AGE OF YOUNG HADDOCK 



445 



Table 3. — Length composition of young-of-the-year had- 

 dock collected on Georgtn Bank and in the Gulf of 

 Maine in 1951 



Figure 3. — Mean lengths of young-of-the-year haddock 

 collected on Georges Bank and in the Gulf of Maine in 

 1957. 



averaging 4.5 mm. long. Presumably these fish 

 had been spawned only 1 or 2 weeks previously. 

 In collections made in May 1957, postlarval had- 

 dock, averaging 9.6 mm. long, were taken. In 

 June, young haddock 18.0 mm. long were collected 

 at or near the surface but by July, the haddock 

 had grown to an average length of 85.8 mm. and 

 were in the middepths, mostly at 20 meters. 



Midwater trawling from the Albatross III in 

 September caught young haddock, average length 

 99.2 mm., slightly deeper in the middeptlis, 

 presumably moving down to begin their existence 

 on the sea bottom. 



In a collection of juvenile haddock, made with 

 a one-half-inch mesh otter trawl in October and 

 November 1957, the fish averaged 132.0 mm. It is 

 at this time that most haddock scales fonn the 

 accessory annuhis discussed previously. 



The December collection represents juvenile 

 haddock taken by a commercial otter trawler. 

 The young-of-the-year haddock now average 

 179.0 mm. in length and liave almost attained 

 their full first year's growth. The average length 

 for the December sample agrees well with the aver- 

 age length of 196 mm. for 1 -year-old fish in the 

 data. 



An earlier collection of 419 haddock scales and 

 length measurements was made on Georges Bank 

 during Alhafross III cniise 56 (Feb. 1-13. 1955) 



(table 4 and fig. 4). The length frequency of 

 these fish shows distinct modes at 18, 30, and 42 

 cm. Examination of the scales revealed that all 

 of the 14 haddock that measured from 11 to 21 cm. 

 (the first mode) had one aiuuilus. More than 

 61 percent of the 105 liaddock from 22 to 36 cm. 

 (the second mode) had 2 annuli, while most of the 

 remaining 39 percent of this size gi-oup had 3 such 

 marks. The third mode was composed mostly 

 (more than 71 jjercent) of fish with 3 annuli. 



If haddock spawned throu<!:hout the ye^r, a 

 length-frequency curve of tlie population would 



