Journal of Pharmacognosy and Phytochemistry 2018; 7(6): 2131-2136 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; 7(6): 2131-2136 Study on Gonadosomatic index (GSI) during the Received: 07-09-2018 Accepted: 09-10-2018 three seasons (pre-spawning, spawning and post- spawning periods) of Schizothorax niger Heckel in Iqra Farooq Wani Faculty of Fisheries, Rangil, dal lake, Kashmir Ganderbal, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Jammu and Kashmir, Iqra Farooq Wani, FA Bhat, MH Balkhi, TH Shah, FA Shah and BA Bhat India Abstract FA Bhat The present study was conducted to investigate changes in Gonadosomatic index (GSI) of Schizothorax Faculty of Fisheries, Rangil, niger Heckel during the three seasons (pre-spawning, spawning and post-spawning periods) in Dal Lake, Ganderbal, Sher-e-Kashmir Kashmir from November, 2014 to July, 2015. Fishes ranging in length from 75-374mm and in weight University of Agricultural from 56-557g were taken during the study. The mean GSI of the fish Schizothorax niger Heckel was Sciences and Technology of Kashmir, Jammu and Kashmir, found to be 7.94 and its range varied from 0.78-27.28. The mean value of GSI in S. niger Heckel during India pre-spawning period was found as 2.02±1.22. During spawning and post-spawning periods, the mean values of GSI were recorded as 20.37±3.87 and 1.43±0.42 respectively. The results suggest that the MH Balkhi maximum Gonadosomatic Index in Schizothorax niger Heckel were recorded in March, i.e. during Faculty of Fisheries, Rangil, spawning period (mean value of 20.37 in females). The GSI then started decreasing gradually and was Ganderbal, Sher-e-Kashmir recorded minimum in July (mean value of 1.43 in females). Thus the peak breeding season of the fish University of Agricultural during the present study was found in March. Absolute Fecundity and Relative Fecundity of S. niger Sciences and Technology of were recorded with a mean values of 21981.60 and 109.82 respectively. A positive correlation was Kashmir, Jammu and Kashmir, observed during spawning period between GSI and Relative Fecundity at p<0.05 level of significance. India Understanding reproductive behaviour of fishes is not only important for elucidating the basic biology of the fishes but it can also help in their management and conservation. TH Shah Faculty of Fisheries, Rangil, Ganderbal, Sher-e-Kashmir Keywords: Schizothorax niger, Dal Lake, Gonadosomatic index (GSI), fecundity, Kashmir valley University of Agricultural Sciences and Technology of 1. Introduction Kashmir, Jammu and Kashmir, The state of Jammu & Kashmir covers an area of about 2, 22, 236 sq. km and extends from India 32° 17 N to 36° 58 N latitudes and from 73° 26 E to 80° 30 E longitudes (Sodhi et al., 2013) [35] FA Shah . The valley of Kashmir is surrounded by the mighty Himalayas which vary in their heights Faculty of Fisheries, Rangil, between 1000 to 1800 feet above mean sea level, extending from 33º 22 N to 34º 43 N and Ganderbal, Sher-e-Kashmir 73º 52 E to 75º42 E covering an area of about 15,948 sq. km. It has a total water spread of University of Agricultural about 32765.3 hectares which constitute about 2% of its total area of J & K (Sodhi et al., 2013) Sciences and Technology of [35] Kashmir, Jammu and Kashmir, . The valley has a temperate climate and is known for its seasonality. It has a unique India position in harboring rich and diverse types of aquatic habitats, occupying 6% of its total land area (Zutshi and Gopal, 2000) [44]. These water bodies are of immense importance for BA Bhat providing potable water and also ensuring stability of the microclimate of the area, ground Faculty of Fisheries, Rangil, water recharge and generating employment by boosting tourism, fisheries and recreation. The Ganderbal, Sher-e-Kashmir University of Agricultural valley is famous throughout the world for its waters both lentic and lotic. The lentic waters Sciences and Technology of include Wular lake, Dal lake, Manasbal lake, Nilnang and many other lakes, while the lotic Kashmir, Jammu and Kashmir, habitats include numerous streams like Sind, Lidder, Branghi, Veshu, Dudhganga, etc. all India being directly or indirectly connected with the River Jhelum (also called Vitasta/Vyeth), the lone natural drainage system of the valley. These aquatic habitats harbour a number of native fishes like Schizothorax spp., Glyptothorax spp., Triplophysa spp., etc. as well as the exotic fishes like Onchorhynchus mykiss, Salmo trutta fario, Cyprinus carpio, Carassius carassius etc. The water bodies of Kashmir valley support a wide variety of indigenous and exotic fish species. The major ichthyofauna of Kashmir is represented mainly by the Central Asiatic fauna in which Schizothorax group is predominant (Sunder et al., 1979) [36]. Fishes belonging to Correspondence families Cyprinidae, Cobitidae, Siluridae, Poecilidae, Sisoridae and Salmonidae are found in FA Bhat Faculty of Fisheries, Rangil, the valley. The cyprinidae is mainly represented by the schizothoracids (snow trouts). A Ganderbal, Sher-e-Kashmir comprehensive survey to assess the potential of Schizothoracines from various lakes and University of Agricultural streams of Kashmir valley was made by Raina et al. (1985) [30]. Schizothoracids are indigenous Sciences and Technology of fish species and are commercially important with wide market demand. Yousuf (1996) [41] Kashmir, Jammu and Kashmir, reported 42 species of fishes from Kashmir while Balkhi (2007) [3] reported 40 species. India ~ 2132 ~ Journal of Pharmacognosy and Phytochemistry However, not more than 22 species are existing at present 2.1 Morpho-histological study of gonads: (Kullander et al., 1999; Bhat et al., 2010) [19, 4]. Dal lake of The fish specimen (female) were dissected open and their Kashmir is situated in the north-east of Srinagar at mean gonads were collected to record their weight. GSI (Gonado latitude of 34° 07’ N and longitude of 74° 52’ E and at an Somatic Index) was determined using the formula as given by altitude of 1584 m.a.s.l., is probably of fluvial origin having Desai (1970) [11]: been formed from the ox-bows of the river Jhelum. The lake covers an area of about 11.4 km2 (Qadri and Yousuf, 2008) [29]. Fishes like Cyprinus carpio var. communis, Cyprinus carpio var. specularis, Schizothorax niger, Carassius carassius, Crossocheilus diplochilus, Schizothorax esocinus, Schizothorax curvifrons, Puntius conchonius have been 2.2 Fecundity reported to be present in the Dal Lake (Shafi et al., 2005) [32]. The gravimetric method was used for studying fecundity, Among Schizothoracids, Schizothorax niger Heckel is a which is based on the relation between ovary weight and the [25] valuable fish of Kashmir region, but is now, in stiff oocyte density in the ovary (Murua et al., 2003) . Fecundity competition with other exotic fishes e.g. Cyprinus carpio was estimated by counting the number of mature ova from a (Yousuf, 1996) [41]. Schizothorax niger Heckel locally known known weight of mature/ripe ovary. The ovary sub samples as Ael Gad is a prized fish of Kashmir and belongs to family were obtained from the anterior, middle and posterior regions [16] Cyprinidae. Schizothorax niger being a lacustrine fish occurs of both the ovaries (James et al., 1978) . The subsamples in lakes of Kashmir in good numbers including Dal Lake. were spread evenly on a counting slide with a few drops of This fish is restricted to lentic water bodies of Kashmir and water and the number of mature ova was counted and average differs from the other species of genus Schizothorax in color number of three portions was used to determine the fecundity pattern, morphometry, scale counts, gill racker counts, by the following formula: pharyngeal bone and tooth shape. Schizothorax niger Heckel prefers clean and cold pockets of water in lakes for egg- laying, and it also lays eggs on the roots of willow trees. Schizothorax niger Heckel is fusiform with a short blunt slightly prognathous upper jaw having inferior mouth (upper Relative fecundity i.e. number of eggs/1g of body weight jaw a little projecting beyond lower jaw) horse-shoe shaped, (unit body weight or ovary weight) was obtained by dividing nearly horizontal broader than long. Schizothorax niger absolute fecundity with total weight of fish (in grams). Heckel is herbi-omnivore. As all other Schizothoracids shows breeding migrations, moving upstream to spawn, however, S. niger does not show any such migration and spawns in the shallow peripheral areas of the lake in close vicinity of springs on sandy bottoms (Vass and Raina, 1979) [38]. It plays The gravimetric method was used for studying fecundity, an important role in capture fishery of the flat land lakes of which is based on the relation between ovary weight and the the valley, especially Dal, Manasbal, and Wular. The oocyte density in the ovary (Murua et al., 2003) [25]. The data spawning season extends from spring to early summer. collected was analyzed using appropriate statistical tools with Understanding reproductive behaviour of fishes is not only the help of statistical software SPSS version 20 and Microsoft important for elucidating the basic biology of the fishes but it excel. can also help in their management and conservation. The term ‘fecundity’ denotes the egg laying capacity of a fish or the 3. Results number of ripe eggs produced by a fish in one spawning 3.1 Length of fish (mm) season. Knowledge of fecundity is also an important aspect in The mean length of Schizothorax niger Heckel collected from stock size assessment, stock discrimination (Holden and Raitt, Dal Lake was found to be 249.05 mm and its range varied 1974) [14] and rational utilization of stock (Morales, 1991) [24] from 75-374 mm.