International Research Journal of Biological Sciences ___________________________________ ISSN 2278-3202Vol. 4(7), 1-3, July (2015) Int. Res. J. Biological Sci. International Science Congress Association 1 Variation in Reproductive cycle of a Teleost Fish Rasbora Daniconius of Shahdol District, MP, India with Special Reference to Gonadosomatic Index: A Quantitative StudyKumar K. Department of Zoology, Pt. S. N. S. Govt. P. G. College, Shahdol, M.P., INDIA Available online at: www.isca.in, www.isca.me Received 7th April 2015, revised 17th May 2015, accepted 22nd June 2015 Abstract The present piece of research work carried out to explore the variations in reproductive physiology in an experimental teleost fish, Rasbora daniconius at the different ecological habitats. The experimental fish species was collected from the different selected experimental sites at regular intervals and the gonadosomatic index was observed. A great deal of variation in gonadosomatic index was observed in fishes collected from the different sites. At a particular site the gonadosomatic index value was very diminished in comparison to other sites. The diminished value of GSI at a particular site was due to heavily intoxicated water reservoir. Keywords: Rasbora sps., Gonadosomatic index, experimental sites.Introduction Life arose in aquatic medium. There is no existence of life without water. Aquatic dwellers are therefore said to be the progenitors of the present day bio diversified faunal species. Aquatic vertebrates are of course the ancestors of all living vertebrate creatures. Fishes are the first evolved gnathostomes with all possible vertebrate features. The experimental fish, Rasbora daniconius is commonly known as Slender Rasbora, usually belonging to Class –Actinopterygii, Order – Cypriniformes and inhabiting a variety of water bodies like ditches, ponds, sandy streams and rivers in Indian continents (figure-1). The genus Rasbora includes about 83 recognised species. It exhibits a peculiar social behaviour as it forms a large school. It is small sized teleost fish with an average body length of 8.0 cm and exhibits surface feeding habit and mainly feeds on aquatic insects and detritus. It breeds during rainy season. Shahdol district is surrounded by a large number of water reservoirs including small and large ponds, narrow canals and different rivers. Three sites have been selected for conducting experimentation. All the three sites lie under the boundary of Shahdol district. These sites are – Dhangawan, Birhouli and Diyapipar, situated within a periphery of 50 kms distance. These selected sites are very prone as it faces an overload of pesticide pollution by the local farmers for the maximum yield of crops. Besides it also has chemical pollution, discharged by the different industries located nearby the experimental sites. Material and Methods The experimental teleost fish, Rasbora daniconius was collected at regular intervals from all the three selected experimental sites for a complete year and brought to laboratory with full care. The collected fishes were measured and weighed. The collected fishes were dissected and the gonads were removed. The gonads were measured and weighed. After taking volume and weight, the gonads were fixed and slides were prepared for the histological studies. Observation: In any teleost fish, the efficacy of gonadal functioning is measured by the gonadosomatic index value. In the present experimental teleost fish, Rasbora daniconius the gonadosomatic value has been calculated by adopting the following formula: GSI =Weight of the Gonad x 100 Weight of the Body Figure-1 Rasbora daniconius Research Journal of Biological Sciences ___________________________________________________________ ISSN 2278-3202 Vol. 4(7), 1-3, July (2015) Int. Res. J. Biological Sci. International Science Congress Association 2 A bird’s eye review on gonadosomatic index of the experimental teleost fish, Rasbora daniconius explains that the value of gonadosomatic index of the collected fishes from all the three sites is maximum in the month of August, the onset of rainy season, also evidenced by Kottelat and Tan3,4. During spawning period the value of GSI is at the peak in both the fishes collected from Dhangawan and Diyapipar, whereas the value of GSI is lesser in the fishes collected from the Birhouli site (table–1 and figure-2). Table-1 Average Value of gonado-somatic index of Rasboradaniconius collected from the selected experimental sites throughout a year Month Average Values of Gonado-somatic Index At Dhangawan At Birhouli At Diyapipar January 0.6261 0.5819 0.5374 February 0.8263 0.7237 0.7813 March 0.9357 0.8104 0.9142 April 1.8534 1.2109 1.5379 May 4.7930 3.0304 4.6391 June 7.0874 5.0910 6.9674 July 12.0063 10.1014 11.9354 August 13.0147 11.0041 12.8043 September 6.3472 7.7842 7.9821 October 3.0031 2.0092 3.3049 November 0.9342 1.0434 1.0093 December 0.1378 0.0124 0.3217 During pre-spawning period the increasing pattern of GSI value shows normal trend in the fishes collected from Dhangawan and Diyapipar while the trend shows abnormal pattern in the fishes collected from Birhouli site. The abnormal pattern of GSI value is the indicator of abruption in reproductive cycle of the fishes collected from Birhouli site, similar facts observed by Rehman et. al.. Results and Discussion Based on facts observed it is evident that the reproductive cycle in the fishes collected from Birhouli is not functioning normally, rather it shows irregular gonadal physiology as supported by the observed lesser gonadosomatic value. The water reservoir of such experimental site gets much more toxic pesticide residue used by the local farmers of the area as well as the industrial wastes and thermal wastes are also drained in the reservoir, as evident by the findings of Kumar and Katare showing water of the experimental site with acidic pH, higher value of TDS, dissolved carbon dioxide and salinity while lower value of Dissolved Oxygen and nitrate contents. The irregular functioning of gonads might be due to highly intoxicated water in the water reservoir. As the experimental fish constitutes one of the most important food chain in pond ecosystem thus it gives an alarming signal of threat on life of all the water dwellers. The drained wastes (both industrial and thermal) must be treated well before draining into the nearby water reservoir. Figure-2 Column diagram of Average Value of gonado-somatic index of Rasboradaniconius at experimental sites Research Journal of Biological Sciences ___________________________________________________________ ISSN 2278-3202 Vol. 4(7), 1-3, July (2015) Int. Res. J. Biological Sci. International Science Congress Association 3 Conclusion On the basis of observation it seems that the water contents in the water reservoir in one of the experimental site, i.e. Birhouli is getting more toxic effluents discharged from the nearby industries and pesticide residues after agricultural use. The released pollutants are polluting the water bodies slowly but continuously as evidenced by the observed deteriorating gonadosomatic index value in the collected fishes. If it is not being checked, it would result in extinction of many fish species and thus destabilises the aquatic ecosystem and natural environment. Acknowledgement The author is thankful to Madhya Pradesh Council for Science and Technology, Bhopal (M.P.) for providing financial assistance vide Sanction Letter No. 4309/CST/RD/2010, dated – 22.03.2010 and Principal, Pt. S. N. S. Govt. P. G. College, Shahdol for providing laboratory facilities. References 1.Doha S. and Hye M.A., Fecundity of Padma river hilsa, Pak. J. 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