Table 1 .--Collection data on skipjack tuna ovaries collected in the tropical Atlantic Ocean, 1964-67--Continued. 



Ship 



Position 

 Lat. N. Long. 



Fork length 

 range 



Fish in each 

 developmental stage 

 12 3 5 



Total fish 



Mm. 



No. No. 



No. 



No. 



142 



197 



17 



22 



26 



43 



98 



108 



130 



131 



132 



133 



21 



96 



103 



109 

 113 

 118 

 121 

 129 



133 

 142 

 379 

 391 

 50 



62 



11 



31 



27 

 21 



2 

 1 



1 

 1 



2 

 1 

 1 

 34 

 7 



1 

 22 

 1 

 1 

 9 



4 

 5 

 3 

 4 

 4 



2 



2 



1 



14 



15 



4 



1 

 2 

 1 

 1 

 1 



2 



1 



1 



34 



7 



1 

 22 

 1 

 1 

 9 



4 

 5 

 3 

 4 

 4 



2 

 2 

 2 

 15 

 9 



19 

 10 

 11 

 31 



27 



21 



1 Island banks from U.S. Virgin Islands to the northern banks of Montserrat, British West Indies. 



that advanced and spawned stages indicated 

 that spawning was imminent or recent. 



CONDITION OF OVARIES AND 



DISTRIBUTION OF LARVAL 



AND JUVENILE SKIPJACK TUNA 



The length at maturity for skipjack tuna 

 near Cap Vert (eastern tropical Atlantic) is 

 about 450 mm., according to Postel (1955). 

 In the present study, the minimum size at 

 maturity was considered to be the length of 

 the smallest fish in developing, advanced, or 

 spawned stages. The minimum size at matu- 

 rity for skipjack tuna in the eastern tropical 

 Atlantic was 435 mm. fork length, deter- 

 mined from a fish in the developing stage; the 

 minimum size at maturity in the western 

 tropical Atlantic was 410 mm. fork length, 

 determined from a fish in the spawned stage. 

 Seven fish smaller than 435 mm. from the 



eastern tropical Atlantic, and nine fish smaller 

 than 410 mm. from the western tropical 

 Atlantic were in the early developing stage 

 and were considered immature. 



The percentage of skipjack tuna near spawn- 

 ing or recently spawned was greater in the 

 western tropical Atlantic than in the eastern 

 tropical Atlantic. Among ovaries of eastern 

 tropical Atlantic specimens, 73 percent were 

 in the early developing stage and 27 percent 

 were in the developing, advanced, and spawned 

 stages. In the western tropical Atlantic, 7 per- 

 cent of the ovaries were in the early develop- 

 ing stage, and 93 percent were in the advanced 

 and spawned stages. All ovaries collected in 

 the New York area were in the early develop- 

 ing stage. 



Spawning seasons of skipjack tuna have been 

 reported as June to September for males and 

 July to October for females, near Cap Vert 

 (Postel, 1955); from May to September near 

 Dakar (Frade and Postel, 1955); all year, with 



