in Japan must be made for the shortbill spearfish (see 

 2.1). 



5.42 Selectivity 



The longline gear takes fish distributed at a depth 

 range roughly from 50 to 150 m, while the pole-and- 

 line and the purse seine gears catch those living near 

 the surface. For tunas, this means that the longline 

 fishery exploits larger fish than does the surface 

 fishery. 



Concerning the effect of selective properties of the 

 longline gear on growth studies, Suzuki (1971) set 

 forth the following hypothesis and examined the 

 possibility of gear selectivity in connection with Lee's 

 phenomenon: If a fishery exploits fish within a certain 

 size range, the fishery tends to catch larger in- 

 dividuals out of the young fish group whose size is 

 near the lower limit of the selective range of the gear 

 and smaller ones out of the old fish group whose size is 

 near the upper limit. The catches, therefore, tend to 

 represent larger members for the young group and 

 smaller ones for the old group compared with fish ac- 

 tually distributed in the sea. Applying this to the 

 longline fishery, samples from the catch would result 

 in erroneously larger estimates of growth coefficient 

 and smaller estimates of asymptotic length. 



6 PROTECTION AND MANAGEMENT 



Protection and management are the most impor- 

 tant and urgent issues we now face in the world tuna 

 resources. Presently, little attention is paid to the 

 shortbill spearfish stock(s) because it is less important 

 in the commercial and sport fisheries. This, however, 

 does not appear to fix the relative value of the short- 

 bill spearfish in the future management of the fishery. 



7 POND FISH CULTURE 

 Not applicable. 



LITERATURE CITED 



CRAIG, W. L. 



1958. The shortnose spearfish Tetrapturus angustirostris 

 Tanaka. A species new to the near shore fauna of the east- 

 ern Pacific Ocean. Calif. Fish Game 44:275-280. 

 DE BUEN, F. 



1950. Contribucion a la icticJogia. 3. La familia Istiophori- 

 dae y descripcion de una especie uruguaya (Makaira per- 

 ezi de Buen). Publ. Cient. Serv. Oceanogr., Montevideo 

 5:163-178. 



DERANIYAGALA, P. E. P. 



1951. The Istiophoridae and Xiphiidae of Ceylon. Spolia 

 Zeylan. Bull. Natl. Mus. Ceylon 26:137-142. 



DE SYLVA, D. P. 



1957. Studies on the age and growth of the Atlantic sailfish, 

 Istiophorus americanus (Cuvier), using length-frequency 

 curves. Bull. Mar. Sci. Gulf Caribb. 7:1-20. 



FOWLER, H. W. 



1928. The fishes of Oceania. Mem. Bernice P. Bishop 

 Mus. 10, 540 p. 

 HIRASAKA, K., and H. NAKAMURA. 



1947. On the Formosan spearfishes. Bull. Oceanogr. Inst. 

 Taiwan 3:9-24. 

 HOWARD, J. K., and S. UEYANAGI. 



1965. Distribution and relative abundance of billfishes 

 (Istiophoridae) of the Pacific Ocean. Univ. Miami Inst. 

 Mar. Sci., Stud. Trop. Oceanogr. 2, 134 p. 

 JONES, S., and M. KUMARAN. 



1964. Distribution of larval billfishes (Xiphiidae and Istio- 

 phoridae) in the Indo-Pacific with special reference to the 

 collections made by the Danish Dana Expedition. Proc. 

 Symp. Scombroid Fishes, Part 1, p. 483-498. Mar. Biol. 

 Assoc. India, Mandapam Camp. 

 JORDAN, D. S., and B. W. EVERMANN. 



1926. A review of the giant mackerel-like fishes, tunnies, 

 spearfishes and swordfishes. Occas. Pap. Calif. Acad. 

 Sci. 12:1-113. 

 KATSUO-MAGURO NENKAN. 



1969. Katsuo-Maguro Nenkan (Skipjack-Tuna Yearbook). 

 [In Jap.] Suisan Shinchosha, Tokyo, 950 p. 

 KOGA, S. 



1959. Fishing condition of tunas and marlins in the western 

 South Pacific Ocean. [In Jap., Engl, abstr.] Bull. Fac. 

 Fish. Nagasaki 8:57-79. 

 1967. Studies on the fishery biology of the tuna and marlin 

 in the Indian and the South Pacific Ocean. [In Jap., 

 Engl, summ.] J. Shimonoseki Coll. Fish. 15:51-256. 

 KOGA, S., H. IMANISHI, and S. TAWARA. 



1972. A fishing condition of the tuna and marlin in the cen- 

 tral South Pacific. [In Jap., Engl, abstr.] J. Shimono- 

 seki Coll. Fish. 20:213-233. 

 KOTO, T. 



1963. Some considerations on the growth of marlins, using 

 size frequencies in commercial catches. III. Attempts to 

 estimate the growth of striped marlin, Tetrapturus audax 

 (Philippi) in the Western North Pacific Ocean. [In Jap.] 

 Rep. Nankai Reg. Fish. Res. Lab. 17:63-85. 



KOTO, T., and K. KODAMA 



1962a. Some considerations on the growth of marlins, using 

 size-frequencies in commercial catches. I. Attempts to es- 

 timate the growth of sailfish. [In Jap., Engl, abstr.] 

 Rep. Nankai Reg. Fish. Res. Lab. 15:97-107. 



1962b. Some considerations on the growth of marlins, using 

 size-frequencies in commercial catches. II. Attempts to es- 

 timate the growth of so called white marlin, Martina 

 marlina (J. and H.) [In Jap., Engl, abstr.] Rep. Nan- 

 kai Reg. Fish. Res. Lab. 15:109-126. 

 KUME, S., and J. JOSEPH. 



1969a. The Japanese longline fishery for tunas and bill- 

 fishes in the eastern Pacific Ocean east of 130°W, 1964- 

 1966. [In Engl, and Span.] Bull. Inter-Am. Trop. Tuna 

 Comm. 13:277-418. 



1969b. Size composition and sexual maturity of billfish 

 caught by the Japanese longline fishery in the Pacific 

 Ocean east of 130°W. [In Engl., Jap. summ.] Bull. 

 Far Seas Fish. Res. Lab. (Shimizu) 2:115-162. 

 LA MONTE, F. R. 



1955. A review and revision of the marlins, genus Makaira. 

 Bull. Am. Mus. Nat. Hist. 107:323-358. 

 MATSUBARA, K. 



1955. Fish morphology and hierarchy. Part I. Ishizaki- 

 Shoten, Tokyo, 789 p. 



53 



