Journal of Marine Biology

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In recent years, use of medical herbal as immune-stimulants and immune system booster in diets of fish was increased. In order to study the effect of milk thistle ectract (Silybum mariamun) ,silymarin, on non-specific immune system of rainbow trout (Oncorhynchus mykiss) , fish were fed on diets containing 0,100,400 and 800 of medical supplementary silymarin mgr/kg diet for 28 days .The levels of following parameters of plasma , immunoglobulin IgM , total complement, lysozyme and peroxidase were measured . There was no significant difference between levels of immunoglobulin IgM, total complement and lysozyme in plasma of fish fed under diets of medical supplementary silymarin compared with control group (p>0.05), but the levels of peroxidase in the later mentioned groups fish fed under diets of silymarin were significantly higher than control group(p<0.05). The result indicated that milk thistle- extract, silymarin, caused positive effects on the immune system of rainbow trout.

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In this study, embryos of Rainbow trout, in 1-30 days post hatching (1-30 dph) were prepared from Jam Raising and propagating center in Kalat nadery, mashhad. Samples were fixed in 10 percent buffered formaldehyde and transferred to laboratory. Samples were prepared through usual histological method. Developmental stages of different layers of skin (epithelium and dermis) were studied under light microscope. According to the results, epidermal cells in single layer with few small mucosal cells and mesenchymal dermal layer during first days were observable. During the second week, by increasing the thickness of epidermal layer, high number of mucosal cells, sensory buds formation and mesenchymal dermis layer were observed until the day 30th, these developmental events were progressed. Having knowledge about the chronological stages of skin development, may be helpful in diagnosis and treatment of fish related diseases and so these results may be helpful for raising them and suitable economic goal.

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In order to study the effect of replacementof fish meal of diet by soybean meal in the levels of 0,25,50 and 75 percent of diet, on fatty acid profile and quality changes of fillet in Rainbow trout (Oncorhynchus mykiss), four isocaleric and isonitrigenous diet was formulated and feed during 8 week. All treatment were carried out in 2 m3 fiberglass tank with 30 fish per tank. Fish were fed 3 times daily at libitum. At the end, of the experiment, fatty acid composition of fillets was evaluated and TBA at 4 c was measured over 9 days period. Results indicated that Σ N-6 PUFA in the trout fed the highest soybean meal level were significantly higher than other treatment, also Σ N-3 PUFA in the trout fed no soybean meal, was significantly higher than other treatments .fillet TBA in the trout t fed no soybean meal, was significantly higher than other treatment at 4*C over 9 days period. statistical analysis showed that effect of diet, storage time and diet×storage time on the TBA was significant in the 95 confidence level. In summery replacement of fish meal by soybean meal showed significant changes in the fatty acid profile and lipid oxidation capacity of fillets.

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The key to successful aquaculture industry is in the formulation of suitable food formulas containing all necessary elements for growth and improvement of quality in aquatic animals. Rainbow trout is the main Iranian cultivated cold water fish and introducing rations for improving its health and growth, are very important. In this research, 204 rainbow trouts with average initial weight of 50 g received different amounts of manganese sulfate in 4 treatments with 3 repetitions, for 90 days. The amount of manganese sulfate for the treatments 1, 2 and 3, were measured as 48, 78 and 98 mg/kg of food respectively. Treatment 3 had highest increase in growth with 135 g in weight, 7.5 cm in length, with SGR index of 1.66, PER index of 1.62 and FCR index of 1.60. the control group had the lowest increase in growth with 126 g in weight, 5.69 cm in length, and SGR index of 1.41, PER index of 1.56 and highest FCR index of 1.71. the results indicated no significant changes between treatments and controls (P>0.05). There was no significant difference (P>0.05) in survival among treatments. Therefore, despite the increase in growth of rainbow trout with diet containing manganese, but the differences were not significant statistically.

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This research was aimed to investigate the effects of pomegranate (Punica granatum) seed kernel meal (pskm) as a supplement in the diet of rainbow trout (Oncorhynchus mykiss). The experiment was carried out in better and more favourable growth of color parameters, in a period of 90 days from December 2014 until March 2015, in Abzi Eksir Koesar Complex, situated in south east of Tehran. Fish population included 600 fingerlings with average weight of 6.74 g and average Fork length of 5,50 cm which were divided to five treatments, each treatment had three replicates. One of them was control group, without any pskm and four main treatments with added 1, 2, 3 and 4 percent of pskm to their food, respectively, were main treatments. Results of spectrophotometer tests represented increase of brightness parameter or transparency (L^*) with the maximum of 58.60 and increasing of the red to green parameter (a^*) with maximum amount of 2.94 in treatment 1. Results also indicuted that the maximum parameter from blue to yellow (b^*), with amount of 10.12 was related to the control group. Provided indicuted that, using pomegranate seed kernel meal to improve the color of Oncorhynchus mykiss meat, especially at the level of 1%, has significant impact which is possibly due to the presence of the effective pigment, particularly astaxanthin in pskm. It should be noted that this article is derived frome the master‘s thesis.

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Amino acids play a vital role as building blocks of proteins and as intermediaries in metabolism. In addition, amino acids are associated with health and amino acid deficiency leads to various diseases. Hence, the knowledge of amino acid composition of foods is important as a basis for determining the nutritional value of substances. Various factors such as type of diet and nutrition, age, weight, maturity, etc. affect changes in the body's nutritional composition, including proteins. In this study, the effect of size (length and weight) on amino acid changes in rainbow trout with 50±10, 250±10 and 600 ± 10 g weight groups and 12±5, 22±5 and 38±5 cm length groups was studied in the summer of 2019. The results of amino acid analysis showed that the amount of essential amino acids including: arginine, histidine, leucine, methionine, thronin, lysine, phenylalanine and valine in different weights and lengths were not significantly different (P> 0.05). Also, the amount of non-essential amino acids including: aspartic acid, gluten, serine, glycine, alanine, proline, tyrosine and cystine in different weights and lengths were not significantly different (P> 0.05). The results of this study showed that in rainbow trout, fish size has no significant effect on the amount of amino acids. Also, the results of this study and its comparison with other fish showed that rainbow trout is a fish rich in essential and non-essential amino acids that are needed for human health. In addition, this fish is richer in terms of amino acids arginine, methionine, lysine, phenylalanine, tyrosine and proline than some fish such as common carp and the amount of aspartic acid, serine, glutamic acid, glycine and alanine is less than other fish.