Zooplankton Diversity in Madduvalasa Reservoir, India

The zooplankton diversity was studied in four stations at the Madduvalasa reservoir from June 2014 to May ’15 and forty five species were identified. Among eight groups, the diversity of Rotifera comprises of 17 species (21.37%), Cladocera 8 (16.44%), Copepoda 5 (17.28%), Ostracoda 2 (15.21 %), Protozoa 3 (12.24%), Crustacea 9 (11.26%), Mollusca 1 species (01.60%) respectively along with fish larvae and eggs (04.61%). The monthly and group wise zooplankton density analyzed and found that the number was higher during summer, followed by monsoon and lowest during winter. Key-words: Copepoda, Madduvalasa reservoir, Monthly variation, Rotifera, Zooplankton -------------------------------------------------IJLSSR----------------------------------------------INTRODUCTION Plankton is one of the most favourable food items for many aquatic organisms; almost all the fishes at their larval stages depend on it and some of them exclusively feed on zooplankton. They invariably form an integral component for fresh water communities and contribute to biological productivity [1] . In the last two decades, much attention has been paid in tropical countries towards the study of biology, ecology and toxicology of zooplankton due to their important role in rapidly emerging concepts in environmental management like Environmental Impact Assessment (EIA). Zooplankton is good indicator of the changes in water quality because they are strongly affected by environmental conditions and respond quickly. The study of zooplankton is necessary to evaluate the fresh water reservoir in respect to their ecological and fishery status . The Zooplankton community fluctuates according to physicochemical parameters of the environment, especially Rotifer species change with biotic factors [3] . Zooplankton is the link between phytoplankton and fish; hence, their qualitative and quantitative studies are of great importance. Access this article online Quick Response Code Website: www.ijlssr. com DOI: 10.21276/ijlssr.2017. 3.1. 4 MATERIALS AND METHODS Study Area: Sri Gorle Sriramulu Naidu Madduvalasa reservoir is present in the Madduvalasa village of Srikakulam district, Andhra Pradesh, India (Fig. 1). Samples were collected from four stations of the above reservoir i.e., S1: Narendra puram, S2: Vangara, S3: Kottisa and S4: Gudivada agraharam. Fig. 1: Madduvalasa reservoir (18° 35' 30''N Latitude and 83° 37' 20'' E longitude) Collection of sample, preservation and identificationZooplankton samples were collected randomly with plankton net (bolting silk mesh size 25μ) on monthly basis from June 2014 to May 15, between 9.00 to 10.00 am. 100 lit of surface water was sieved through the plankton net and transferred to plastic containers and 4% Research Article (Open access) Int. J. Life Sci. Scienti. Res., VOL 3, ISSUE 1 Copyright © 2015-2017| IJLSSR by Society for Scientific Research under a CC BY-NC 4.0 International License Page 772 formalin was added for preservation; density [4] and the diversity of zooplankton was studied by Lackey’s drop count method under light microscope. The total number of zooplankton present in a litre of water sample calculated by using the following formula: N = n × v / V Whereas, N = Total no. of organisms/ lit of water filtered, n = Number of organisms counted in 1 ml of sample, v = Volume of concentrate plankton sample (ml), V= Volume of total water filtered through (L) The systematic identification of plankton was made by using standard keys of various authors . Biodiversity: The statistical calculation on biodiversity of zooplankton was studied using the formula of ShannonWiener diversity index and Menhinick’s index [11-12] which was calculated as follows: 1: Shannon Wiener diversity index Shannon-Wiener index denoted by H = SUM [(pi) × ln(pi)] Whereas, SUM = summation pi = proportion of total sample represented by species i Divide no. of individuals of species i by total number of samples S = number of species = species richness Hmax = ln(S) Maximum diversity possible E = Evenness = H/Hmax 2: Menhinick’s index Menhinick’s index (d1) = S / /N Where, d1 = Menhinick’s index S = total number of species. N = total number of organism (density) RESULTS In the present study, diversity and monthly availability of zooplankton in Madduvalasa reservoir were analyzed and given in Table 1. Forty five species were identified in four stations, which consist of rotifera, cladocera, copepoda, ostracoda, protozoa, crustacea, mollusca along with fish larvae and fish eggs. Table 1: Check list of Zooplankton species at Madduvalasa reservoir, Srikakulam dt. Group Family Species Rotifera Brachionidae Brachionus angularis (Gosse,1851) Brachionus calyciflorus (Pallas, 1766) Brachionus caudatus (Haner, 1937) Brachionus diersicornis (Daday, 1883) Brachionus plicatelis Brachionus quadridentata (Hermann, 1783) Keratella cochlearis (Gosse,1851) Keratella tropica (Apstein, 1907) Lecanidae Lecane lunaris (Ehrenberg,1982) Lacane monostyla (Daday, 1897) Gastropodidae Gastropus minor (Rousselet 1892) Asplanchnidae Ascomorpha ovalis (Begendal, 1892)