Table 2. --Distribution of larval and juvenile skipjack in the Atlantic Ocean as 

 reported by various observers, 1959-67--Continued 



1 Bush Key, Dry Tortugas, Fla. 

 2 Cuban waters 



I conclude, from the condition of the ovaries 

 and the occurrences of larvae and juveniles, 

 that skipjack tuna spawn throughout the year 

 in the areas of study in the tropical Atlantic 

 Ocean. 



FECUNDITY 



Fecundity of skipjack tuna has not been re- 

 ported previously for fish from the Atlantic 

 Ocean, but has been determined for fish from 

 the Pacific Ocean (Yabe 1954, Joseph 1963, 

 and Yoshida 1966) and the Indian Ocean (Raju 

 1964). I determined the fecundities of 13 

 skipjack tuna, 465 to 809 mm. fork length, 

 collected within 13 days (March 26 - April 7, 

 1966) near St. Vincent Island in the Caribbean 

 (table 1), on Geronimo cruise 7 (station 133) 

 and Undaunted cruise 2 (stations 103, 109, and 

 113). 



A sample of eggs of yellowfin tuna (Thunnus 

 albacares) taken anywhere along the length of 



a single ovary or from either member of a 

 pair is representative of eggs throughout the 

 ovary, according to June (1953). Yuen (1955) 

 confirmed this finding for big eye tuna ( Thunnus 

 obesus) , Otsu and Uchida (1959) for albacore 

 ( Thunnus alalunga), and Raju (1964) for skip- 

 jack tuna. I therefore used the following sam- 

 pling procedure in estimating the number of 

 eggs in seven ovaries that had been frozen and 

 six that had been preserved in Formalin. 



After excess tissue and moisture had been 

 removed from the thawed or preserved ovaries, 

 they were weighed to the nearest 0.1 g. Apie- 

 shaped sample of about 0.5 g. was taken from 

 the center of either the right or left ovary of 

 each fish and weighed to the nearest 0.01 g. 

 The samples from frozen ovaries were put in 

 modified Gilson's fluid (Simpson, 1951), and 

 then placed on a shaker table (continuously 

 agitating) to increase the rate of breakdown 

 of the connective tissue and free the individual 

 eggs. The process took about 2 weeks. The 

 eggs in samples from preserved ovaries were 



12 



