Quinonez-Velazquez: Age validation and growth of Melanogrammus aeglefinus and Pollachius virens 



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to a demersal life stage, it was possible that indi- 

 viduals were present in both pelagic and demersal 

 zones at this time. Perhaps pollock juveniles were 

 moving from the oceanic to the coastal zone; if so, 

 this change in habitat could explain the reduction in 

 numbers of juvenile older than 60 d in our sampling. 

 I assume that conclusions drawn for juvenile had- 

 dock are valid only during the first eighty days for 

 pollock. This period corresponds to the transition 

 from a primarily pelagic to predominantly demersal 

 life stage, which occurs when haddock reach about 

 20-25 mm in length (Koeller et al., 1986) and when 

 pollock reach 10-15 mm. Although >25-mm haddock 

 were captured in the water column, they probably 

 had adopted a predominantly demersal life style. 

 Thus, the acceleration in growth of >50-d juveniles 

 could have reflected exploitation of abundant food 

 resource after settling on the bottom (Mahon and 

 Neilson, 1987). 



In the present study, average growth rates were 

 0.21 mm/d in the first month and 0.42 mm/d in the 



second month for larval haddock and 0.18 mm/d in 

 the first month and 0.23 mm/d in the second month 

 for larval pollock. Growth continued exponentially 



