علوم زیستی دریا
Gholamreza Eskandari; Ahmad Savari; Perita Kochanian; Aseiied aminollah Taghavi Motlagh
Volume 11, Issue 1 , November 2012, , Pages 49-57
Abstract
In the present study, length structure, mortality and exploitation rate of Otolithes ruber during a ten-year period were studied. Sampling was carried out by using bottom trawl net in the fishing area in Northwest of Persian Gulf over 1 year study period. Length data was also collected from fisheries ...
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In the present study, length structure, mortality and exploitation rate of Otolithes ruber during a ten-year period were studied. Sampling was carried out by using bottom trawl net in the fishing area in Northwest of Persian Gulf over 1 year study period. Length data was also collected from fisheries research institute and fishery organization. Age determination was done by reading annual rings on sectioned otolith. Growth parameters were calculated based on age and length data. These data were used to estimate natural mortality rate. Total mortality was obtained from the age curve. Logarithmic catch and natural mortality were calculated from Pauly's equation. The averages of length in the last ten years were 35 to 39 cm. The samples ranged in length from 12 to 58 cm with the maximum frequencies between 28-44 cm. Length distribution was normal in this study. The maximum catch was composed of fish in the 40 to 48 cm length range with an average age of 2 to 3 years. The average total mortality, natural mortality and fishing mortality were 0.98, 0.56, and 0.42 respectively. Mortality was higher in age group 0 and age group 1, but mortality of the other age groups dramatically decreased. Exploitation rate in the last ten years were 0.42 indicating a near complete exploitation. Based on the results a more effective exploitation strategy is suggested in this region.
Mohammad Zakeri; Peseta Kochanian; Jasem Marammazi
Volume 11, Issue 2 , November 2012, , Pages 58-66
Abstract
The crude protein content and amino acid compositions of muscle from wild and cultured of male and female Acanthopagrus latus were determined by HPLC. There were quantitative differences between individual amino acids in the tissues investigated, depending on the sex and location. It was noted that, ...
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The crude protein content and amino acid compositions of muscle from wild and cultured of male and female Acanthopagrus latus were determined by HPLC. There were quantitative differences between individual amino acids in the tissues investigated, depending on the sex and location. It was noted that, among all the samples studied in tissues, sexes and locations, lysine and isoleucine were the principal essential amino acid (EAA) and glutamic acid was mainly for non-essential amino acid (NEAA). Lysine and isoleucine of male muscles had a significantly higher (P<0.05) amount than female muscles. The crude protein content in male and female muscles was not found to be significantly different. Depending on location, the percentages of arginine, leucine, isoleucine, lysine, serine, glycine, alanine and tyrosine were significantly different (P<0.05) in muscles of wild and cultured fish. The wild seabream possessed considerably higher protein content than cultured seabream muscle. The results showed that wild male fish muscle contained a higher (P>0.05) level of EAA than other groups. The results indicate that the Acanthopagrus latus is a healthful component of the human diet.
Aali Hosseini; Preeta Kochanian; Jasem Ghofleh Marammazi; Vahid Yavari; Ahmad Savari
Volume 10, Issue 2 , September 2012, , Pages 26-36
Abstract
A total of 311 specimens were collected from November 2006 to October 2007 . We estimated Population parameters from length frequency data. These cases consist of the von Bertalanffy growth parameters and mortality, as well as exploitation rate. The result indicated that pickhandle ...
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A total of 311 specimens were collected from November 2006 to October 2007 . We estimated Population parameters from length frequency data. These cases consist of the von Bertalanffy growth parameters and mortality, as well as exploitation rate. The result indicated that pickhandle barracuda had L∞ =109.21 cm total length, K=0.37 and theoretical age at zero length, = -0.5 The total mortality rate (Z) was estimated to be 1.91, the fishing mortality rate (F) and the natural mortality(M) were 1.30 and 0.61, respectively. The exploitation rate (E) was 0.68. The exploitation rate indicated that the stockis in high pressure of catch and overexploited.
Mohammad Khosravizadeh; Jasem Ghofleh Marammazi; Preeta Kochanian; Mansour Nikpey; Ebrahim Rajabzadeh; vahid Yavari; Mohammad Reza Sahraeian
Volume 10, Issue 1 , September 2012, , Pages 53-64
Abstract
Study was conducted to investigate the effects of various energy levels on growth performance, food conversion ratio (FCR) and whole body composition in Gattan, Barbus xanthopterus fingerlings (12.12±0.28 g) for 8 week. Feeding trial was conducted using 3 semipurfied diets containing 3 levels ...
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Study was conducted to investigate the effects of various energy levels on growth performance, food conversion ratio (FCR) and whole body composition in Gattan, Barbus xanthopterus fingerlings (12.12±0.28 g) for 8 week. Feeding trial was conducted using 3 semipurfied diets containing 3 levels of digestible energy (DE 2.5, 3 and 3.5 kcal/g) and same protein level 35%, in a flow-through system (1L/min) at 26.2 ± 0.460C. Triplicate groups of 15 fish (12.12±0.22 g) each, were stocked in 300-L circular polyethylene tanks and fish were fed to satiety thrice daily throughout the feeding trial. The best of total weight gain (146.67 g), FCR (2.21), protein efficiency ratio (1.31), apparent net protein utilization (ANPU%) (34.69) and condition factor (CF) (1.26) were observed in diet containing 3 kcal/g DE. The viscerosomatic index (VSI) and hepatosomatic index (HSI) did not show any significant difference between treatments (P>0.05). The final whole body moisture content decreased significantly with increasing energy levels in diets (P<0.05). Although whole body lipid and protein contents did not show significant variation among treatments (P>0.05), but the highest lipid and protein deposition were observed in diets containing 3.5 and 3kcal/g DE, respectively. Comparison between varying levels of dietary energy on the growth, feed utilization and whole body composition of Gattan indicated that 3 kcal g-1 DE could be the preferential dietary energy levels in fingerlings of this species.