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Fishery Bulletin 97(2), 1999 



years for yolksac check diameters for either haddock 

 or pollock larvae (ANOVA, P>0.0.5). Within some 

 haddock otolith nuclei, 1-3 increments were ob- 

 served. Outside the nucleus, 6-8 growth increments 

 of irregular width were observed between the nucleus 

 check and a second well-marked check. Bolz and 

 Lough ( 1983 ) observed 2-8 faint increments bounded 

 by a discontinuous zone that appeared to be analo- 



gous to the yolksac check found in larval cod otoliths 

 by Radtke and Waiwood ( 1980). Accordingly, I inter- 

 preted the second well-defined mark as a check 

 resulting from yolksac resorption. The mean dia- 

 meter of the yolksac check was 34.9 ±2.8 |im in had- 

 dock and 35.3 ±2.6 ^m in pollock. Several (mean 7 ± 

 1.8) narrow (<1 |im) increments were found immedi- 

 ately after the yolksac resorption check. Increment 

 width increased rapidly in subsequent 

 increments. 



The relation between otolith and lar- 

 val fish sizes was best described by a In- 

 In regression (Fig. 5). For haddock and 

 pollock, significant differences were found 

 between cruises ( ANCOVA, P<0.05 ); how- 

 ever, no significant differences were 

 found among years (ANCOVA, P>0.05) 

 for either species (Table 4). Among had- 

 dock samples, a multiple range test re- 

 vealed four homogeneous groupings in 

 the samples from the ten cruises analyzed 

 (P<0.01). The groupings were interpret- 

 able in terms of monthly sagittal growth. 

 The first group integrated larvae from 

 March to April; the second, larvae from 

 May; the third, larvae from June; and the 

 fourth, larvae from July. With pollock, the 

 multiple range test showed three homo- 

 geneous groupings among the pollock 

 sampled during the ten cruises (P<0.01 ). 

 The first group integrated larvae from 

 November to January; the second, larvae 

 from February; and the third, larvae from 

 March to April. It was possible to distin- 

 guish different stages in sagittal growth 

 from otolith structure. Sagittae from the 

 early developmental stages of haddock 

 and pollock larvae were almost circular 

 in shape, and there was one fiat and one 

 convex-side, accessory nucleus developed 

 in the sagittae of postlarvae. As the lar- 

 vae developed, the otoliths grew faster 

 along the anteroposterior axis and be- 

 came oval shaped. 



Haddock and pollock larval and juvenile 

 growth 



Figure 2 



Light micrographs of sagittae. (A) Sagitta from a ,5.93-mm, .5-day-old, 

 haddock lar\'a. (B) Saggita from a'4.98-mm, 3-day-old, pollock lari'a. H = 

 hatch check. Growth increments appear as light and dark zones. The 

 lan'ae were hatched from eggs collected from the Western and Emerald 

 Banks area. Bar represents .5 [jm. 



For both haddock and pollock, the first 

 otolith increment was laid down the day 

 after hatching. Thus, the age of larvae 

 and juveniles was indicated by the num- 

 ber of increments in the sagittae. Daily 

 increments were counted in otoliths from 

 1121 individuals of a total of 3126 cap- 



