Short communication: optimization of semi-quantitative RT PCR analysis for CPT I gene expression in rainbow trout (Oncorhynchus mykiss)

A key enzyme in mitochondrial β¬oxidation, carnitine palmitoyltransferase (CPT) I, is transcriptionally regulated in mammals, but this enzyme also experiences allosteric modulations (Harano et al., 1985; Murthy and Pande, 1987; Bezaire et al., 2004). CPT I is located on the inner side of the outer mitochondrial membrane and catalyses the conversion of acyl-CoA to fatty acylcarnitine (Kerner and Hoppel, 2000; Price et al., 2000). Quantitative RT-PCR is a reliable technique for measuring transcripts in small amounts of tissue (Spriewald et al., 2000). With this technique, multiple mRNAs can be assayed simultaneously in a relatively short period of time. Here we describe the standard procedure, optimized in our laboratory, to assess CPT I levels with β¬actin as an internal control in rainbow trout, and all the necessary controls to ensure a quantitative analysis. RNA Extraction and Reverse Transcription Total cellular RNA was isolated from liver of rainbow trout using RNX reagent (Cinnagen-Iran). To obtain cDNA, 1 µg of total RNA was subjected to reverse transcription polymerase chain reaction (RT-PCR) with MuLV reverse transcriptase using the RevertAidTM M¬MuLV Reverse Transcriptase Kit (Fermentase Life Science, Germany) and random hexamer primer. Reaction conditions in the reverse transcription step are mostly dependent on the enzyme and the primers of choice. Whereas other protocols to require the use of specific primers, we prefer to reverse transcribe the total RNA population with random hexamers so that different PCR analyses could be performed on the same cDNA sample

Determination of CPUA and distribution pattern of families Haemulidae, Nemipteridae and Ariidae in the Oman Sea

This trawl survey was carried out during 2013 for the stock assessment of families Haemulids, Nemipterids and Ariids in the Oman Sea. Sampling was carried out at five different stratum and depths. The highest value of CPUA of Haemulidae was estimated for Pomadasys stridens in “B” stratum (885.78 kg nm^-2), for Pomadasys kaakan at depths of 10-20 m (330.35 kg nm^-2), and for Nemipteridae it was estimated for Nemipterus japonicus in “D” stratum (1042.31 kg nm^-2) at 30-50 m depths (1734.97 kg nm^-2), and for Ariidae, it was estimated for Netuma thalassina in the stratum B (752.64 kg nm^-2) at 20-30 m depths (428.33 kg nm^-2). The highest biomass for Haemulidae was estimated in stratum B (320.53 ton) at 50-100 m depths (282.98 tons), and for Nemipteridae in “D” stratum (559.72 tons) and at depths of 30-50 m (604.04 tons), and for Ariidae it was estimated in “B” stratum (272.35 tons) and at 50-100 m depths (255.12 ton). Based on the results obtained, the highest species diversity for Haemulids was in “A” stratum at depths less than 50 m, while for Nemipterids it was similar in the total study area and different depth layers. Highest species diversity for Ariids were found in “A” and “D” strata at depth layers of 10-20 m and 30-50 m, respectively. In light of the fact that fishing efforts decreased during these years, our results illustrate that CPUA and biomass have ascending trends which indicate the relative stability of the stocks of these families

The interactive effect of water-borne cadmium and environmental hypoxia on common carp (Cyprinus carpio) metabolism

Regarding to the tight association between aquatic hypoxia and heavy metal contaminations in one hand and the role of both parameters on fish respiration, metabolism of carp could be assessed under single and mutual exposures to hypoxia and cadmium. Following measuring LC50-96h of cadmium (43.679 mg/l) for this species, 80 common carp were exposed to 10 different treatments, including control, acute (43.68 mg/l), sub-lethal (21.84 mg/l) and chronic (4.37 mg/l) cadmium as well as hypoxia for immediately (20% of saturation), 24h (40%) and 7 days (60%), and joint exposure of each similar treatment. By using of respirometer technique, we measured oxygen consumption rate in different time spans to calculate each individual standard metabolic rate (SMR), maximum metabolic rate (MMR), aerobic scope (AS), factorial aerobic scope (FAS) and critical oxygen tension (PCrit). Obtained data show that acute and sub-lethal cadmium treatments led to significant (P<0.05) increases in all metabolic indices in comparison with control group whilst the MMR and AS have been reduced (P<0.05) following hypoxia treatments. Combined treatments of hypoxia and cadmium led to reduce SMR and PCrit in all treatments and MMR, AS and FAS only in acute and sub-lethal treatments. In overall, hypoxia can act as a limiting stressor in carp while cadmium can account as a loading stressor

The sub-lethal effects of cadmium on some gill histopathology in the cultivated Sterlet (Acipenser ruthenus)

The sub-lethal effects of water-born Cadmium (Cd) on histopathological changes of gill tissues were investigated on Sterlet, Acipenser ruthenus. In this research, 60 fish (41.69 ± 0.95 g and 23.98 ± 0.14 cm) were randomly distributed in 4 experimental groups, each with 3 replicates. The fish were exposed to different concentrations of Cd for 21 days under semistatic experimental condition as: 0, 16, 32 and 64 µg/L Cd. At the end of the experiment, the gill tissues were fixed in Bouin's solution for histopathological studies. Qualitative and quantitative changes of the gill tissues were analyzed. Several qualitative changes including hyperplasia, hypertrophy of epithelial cells and epithelial edema as well as necrosis, rings and fusion of gill filaments and secondary lamellae were observed in all treated fish including control group. Quantitative analysis based on organ index (Iorg) showed significant increase in histopathological changes in the gill tissues coincided by elevation of Cd concentration in the water. However, there was no significant differences in the organ index between control and 16Cd group.The results of this study demonstrate severe histopathological changes in the gill tissues after exposing to sub-lethal concentration of water-born Cd under experimental condition. The results of this study might be used as a guildline for evaluation of histopahological changes being induced by heavy metals in natural or cultivated environment for sturgeon fish

Age, growth and reproduction of Chondrostoma regium (Heckel, 1843) from the Zayandeh Roud River, Iran

Age, growth and reproduction were investigated for Chondrostoma regium, collected monthly (November 2007- August 2008) from the Dimeh Spring region, Zayandeh Roud River, Iran. The maximum age of collected female and male fish were estimated based on scale increments as five and four years respectively. Von Bertalanffy growth equations were calculated as Lt=246[1-e^-0.206(t-0.034)], Wt=163.29[1-e^-0.206(t-0.034)]^2.77 for females and Lt=253.1[1-e^-0.206(t-0.175)], Wt=188.25[1-e^-0.206(t-0.175)]^2.99 for males. Size ranges of the male and female specimens were almost similar. The fork length range for females was 10.5-18.0 cm and 10.7-19.7 cm for males; and the weight range was 15.7-85.4 g in females, and 14.5-88.5 g in males. The female-male ratio was 1.8:1 (p<0.05), and for both sexes gonadal development and sexual maturity occurred in the second year of their life. Length-weight relationships revealed isometric growth pattern for males and a negative allometric growth for females. Monthly data of Gonadosomatic Index, and ovary condition suggested that spawning occurred during May and June. The mean absolute and relative fecundity was calculated as 2429±1512 (eggs/female) and 78.1±18.7 (egg/g), respectively, and fecundity was significantly correlated with both body weight (r^2=0.90) and fork length (r^2=0.84)

Effect of dietary wood betony, Stachys lavandulifolia extract on growth performance, haematological and biochemical parameters of common carp, Cyprinus carpio

A 6 week study was conducted to assess the effects of wood betony (WB), Stachys lavandulifolia extract on growth performance, hematological and biochemical parameters of common carp, Cyprinus carpio. Different levels of the WB extract (0, 2, 4 and 8 % weight per weight, W/W, 0WB, 2WB, 4WB and 8WB) in the diet were used. The results showed that final weight and weight gain were significantly improved by WB (p0.05). There were no significant differences in hemoglobin, hematocrit, mean erythrocytes of hemoglobin, mean erythrocyte volume, mean hemoglobin erythrocyte concentration and white blood cell (WBC) counts (p>0.05), while, red blood cells (RBC) counts showed significant declining trend by increasing the level of the plant extract from control to 8WB (p<0.05). Significant elevation in the levels of total protein, albumin and globulin and albumin/globulin ratio by increasing WB concentration in the diet were observed (p<0.05). Diet enriched by WB could decrease serum level of triglycerides and cholesterol in comparison with the control (p<0.05). Based on the results of this study, it could be concluded that feeding common carp with WB can improve growth and some immunity characteristics as well as lipid metabolism

Effect of dietary canola oil level on the growth performance and fatty acid composition of fingerlings of rainbow trout (Oncorhynchus mykiss)

This study evaluated the suitability of canola oil as a source of supplemental dietary lipid for rainbow trout. Triplicate groups of the 30 fingerlings held under identical culture conditions were fed twice daily by iso-nitrogenous, iso-calorific and iso-lipidic diets for eight weeks. Experimental diets consisted of 30.3% protein, 18.7 kJg^-1 energy and 16.7% lipid from fish oil (FO), canola oil (CO) and 1:1 blend of the two oils (FCO). Moisture, ash, protein, lipid, final body weight, condition factor, feed conversion ratio, survival and hepatosomatic indices were not affected by treatments. Specific growth rate and weight gain of fish reared on fish oil diet (FOD) and canola oil diet (COD) were significantly higher than those fed with the fish and canola oils diet (FCOD). Protein efficiency ratio was highest in fish fed with the COD. Whole body fatty acid compositions mirrored those of diet treatments. The highest amounts of HUFAs were detected in fish fed with FOD, which was significantly different from other treatments. In all treatments PUFAs/SFAs and n-6/n-3 ratios were higher than 0.45 and lower than 4, respectively. Our results indicate the fingerlings can be reared on diets in which FO has been replaced with CO, with no significant effects on fish growth performance

Impact of the environmental contaminants on aquatic organisms

Following an unsustainable development of industry resulting from human population growth and its corresponding demands, the concern for the environmental implication of natural and artificial pollutants stemming from human activities has increased. Environmental pollutants in air, water, soil, sediments, food and consumer products, can get into the body of organism through eating, breathing or be absorbed through the skin. They will be assimilated into the blood stream and have direct or indirect impact on their physiological performance. Among others, it seems that aquatic organisms are more exposed to the most pollutants so that aquatic environments are the ultimate destination of pollutants like industrial effluents, urban wastewaters and agricultural run-off. Pollutants such as heavy metals and chemical compounds are considered to be very toxic and their accumulations through biological magnification can damage the ecosystem and its biodiversity. Some of these pollutants which are known as �Endocrine Disrupting Chemicals (EDCs)� can affect the endocrine system of aquatic organisms leading to problems in reproductive behaviors, reproductive organs, quality of sexual gametes, reproductive potential, growth and development and other related immunological issues for animals or even humans. These compounds can mainly interfere with the aquatic populations through disturbance in hormonal performance especially sexual hormones. This not only disturbs the ecological balance but also causes biodiversity reduction, unsustainable aquatic population and destruction of ecosystems, subsequently. This study aimed to investigate the role of environmental pollutants and their side effects on aquatic organisms and hence human health

Effects of Sediment Characteristics on the Accumulation and Transfer Rate of Heavy Metals in Mangrove Trees (Case Study: Nayband Bay and Qeshm Island )

In this paper, the accumulation of heavy metals of Nickel (Ni) and Vanadium (V) was measured in habitat sediments, mangrove roots and leaves (Avicennia marina). Besides, the transfer of Ni and V from the sediment to root and to the leaves in Nayband Bay and Qeshm Island were studied. The samples were gathered by Systematic-random Sampling using selective transects at 16 stations at the end of mangrove cover in both sides of land and sea in two habitats with three replicates of sediment, root and leave samples. The bed characteristics including sediment texture, pH, EC and organic matters were determined. The concentration of Ni and V was measured by atomic absorption spectroscopy (AAS), and then the metal transfer factor from sediment to root and root to leave was calculated. The correlation of the metal transfer factor and sediment characteristics was analyzed using the SPSS software (version 19). In the sample of sediments, roots and leaves respectively, the most concentrations of nickel and vanadium were measured. About transfer of Ni and V, transfer rate from sediment to root was much higher than from root to leave. In addition, the highest transfer factor from sediment to root and from root to leave was obtained for V in Qeshm habitat (0.502) and for Ni (0.749) in Nayband Bay. It seems that the difference between sediment textures in the two habitats and widespread oil and gas activities in Nayband Bay might be the notable reasons for the difference in transfer rates in two the habitats. Therefore, we conclude that the finer texture of Qeshm habitat increased transfer of V from sediment to root, and the coarser texture associated with increasing air pollution in Nayband Bay caused more Ni to accumulate in the leaves

Distribution, Abundance and Biodiversity of Phytoplankton from Hanna Dam Lake, Isfahan, Iran

Phytoplankton are the base of production in aquatic ecosystems and have a major importance in the freshwater environment both in terms of fundamental ecology and in relation to human use of natural resources. The purpose of this research was to determine distribution, abundance and biodiversity of phytoplankton community in Hanna Dam Lake, located in Isfahan province. The sampling was carried out in mid-season from 6 fixed stations during one-year period. Abundance ranges of diatoms, Chlorophyceae, Desmids, Dinophyceae, and Cyanophyceae were estimated 405-2395, 786-6778, 0-14, and 0-70 cells/mL in spring 1281-3879, 1987-4518, 13-173, 0-157, and 0-85 cells/mL in summer 593-1265, 1926-4980, 0-14, 0-51, and 0-37 cells/mL in autumn 48-264, 116-624, 0-13, 0-51, and 0-131 cells/mL in winter, respectively. Cyclotella, Cocconeis and Surirella from diatoms Chlorella, Oocystis , and Tetraedron from Chlorophyceae were dominant in spring. In summer, Cyclotella and Surirella from diatoms Mougeotia, Chlorella and Scenedesmus from Chlorophyceae Closterium from Desmids Prorocentrum from Dinophyceae and Chroococcus from Cyanophyceae were dominant. In autumn, the dominant genera were Cyclotella and Surirella from diatoms Mougeotia andChlorella from Chlorophyceae Closterium from desmids Ceratium from Dinophyceae Chroococcus from Cyanophyceae while in winter Cocconeis and Amphora from diatoms Chlorella and Tetraedron from Chlorophyceae Closterium from desmids Ceratium from Dinophyceae Tolypothrix from Cyanophyceae were dominant. The diversity indices of Simpson, Shannon-Wiener, and Margalef were obtained at ranges of 0.40-0.72, 1.23-2.29, and 0.95-1.59 in spring 0.59-0.77, 1.97-2.73, and 2.13-2.80 in summer 0.50-0.71, 1.56-2.31, and 0.96-1.82 in autumn 0.13-0.63, 0.27-1.42, and 0.10-0.97 in winter, respectively. The highest biodiversity was obtained during spring and summer. Our results showed that this lake could be classified as eutrophic lake based on water quality, abundance, composition and biodiversity of phytoplankton