Stequert et al : Age and growth of Thunnus albacares 



131 



bony structures in the Pacific (Yabuta et al., 1960) 

 or in the Indian Ocean (Huang et al., 1973) gave re- 

 sults similar to ours (Fig. 11 A). Studies conducted 

 on length-frequency analyses have also led to com- 

 parable results. The results for the Pacific yellowfin 

 tuna of Hennemuth (1961) are close to those of the 

 present study. The growth estimation of Le Guen and 

 Sakagawa ( 1973 ) for the eastern Atlantic shows slight 

 differences for young individuals: until 2 years of age, 

 young yellowfin tuna grow more slowly than those from 

 the Indian Ocean; however, after 2 years of age, growth 

 is the same for eastern Atlantic and Indian Ocean popu- 

 lations. Two growth stanzas have been observed in the 

 western Atlantic (Capisano and Fonteneau, 1991; 

 Gascuel et al., 1992 ) and in the Indian Ocean ( Marsac 1 ), 

 but we did not observe the accentuated inflection in 

 the growth of juveniles reported by these studies. 



A comparison of our results with other estimates 

 based on otoliths yields similar growth models (Fig. 

 11B). Age estimates given by Yamanaka 3 for the 



smallest fish in the Philippines (FL between 25 and 

 50 cm) are equal to those of the small yellowfin tuna 

 caught by the French purse seiners in the Indian Ocean. 

 The length of our smallest fish (6 months old) is only a 

 few centimeters larger than that proposed by Uchiyama 

 and Struhsaker ( 1981 ) for the Pacific but is exactly the 

 same for individuals older than 1 yr. The growth curve 

 established by Wild (1986) for eastern Pacific yellow- 

 fin tuna shows growth rates slightly greater than those 

 of the western Indian Ocean, but for 2-yr-old individu- 

 als, the lengths are equal (FL=90 cm). 



For the Indian Ocean, however, studies of yellow- 

 fin tuna growth rates yield contradictory results. 

 Growth rates calculated in the present study are 

 similar to those obtained in the small-scale fisheries 

 of the Maldives (Anderson 5 ) and Sri Lanka (Mal- 

 deniya and Joseph 4 ) but are significantly different 

 from those obtained for the same Indian Ocean popu- 

 lation landed by French purse seiners (Marsac 1 ; 

 Marsac and Lablache 6 ). Differences in length are 



