NOTE Taylor and Murphy: Reproductive biology of Xiphias gladius in Straits of Florida 



50 



i 30 

 UJ 



3 



o 



UJ 20 



a. MALE 

 n = 117 



El CLASS 4 

 n CLASS S 

 ■ CLASS 6 

 D CLASS 7 

 n CLASS 8 



H B ff 1 1 



NS 



JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 

 COLLECTION MONTH 



> 

 U 



z 



UJ 



o 



UJ 



20- 



b. FEMALE 

 n = 71 



M CLASS 4 

 a CLASS 5 

 ■ CLASS 6 

 D CLASS 7 

 n CLASS 8 



^^m f" ■"! ^^B 



I 



inj 



Fl.H.^.H 



NS 



1 I T 



JUL AUG SEP OCT NOV DEC 



JAN FEB MAR APR MAY JUN 



COLLECTION MONTH 



Figure 3 



Monthly frequencies of gonad development classes for mature (> Class 4, 

 see "Methods and materials") swordfish Xiphias gladius collected off 

 southeast Florida during the period June 1977-November 1980. NS indicates 

 no samples taken. 



in the Mediterranean first reach matur- 

 ity at 106-135cm LJFL, and about 50% 

 of the females > 135 cm are mature. This 

 is in contrast to our findings that the 

 smallest mature females off Florida were 

 ~170cm LJFL and that 50% of females 

 reached maturity when ~180cm. 



Female swordfish from the Pacific 

 Ocean mature at sizes comparable to or 

 somewhat smaller than those in the west- 

 ern Atlantic. From 1949 to 1958, Yabe 

 et al. (1959) examined 372 female sword- 

 fish taken by a Japanese longline fleet in 

 the North Pacific. They found only five 

 mature females and suggested that 

 females in the North Pacific begin to 

 mature at 150-170cm EFL (170-192 

 LJFL). Kume and Joseph (1969) con- 

 cluded that female swordfish off Califor- 

 nia begin to mature at slightly smaller 

 sizes, 139cm EFL (158cm LJFL), and 

 are regularly found in ripe condition at 

 >170cm (192cm LJFL). 



The ages-at-maturity we estimated for 

 male (1.4yr) and female (5.5yr) swordfish 

 off southeast Florida are somewhat 

 younger and older, respectively, than 

 those determined for male and female 

 swordfish collected farther north in the 

 U.S. South Atlantic. From a relatively 

 small sample collected off North Carolina 

 and South Carolina, Wilson (1984) deter- 

 mined that males mature between ages 

 2 and 3 (15 mature males of 24 exam- 

 ined). Females mature between ages 4 

 and 5 (2 mature females of 18 examined). 

 Although Wilson (1984) relied on a dif- 

 ferent technique (thin-sectioned otoliths) 

 than did our study (thin-sectioned spines) 

 to determine swordfish ages, he com- 

 pared the two aging techniques and found 

 they provided similar swordfish ages 

 through at least age 5. 



Female swordfish mature at a younger 

 age in the eastern Mediterranean Sea 

 than in the western Atlantic or Pacific 

 Oceans. In the eastern Mediterranean, 



Figure 4 



Monthly mean and range (vertical bars) of individual 

 mean oocyte diameters for all mature (Class >4) sword- 

 fish Xiphias gladius collected off southeast Florida dur- 

 ing the period June 1977-November 1980. Numbers 

 indicate sample size; NS indicates no samples taken. 



