LUX: AGE AND GROWTH OF WINTER FLOUNDER 



6 8 



IN YEARS 



Figure 6. — Mean calculated lengths at each annulus 

 for male and female winter flounder from Georges Bank 

 compared with growth data for fish from Narragansett 

 Bay, R.L (Berry et al., 1965), Shinnecock Bay, N.Y. 

 (Poole, 1966), and Conception Bay, Newfoundland 

 (Kennedy and Steele, 1971). (Open symbols for Georges 

 Bank represent fewer than five fish.) 



10) and females, 7.2 cm (it = 18). Length in 

 late fall of the first year in Connecticut waters 

 in 1958 and 1959 was similar to the above, 

 being about 7.0 cm standard length (Pearcy, 

 1962), which is about 8.7 cm total length. 

 Lengths calculated at the first annulus on 

 otoliths of winter flounder in Rhode Island 

 waters by Berry et al. (1965) were somewhat 

 greater, being 12.5 cm for males and 13.5 cm 

 for females. 



Bertalanffy growth equations of the form 



lt=l^[l-exp{-K{t-to))] 



in which If is length at age t, l^ is the 

 theoretical maximum length, K is the rate of 

 change in length increment, and to is the age 

 at which growth in length theoretically begins, 

 were fitted by the method of Ricker (1958), 

 to the mean lengths at each age for males and 

 females from eastern Georges Bank (Table 3). 

 The resulting equations 



If = 550 [1 -exp(-0.37(^ + 0.05))] (male) 

 If = 630 [1 -exp(-0. Sift- 0.05))] (female) 



express the growth rates for fish of age 3 and 

 beyond (Figure 7). 



Estimates of l^ given here are principally 

 for use in developing a mathematical expression 

 of growth rather than to accurately portray 

 maximum attained length. The l^ of 55.0 cm 

 for males, for example, is somewhat shorter 

 than the maximum observed length of 57.0 cm. 

 Likewise, the / x of 63.0 cm for females is 

 considerably shorter than the 70.0 cm maximum 

 observed. 



Inclusion of more large and old fish in the 

 samples might have altered the form of the 

 computed growth curves slightly. Until more 

 accurate equations are derived, however, those 

 given above will provide reasonable accuracy 

 for yield per recruit calculations for both 

 eastern and western Georges Bank. 



ACKNOWLEDGMENT 



Robert N. Hersey, Northeast Fisheries 

 Center, National Marine Fisheries Service, 

 NOAA, Woods Hole, made independent age 

 determinations of the fish included in this 

 study and performed most of the growth 

 calculations. His assistance is gratefully 

 acknowledged. 



LITERATURE CITED 



Berry, R. J., S. B. Saila, and D. B. Horton. 



1965. Growth studies of winter flounder, Pseiido- 

 pleitronectes americanus (Walbaum), in Rhode 

 Island. Trans. Am. Fish. Soc. 94:259-264. 

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



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

 Serv.. Fish. Bull. 53, 577 p. 

 Carlander, K. D., and L. L. Smith Jr. 



1944. Some uses of nomographs in fish growth 

 studies. Copeia 1944:157-162. 

 Deuel, D. G., and J. R. Clark. 



1968. The 1965 salt-water angling survey. U.S. Fish 

 Wildl. Serv., Resour. Publ. 67, 5 1 p. 



Fraser, C. M. 



1916. Growth of the spring salmon. Trans. Pac. Fish. 

 Soc. 2d Annu. Meet., p. 29-39. 

 Grosslein, M. D. 



1969. Groundfish survey program of BCF Woods 

 Hole. Commer. Fish. Rev. 31(8-9):22-30. 



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