BOLZ and LOUGH: GROWTH OF LARVAL COD AND HADDOCK 



CL 



o 



0. 00 



10 15 20 25 



ESTJMRTED AGE IN DOTS 



5 



35 



40 



FIGURE 8.— Growth comparison of larval Atlantic cod and haddock at different temperatures. The 5°C 

 curve for cod and the 7 : C for haddock are based on an analysis of the no. of daily increments counted on 

 otoliths from larvae collected during the spring of 1981 on southeastern Georges Bank. The 7°C curve for 

 cod is hypothetical and incorporates the percent per day increase in growth for a 2°C temperature rise 

 found in laboratory rearing experiments (Laurence 1978; Laurence et al. 1981). 



of these thin increments found in cod (11) than in 

 haddock (8) may have been due in part to slower 

 growth in the cooler, late- winter water. It is also pos- 

 sible that the larger diameter of the yolk-sac check 

 ring in cod (27.2 jiim) than in haddock (23.5 jum) was 

 indicative of the cod larvae having spent a longer 

 period of time in the yolk-sac phase. However, more 

 extensive SEM work on the region between the 

 nuclear and yolk-sac check rings is needed to confirm 

 the exact number of daily increments for a large sam- 

 ple size. 



ACKNOWLEDGMENTS 



We gratefully acknowledge the technical help and 

 guidance provided by Susan Houghton with the 

 scanning electron microscope portions of this 

 paper. 



LITERATURE CITED 



Anderson, J. T. 



1982. Distribution, abundance and growth of cod (Gadus 

 morhua) and redfish {Sebastes spp.) larvae on the Flemish 

 Cap, 1981. Northwest Atl. Fish. Organ. SCR Doc. 82/VI/ 

 37, 11 p. 



Bailey, R. F. J., K. W. Able, and W. C. Leggett. 



1977. Evidence for the presence of metamorphic check in 

 capelin (Mallotus villosus) otoliths and implications for 

 age determination. J. Fish. Res. Board Can. 34:2008- 

 2014. 



Bigelow, H. B., AND W. C. Schroeder. 



1953. Fishes of the Gulf of Maine. U.S. Fish Wildl. Sen., 

 Fish. BulL 53, 577 p. 

 Brothers, E. B. 



198 1. What can otolith microstructure tell us about daily and 

 subdaily events in the early life history of fish? In R. Las- 

 ker and K. Sherman (editors), The early life history offish, 

 p. 393-394. Rapp. P.-V. Reun. Cons. Perm. Int Explor. 

 Merl78. 

 Brothers, E. B., C. P. Mathews, and R. Lasker. 



1976. Daily growth increments in otoliths from larval and 

 adult fishes. Fish. Bull., U.S. 74:1-8. 

 Brothers, E. B., and W. N. McFarland. 



1981. Correlations between otolith microstructure, growth, 

 and life history transitions in newly recruited French 

 grunts \Haemulon flavolineatum (Desmarest), Haemuli- 

 dae|. In R. Lasker and K. Sherman (editors), The early life 

 history of fish, p. 369-374. Rapp. P.-V. Reun. Cons. Int. 

 Explor. Mer 178. 



Campana, S. E., and J. D. Neilson. 



1982. Daily growth increments in otoliths of starry flounder 

 (Platichthys stellatus) and the influence of some en- 

 vironmental variables in their production. Can. J. Fish. 

 Aquat. ScL 39:937-942. 



COLTON, J. B., AND R. R. MARAK. 



1969. Guide for identifying the common planktonic fish eggs 



and larvae of continental shelf water, Cape Sable to Block 



Island. U.S. Bur. Comm. Fish., Biol. Lab., Woods Hole, 



Mass., Lab. Ref. Doc. 69-9, 43 p. 



Ellertsen, B. E., Moksness, P. Solemdal, T. Str^mme, S. 



Tilseth, T. Westgard, and V. (J)iestad. 



1980. Some biological aspects of cod larvae (Gadus morhua 

 L.). Fiskeridir. Ser. Havunders. 17:29-47. 

 GEFFEN, A. J. 



1982. Otolith ring deposition in relation to growth rate in her- 

 ring (Clupea harengus) and turbot (Scophthalmus max- 



835 



