DeMartini et al.: Population density, fecundity, and egg size of Panulirus marginatus 



25 



The standard errors of 6 were 0.1787 and 0.1472, respec- 

 tively. A log-linear fit of the F-CL data (LaF=2.5533 LnCL 

 -hi. 3977) was nominally inferior (r-=0.886) to the curvilin- 

 ear fit but was required for the general linear model used 

 in the ANCOVA comparisons that follow below. Fecundity 

 subsamples averaged 1.5 ±0.14(SE)'7f of total brooded egg 

 mass weight. Brooded egg masses weighed an average 

 51.4 g and ranged from 15.8 to 109.2 g. CVs of the three 

 replicate estimates of RF averaged 1.2 ±0.1V'/(. Mean RF 

 was 5882 ±160(SE) eggs per g of brooded eggs and ranged 

 nearly twofold from 4030 to 7930 eggs per g of eggs among 

 the 40 females. Based on the aforedescribed nonlinear best 

 fit, the fecundity of the median-size (53.8 mm TW, 80.9 mm 

 CD female caught at Necker Bank in 1999 by the com- 

 mercial trap fishery was an estimated 306,400 ±90,200 

 (95% CI) eggs. 



Egg size The mean (±SE) diameter of early-stage eggs 

 carried by the 40 berried females was 0.69 ±0.007 mm, 

 with a range of 0.61 to 0.79 mm. Analogous median (25th, 

 75th percentile) diameters were 0.70 (0.65, 0.72) mm. The 

 corresponding egg weights were 0.17 ±0.005 and 0.18 

 (0.15, 0.20) mg (range: 0.13-0.25 mg). Individual egg size 



(diameter: Fig. 3; weight) was unrelated (both P>0.63) to 

 female body size (TW). Individual egg weight was a power 

 function of egg diameter (Table 1). 



Temporal comparisons of fecundity and egg size 



Fecundity Size-specific fecundities differed among the 

 three periods, and body-size-adjusted means differed for 

 each period (Table 2, Fig. 4). Size-adjusted mean fecun- 

 dity in 1999 was 18% greater than in 1991, which in turn 

 was 16% greater than during 1978-81. Lobster in 1999 

 thus exhibited a cumulative 36% increase in size-specific 

 fecundity over that described for lobster collected during 

 1978-81. The statistical power ( 1 minus /3, where ji is the 

 probability of making a type-II error) to detect an effect 

 size equal in magnitude to the changes observed between 

 1978-81, 1991, and 1999 was estimated as >97% at a = 

 0.05. 



Egg size Brooded eggs on average were about 5% greater 

 in diameter (equivalent to 15% greater volume assuming 

 the volume of a sphere, V=4/3 nr') and were 11%^ heavier 

 in 1999 compared to 1991 (Table 3). The precision of our 



