histology laboratory. These slides are presently 

 available for microscopic examination. 



During the spawning season, whole "ripe" ovar- 

 ies from fish weighing 15.9 to 38.0 kg (35.0 to 84.0 

 lb) were removed, weighed to the nearest 10 grams, 

 and injected with 10% Formalin for fecundity esti- 

 mates. These ovaries were usually "running ripe," 

 i.e., large ova had ruptured from follicles and were 

 flowing into the center of the lumen. Fecundity esti- 

 mates were obtained by the subsampling by weight 

 method described by Bagenal and Braum (1968) and 

 Moe (1969). Techniques for determining distribu- 

 tion of mature ova within various sections of the 

 ovary followed Otsu and Uchida (1959). Ova were 

 successfully disassociated from ovarian tissue with 

 microdissecting needle and forceps. 



Monthly plankton and night-light collections were 

 conducted from June 1970 through October 1971. 

 Surface and oblique tows were made with 1 m plank- 

 ton nets (mesh size 602 ju for body section and 295 

 H for cod end). Supplemental daylight collecting 

 trips were conducted aperiodically. 



RESULTS AND DISCUSSION 

 Age and Growth 



De Sylva (1957) reported that sailfish grow 

 rapidly, attaining a weight of 9.1 kg (20 lb) within a 

 year. Using the Petersen method, he estimated the 

 average life span as 2-3 yr, but suggested that these 

 results be checked by the more conventional as- 

 sessment method of utilizing annular marks. Al- 

 though Koto and Kodama (1962) indicated that cir- 

 culi in scales, otoliths, centra, and fin rays of "Mar- 

 lin" could not be recognized as annular, considera- 

 ble effort is being expended to develop a technique to 

 age individual sailfish. Sailfish pectoral and dorsal 

 fin spines, branchiostegal rays, operculi, and ver- 

 tebral centra were examined for growth marks; 

 scales and statoliths were considered too small to be 

 used. Two structures, vertebral centra and dorsal fin 

 spines, showed distinct circuli which appeared to 

 increase in number with fish length. However, each 

 sailfish centrum is fused to part of the adjacent 

 neural arch, and it is extremely difficult to remove 

 the centra without damaging a specimen destined for 

 trophy mounting. Therefore, dorsal fin spines III, 

 IV, and V were selected as the aging structure since 

 each of these spines has a relatively large base and is 

 easily extracted. Spine removal poses no problem 



for the taxidermist because dorsal fins are not used in 

 trophy preparation. 



Increase in trunk length was compared with in- 

 crease in width of the fourth (IV) spine for 132 

 specimens (Fig. 6). The linear equation,)' = 47.600 

 + 9.881jc, describes a line fitting the regression. An 

 analysis of variance (Table 1) attests to the goodness 

 of fit, thus satisfying the proportional growth re- 

 quirement for use of a bony structure in aging (Par- 

 rish, 1958; Watson, 1967). 



E 11 

 E 



k 10 



N-- 132 

 y 47.600 + 9.881* 

 '=0.903 



1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 



SPINAL WIDTH (mm) 



Figure 6. — Relationship of trunk length and fourth dorsal 

 spine width. Spinal width was measured at 0.5 mm above 

 the dorsalmost portion of each condyle. 



Table 1. — ANOVA regression of trunk length on fourth 

 spine width. 





Sum of 



Mean 





Source d.f. 



squares 



square 



F 



Spine width 1 



42,426.8363 



42,426.8363 



'576.807 



Residual 130 



9,562.0936 



73.5546 





Total 131 



51,988.9299 







v = 47.600 + 9.881 x 









S-b 0.169 









% variation = 81.607 









r = 0.903 









1 Sig. atP = 0.05. 









84 



