878 



Fishery Bulletin 98(4) 



80 



60 



40 



20 



37 



80 



60 - 



40 



20 



39 

 /. valjes 



40 



1.6 



2.4 



2.8 



3.2 



3.6 



k values 



21 



Figure 2 



Plots of the frequency histogram of 200 bootstrapped estimates of /_ and k for P. 

 fii'misulcatus males. 



Our tests, in which the two tiger prawn species were com- 

 pared, show that the significance of the results varies with 

 the hypothesis. In our example, we have tried to choose 

 lengths and ages that were approximately comparable. 

 The results of the six tests for any particular interspecific 

 or intraspecific hypothesis under either scenario are not 

 directly comparable because methods 1, 2, and 4 compare 

 growth rate at age (6 month or 1 yr) and the other meth- 

 od.s compare growth rate in relation to length (30 mm or 

 35 mm). This distinction is more important for the interspe- 

 cific comparisons because growth rate, rather than sexes, is 

 more likely to vary between species for most phyla. 



Discussion 



Tests to compare growth by comparing length-at-age 

 (method 1) show that there were no significant differences 

 in the size of each sex of the two species, but there were 

 highly significant differences in size between the sexes 

 of each species. This finding differs from the interpreta- 

 tion if /j-values were compared (method 6). In the situa- 

 tion where a farmer is deciding which species reaches a 

 minimum marketable size earlier, we think that method 

 1 would be the most logical to use. However, if the farmer 

 were trying to decide the potential benefit or tradeoff of 



