TURNER ET AL.: TILEFISH IN MIDDLE ATLANTIC-SOUTHERN NEW ENGLAND 



RESULTS 



Otoliths were collected from 755 tilefish in 1978. 

 Ninety percent of the sections (682) were readable 

 and used for age and growth studies. Of these, 305 

 were females, 233 were males, and 144 were of 

 unknown sex. Changes in growth pattern of the 

 otolith of some of the largest fish presented problems 

 for analysis of growth rates. Thirteen fish (11 females 

 and 2 males) of 84-108 cm FL stopped depositing 

 tissue on the ventral side of the otolith but continued 

 to grow on the medial face (Fig. 1C). Fish with this 

 aberrant otolith growth pattern were not included in 

 marginal increment analysis or in estimation of the 



OS:FL relationship. However, measurements were 

 made to annuli formed before the otolith growth 

 change. 



Validation 



Mean marginal increments in ocular micrometer 

 units were lowest in June and increased to a max- 

 imum in January and February (Fig. 3). ANOVA 

 indicated highly significant differences between 

 monthly means (P< 0.01). We concluded that annuli 

 were formed once and only once each year, and most 

 fish completed annulus formation by 1 June. 

 Younger tilefish apparently formed annuli later than 



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FIGURE 3. — Mean marginal increment in ocular micrometer units by month for eight age groups 

 of tilefish, based on number of annuli formed. Number of annuli is in the upper right corner of 

 each graph, the horizontal bar is the mean, the number just above or below the mean is the sample 

 size, and the vertical line is the 95*7r confidence interval. Some confidence intervals exceed the 

 size of the graph with their smallest values <0 and their largest values given above the end 

 of the interval. 



755 



