species in the eastern Pacific and in the 

 Atlantic are both known under the same 

 scientific name even though three distinct 

 stocks of fish are probably here involved. 



Tuna Spawning Areas 



Figures li* and 15 contain the avail- 

 able information on the areas of spawning 

 and larval occurrence for two species of 

 tuna, yellowfin and skipjack. The identi- 

 fication of the larvae of other species 

 from plankton catches has not yet been made. 

 Essentially these represent areas in which 

 samples of plankton have been sorted for 

 tuna larvae and the resultant data are 

 available. They are poor guides to the 

 relative abundace of tuna larvae, especially 

 for the Indian Ocean where the collections 

 from the rich Dana collections were not 

 available. These figures illustrate two 

 points: 



1. Larvae appear to be abundant 

 in tropical waters of the open 

 ocean. 



2. Although important skipjack 

 fisheries exist off the coasts 

 of Japan and the Americas, 

 larvae are quite scarce in 

 these regions. 



• • 



-pvi ii nwi in L ,\n\ \i 



Figure 14. — Distribution of yellowfin 

 tuna larvae. 





SKII'JAI l< I MUM 



w tr w no- iv 



Wito-ta'Wtiyta-vxrsr x- 



BIBLIOGRAPHY 



ALVLRSON, F. G. 



1959. Geographical distribution of 

 yellowfin tuna and skipjack catches 

 from the eastern tropical Pacific 

 Ocean, by quarters of the year, 1952- 

 1955. Bull. Inter-Amer. Tropical Tuna 

 Comm. 3(h):l6?-213. 



ANDERSON, A. W. , "*'. H. STOLTING, AND 

 ASSOCIATES 

 1952. Survey of the domestic tuna indus- 

 try. U. S. Fish and Wildlife Service, 

 Spec. Sci. Rept. — Fish. No. 10U, h36 p. 



AUSTIN, T. S. 



1958. Variations with depth of oceano- 

 graphic properties along the Equator 

 in the Pacific. Trans. Amer. Geophysi- 

 cal Union 39(6) :1055-1063. 



BELLOC, G. 



195k. Les Thons de la Mediterranee. 



I. 



Figure 15. — Distribution of skipjack 

 tuna larvae. 



Germon, pelamide et malva. Gen. Fish. 

 Council Medit. Proc. and Tech. Pap. 

 2:283-322. 



1955^ Les Thons de la Mediterranee. 

 II. Thonine et Bonite. Gen. Fish. 

 Council Medit. Proc. and Tech. Pap. 

 3:U71-U97. 



BROCK, V. E. 



19li9. A preliminary report on Parathun- 

 nus sibi in Hawaiian waters and a key 

 to the tunas and tuna-like fishes of 

 Hawaii. Pacific Science 3(3) i271-277. 



CRANE, J. 



1936. Notes on the biology and ecology 

 of the giant tuna, Thunnus thynnus 

 Linnaeus, observed at Portland, Maine. 

 Zoologica, N. Y., 21:207-212. 



