STUDY OF GONADO-SOMATIC INDEX AND ABSOLUTE FECUNDITY OF BANGANA DERO (HAMILTON, 1822) UNDER COLDWATER CONDITIONS.

N.N.Pandey 1 , Amrita Rani 2* , Bipin Vishwakarma 1 , Raghvendra Singh 1 and D. Sarma 1 . 1. Directorate of Coldwater Fisheries Research, Bhimtal-263136, Nainital, Uttarakhand. 2. College of fisheries, West Bengal University of Animal and Fisheries Sciences. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

An attempt was made to assess the Gonadosomatic Index (GSI) and Fecundity of an indigenous carp, Bangana dero widely distributed all along the foot hill regions of Himalayan ranges of India, Pakistan, Bangladesh, Nepal, Myanmar and China. This species has good food value with fair market demand. GSI of female fish was ranging from 1.192 to 15.785 with a highest value in the month of July (15.546±1.104) and lowest level observed in January (1.132±0.136). Single peak of GSI in the month of July indicates the spawning season of Bangana dero. The absolute fecundity was ranging from 72265 to 184322 ova with an Average fecundity was recorded as 1,11,200-1,44,416.Present findings highlight the reproductive potential of Bangana dero, which will be very helpful for the development of breeding and seed production of this species.
Bangana dero (Hamilton, 1822) is a minor carp, commonly known as 'Kalabans' in India, 'Gardi' and 'Kathalegi' in Nepal, 'Kursa' in Bangladesh , is one of the popular food fish and is widely distributed all along foot hill regions of Himalayan ranges of India, Pakistan, Bangladesh, Nepal, Myanmar and China (Talwar and Jhingran, 1991). It is very important to know about GSI and fecundity of this carp, to get more and more information about its reproduction potential and usefulness as a candidate species for hill aquaculture.
Scanning of literature shows that there are no systematic work has been done on the fecundity and gonadosomatic index of B. dero. Therefore, the present study was undertaken to determine the fecundity and gonadosomatic index of B. dero.

Materials And Methods:-
To record the average value of GSI and absolute fecundity , three female fishes of B. dero weighing from 150-350 g and length ranging from 19.60 to 30.50 cm were collected from fish market Ramnagar, Uttarakhand (29° 29.038' N latitude, 79.08777' E longitude and altitude 410 m MSL) every month from January 2017 to December 2017. Total length of each fish was measured with help of a meter scale to the nearest 0.1cm. The body weight of each fish was measured by means of a single pan balance. Two lobes of the ovary from each sample fish were removed carefully by dissecting out the abdomen and placed in modified gilson's fluid. It helped to preserve the ovary as well as made it much easier to separate the eggs from the ovarian wall. Gravimetric method was used to determine the fecundity of fish (Murua and Saborido-Rey, 2003). For estimating the absolute fecundity ovaries were taken after dissection and weighed on a single pan electronic balance. One gram each from six cross sectional samples was taken from anterior, middle and posterior regions of the paired ovary and the pieces were kept separately. Then the numbers of the ova were counted from these parts of the ovary. The total number of ova in the entire ovary was computed and the mean was calculated. GSI and absolute fecundity were estimated using following formulae. Our findings matched with the GSI pattern reported by (Pandey et al., 2011) in L. dyocheilus. Similar trend in GSI was also recorded by (Gupta et al.,2013) in L. dyocheilus kept under captive condition who observed normal ovarian development of fish. Greater value of GSI reflects the ovarian maturity in the fish (Mishra and Saksena, 2012). GSI can not only be used to predict the breeding season but also indicate the maturity status and periodicity of spawning of a fish . Highest value of GSI in the month of July clearly indicates the fish spawned once in a year with one spawning peak highest in the month of July. Results presented in the table shows sudden decrease in gonad weight from September to January as indicated by the decline of GSI after spawning.
The absolute fecundity was ranging from 72,265 to 1,84,322 ova with an Average fecundity were recorded as 1,11,200-1,44,416. However, variation was observed in absolute fecundity from May to August presented in the Table 2. Value of absolute fecundity in present experiment was found almost similar to previous studies conducted for B. dero, (Biswas et al., 1984); L. dyocheilus, (Sarkar et al., 2001;Gupta et al., 2013); Cirrhinus reba (Lashary et al., 2007). Results clearly indicate that female fish with greater weight had higher fecundity. Similar kind of observation was also recorded (Khan et al., 1992;Gupta et al., 2013).
Fecundity of this fish is very high as compared to other cold water fishes, which reflects the importance of this fish to be incorporated into coldwater aquaculture sector as a new candidate species. Present findings highlight the reproductive potential of B. dero, which will be very helpful for the development of breeding and seed production of this species.