Ecological indices of freshwater copepods and cladocerans from Dharmapuri District, Tamil Nadu

Abstract

Zooplankton populations of tropical freshwater bodies depend on the primary productivity and physico-chemical parameters.Copepods and cladocerans constitute the dominant groups of freshwater habitat. They inhabit the ponds, lake, rivers and reservoirs and reported to occur more abundantly in ponds and lakes than in rivers (Reid, 1986; Raghunathan, 1983;Sharma, 1991). Some genera of copepods and cladocerans are cosmopolitan in distribution, while others are restricted to some continents (Brooks, 1959;Williamson, 1991). Depth of the pond, water transparency, pH and predators determine the distribution and abundance of copepods (Confer et al., 1983; Patalas, 1971). Dussart (1984) reviewed the systematic and distribution of tropical freshwater zooplankton from all over the world.The successions of zooplankton populations depend upon the interspecific and intraspecific interaction and predation potential (Fernando, 1980). There has been some report on the species composition and species diversity of harpacticoid copepod in tropical reef lagoon (Villers & Bodiou, 1996). The freshwater bodies such as ponds, lakes, rivers and reservoirs of Dharmapuri district, Tamil Nadu characterize tropical freshwater ecosystem.The present paper deals with the copepod and cladoceran populations of fifty freshwater bodies with regard to ecological indices of winter and summer populations. MATERIALS AND METHODSZooplankton samples were collected during September, 1999 (winter) and April, 2000 (summer) from fifty freshwater bodies of Dharmapuri District, Tamil Nadu. Samples were collected during early hours of the day (6.00am), using a plankton net made up of bolten silk (mesh size 100µm)During the study period temperature and pH of the water sample were recorded. The samples were preserved in 5% neutral buffer formalin for qualitative analysis and identified following the taxonomic keys provided by Rajendran (1973), Pennak (1978), Tonapi (1980), Barnes (1982), Battish (1992), Maas (1994), Reddy (1994) and, Dussart and Defaye (1995) for copepods and Michael (1973( ), Venkataraman (1983, Sharma and Michael (1987), Raghunathan (1989) and Murugan et al. (1998) for cladocerans. For quantitative analysis, 100L of water sample was filtered through the plankton net and the plankton sample was carefully transferred with out any loss to a plastic container and preserved in 5% neutral buffer formalin.Copepods and cladocerans were enumerated using SedgewickRafter chamber following Santhanam et al. (1989). The data was analyzed for ecological indices such as similarity and dissimilarity, index of dominance, index of diversity, index of evenness and species richness following the methods described by Odum (1983). (Fig. 1-4). RESULTS Copepods May 2004May 2004 DISCUSSION In this study H. viduus and S. (R.) indicus, S. (R.) indicus andT. hyalinus showed similar dissimilarity range in both the seasons, but H. viduus and T. hyalinus showed similar range during summer season, whereas in winter season other copepods showed similar range (0.76-...

Ecology and abundance of zooplankton in Karanja reservoir

“…The results indicates that the maximum number of genera occurred during winter season than summer and monsoon season which also reported by Abdus et al (1995) , Kumar (2001) . The less number of genera might be attributed to the less nutrients in the reservoir which consequently result in less productivity or might be due to the depletion of important factors such as dissolved oxygen and pH (Fig.…”

Diversity of Rotifers in Sonala Dam, Sonala Dist. Washim (M.S.) India

“…(Sharma et al, 2013). Present observations of Rotife rs in Sonala Dam were similar with the observations of Edmondson (1965), Dhanpati (2000, Kumar (2001), Sitre S. R.(2012) and Sharma (2013). Edmondson (1965) obse rved high rotifer population in winte r, which could be attributed to the favorable temperature and the availability of abundant food in the form bacteria, nanoplanktons and suspended particle s. Pre sent study, reports rich rotife r population represented by 16 species.…”

“…Rotifers are chiefly freshwater forms and presence of these organisms in abundance is related to suitable conditions for their survival (Dhanpati, 2000). The diversified rotifer fauna of lake can be linked to favorable conditions and availability of abundant food in the form of bacteria, nanoplankton and suspended detritus in the lake wate r (Sitre S. R. 2012).During monsoon season lower values of rotife r population density and diversity was observed which could be due to dilution of water resulting in less nutrients (Kumar, 2001).…”

Influence of salinity on the life table demography of a rare Cladocera Latonopsis australis

“…Earlier studies on Cladocera from Indian waters include those from the freshwater systems (Fernando 1980;Michael and Sharma 1988;Murugan et al 1998;Raghunathan and Suresh Kumar 2002;Sivakumar and Altaff 2004) and coastal/brackish water environments (Madhupratap and Haridas 1975;Goswami and Devassy 1991;Shrivastava et al 1999;Achuthankutty et al 2000). On one hand, reports from freshwater environments suggest Latonopsis australis as a typical freshwater species and a cladoceran of interest (Raghunathan and Suresh Kumar 2003).…”