International Journal of Marine Science 2015, Vol.5, No.51: 1-11
5
Table 2.List of oligochaete species in paddy fields and channels of Maranchery Kole wetlands. + = species present - = species absent
Naididae
Paddy fields
Channels
Jan 2011 Feb
Mar
Apr
May 2011 Jan 2011
Feb
Mar
Apr
May 2011
Pristinella minuta
Stephenson, 1914
-
-
+
-
-
-
+
+
+
+
Pristinella jenkinae
Stephenson, 1931
+
-
-
+
-
+
+
+
+
Pristinella accuminata
Liang, 1958
-
-
-
-
-
-
+
-
-
+
Pristina menoni
Aiyer, 1929
-
-
-
-
-
+
-
-
+
-
Branchodrilus semperi
B
ourne, 1890
-
-
-
+
+
-
+
+
-
+
Branchodrilus hortensis
Stephenson, 1910
-
+
-
+
-
-
-
-
-
-
Stephansonia trivandriana
Aiyer, 1926
+
+
-
-
-
-
-
+
-
+
Homochaeta
Sp.
+
-
-
+
-
-
-
-
-
-
Allonais gwaliorensis
Stephenson, 1920
-
-
-
-
-
-
-
-
-
+
Allonais paraguayensis
paraguayensis
Michaelsen, 1905
-
-
-
-
-
-
-
-
-
+
Dero zeylanica
Stephenson, 1913
-
-
-
-
-
-
-
-
-
+
Tubificidae
Aulodrilus pluriseta
Piguet,1906
+
-
+
+
-
+
+
+
+
+
Aulodrilus
Sp
.
+
-
+
-
+
+
-
-
-
+
Aulodrilus pigueti
Kowalewski,1914
+
-
+
-
-
+
+
+ - -
+
Lumbriculidae
Lumbriculus variegates
Muller, 1773
-
-
-
-
-
-
+
-
-
-
(mean=1.88±0.34) than paddy fields (mean=1.65±0.68).
The highest diversity value was observed in January
2011 (2.41), the beginning of the crop season in the
paddy fields and lowest in May 2011 (0.91). On the
contrary, in the channels, the highest diversity was in
May 2011 (2.42), the end of the crop season and
minimum in February 2011 (1.53) (Figure 4). Though
in paddy fields, the maximum and minimum diversity
was recorded in the beginning and end of the crop
season respectively, no linear declining pattern in
diversity value was apparent. Channels showed an
increasing trend in diversity from the beginning (1.73
in January) to end of the crop season (2.23 in May
2011) except a very slight decline in diversity in
February and April (1.88). Margalaf’s species richness
also was higher in channels (mean=0.84±0.25) against
paddy fields (mean=0.70±0.36) (Figure 5). However
there existed a significant variation in evenness
between paddy fields and channels, it showed a higher
value in paddy fields (mean=0.93±0.05) than channels
(mean=0.73±0.12) (Figure 6). Evenness was maximum
in February (1.00) in paddy fields and the minimum
evenness was observed in March (0.37). In channels,
evenness was maximum in April (0.94) and minimum
in February (0.59). In paddy fields, species richness
followed the similar trend as diversity, showed maximum
