



FEBRUARY 

 NO Senphus in Samples 



10 



10 



NO Senphus in Samples 



Midwater 

 NO Senphus in Samples NO Senphus in Somples 



Epibenthic 

 NO Senphus in Samples NO Senphus in Samples 



NO Senphus m Somples 



O 3 6 9 12 15 18 21 24 27 30 O 3 6 9 12 15 18 21 24 27 30 O 3 6 9 12 15 18 21 24 27 30 O 3 6 9 12 15 18 21 24 27 30 



STANDARD LENGTH (mm) 



Figure 4.— Mean monthly concentrations of 10 larval size classes of queenfish, Seriphus politus, in three water column 

 levels, March 1978-February 1979. Each monthly value represents a mean of 4 replicates from each of 4 transects (total 

 replicates = 16). 



larvae seek and remain in patches of the dino- 

 flagellate Gymnodinium splendens in both day 

 and night. Vertical differences in anchovy larval 

 concentrations were shown by Ahlstrom (1959) 

 to correspond to the level of the thermocline. In 

 the San Onofre nearshore region, the maximum 

 depths of the sampled transects were only 11 to 

 15 m, and the vertical zone is substantially com- 

 pressed compared with offshore waters. Studies 

 have indicated high concentrations of food in this 

 nearshore area (Barnett and Sertic 1979). Con- 

 centrations of chlorophyll aim below the sur- 



face and 1 m above the bottom were nearly equal 

 during all times of the year from August 1976 to 

 September 1978 at depths of 7 to 8 m and 18 to 30 

 m off San Onofre. Because adequate food may 

 exist throughout the water column, a range of 

 size classes is encountered at all depths. The 

 apparent downward movement of larger ancho- 

 vy larvae appears to be a natural behavioral re- 

 sponse. 



White croaker and queenfish larvae migrate 

 toward the bottom after hatching. This vertical 

 movement is associated with their adult life his- 



900 



