98 WATT 
Table 1. Statistics calculated from linear measurements for six populations of Mimopeus. 
Dimension Population Species Mean ADE C.V. Range N 
mm mm 
Little Barrier I e. 2.73 0.26 9.6 2.3-3.1 22 
Mt. Mangere e, 3.14 0.15 4.3 2.9-3.5 20 
Pr.L. Pararaha e.m. 3.05 0.14 4.6 2.8-3.3 20 
Three Kings Is tu. 3.62 0.21 5.8 3,2-4.2 24 
Red Rocks O.S. 4.61 0.25 5.4 4.3-5.3 20 
Poor Knights Is ta. 5.26 0.19 5.6 4.8-5.6 22 
Little Barrier I e. 4.94 0.40 8.2 3,9-5.5 22 
Mt. Mangere e. 5.12 0.31 6.0 4.4-5.7 20 
Pr.W. Pararaha e.m. 5.02 0.24 4.8 4.6-5.6 20 
Three Kings Is_ tu. 6.58 0.52 Ta 5.5-7.3 24 
Red Rocks 0.8. 7.67 0.47 6.1 7.1-9.1 20 
Poor Knights Is ta. 8.54 0.44 D2 7.7-9.2 22 
Little Barrier I e. 2.31 0.17 54) 1.9-2.7 22 
Mt. Mangere & 2.55 0.14 5.6 2.3-2.9 20 
H.W. Pararaha e.m. 2.48 0.12 4.8 2.2-2.7 20 
Three Kings Is _ tu. 3.00 0.19 6.3 2.5-3.3 24 
Red Rocks O.S. 3.64 0.23 6.2 3.5-4.3 20 
Poor Knights Is ta. 3.98 0.16 4.0 3.7-4.2 22 
Little Barrier I e. 8.42 0.56 6.6 7.0-9.2 22 
Mt. Mangere e. 8.50 0.39 4.6 7.8-9.3 20 
EL.L. Pararaha e.m. 8.21 0.36 4.4 7.5-9.0 20 
Three Kings Is _ tu. 9.47 0.71 7.5 8.3-10.7 24 
Red Rocks O.S. 12.84 0.60 4.7 11.8-14.4 20 
Poor Knights Is ta. 16.18 0.74 4.6 14.9-17.4 22 
e.elongatus, m.elongatus West Coast, 0.s.opaculus Central North I., ta.insularis, tu.turbotti 
From Table 2 and Fig.1 it is apparent that in a single population the means of 
males differ (often significantly) from the means of females. It is also apparent that 
the means of dimensions of a single sex differ significantly between populations, 
due to geographical variation in size in M. elongatus. Marked differences from 
“normal distribution” in Fig.1 are probably attributable to the relatively small 
samples. 
In some cases one sex (usually male) is considerably more variable than the 
other. This is true of all five dimensions of the Little Barrier Island population, of 
four dimensions of M. turbotti, and of three dimensions of the Mt. Mangere 
population. 
An index of sexual dimorphism in each dimension has been caculated by 
expressing the difference of the means as a percentage of their sum 
M, 7 M, 
(i.e. index = —______ X 100, where M_,, M, are the means 
M + M, 
of female and male respectively. If the index is negative, M, is greater than M ). 
These indices for the four elongatus populations are listed below. 
