70 
V.L.R. Clarke, R.A. H 0 "'’ 
RESULTS 
The mean SVL of females exceeds that of males 
for all species except S. anomalus. The mean TVL is 
greater in males than females of each species (Table 
1 ). 
Tail-body ratio is strongly dimorphic with TBRs 
of males being higher than females (Table 2) and 
no overlap occuring between males and females in 
most species. An exception is observed in S. 
fasciolatus fasciolatus where the minimum male TBR 
is 0.1186 and the maximum female TBR is 0.1233. 
However, all other females in this species have a 
TBR <0.0918. Table 2 also shows the mean and 
range of tail-body ratios recorded for males and 
females in the subspecies of S. fasciolatus and V. 
multifasciata. The TBRs for the different sexes in the 
two subspecies V. multifasciata multifasciata and V. 
multifasciata snelli are different, with the ranges for 
the sexes in the two subspecies overlapping. There 
were insufficient specimens of S. fasciolatus fasciatus 
to allow comparison with the nominate subspecies 
S. fasciolatus fasciolatus. 
The juvenile and unsexed Simoselaps and 
Vermicella specimens in this study were assigned to 
males and females on the basis of their tail-b°d> 
ratios and the sex ratio obtained was similar to th a 1 
of the sexed population. 
There is no overlap in TBRs between males an( d 
females in S. bertholdi from different geographic 1 ' 1 ' 
regions, although there is some variation in the 
mean TBRs for the two sexes in the different 
regions. The TBR of southwest males is 
significantly lower on average than those in the 
northwest (Mann-Whitney U, p = 0.0035) and east 
(p = 0.0012), while females are not significant!.'' 
different between areas. 
DISCUSSION 
In snakes it is common for females to exceed 
males in average size (Fitch, 1981; King 1989). The 
fossorial snakes investigated in this study folio" 
this trend with females having greater mean SVLs 
than males and results are similar to those obtained 
by Shine (1984) in his study of fossorial snakes ' n 
Australia. However, S. anomalus provides an 
Table 1 The mean snout-vent lengths and tail-vent lengths for male and female Simoselaps and Vermicella together 
with standard deviation, range and sample size. Significant differences between the sexes at P<0.01 are 
indicated by a single asterisk (*) and at P<0.001 by a double asterisk (»*). 
Snout-vent length Tail—vent length 
(cm) (cm) 
Species 
S. anomalus 
S. approximans 
S. bertholdi 
S. bimaculatus 
S. calonotos 
S. littoralis 
S. minimus 
S. roperi 
S. semifasciatus 
S. fasciolatus fasciatus 
S. fasciolatus fasciolatus 
V. multifasciata multifasciata 
V. multifasciata snelli 
Total 
Sex 
No 
Mean 
M 
18 
15.2 
27 
F 
5 
14.1 
M 
14 
27.0 
31 
F 
10 
27.8 
M 
87 
16.9” 
213 
F 
80 
19.7” 
M 
27 
24.9” 
65 
F 
29 
29.8** 
M 
37 
19.3** 
81 
F 
32 
21.7** 
M 
29 
16.0** 
84 
F 
40 
20.9** 
M 
2 
17.6 
3 
F 
1 
20.5 
M 
9 
26.2 
12 
F 
2 
27.6 
M 
65 
23.0** 
154 
F 
64 
26.0** 
M 
2 
27.5 
4 
F 
M 
18 
25.6 
40 
F 
17 
27.0 
M 
2 
33.3 
9 
F 
6 
41.5 
M 
4 
34.0 
13 
F 
8 
36.4 
SD Range No 
1.6 
11.5-17.7 
18 
3.3 
10.5-19.1 
5 
3.4 
21.0-32.5 
14 
4.1 
20.5 - 35.5 
10 
2.2 
10.0-21.8 
86 
3.7 
10.0 - 29.0 
81 
3.8 
19.0-30.5 
27 
5.6 
20.5 - 39.0 
28 
1.9 
13.8 - 22.3 
36 
2.3 
15.2-25.2 
32 
2.0 
11.8-20.5 
29 
5.3 
12.3-35.8 
40 
2.3 
16.0-19.2 
2 
20.5 - 20.5 
1 
3.4 
21.8-32.5 
9 
3.6 
24.9 - 30.0 
2 
3.4 
13.8 - 30.0 
65 
4.1 
15.0 - 34.2 
63 
0.7 
27.0 - 28.0 
2 
4.9 
13.4-31.2 
18 
7.1 
15.0-35.0 
17 
5.3 
29.5 - 37.0 
2 
10.2 
24.6-51.3 
6 
2.9 
31.1-38.0 
4 
9.3 
21.2-48.5 
8 
Mean 
SD 
Range 
2.2** 
.3 
1.6 - 2.5 
1.5” 
.3 
1.1-19 
2.8** 
.4 
2.2 - 3.4 
2.2” 
.2 
1.8 - 2.6 
2.3” 
.4 
1.3-3.0 
1.8” 
.4 
0.9 - 3.0 
2.6” 
.4 
2.0 - 3.2 
2.1” 
.3 
1.4-2.7 
3.2** 
.4 
2.3 - 4.0 
2.8** 
.3 
2.0 - 33 
2.3 
.3 
1.7 -2.9 
2.1 
.6 
1.1-3.1 
2.4 
.4 
2.1-2.7 
2.1 
2.1-2.1 
2.6* 
.3 
2.1-3.0 
1.8* 
.6 
1.4-2.2 
2.6” 
.4 
1.5-3.7 
2.0** 
.4 
1.0-3.0 
3.7 
.1 
3.6 - 3.7 
3.3” 
.6 
1.7-3.9 
2.3** 
.8 
1.1-3-7 
2.4 
.2 
2.2 - 2.5 
1.9 
.5 
1.0 -2.7 
1.8 
.2 
1.6 -2-0 
1.5 
.4 
0.9 - 20 
