532 



Fishery Bulletin 97(3), 1999 



40 



30- 



20 



10- 



Analysis of relative growth in ma- 

 jor chela height for males ( Fig. 6C ) and 

 females (Fig. 6D), when scaled to cara- 

 pace length, produced remarkably 

 similar results to that for relative 

 growth in chela width, suggesting 

 some interdependency of those mea- 

 sures. Transition points were opti- 

 mally located at a mean carapace 

 length of 11.0 mm for males and 11.2 

 mm for females, and postmaturation 

 growth differed significantly between 

 the sexes (Table 1). On the basis of al- 

 lometric coefficients (Table 2 ), positive 

 prematuration allometric growth once 

 again did not differ between the sexes, 

 whereas negative postmaturation 

 growth in females differed signifi- 

 cantly from the strongly positive allo- 

 metric growth in postmaturation 

 males. Analysis of chela width scaled 

 to chela height in both sexes did not indicate signifi- 

 cant prematuration differences between males and 

 females, and growth in both sexes was isometric or 

 nearly so (Tables 1 and 2). However, following tran- 

 sition to the postmaturation phase in males, rela- 

 tive growth in chela width exceeded that of height. 

 The opposite effect was seen in postmaturation fe- 

 males; negative allometric growth was seen in chela 

 width, when compared to chela height. 



Analysis of total length scaled to carapace length 

 revealed large measures of error (Tables 1 and 2), as 

 expected in size measurements that include the 

 length of a soft, stretchable abdomen. Allometric co- 

 efficients indicated that slopes did not significantly 

 differentiate prematuration growth from an isomet- 

 ric pattern in either sex, whereas postmaturation 

 growth on the basis of this parameter appeared to 

 be negatively allometric but similar in rate for both 

 males and females. 



Large measures of error associated with wet weight 

 measurements in relation to carapace length, espe- 

 cially at small sizes, limited detection of possible sex 

 differences in allometric coefficients based upon this 

 parameter and did not resolve significant differences 

 between growth phases of either sex (Table 2). Only 

 in the postmaturation phase were allometric coeffi- 

 cients based upon wet weight significantly more posi- 

 tive in males than in females. The more sensitive 

 analyses of wet weight based upon regressions by 

 reduced major axis (Fig. 7, A and B; Table 1) detected 

 highly significant differences between postma- 

 turation males and females, regardless of whether 

 ovigerous females were included or excluded from 

 the analysis, and also resolved significant differences 



V//J//J/A 



10 11 12 13 14 



Carapace length (mm) 



15 



16 



Figure 4 



Size class (CL) frequency ciistribution of all ovigerous females in sampled 

 Colombian populations of Lepidophthatmus sinuensis, December 1991 

 through December 1995 (number by class appears above each bar I. 



in rates of mass accumulation between prema- 

 turation and postmaturation growth phases. Opti- 

 mized transition points in piecewise regression analy- 

 ses of wet weight to length relationships were near 

 9.8 mm CL for females and near 11.3 mm CL for 

 males. These regression breaks suggest that matu- 

 ration in males occurs at slightly higher wet weights 

 ( 1.5 to 2 g) than in females (usually near 1 g). 



Dry weights and ash free dry weights were deter- 

 mined for limited subsets of our sample and were 

 not subjected to regression analysis. The proportional 

 relation of dry to wet weight in ovigerous females 

 (0.47 ±0.06; /!=8) was slightly but significantly higher 

 than in nonovigerous females (0.36 ±0.03; n=76} and 

 males (0.33 ±0.05; n = l2), whereas the relation of ash 

 free dry weight to wet weight in ovigerous females 

 (0.052 ±0.003; n=8) was not significantly different 

 from that of either nonovigerous females (0.059 

 ±0.011; n=41) or males (0.055 ± 0.003; n=2). 



Discussion 



Sex ratio 



Strongly female-biased sex ratios in the monitored 

 population of Lepidophthalmus sinuensis are in 

 marked contrast to those reported in intertidal popu- 

 lations of L. louisianensis on the Mississippi coast in 

 the northern Gulf of Mexico (Felder and Griffis, 

 1994), which were variable but averaged near 1:1. 

 However, female-biased ratios have been reported in 

 populations of L. louisianensis from the Louisiana 

 coast in the northern Gulf of Mexico (Felder and 



