Powles and Warlen: Recruitment season, size, and age of Anguilla rostrata entering an estuary near Beaufort 



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Brunswick ( 209 d ) were significantly older than those from 

 North Carolina (^2=1. Ill, P=0.407; F2=1.140, P=0.373) 

 with respect to total age. Although New Jersey fish ap- 

 peared to be longer (60.9 mm TL) than New Brunswick el- 

 vers (58.1 mm TL), the difference in mean length was not 

 significant (F._;=1.283, P=0.266). 



Although total mean age (d) counts were not signifi- 

 cantly different between sites (Table 3), glass-eel age (the 

 portion between metamorphosis zone and elver mark of 

 otolith) differed between all three sites (NC vs. NJ, F.,= 

 7.713, P=0.005; NJ vs. NB, F2=1.622, P=0.091). FurtheV 

 more, when glass-eel ages were regressed against lati- 

 tude, the relationship was significant (slope=0.303, adj. 

 r-=0.83.5, P=0,028). 



In hght of Jessop's (1998) finding of a decrease in length 

 over the recruitment season for elvers in the Bay of Fun- 

 dy waters, we re-examined our age data by month and 



length. Could it be that even though our lengths showed 

 no significant seasonal decrease, shorter fish were, on av- 

 erage, older than longer fish? The regression of the capture 

 date against total mean age suggested an increase in age 

 over time (Table 4), but the relationship was weak (adj. 

 /■^=0.053). Furthermore, an F-test revealed no difference 

 in incremental total age between any month. But total age 

 is apparently not to be trusted (Cieri and McCleave, 2000). 

 When we regressed mean length against only the glass- 

 eel zone age, it revealed just the opposite relationship: 

 a negative slope (Table 4), with a good relationship (adj. 

 r'^=0A99}. The smaller fish during the recruitment period 

 were indeed older, as suggested by Jessop ( 1998). The lon- 

 ger fish, on average, had fewer increments in their glass- 

 eel growth zone than the shorter fish, suggesting that the 

 latter had taken longer to reach Beaufort estuary from the 

 Sargasso Sea. 



