Animal Molecular Breeding 2015, Vol. 5, No. 1, 1-8
4
dendrogram was constructed by using UPGMA
(Unweighted Pair Group Method with Arithmetic
mean) to group individuals into discrete clusters.
2 Results
2.1
Morphological variations
Basic statistical information including the range, mean
and standard deviation of each of the five direct
measurements of the shell characteristics of the snails
are shown in Tables 2 and 3. Awide range of sizes was
found among the snails procured from Akwa Ibom and
Cross River States, respectively. For example, the height
of shell differed significantly amongst the samples from
these two localities with standard deviations of 0.55 and
0.45, revealing greater heterogeneity amongst them.
Such significant differences were also seen in the width
(with standard deviations of 0.48 and 0.38) and aperture
height of the shell (with standard deviations of 0.36 and
0.44, respectively), for the same samples.
Table 2 Basic statistical data (range, mean and standard deviation) of the shell characteristics of
Archachatina marginata
from different
locations in Nigeria
Variable
Akwa Ibom State (n = 4)
Edo State (n = 5)
Cross River State (n = 7)
Height of shell (HS)
Range
5.0 – 6.0
9.0 – 10
3.8 – 5.2
Mean
5.48
9.4
4.37
SD
0.55
0.38
0.45
Width of shell (WS)
Range
1.3 – 2.2
3.8 – 4.3
1 – 2
Mean
1.93
4.08
1.39
SD
0.48
0.22
0.38
Spire length of shell
Range
0.1 – 1.3
2.6 – 3.2
0.3 – 1.3
Mean
0.8
2.84
0.71
SD
0.50
0.23
0.27
Aperture height of shell
Range
0.6 – 1.4
3 – 3.5
0.2 – 1.4
Mean
1.1
3.14
0.64
SD
0.36
0.28
0.44
Aperture width of shell
Range
0.1 – 0.3
0.5 – 0.6
0.1 – 0.2
Mean
0.18
0.52
0.13
SD
0.10
0.05
0.05
Note: Range and mean ( ) values are given in centimeters; n = number of accessions
Table 3 Mean values of the characteristics within each group of
Archachatina marginata
accessions
Cluster
Location of collection Shell height
(cm)
Shell width
(cm)
Spire height
(cm)
Aperture height
(cm)
Aperture width
(cm)
1.
C/River
4.23
1.13
0.6
0.63
0.13
2.
C/River
4.57
1.73
0.87
0.67
0.13
3.
Edo
10
4.3
3.2
3.5
0.5
4.
Edo
9.25
4.03
2.75
3.05
0.53
5.
A/Ibom
5.63
2.13
1.03
1.23
0.2
The accessions in Clusters 1 and 2 were collected from
Cross River State and their calculated means for the
five characteristics were not significantly (
p
>0.05)
different from one another. Those collected from Edo
State are in Clusters 3 and 4 while those from Akwa
Ibom State are in Cluster 5 (Table 3). One accession in
Cluster 3 (B52) with light brown skin seems to be a
hybrid between the pigmented and non-pigmented
snails in Groups 1 and 2 and they tend to have the
highest mean values in the five characteristics examined.
