REARING TILAPIA FOR TUNA BAIT 



19 



ratio), or on rabbit ration. The adults fed ex- 



teiisivoly on tlie filamentous al<rae <rro\vin<r on (he 

 tank walls. 



Fry Growth 



a. Each of the fry tanks, which had an area of 

 71.5 sq. ft., yielded about 3 Inickets of bait-size 

 fish in U)-l-2 weeks wlien stocked with u,UOO to 

 T,00() fry. 



1). We predict that by providing more space per 

 tish, bait -size tish could be produced in 8 weeks. 



ProdJction Costs 



a. In the first year of operation (1958), the 

 Paia plant produced approximately 4:70 buckets 

 of bait-size tilapia at a cost of $0.76 per pound, 

 not including tlie salary of the supervising .scien- 

 tist. Jf the plant had been operated on a commer- 

 cial basis, employing one caretaker half-time, we 

 estimate that the total production cost including 

 labor would have been $1.37 per pound. 



b. In the second year of operation (1959), the 

 Paia plant produced approximately -174 buckets 

 of bait-size tilapia at a cost of $1.01 per pound, 

 not including the salary of the supervising scien- 

 tist. If the plant had been operated on a com- 

 mercial scale, employing one caretaker half-time, 

 we estimate that the total cost including labor 

 would have been $1.61 per pound. The higher 

 average cost in 1959 was due to larger expendi- 

 tures for water, electricity, and fish food than in 

 1958. 



c. Better plant design with a proportionately 

 greater amount of fry-tank space would have re- 

 sulted, we believe, in faster growth of the young 

 fish and, therefore, lower production costs. 



LITERATURE CITED 



Brock. Verno.n E., and Michio Takata. 



lO.'jo. Contribution to the problems of bait fish 

 capture and mortality, together with experiments 

 in the use of tilapia as live bait. Industrial Re- 

 search Advisory Council, Hawaii. Grant No. 4!). 

 Final Report, 39 p. 



Chapman, I). G. 



1948. Problems in enumeration of populations of 

 spawning sockeye .salmon. Part II. — A mathe- 

 matical stud.v of confidence limits of salmon popu- 

 lations calculated from sample tag ratios. In- 

 ternational Pacific Salmon Fisheries Commission, 

 Bulletin II, p. 67-8.5. 



Chen, Tung-Pai. 



19.").'?. The culture of tilapia in rice paddies in Tai- 

 wan. Chinese-American Joint Commission on 

 Rural Reconstruction, Fisheries Series, No. 2, 

 30 p. 



Davis, H. S. 



195G. Culture and disease.s of game fish. University 

 of California Press, Berkeley and Los Angeles. 

 332 p. 

 King, Jobeph E., and Peter T. Wilson. 



1957. Studies on tilapia as .skipjack bait. U.S. Fish 

 and Wildlife Service, Special Scientific Report — 

 Fisheries No. 22.5, 8 p. 



MuRPHT, Garth I. 



1960. Introduction of the Marquesan sardine, 

 HarenguUi vittata (Cuvier and Valenciennes), 

 to Hawaiian waters. Patific Science, vol. 14, no. 

 2, p. 185-187. 

 Pongsuwana, U. 



1056. Production of Tilapia mossamiica in an ex- 

 perimental pond at Bangkhen. Thailand. Indo- 

 Paeific Fisheries Council Proceedings, vol. 6, no. 

 2, p. 197-201. 

 Swingle, H. S. 



1960. Comparative evaluation of two tilapias as 

 pondfishes in Alabama. Transactions of the Amer- 

 ican Fisheries Society, vol. 89, no. 2, p. 13.5-148. 

 Tester. Albert L., Heeny I'uen. and Michio Takata. 

 1954. Reaction of tuna to stimuli, 1953. U.S. Fish 

 and Wildlife Service, Special Scientific Report — 

 Fisheries No. 134, 33 p. 

 UcHiDA, Richard N., and Joseph E. King. 



1962. Tank culture of tilapia. U.S. Fish and Wild- 

 life Service, Fishery Bulletin 199. vol. 62, p. 21-52. 

 Vaas, K. F., and A. E. Hofstede. 



1952. Studies on Tilapia mossambica Peters (ikan 

 mudjalr) in Indonesia. Contribution No. 1, Inland 

 Fisheries Research Station, Djakarta-Bogor, Indo- 

 nesia, 68 p. 

 Yamashita, Daniel T. 



1958. Analysis of catch statistics of the Hawaiian 

 skipjack fishery. U.S. Fish and Wildlife Service, 

 Fishery Bulletin 134, vol. 58, p. 253-278. 



APPENDIX 

 POND CULTURE OF TILAPIA 



In 1956 and 1957, personnel of Hawaiian Tima 

 Packers, Ltd., and of the Bureau of Commercial 

 Fisheries seined bait-size tilapia from two ponds 

 adjacent to Honolulu and used the fish in experi- 

 mental live-bait fishing for skipjack. One of the 

 ponds, Kuliouou Pond, is a naturally occurring 

 body of brackish water; the other, Ewa Pond 

 Xo. 6, is an artificially created body of fresh water. 



The number of adult tilapia in each pond was 

 estimated from the frequency of capture of fin- 

 clipped fish (appendix table 1). The quantity of 

 young fish removed from each location in relation 

 to the number of adults and size of the area pro- 

 vide some comparison with the production ob- 

 tained in the brood tanks at the Paia, Maui, 

 hatchery. 



