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The aim of this study was to show the effect of four feeding regimes on thyroid hormones concentrations, growth performance and food coefficient in Rainbow Trout applied through 4 treatments and 3 replications in winter 2006. In this research, samples of rainbow trout with an initial mean weight (SO) 47.19±0.42 used in each rearing unite. Fish were fed twice a day ad libitum as follows: Treatment A (TA): which was the control treatment; Continues feeding, Treatment B (TB): 4 weeks of starvation and 5 weeks of re-feeding, Treatment C (TC): 3 weeks of starvation and 5 weeks of re-feeding, and Treatment 0 (TO): 2 weeks of starvation and 5 weeks of re-feeding. Indexes like food coefficient ratio (FCR), specific growth rate (SGR), daily food intake and thyroid hormones (T3, T4) were also examined during the experiment. Blood samples were taken for thyroid hormones concentration at the beginning of the experiment and at the end of the starvation and every 12 days in re-feeding periods. TB and TC had significant difference (P0.05). There were no significant differences between the treatments in FCR (P>0.05). T3 concentration came down

in comparison with the control treatment at the end of the starvation (day 29) (P

in there-feeding periods. T4 concentrations of fasting groups were lower than the control group at the end of fasting periods (P<0.05), but T4 trend in re-feeding periods increased. According to the results, different treatments of feeding regimes could affect the thyroid hormones concentrations. Fasting periods  reduced  and  re-feeding  periods  increased  thyroid  hormones  concentrations.  TB  and  TC showed more indexes of CG in comparison with TA and TO. We concluded that thyroid hormones alone are enough to assess CG and we suggest to use other growth relating physiological elements in different feeding diets and regimes in future studies to complete the evaluation.

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The effectiveness of pituitary extract from Crucian carp (Carassius auratus Linnaes 1758) in inducing ovulation in Veil Tail Gold Fish (Carassius auratus gibelio Bloch 1783), was examined and the effect of maternal hormone treatment on egg quality in two types of fertilization (fertilization in aquarium and artificial fertilization), were evaluated in 22·c temperature. Fish were injected intrapritoneally with three doses of, 2, 3 and 4mg/kg B.W pituitary extract (PE). With increasing of pituitary dose, practical fecundity also increased from 1775 in control fish to 3201 in fish with 4mg/kg B.W ofPE. Mean time to ovulation was reduced significantly (P<0.05) from 132h in control fish to 13h in fish with 4mg/kg B.W. Ovulated eggs from fish injected with 4mg!kg B.W of PE had lower fertility and hatching rates compared to eggs from fish injected with lower doses and the control fish. The methods of fertilization had no significant effect on the egg quality. In conclusion, the results of this study showed that the pituitary extract of Crucian carp is effective in inducing and shortening of ovulation of Veil Tail Gold Fish and the suggested dose for this species is 3mg!kg B.W.

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One of the well-known herbal drugs is henna (Lawsonia inermis). According to the components in henna, several beneficial properties (i.e., antimicrobial, anti-inflammation, wound healing, trypsin inhibitory and antioxidant) have been reported. The present study was designed to investigate the effects of two natural substances (sodium chloride and henna extract) on experimental skin lesion due to pulling out scales and trypsin injection (0/02 ml, beneath dorsal fin). For this purpose, 54 fish in weight 5/5±0/55 of were divided to 3 groups, with eighteen fish in each group. Fishes were placed in laboratory condition in 22-25 ˚C. Two, four and six days after induction of skin injury, fishes were treated with different agents for 10 minutes. First group was treated in salt water 1%, second group in henna extract 0.5% and the control group without any additives. The fish were sampled weekly, 3 times by sampling from the wound. Macroscopic examination showed that color changes of wound place decreased in henna group in comparison with that other groups. In third week of healing, normal appearance of skin were seen in most of fishes in henna and salt groups. Microscopic study revealed a decrease in inflammatory cells infiltration in henna group second week after induction of skin injury. It seems that henna by decreasing inflammatory process, can also prevent skin damage and secondary infections that can help faster and more effective on wound healing than salt bath in fish.

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This study was conducted to determine statement of some metals and oil pollutants in the southern Caspian Sea (Kelarabad-Mazandaran).Seventy five Surface sediments samples (Triplicate) were collected at three stations from autumn of 2011 to winter of 2012. All samples were prepared by digesting and extracting processes and then determined using Atomic Absorption Spectroscopy and High Performance Liquid Chromatography instruments. Results showed that annual mean contents and standard error (±SE) of surface sediments were observed 59 (±3), 25 (±1), 42 (±2), 28 (±1), 14 (±1), 0.16 (±0.06), 0.020 (±0.005) and 2.81 (±0.73) mg/kg.dw for Zn, Cu, Cr, Ni, Pb, Cd, Hg and PAHs, respectively. Also, sediments samples based on Enrichment factor (EF) and Ggeoaccumulation index (Igeo) were showed no polluted conditions for this region, but sediments were classified low polluted based on CF, Cd and PLI. In addition, Hazard Quotation (HQs) of most of PAHs compound were calculated more than unit in surface sediment which according to results of the evaluation’s risks to health of 16PAHs suggest that there is risk for biota. In a conclusion, according to anthropogenic sources of some metals and PAHs of sediment, it is essential that the management and development of the aquaculture industry in the Mazandaran Coast to be made with environmental considerations and cautions.
 
 

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This study was conducted to evaluate the technical efficiency of Gilan seine fishing cooperatives. In this research, the data envelopment analysis method was used and the data of this research were collected by using a questionnaire from the cooperatives for the year 2017. The results showed that these cooperatives had about 93% technical efficiency on average. So, the cooperatives can have 7% more fishing without increasing their inputs. Also, about 46% of cooperatives are in a state of incremental returns to scale or scale economies and about 26% of cooperatives are in a state of decreasing returns to scale or scale diseconomies. In addition, this study identified the most important reference cooperatives as well as the possibility of reducing inputs for cooperatives that are not 100% efficient. In general, although the fishing cooperatives of Guilan province are in a favorable position in terms of technical efficiency, but, considering the amount of technical efficiency and returns to scale, it is better that the Fisheries Organization of Iran provide more support to cooperatives that are less efficient to become more efficient and reduce costs, and encourage more efficient and superior cooperatives.

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Herpesvirus type 3 (CyHV-3) is the main cause of contagious koi herpesvirus infectious (KHVD) in common carp and koi worldwide. For this purpose, 60 pieces of common carp from farms with losses and farms from Khuzestan province that reported losses in the last few years were sampled during 2017 to 2021 for detection of Koi herpes virus disease by molecular method. In order to increase the virus load in gill and kidney tissues, three gills and kidney samples were separately mixed together for each three fish. DNA extraction from the tissue was performed using the commercial kit of Raha Zist Padtan Company according to the instructions. Afterward, Nested PCR test was performed using Amplicon master mix and polymerase gene primers. The results of the Nested PCR showed that 3 samples (two gill samples and one kidney tissue sample) out of 40 mixed samples tested had 339 kbp band and were considered as positive samples. Sequencing of PCR products and preliminary Blast analysis showed that the sequence of one of the positive samples was similar to the CyHV-3. The results of the alignment of the nucleotide rows and the phylogeny tree of this sequence confirmed Koi herpesvirus and it was registered in the World Gene Bank with the accession number of LC713276.