Effects of dietary carbohydrate levels on growth, survival and body composition in Caspian Kutum (Rutilus frisii kutum, Kamenskii, 1901)

This study was carried out to evaluate the effects of dietary carbohydrate levels on growth performance and body composition of juveniles Caspian Kutum (Rutilus frisii kutum). Fish with initial average weight of 0.8±0.2g (±SD) were fed five isoproteic and isenergic formulated diets with different carbohydrate levels including 15, 20, 25, 30 and 35% in triplicate groups, 4 times daily according to their satiation for 10 weeks. Results showed that increasing the level of carbohydrate to 35% significantly increase some growth indices such as final weight (Wf), weight gain (WG), body weight increase (BWI), specific growth rate (SGR) and protein efficiency ratio (PER). In addition, result of body composition analysis showed that the increase in carbohydrate level lead to increase of protein level. So, the highest amount of protein was observed in fingerlings fed with diet containing 35% carbohydrate. In conclusion, the results indicate that increase in carbohydrate levels from 15 to 35% have not any negative effect on growth parameters and therefore, the level of 35% carbohydrate in the diet of 1-2g Caspian Kutum fingerlings can lead to better efficient in protein and desirable growth

Effect of different levels of Azolla meal on growth performance and digestibility of common carp (Cyprinus carpio)

In this study, the effects of different dietary levels of Azolla meal were investigated on growth performance and digestibility of common carp (Cyprinus carpio) fingerlings during 60 days. Five experimental diets approximately iso-protein (30%) and isolipidic (10%), were formulated with different levels of Azolla meal consisting of 0, 15, 25, 35 and 45%, respectively. In each experimental treatment, triplicate groups of common Carp fingerlings (16.5± 0.2 g) were used in a completely randomized design. Twenty fish were assigned to each experimental unit and stocked in 300 L tank. The results showed that the use of Azolla meal up to 15% had no negative effect on growth performance. The growth of fish was reduced significantly with increasing Azolla meal level of more than 15% of diet. Based on results, the apparent digestibility coefficients (ADC) of dry matter decreased with increasing Azolla meal in diets. The highest ADC of protein was observed in control treatment. However, no significant difference was observed between the treatment 2 (diet with 15% Azolla meal) and control (without Azolla meal) for ADC of protein. In general, results of the present study showed that Azolla meal can be used up to 15% in Cyprinus carpio diet

The effect of alfalfa (Medicago sativa) alcoholic extract on growth performance, feed intake, body composition and blood biochemical parametersof rainbow trout (Oncorhynchus mykiss)

This study was conducted to evaluate the effects of alfalfa (Medicago sativa) extract on growth performance, feed intake, body composition and some of the serum parameters of Rainbow trout (Oncorhynchus mykiss). In this study, a total of 240 rainbow trout were weighted average 8/36±0.2(g) and randomly distributed in four treatments (control), 0.5, 1, 1.5% of extract per (kg) of diet with three replications in plastic tanks. Fish were placed and fed with extract containing food for 60 days. During this time, physicochemical factors of water were measured. At the end of the period, growth index and serum parameters calculated. The results showed that growth performance in treatments that fed with 1% alfalfa extract had a significant difference compared to control treatment (p<0/05). In the indexes of body compositions, an increase in the amount of fat was observed in 1% treatment of the extract, while there was a significant difference with the control group (p<0/05). Serum parameters showed that there were significant differences between fish fed with alcoholic extract of alfalfa and control group (p<0/05). The lowest cholesterol and triglyceride levels and the highest level of protein were observed in the 1.5% extract group. Also, the highest amount of glucose was observed in control treatment. The results of this study showed that the addition of alcoholic extract of alfalfa (1 -1.5 %) to fish diet can improve the growth performance and blood biochemical parameters of rainbow trout

Environmental pollution and toxic substances: cellular apoptosis as a key parameter in a sensible model like fish

WOS: 000449240800014PubMed ID: 30273782The industrial wastes, sewage effluents, agricultural run-off and decomposition of biological waste may cause high environmental concentration of chemicals that can interfere with the cell cycle activating the programmed process of cells death (apoptosis). In order to provide a detailed understanding of environmental pollutants induced apoptosis, here we reviewed the current knowledge on the interactions of environmental chemicals and programmed cell death. Metals (aluminum, arsenic, cadmium, chromium, cobalt, zinc, copper, mercury and silver) as well as other chemicals including bleached kraft pulp mill effluent (BKME), persistent organic pollutants (POPs), and pesticides (organo-phosphated, organo-chlorinated, carbamates, phyretroids and biopesticides) were evaluated in relation to apoptotic pathways, heat shock proteins and metallothioneins. Although research performed over the past decades has improved our understanding of processes involved in apoptosis in fish, yet there is lack of knowledge on associations between environmental pollutants and apoptosis. Thus, this review could be useful tool to study the cytotoxic/apoptotic effects of different pollutants in fish species.Sari University of Agricultural Sciences and Natural ResourcesWe would like to express a special thanks to Prof. Willem B. Van Muiswinkel for critical comments on the manuscript. We are indebted to Dr. B. Di Giacomo for help in realizing the figure in this manuscript. H. AnviriFar has been supported by a PhD student grant from Sari University of Agricultural Sciences and Natural Resources

Modeling habitat preferences of Caspian kutum, Rutilus frisii kutum (Kamensky, 1901) (Actinopterygii, Cypriniformes) in the Caspian Sea

Predicting and modeling of habitat preferences of fish is a very important issue for aquatic management. Classification trees (CTs) were used to predict the habitat preferences of the Caspian kutum (Rutilus frisii kutum, hereafter kutum) in the southern Caspian Sea. The applied model was optimized with genetic algorithm (GA) and greedy stepwise (GS) to select the most explanatory variables for predicting the presence/absence of kutum. The suitability index was considered to determine the quality and suitability of fish habitat in the sea. The results of Paired Student's t tests showed that there was a significant difference between predictive performances of models before and after variable selection methods. Both optimizers improved the predictive power of CTs and resulted in a better understanding of CTs by making a selection of the sea characteristics that were used as inputs to the models. The results show that the effect of different seasons, sea depth, and photosyntheticaly active radiation were the main predictors affecting the habitat preferences of kutum in the Caspian Sea. Constructed trees in combination with GA and GS showed high capability when applied to predict the habitat preferences of this valuable commercial fish species. Determining the habitat needs of the target fish will enhance local fisheries performances and the long-term conservation planning of the fish to implement the ecosystem-based management in the Caspian Sea