International Research Journal of Environment Sciences________________________________ ISSN 2319–1414Vol. 2(2), 38-43, February (2013) Int. Res. J. Environment Sci. International Science Congress Association 38 Studies on Ichthyofaunal Diversity of Karanja Reservoir, Karnataka, India Kumar Naik A.S., Benakappa S., Somashekara S.R., Anjaneyappa H.N., Jitendra Kumar., Mahesh V., Srinivas H. Hulkoti and Rajanna K.B Department of Fisheries Resources and Management, College of Fisheries, Karnataka Veterinary, Animal and Fisheries Sciences University, Mangalore, Karnataka, INDIAAvailable online at: www.isca.in Received 23th January 2013, revised 1st February 2012, accepted 15th February 2012 Abstract The present work is an attempt to assess the biodiversity of fish fauna in Karanja Reservoir located in the northern part of Karnataka between 17°2230 N latitude and 76°59 E longitude. During the study period, it was observed that the 64 species of finfishes belonging to 37 genera, 16 families and 5 orders were recorded. Among them order Cypriniformes represented 31 fish species followed by Siluriformes 20, Perciformes 10, Osteoglossiformes 2 and order Synbranchiformes 1 fish species. The Simpson’s index of diversity (1- Lambda') was highest in Athiwala (B) (0.9235) followed by Byalahalli (A) (0.8970) and Kheni Ranjola (C) (0.8842). This indicated that the greater fish biodiversity in Athiwala fish landing centre when compared to other two centres. Overall the number of fish landings was more in A (S= 60, N= 7342) followed by B (S= 59, N= 5507), A (S= 59, N= 3487) and the species richness (d) was more in B (7.1106). However, Margalef’s species richness (d) showed clear differences between the centres. Further the number of dominant species (N) was more in B. The similarity in species composition and abundance among centres was in the range of 76.21-83.46. In this study an attempt has been made to evaluate the ichthyofaunal diversity in the region and suggests mitigating measures. Keywords: Karanja Reservoir, Fish diversity, species richness Karnataka. Introduction Karnataka, the eighth largest State in India, is situated on the western edge of the Deccan plateau. The climate and physiography of the region make the state one of the most important in the country with regard to water resources. Total 74 reservoirs in Karnataka state cover an area of 2, 28,657 ha among them, 46 belong to the category of small reservoirs, ( 1000 ha) with a water spread area of 15, 253 ha, 16 medium reservoirs have water spread area of 29, 078 ha and the large reservoirs (.71;ᜰ 5000 ha) over 1, 79, 556 ha. Among the small reservoirs, those less than 500 ha outnumber the rest. Thus, Karnataka has 4, 37,292 ha of water spread area under different categories of man-made impoundments. Large reservoirs constitute 80% of the total area, followed by the medium (13%) and small (7%) ones. A large number of studies covering a wide variety of ecosystems and organisms suggest that species richness tends to vary strongly with ecosystem production and habitat heterogeneity. Biodiversity is manifested at all levels of bio-organization from cell to ecosystem and refers to enumerable kinds of living organisms inhabiting terrestrial, marine and freshwater ecosystems Ichthyofaunal diversity refers to variety of fish species depending on context and scale; it could refer to alleles or genotypes within of life forms within a fish community and to species or life forms across aqua regimes. Studies of spatial and temporal patterns of diversity, distribution and species composition of freshwater fishes are useful to examine factors influencing the structure of the fish community. Fish species are also an important indicator of ecological health and the abundance and health of fish will show the health of water bodies. Human activities such as modification of the environment, culture, harvesting and effects of modernization have contributed to the pollution of water bodies which serve as habitat for fishes. Karnataka's total water area under man-made impoundments covering an area of 4, 37,292 ha is undoubtedly one of the largest in the country, holding tremendous potential for fisheries development. Yet, very little scientific studies have been made on the reservoirs of the State. Karanja Reservoir is one of the important reservoirs in Northern Karnataka that need serious attention in its management and conservation of fishery resources. Detailed studies on fish fauna of this reservoir are still lacking. It is partly for this reason that we were inspired to conduct the current study on the fish diversity of Karanja Reservoir so as to determine the current conditions of the fish fauna of the river.Material and Methods The Karanja reservoir a major perennial reservoir of the district and located at Bhalki taluka of the Bidar district at 17°2230 N latitude and 76°59 E longitude (Figure.1). It is created due to the construction of dam across the river Karanja, a tributary of Manjra River of Godavari system. It is a medium reservoir having water spread area of 5,673 ha with gross irrigation potential of 1, 62,818 hectares. Sampling for fish was conducted from the month of July 2008 to June 2009 at three very important pre-selected fish landing center viz., Byalahalli (A), Athiwala (B) and Kheni Ranjola (C). Fishes were sampled International Research Journal of Environment Vol. 2(2), 38-43, February (2013) International Science Congress Association monthly at all the three fish landing centres set up in the study areas of the reservoir using gill nets (mesh size measuring 30, 45, 50 and 60 mm). Identification of fish species: ll fish caught were identified to species level using standard taxonomic viz. Fishes of India, FAO identification sheets, ITIS (Integrated Taxonomic Information System) standard report (http://www.itis.gov), Fish Base (http://fishbase.org) and other refere nce books. Diversity indices: The diversity of fishes was calculated by Shannon- Weiner and Pielou's evenness indices. Since individual size of fish species differed greatly, the indices are expressed in terms of biomass and not in terms of number of ind ividuals. Hill's abundance was used to examine the variation in the number of dominant species. Species richness was calculated by Margalef's index. The similarity in species composition was studied by calculating the Bray Coefficient. However, all the diversity indices were done by Diagrammatic representations of the Siluriformes, 31.25% Perciformes, 15.62% Osteoglassiformes, 3.12% Environment Sciences_______________ _________________________ International Science Congress Association monthly at all the three fish landing centres set up in the study areas of the reservoir using gill nets (mesh size measuring 30, ll fish caught were identified to viz. Fishes of India, FAO identification sheets, ITIS (Integrated Taxonomic Information System) standard report (http://www.itis.gov), Fish nce books. The diversity of fishes was calculated by Weiner and Pielou's evenness indices. Since individual size of fish species differed greatly, the indices are expressed in terms of biomass and not in terms of number of ividuals. Hill's abundance was used to examine the variation in the number of dominant species. Species richness was calculated by Margalef's index. The similarity in species composition was studied by calculating the Bray -Curtis the diversity indices were done by using the PRIMER V.5 analytical package developed by Plymouth Marine Laboratory, U.K. Results and Discussions The result of the present study revealed the occurrence of 64 fresh water fish species belonging to 37 genera, 16 families and 5 orders were recorded. The order Cypriniformes was dominant with 31 fish species (48.43%) followed by order Siluriformes 20 (31. 25%), Perciformes 10 (15.62%), Osteoglossiformes 2 (3.12%), and Synbranchiformes with one fish species (1.56%) (figure .2). Although, 64 species were recorded, the Cyprinidae was observed as the dominant family with 27 fish species (42.18%) followed by Bagridae, 9 fish species (14.06 %) (figure .3).The distribution of fish species is quite variable because of geographical and hydrological conditions. The fish species density, abundance and distribution recorded from three fish landing centres are shown in table Figure-1 Location of Karanja Reservoir Figure-2 Diagrammatic representations of the % number contribution of each order Cypriniformes, 48.43% Siluriformes, 31.25% Perciformes, 15.62% Symbranchiformes,1.56% _________________________ ______ ISSN 2319–1414 Int. Res. J. Environment Sci. 39 using the PRIMER V.5 analytical package developed by The result of the present study revealed the occurrence of 64 fresh water fish species belonging to 37 genera, 16 families and 5 orders were recorded. The order Cypriniformes was dominant with 31 fish species (48.43%) followed by order Siluriformes 25%), Perciformes 10 (15.62%), Osteoglossiformes 2 (3.12%), and Synbranchiformes with one fish species (1.56%) .2). Although, 64 species were recorded, the Cyprinidae was observed as the dominant family with 27 fish species Bagridae, 9 fish species (14.06 %) .3).The distribution of fish species is quite variable because of geographical and hydrological conditions. The fish species density, abundance and distribution recorded from three table -1. of each order