توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Effect of different light regimes on the maturational progress of the whitespotted rabbitfish (Siganus sutor)
نویسنده(ها): ، ، ،
اطلاعات انتشار: IRANIAN JOURNAL OF FISHERIES SCIENCES، دوازدهم،شماره۴، oct ۲۰۱۳، سال
تعداد صفحات: ۱۲
In this study, the effects of different light regimes on the reproductive activity of a typical Indo– Pacific coral reef rabbitfish, Siganus sutor, were evaluated. Forty– five adult fish were exposed to nine different photoperiod (8L: 16D, 12L: 12D, 16L: 8D) and light intensity (1000, 2000, 3000 lux) combinations with three replicates and five other fishes reared under indoor light condition (Control). Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) were calculated after 60 days and compared among different experimental regimes in males and females. In the control group, GSI and HSI mean values were 4.67 and 3.24%, respectively, for females and 10.05 and 2.10%, respectively, for males, and these fish showed differences in comparison with the exposed fish. Females kept under 1000 and 2000 lux light intensities had a higher GSI mean value (9.26 and 10.39%, respectively) and also lower average HSI (2.10 and 2.31%, respectively) in 16L: 8D treatment. A similar result was also obtained for males, whereas the 3000 lux light intensity, 8L: 16D day length combination led to more gonadal development (GSIs of 16.41% in females and 12.03% in males). A comparison of results among different photoperiods also confirmed that maturation was induced better in fish maintained under 16L: 8D in both sexes. This investigation revealed the visible role of both photoperiod and light intensity on inducing maturity in the whitespotted rabbitfish, S. sutor. Thus, rearing of adults exposed to an artificial light regime, including 16L: 8D and 2000 lux light intensity, promotes more gonadal development than that occurring in the wild.

۲Fluctuation of gonadosomatic index during oocyte development in the narrow–clawed crayfish Astacus leptodactylus (Eschscholtz, 1823) in Aras Dam Lake, Iran
اطلاعات انتشار: IRANIAN JOURNAL OF FISHERIES SCIENCES، سيزدهم،شماره۱، Jan ۲۰۱۴، سال
تعداد صفحات: ۹
This study was carried out with the aim of examining the seasonal reproductive cycle of the female crayfish Astacus leptodactylus from Aras Dam Lake, Western–Azerbaijan, Iran. Gonadosomatic index (GSI), and oocyte size were measured in females sampled seasonally in June, August, November(2011), January(2012). Development of the oocytes was categorized according to the diameter and the presence\absence of yolk granules. The ovary development was accompanied by increasing levels gonadosomatic index and egg diameter. Ovarian development histologicaly related to the seasonal GSI . This index was low in June (0.61±0.05) when oocytes started developing and reached the highest value in November (13.53±0.25), when vitellogenic oocytes were abundant in the mature ovary. Our results highlight the relationship between the ovary development and the GSI and egg diameter in the crayfish A.leptodactylus during the reproductive cycle and held important implications for the management of aquatic species. Thus, investigation of female A. leptodactylus reproduction is highly significant for fisheries managers as well as environmentalists concerned with perpetuating crayfish stocks.

۳Antibacterial activities of nisin encapsulated in zein and modified atmosphere packaging on rainbow trout (Oncorhynchus mykiss) fillet during chilled storage 4°C
اطلاعات انتشار: IRANIAN JOURNAL OF FISHERIES SCIENCES، چهاردهم،شماره۲، Apr ۲۰۱۵، سال
تعداد صفحات: ۱۳
Nisin is a widely used naturally occurring antimicrobial effective against many pathogenic and spoilage microorganisms. It has been proposed that reduced efficacy of nisin in foods can be improved by technologies such as encapsulation to protect it from interferences by food matrix components. This study was carried out to evaluate the microbiological quality of fresh trout slices treated with N1 (nisin 0.15 g\kg) and N2 (nisin 0.25 g\kg), NE1(encapsulated nisin 0.15 g\kg), NE2 (encapsulated nisin 0.25 g\kg ) and were then packaged under Modified Atmosphere Packaging (MAP) (45% CO2, 50% N2 ,5% O2) and stored at 4±1 °C for 20 days. The results revealed that nisin in both forms of free and encapsulated was efficient against the proliferation of various categories of spoilage microorganisms; including aerobic and psychrotrophic populations and lactic acid bacteria. The shelf life of the treated products was extended by 4–7 days more than that of the control. As a consequence, nisin, in particular encapsulated nisin, might be considered as an effective tool in preventing the quality degradation of the fillet, resulting in an extension of their shelf life.

۴Assessing genetic diversity of populations of bartail flathead (Platycephalus indicus Linnaeus, 1758) in the Northern part of the Persian Gulf using AFLP markers
نویسنده(ها): ، ، ،
اطلاعات انتشار: IRANIAN JOURNAL OF FISHERIES SCIENCES، چهاردهم،شماره۴، Oct ۲۰۱۵، سال
تعداد صفحات: ۱۳
Genetic diversity of six populations of bartail flathead (Platycephalus indicus Linnaeus, 1758) was investigated using amplified fragment length polymorphism (AFLP). A total of 118 reproducible bands amplified with ten AFLP primer combinations were obtained from 42 fishes that were collected from six different locations in the northern part of the Persian Gulf. The percentage of polymorphic bands was 57.06%. Nei’s genetic diversity was 0.1808±0.2074 – 0.2164±0.1903, and Shannon’s index was 0.2675±0.2949 – 0.3280±0.2727. The results of AMOVA analysis indicated that 66% and 34% of the genetic variation occurred within and among the populations and gene flow was 0.6454. The estimated level of population differentiation as measured by average Fst value across all loci was 0.327. Analyses revealed significant genetic differentiation with low gene flow among the six locations, indicating at least six separate populations of bartail flathead in the northern part of the Persian Gulf.
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