5. Although no conclusive statements can be 

 made about the frequency of spawning of indi- 

 vidual skipjack, the data indicate a possibility of 

 more than one spawning per season. 



6. Estimates of fecundity of skipjack ranged 

 from 0.1 to 2 million ova per spawning. 



7. It was not possible to make any inferences 

 about the stage of development from the gonad 

 index of skipjack. 



8. A contingency test of homogeneity showed 

 that there was a relation between skipjack schools 

 and stage of sexual development; i.e., there was a 

 tendency for skipjack in similar stages of sexual 

 development to be found together in schools. 



LITERATURE CITED 



Brock, Vernon E. 



1954. Some aspects of the biology of the aku, Katsu- 

 wonus pelamis, in the Hawaiian Islands. Pacific 

 Science, vol. 8, No. 1, pp. 94-104. 



Clark, Frances N. 



1934. Maturity of the California sardine (Sardina 

 caerulea), determined by ova diameter measure- 

 ments. California Division of Fish and Game, 

 Fish Bulletin No. 42, 49 pp. 



Hennemdth, Richard C. 



1957. An analysis of methods of sampling to deter- 

 mine the size composition of commercial landings of 

 yellowfin tuna (Neothunnus macropterus) and skip- 

 jack (Katsuwonus pelamis) . Inter-American Tropi- 

 cal Tuna Commission, Bulletin, vol. 2, No. 5, pp. 

 174-243. 



Hoel, Paul G. 



1954. Introduction to mathematical statistics. 2d 

 ed. John Wiley & Sons, Inc., New York, 331 pp. 



Joseph, James. 



1963. Fecundity of yellowfin tuna (Thunnus alba- 

 cares) and skipjack (Katsuwonus pelamis) from the 

 eastern Pacific Ocean. Inter-American Tropical 

 Tuna Commission, Bulletin, vol. 7, No. 4, pp. 257- 

 292. 



June, Fred C. 



1951. Preliminary fisheries survey of the Hawaiian- 

 Line Islands area. Part III — The live-bait skipjack 

 fishery of the Hawaiian Islands. U.S. Fish and 

 Wildlife Service, Commercial Fisheries Review, 

 vol. 13, No. 2, 18 pp. [Also as Separate No. 271.] 

 1953. Spawning of yellowfin tuna in Hawaiian waters. 

 U.S. Fish and Wildlife Service, Fishery Bulletin 77, 

 vol. 54, pp. 47-64. 



MacGregor, John S. 



1957. Fecundity of the Pacific sardine (Sardinops 

 caerulea). U.S. Fish and Wildlife Service, Fishery 

 Bulletin 121, vol. 57, pp. 427-449. 



Mann, Herbert J. 



1955. Construction details of improved tuna longline 

 gear used by Pacific Oceanic Fishery Investigations. 



U.S. Fish and Wildlife Service, Commercial Fisher- 

 ies Review, vol. 17, No. 12, pp. 1-10. [Also as 

 Separate No. 422.] 



Marr, John C. 



1948. Observations on the spawning of oceanic 

 skipjack (Katsuwonus pelamis) and yellowfin tuna 

 (Neothunnus macropterus) in the northern Marshall 

 Islands. In Milner B. Schaefer and John C. Marr, 

 Contributions to the biology of the Pacific tunas, 

 pp. 201-206. U.S. Fish and Wildlife Service, 

 Fishery Bulletin 44, vol. 51. 



Matsui, Kizo. 



1942. Gonads of skipjack from Palao waters. U.S. 

 Fish and Wildlife Service, Special Scientific Re- 

 port—Fisheries No. 20 (1950). Translated from 

 Kagaku Nanyo, vol. 5, No. 1, pp. 117-122. 



Matsumoto, Walter M. 



1958. Description and distribution of larvae of four 

 species of tuna in central Pacific waters. U.S. 

 Fish and Wildlife Service, Fishery Bulletin 128, 

 vol. 58, pp. 31-72. 



Orange, Craig J. 



1961. Spawning of yellowfin tuna and skipjack in 

 the eastern tropical Pacific, as inferred from studies 

 of gonad development. Inter-American Tropical 

 Tuna Commission, Bulletin, vol. 5, No. 6, pp. 

 459-526. 



Otsu, Tamio, and Richard N. Uchida. 



1959. Sexual maturity and spawning of albacore in 

 the Pacific Ocean. U.S. Fish and Wildlife Service, 

 Fishery Bulletin 148, vol. 59, pp. 287-305. 



Schaefer, Milner B., and John C. Marr. 



1948. Spawning of yellowfin tuna (Neothunnus ma- 

 cropterus) and skipjack (Katsuwonus pelamis) in 

 the Pacific Ocean off Central America, with de- 

 scriptions of juveniles. In Milner B. Schaefer and 

 John C. Marr, Contributions to the biology of the 

 Pacific tunas, pp. 187-195. U.S. Fish and Wildlife 

 Service, Fishery Bulletin 44, vol. 51. 



Schaefer, Milner B., and Craig J. Orange. 



1956. Studies of the sexual development and spawn- 

 ing of yellowfin tuna (Neothunnus macropterus) and 

 skipjack (Katsuwonus pelamis) in three areas of the 

 eastern Pacific Ocean, by examination of gonads. 

 Inter-American Tropical Tuna Commission, Bulle- 

 tin, vol. 1, No. 6, pp. 283-349. 



Shimada, Bell M. 



1951. Juvenile oceanic skipjack from the Phoenix 

 Islands. U.S. Fish and Wildlife Service, Fishery 

 Bulletin 64, vol. 52, pp. 129-131. 



Snedecor, George W. 



1946. Statistical methods. 4th ed. The Iowa State 

 College Press, Ames, Iowa, 485 pp. 



Wade, Charles B. 



1950a. Juvenile forms of Neothunnus macropterus, 

 Katsuwonus pelamis, and Eulhynnus yaito from 

 Philippine seas. U.S. Fish and Wildlife Service, 

 Fishery Bulletin 53, vol. 51, pp. 395-404. 

 1950b. Observations on the spawning of Philippine 

 tuna. U.S. Fish and Wildlife Service, Fishery 

 Bulletin 55, vol. 51, pp. 409-423. 



SKIPJACK SPAWNING IN MARQUESAS AND TUAMOTU AREAS 



487 



