(675.) Proceedings of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— Life History of the Atlantic 

 Blue Marlin, Makaira nigricans, with Special Reference to 

 Jamaican Waters. By Donald P. de Sylva. July 1974, 

 p. 80. Abstract only. 



ABSTRACT 



Nomenclature and systematics of the Atlantic blue marlin are 

 briefly reviewed. Its seasonal distribution in the Atlantic is 

 analyzed from commercial and sport fish records. The spawning 

 season in the North Atlantic, whicn occurs from late spring through 

 late fall, is discussed. Larvae and juveniles are not common, but are 

 easily identifiable. Spawning probably occurs far offshore, with the 

 young developing in waters of the high seas. Feeding probably 

 occurs in the deeper strata. Tunas, frigate mackerels, and 

 cephalopods are the main food items. The growth rate has not been 

 determined, but it is suspected that blue marlin exceed 15 yr. 

 Females attain a much larger size than the males; this is attributed 

 to differential mortality. The blue marlin probably undergoes 

 reasonably extensive migrations, and may be considered to 

 comprise populations at lea.st in the North Atlantic and South 

 Atlantic Oceans. The sport fishery, which is extensive and 

 expensive, and valuable economically, is thoroughly discussed. The 

 commercial fishery for the species in the Atlantic is incidental to the 

 tuna fisheries, yet there are some indications that the blue marhn is 

 in some danger of being depleted through commercial activities. 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— On the Biology of Florida East 

 Coast Atlantic Sailfish, {Isiiophorus platypierus). By John 

 W. Joliey, Jr. July 1974, p. 81-88. 



and July. There is also the possibility that sailfish spawn m other 

 months. First maturity in striped marlin and sailfish occurred in the 

 155-165 cm eye fork length class. Fecundity estimates ranged from 

 2 to 5 million eggs for four sailfish and from 11 to 29 million eggs for 

 three striped marlin. It appears that striped marlin move offshore 

 from the Mexican coastline to spawn while sailfish remain closer to 

 shore. 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— Scientific Billfish Investigation: 

 Present and Future; Australia, New Zealand, Africa. By 

 Charles 0. Mather. July 1974, p. 102. Abstract only. 



ABSTRACT 



I. Scientists, anglers, skippers, and mates investigate and apply the 

 scientific method. 



The importance of knowledge, organization, and skills 

 requirea of the scientist, angler, skipper, and mate in order 

 to bring about a better understanding of the billfish and 

 better methods of catching billfish is discussed. 



II. The need for more observations and recording of data. 



The following data should be given important consideration: 

 temperature, depth, time, winds, currents, strike-catch 

 ratio, bait, and the ship's log: these topics are reviewed. 



III. Scientific research projects for consideration in the future. 



Potential research projects in Australia, New Zealand, and 

 Africa are presented. Some projects worthy of consideration 

 include: (1) breeding of black marUn at the Great Barrier 

 Reef, Australia: (2) transplanting of small black marlin to a 

 natural salt water lake for study and observation of growth 

 and development (Australia); (3) migration studies by track- 

 ing (Australia, New Zealand, Africa); (4) general blood cell 

 surveys (New Zealand); (5) general chromosome surveys 

 (New Zealand); and (6) sensory and motor responses of bill- 

 fish in relation to sight, smell, and pain (Africa). 



ABSTRACT 



The sailfish, htiophorus platypterus, is one of the most 

 important species in southeast Florida's marine sport fishery. 

 Recently, the concern of Palm Beach anglers about apparent 

 declines in numbers of sailfish caught annually prompted the Florida 

 Department of Natural Resources Marine Research Laboratory to 

 investigate the biological status of Florida's east coast sailfish 

 populations. 



Fresh specimens from local sport catches were examined 

 monthly during May 1970 through September 1971. Monthly 

 plankton and "night-light" collections of larval and juvenile stages 

 were also obtained. Attempts are being made to estimate sailfish 

 age using concentric rings in dorsal fin spines. If successful, growth 

 rates will be determined for each sex and age of initial maturity 

 described. Females were found to be consistently larger than males 

 and more numerous during winter. A significant difference in 

 length-weight relationship was also noted between sexes. 



Fecundity estimates varied from 0.8 to 1.6 million "ripe " ova, 

 indicating tliat previous estimates (2.5 to 4.7 million ova) were 

 probably high. Larval istiophorids collected from April through 

 October coincided with the prominence of "ripe" females in the sport 

 catch. Microscopic examination of ovarian ti.ssue and in.spection of 

 "ripe" ovaries suggest multiple spawning. 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— Some Biological Observations of 

 Billfishes Taken in the Eastern Pacific Ocean, 1967-1970. 

 By Maxwell B. Eldridge and Paul G. Wares. July 1974, 

 p. 89 101. 



ABSTRACT 



From 1967 through 1970 sport-caught billfishes were sampled 

 at Mazatlan, Sinaloa; and Buena Vista, Baja California, and at San 

 Diego, California. Lengths, weights, morphometries, meristics, and 

 gonad data were gathered on a total of 2,056 .striped marlin, 821 

 sailfish, 61 blue marlin. and 1 black marlin. This paper presents 

 information on reproduction, average length and condition factor, 

 food habits for 1970. and notes on parasites. 



Developing gonads were found only in the Mexican fish. Our 

 data on reproduction indicated that both striped marlin and sailfish 

 spawn once per year with peak spawning activity probably in June 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— Biology of Swordfish, Xiphias 

 Gladius L., in the Northwest Atlantic Ocean. By James S. 

 Beckett. July 1974, p. 103-106. 



ABSTRACT 



The present knowledge of the biology of .swordfish in the 

 northwest Atlantic Ocean is summarized. Distribution of swordfish 

 is bounded by 13°C surface isotherms with smaller (under 160 cm) 

 fi.sh in water above 18°C. Males are smaller (under 200 cm) than 

 females and are more frequent in warmer, southern areas. Large 

 fish make feeding excursions to the bottom, to depths of 500 m or 

 more and temperatures 5 10°C. Females attain sizes of 550 kg and 

 males 120 kg, but average size was 54 kg in 1970 commercial 

 landings. Growth is thought to be rapid with weights of 4. 15, 40, 70, 

 and 110 kg attained at annual intervals. Spawning is confined to 

 warmer (over 24°C) southern waters. Tagging data (13 recoveries) 

 suggest fish spend the summer in one locality and return there in 

 subsequent years. High recoveries (18.3%) have been made of fish 

 tagged while swimming free. 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9 12 August 1972, Part 2. Review 

 and Contributed Papers— Some Morphometries of Bill- 

 fishes From the Eastern Pacific Ocean. By Paul G. Wares 

 and Gary T. Sakagawa. July 1974, p. 10'7-120. 



ABSTRACT 



Length-weight and morphometric data collected over 4 yr 

 (1967 70) from sport fisheries at three eastern Pacific locations are 

 pre.sented for striped marhn iTetrapturus audojc). sailfish {htio- 

 phorus platypterus), and blue marlin tMakaira nigricans). The data 

 were gathered from San Diego, California (U.S.A.). Buena Vista, 

 Baja California Sur (Mexico), and Mazatlan. Sinaloa (Mexico). 



Regression of eye fork length and covariance analysis were used 

 to compare maximum body depth, depth at vent, pectoral fin 

 length, dorsal fin height, maxillary length, snout to mandible and 

 snout to posterior orbit lengths between sexes and areas for each 

 species. Regression equations are given for converting fork length 



