100 



Fishery Bulletin 102(1) 



than Lizard Island group females, maturation schedules 

 were generally similar (Fig. 6). At both island groups, age 

 2 was the age at both earliest maturity and 50% maturity, 

 and 93-100% of females had matured by age 4 (Fig. 6A, 

 Table 3). Thus, maturation was rapid, beginning early in 

 life and ending within a 2-year period with nearly all mem- 

 bers of a cohort mature. Length-specific maturation sched- 

 ules also exhibited similarity between the island groups 

 with mature fish first appearing in the 160-179 mm FL 

 size class, estimated 50% maturation in the 180-199 mm 

 FL size class, and 93-100% maturity at the 220-239 mm 

 FL size class (Fig. 6B, Table 3). 



310 

 300 -| 

 290 

 280 

 270 -| 

 260 

 250 - 

 240 - 

 230 



0.4 



0.5 



0.6 



0.7 



0.8 



0.9 



K 



Figure 4 



Fork length at age and estimated von Bertalanffy growth 

 turves for male  solid lines) and female (□. broken lines) 

 Lutjuiius larpinuiliiliis at the Palm iA> and Lizard iBl island 

 groups and estimated 959! joint confidence regions of the 

 parameters A" and l. (C), Parameter estimates are presented 

 in Table 2. 



Spawning season 



Mature female LSI values were highest in August through 

 October with a maximum in September ( Fig. 7A). The peak 

 in GSI lagged that of LSI by two months with the high- 

 est values occurring from October through December and 

 with a maximum in November (Fig. 7A>. The absence of a 

 January sample unfortunately leaves some ambiguity as to 

 whether GSI, and therefore presumably spawning activity, 

 would still be high at this time or if it would have begun 

 to decline. Male GSI values also exhibited a November 

 maximum (Fig. 7B). Male LSI values, however, did not 

 show any clear trend of increase and decline throughout 

 the year and peaks in April, May, and August that did 

 not correlate with future GSI values as clearly as seen in 

 the female data (Fig. 7). Unlike LSI values for females, 

 monthly mean male LSI values were always greater than 

 the corresponding GSI values. 



The seasonal pattern of L. carponotatus spawning 

 activity suggested by monthly trends in the proportions 

 of mature ovarian stages can be interpreted as differ- 

 ent from that suggested by GSI values. The lowest GSI 

 values in the October-December peak period were close 

 to twice as great as the next highest values in Septem- 

 ber and February < Fig. 7A). However, the percentage of 

 stage-IV ovaries in the September sample was greater 

 than 50%. which is well over half the percentage of the 

 October sample; whereas the February sample comprised 

 approximately the same percentage of stage-rV ovaries as 

 October (Fig. 8). Also, more than 50% of the March sample 

 was stage-rV ovaries (Fig. 8). whereas its GSI value was 

 close to that of the months with relatively few ripe ovaries 

 (Fig. 7A). Furthermore, September and March had the 

 highest proportions of ripening (stage-Ill I females and 

 thus far fewer resting mature (stage-II) females than the 

 April to August period of limited spawning activity I Fig. 

 8). Therefore, regardless of whether September, February, 

 and March are defined as nonspawning months or months 

 of limited spawning activity based upon GSI, analysis of 

 ovarian stage frequencies suggests these to be periods 

 of greater spawning activity than might be predicted 

 with GSI. Clearly, the presence of advanced oocytes is a 

 much better indication of imminent spawning than any 

 measure of gonad size; therefore the reproductive stage- 

 frequency data undoubtedly provide the more accurate 

 picture of L. carponotatus spawning patterns. 



Of 59 ovaries staged from the October 1997 Lizard 

 Island group sample, eight were at stage I, two were at 

 stage II, and 49 (96% of mature females in the sample) 

 were at stage PV. This finding suggests that the island 

 groups share at least October as a common period of ac- 

 tive spawning. 



Reproductive differences between locations and among 

 size classes 



The variation in GW among females of like body sizes 

 during peak spawning months increased to some degree 

 with increasing TW, but there was a generally homoge- 

 neous spread of data around the predicted regression 



