Maedeh Jalali et al./ Elixir Aquaculture 60 (2013) 16318-16320 16318 Introduction The interest in the development of warm water fish culture in Iran has been increased in recent years. About 97,262 tonns of warm water fishes were cultured in the 1386 out of which 25,211 tonnes were produced in the Khuzestan province and shyrbot constitute a significant share of that (Iranian Fisheries Statistical Yearbook, 2007). Shyrbot, Barbus grypus, belong to the Cyprinidae family which lives in the Euphrates river basin, watershed of the Persian Gulf and catchment of Hormuz strait (Coad, 1993). It is an important member of fresh water fishes and it is commercially important due to its food value for indigenous people of Khozestan. But, despite of high economic value, not much information is available on optimal conditions for breeding and rearing of these fish. Body composition” is the analysis of water, fat, protein, and ash contents of the fish (Love 1980). The live weight of majority of fish usually consists roughly of 70-80% water, 20-30% protein and 2-12% lipid (Love 1980, Weatherley and Gill 1987). But, in general, it has been observed that a number of physical, abiotic and biotic factors affect the body composition parameters. Various studies have been made on body composition of various fish species (Ali et al., 2005; Dempson, et al., 2004; Berg, et al., 2000; Jonsson and Jonsson, 1998; Grayton and Beamish, 1997; Salam and Davies, 1994; Salam and Mahmood, 1993; Salam et al., 1993). With a rich source of brackish water Iran and in view of growth potential and popularity among fish consumers, present study was undertaken with an aim to compare the body composition of Barbus grypus cultured under different salinity to assess the condition of fishes in different environments. Materials and Methods A total of 500 shyrbot (Barbus grypus) fingerlings with an average weight of 3.69g were purchased and transferred to the Aquaculture Institute of South, Iran. They were acclimatized for one week in 1m 3 fiberglass tanks containing freshwater with 29.2°C temperature and pH=7.4. In order to adapt the fishes to brackish water, fishes were divided into 5 different treatments and were introduced to 0, 3, 6, 9, and 15ppt for 3 weeks. From each treatment 45 fishes were randomly selected and after biometry 15 fishes were introduced to one aquarium (3 repetitions) holding 30 liters of brackish water with different salinity. Five percent of the biomass was fed 5 times a day. A plastic filter was placed at the bottom of each aquarium to accumulate the remaining food. Water changing was done every 4days. After 60 days of rearing all the fishes from each replicate were weighted individually and kept in the oven at 70°C for 48 hours and re-weighed to measure the amount of moisture from carcasses. Dried carcasses from each replicate were grinded for further analyses. Protein, fat and ash contents were measured using Kjeldahl, Soxhlet and furnace, respectively. This study was conducted using a completely randomized design with 3 replications. Data were analyzed using ANOVA and Duncan test at a confidence level of 99% on SAS software. Graphs were plotted using Excel. Results Water quality parameters (Table 1) including temperature, dissolve oxygen and pH were within the acceptable levels for warm water aquaculture defined by Boyd (1990). Effect of different salinity on body composition of shyrbot fingerlings was compared between the treatments and is shown in table 2 which shows a significant difference (P<0.01) between the treatments. The negative effects of increased salinity were found in fishes reared in 15, 12 and 9 ppt. respectively, where lower fat and as a result smaller diameters and elongated body were observed. Highest level of fat was recorded in freshwater followed by 3 and 6ppt salinity. A comparative study on body composition of Shyrbot (Barbus grypus) fish reared in different salinities Maedeh Jalali 1 , Reza Davoodi 1, *, Abdul Ali Movahedinia 2 and Seyed Abdolsaheb Mortazavi Zadeh 3 1 Department of Fisheries and Aquaculture. Agricultural and Natural Resources College, Persian Gulf University, Bushehr, Iran. 2 Sea Hydrographic Department, Khorramshahr University of Marine Science and Technology, Iran. 3 Research Institute of South Aquaculture, Iran. ABSTRACT Effect of different salinity on body composition of shyrbot fish was investigated. Shyrbot fingerlings with an average weight of 3.96 grams were reared under different salinities (0, 3, 6, 9, 12 and 15g). Analysis of body composition showed a significant effect of different levels of salinity on protein, fat, moisture and ash (p<0.01) of the fishes. The highest level of protein, ash and moisture and lowest amount of fat were obtained in 15ppt salinity followed by 12 and 9ppt salinity. The highest amount of fat was obtained in freshwater followed by 3 and 6ppt. In higher salinities (9, 12 & 15ppt) low fat and energy stored. The results suggest that Shyrbot fingerlings until 6ppt salinity can be easily developed. © 2013 Elixir All rights reserved. ARTICLE INFO Article history: Received: 29 May 2013; Received in revised form: 24 June 2013; Accepted: 9 July 2013; Keywords Shyrbot (Barbus grypus), Salinity, Body Composition. Elixir Aquaculture 60 (2013) 16318-16320 Aquaculture Available online at www.elixirpublishers.com (Elixir International Journal) Tele: E-mail addresses: da_afshin@yahoo.com © 2013 Elixir All rights reserved