Massuti et al ; Otolith microstructure, age, and growth of Coryphaena hippurus 



897 



30 



20 



10 







August 90 (n = 389) 

 mean: 24.10; S.D.: 2.10; range: 21-34 



LL 



20 

 15 - 

 10 - 



5 - 







August 91 (n= 103) 

 mean: 25,89; S.D,: 3.56; range: 18-34 



LX 



10 15 20 25 30 35 40 45 50 55 60 65 70 10 15 20 25 30 35 40 45 50 55 60 65 70 



September 90 (n = 922) 

 mean: 35.35; S.D.: 5.07; range: 23-52 15 



September 91 (n=635) 

 mean: 32.84; S.D.: 4.44; range: 23^5 



10 15 20 25 30 35 40 45 50 55 60 65 70 10 15 20 25 30 35 40 45 50 55 60 65 70 



2 '5 



i 10 



I) 



a. 



5 







October 90 (n = 404) 

 mean: 40.74; S.D.: 4.56; range: 28-58 ig 



h.. 



6] 

 4 

 2 

 



October 91 (n = 600) 

 mean: 42.28, S D.: 5.08; range: 30-61 



10 15 20 25 30 35 40 45 50 55 60 65 70 10 15 20 25 30 35 40 45 50 55 60 65 70 



Fork length (cm) Fork length (cm) 



November 90 (n = 904) 

 ,5 , mean: 46.03; S.D: 4.23; range 37-70 



10 

 5 







20 



15 



10 



5 







November 91 (n= 111) 

 mean: 47.32; S.D.: 5.53; range: 34-65 



J. 



JJ... 



10 15 20 25 30 35 40 45 50 55 60 65 70 



December 90 (n = 16) 

 3Q mean. 48.94, S.D.: 3.82, range: 43-56 



10 15 20 25 30 35 40 45 50 55 60 65 70 



20 

 10 



^ 



yji 



10 15 20 25 30 35 40 45 50 55 60 65 70 



Fork length (cm) 



Figure 5 



Monthly length-frequency distributions of juvenile Coryphaena hippurus caught off 

 Majorca with the surrounding net during the 1990 and 1991 fishing seasons. Fork length 

 in cm (fi=number of specimens; SD=standard deviationi. 



North Atlantic Ocean (Beardsley, 1967; Rose and 

 Hassler, 1968), where a decreased feeding rate when 

 water temperature falls below 23^C and a cessation 

 of feeding at 18°C have been reported (Hassler and 

 Hogarth, 1977). By contrast, in Hawaiian waters, 

 where faster growth rates have been reported, this spe- 

 cies feeds throughout the year and can be expected to 

 grow continuously (Uchiyama et al., 1986). 



The growth-rate values obtained for C. hippurus are 

 within the range reported from otolith microstructures 

 by Brothers et al. (1983) for Atlantic bluefin tuna 

 (Thunnus thynnus), another top-level predator char- 

 acteristic of the western Mediterranean epipelagic eco- 

 system. According to Benetti et al. ( 1995a ), C. hippurus, 

 Scombridae species, and Isurus oxyrhinchus, another 

 Mediterranean pelagic predator, have common factors 



