744 



Fishery Bulletin 91(4), 1993 



>• 

 o 



z 



LU 



3 

 O 



LU 



Q DJ 



JANUARY 1989 

 N = 28 



OCT NOV DEC JAN FEB MAR APR 



Figure 12 



Dates of last accessory primordium formation on right otoliths 

 of Stage-3 and Stage-4 Dover sole, Microstomas pacificus, 

 larvae collected during three sampling cruises in 1989 and 

 1990. Only enclosed otoliths with three or more accessory 

 primordia were considered because origins of single anterior 

 and posterior accessory primordia are usually indistinct. 



LU 

 DC 



3 



< 



o 



Cl 



O 

 ti 

 n. 

 to 

 > 

 < 

 Q 



CHECKS PRIOR TO CAPTURE 



Figure 13 



Relationship between the five most distal stress checks and 

 number of days from their formation to the otolith edge (cap- 

 ture) in 46 Stage-3 and Stage-4 Dover sole, Microstomas 

 pacificus, otoliths collected between 15-17 March 1990. 

 Vertical bars represent 95"7r confidence intervals for means 

 (horizontal bars I. Additional error is associated with convert- 

 ing increments to days, with the regression described in the 

 text. Corresponding lunar phases are displayed on the verti- 

 cal axis. 



cember. The ratio then rose and fell to a second mini- 

 mum (0.003) in mid-January. In each of these lar- 

 vae, the ratio rose again (0.003-0.0035) prior to cap- 

 ture in mid-March. Two Stage-3 larvae and a third 

 Stage-4 larva did not exhibit distinct minima; rather, 

 Sr/Ca ratios remained at about 0.0025 until cap- 

 ture. Sr/Ca ratios first reached this level prior to 

 enclosure. 



An 88.6-mm Stage-5 juvenile (Fig. 20B) with one 

 peripheral annulus had narrow growth increments, 

 making it difficult to determine exact ages associated 

 with microprobe samples. However, the pattern proxi- 

 mal to AP was similar to that of larvae, with one 0.007 

 spike and a 0.004-0.006 peak near the center of the 

 otolith, followed by a decline occurring prior to and 

 during formation of accessory primordia. Sr/Ca ratios 

 remained low for >200 days following formation of the 

 last AP until a second 0.004-0.005 peak formed in the 

 translucent annulus near the otolith edge, which rep- 

 resented capture in March. 



A 172.2-mm juvenile, collected in November 1989 

 and judged to have three complete post-settlement an- 

 nuli and a fourth one forming, had four Sr/Ca peaks, 

 which corresponded to translucent annuli (Fig. 21), 

 distal to accessory primordia. 



