International Journal of Marine Science 2015, Vol.5, No.51: 1-11
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Figure 1 Location of sampling sites in Maranchery Kole wetlands, P refers to paddy fields and C refers to channels
retained in the sieve were collected and preserved in
5% formalin (Holme and McIntyre 1971; Eleftheriou and
McIntyre, 2005). The organisms were separated into
different taxonomic groups (oligochaetes, insects,
gastropods and hirudinea). Oligochaetes were identified
up to species level by temporarily mounting the
specimens using Amman’s Lactophenol (Phenol,
Lactic acid, Glycerol, and water in the ratio of 1:1:2:1)
(Brinkhrust and Jamieson, 1971). The taxonomic keys
of Brinkhrust and Jamieson (1971) and Naidu (2005)
were used for the identification.
Statistical Analysis
One way ANOVA was used to determine the significant
difference in numerical abundance of oligochaetes
between the paddy fields and channels using SPSS
16.0. Abundance data was fourth root transformed to
meet the ANOVA assumptions. The data on oligochaetes
was subjected to multivariate and univariate analysis
by using the Primer software version 6.0 (Clarke and
Gorley, 2006). ANOSIM was used to analyze the
similarity of oligochaete assemblages between paddy
fields and channels. Non metric multi-dimensional
scaling, a hierarchical cluster analysis was used for the
pictorial representation of the pattern of oligochaete
composition in the paddy fields and channels (relative
abundance). Ordinations were based on distance matrices,
which were computed using Bray Curtis coefficient.
The univariate indices of diversity such as species
richness by Margalef’s index (Margalef, 1958), species
diversity by Shannon index (Shannon Wiener, 1949)
and species evenness by
Pielou's index (Pielou, 1966)
were calculated for paddy fields and channels separately.
Results
Environmental parameters
The results of the environmental parameters analyzed
are given in Table 1. There was no significant difference in
environmental parameters analyzed in paddy fields
and channels. Depth showed a marked difference
between paddy fields (0.31±0.11 m) and channels
(1.1±0.28 m). Water and sediment temperature remained
lower in the paddy fields. The water pH was slightly
acidic in both paddy fields and channels. Sediment pH
remained neutral. Organic matter was higher in the
paddy fields (6.95±1.34%), than channels (5.48±1.58%).
The sediment was clayey silt in paddy fields and
sandy silt in channels.
Faunal Composition
The macrobenthic fauna recorded from Maranchery
Kole wetlands included three phyla (Mollusca, Annelida
and Arthropoda) and five classes (Gastropoda,
Oligochaeta, Hirudinea, Insecta and Crustacea) (Figure 2).
