524 



Fishery Bulletin 93(3). 1995 



10 m (Table 6; Fig. 10). However, at the mid-depth of 

 30 m, stages 2 and 3 of Pacific sanddabs were sig- 

 nificantly less abundant in upwelling areas than in 

 non-upwelling areas, and stages 2 and 3 of speckled 

 sanddabs showed a strong tendency for decreased 



abundance in upwelling areas (Table 6; Fig. 10). In 

 contrast, stage 5 in each species tended to be more 

 abundant in upwelling areas than in non-upwelling 

 areas (Table 6; Fig. 10). 



Discussion 



Pacific Sanddabs 



1990 



Sweep 1 Speckled Sanddabs 



Sweep 2 



Sweep 3 



122 123 



Longitude (°W) 



Figure 8 



Salinity contours at the surface during the May-June survey of 1990 with overlaid 

 abundances of stages 2 (represented by squares) and 5 (represented by asterisks) of 

 Pacific and speckled sanddabs, Citharichthys sordidus and C. stigmaeus. Size of 

 each symbol is proportional to the abundance. 



During the springtime series 

 covered by this study, metamor- 

 phosis in both sanddab species 

 occurred at a wide range of 

 sizes, indicating little growth in 

 body size during metamorpho- 

 sis (Figs. 3 and 5). Later meta- 

 morphic stages tended to occur 

 in deeper water than did earlier 

 stages; Pacific sanddabs shifted 

 to deeper water at earlier stages 

 than speckled sanddabs (Tables 

 3 and 4; Fig. 6). Later metamor- 

 phic stages of both sanddabs oc- 

 curred nearer to shore than ear- 

 lier stages, despite the upwel- 

 ling-associated offshore advec- 

 tion of surface waters (Table 6; 

 Figs. 8-10). 



Given the reported variabil- 

 ity of size at metamorphosis in 

 both sanddab species (Ahlstrom 

 et al., 1984; Matarese et al., 

 1989), it was not surprising to 

 observe a large amount of over- 

 lap in the SL's of the different 

 metamorphic stages (Fig. 3). 

 Kendall (1992) reported that 

 speckled sanddabs settled at 

 ages ranging from 113 to 324 

 days. In general, she found that 

 larger, recently settled individu- 

 als had spent more time in the 

 plankton than smaller recently 

 settled ones (Kendall, 1992). 

 Kendall (1992) also reported 

 that settlement marks on the 

 otoliths of speckled sanddabs 

 were generally observed at an 

 otolith radius of 400-450 urn. 

 This corresponds to the otolith 

 diameters observed in stage-5 

 individuals, indicating that 

 these individuals were prepared 

 to settle (Figs. 4 and 5). 



An important aspect of meta- 

 morphosis in flatfishes is the 



