Aquatic Ecology
Year:2015 | Volume:4 | Issue:4|Papers Count:15

The present study was designed to investigate the effects of 0.0125, 0.035, 0.075 and 0.15 ppm sub-lethal concentration of copper on hematological parameters (Hb, HCT, RBC, WBC, MCV, MCH, MCHC, lymphocyte, monocyte, neutrophil and eosinophil count) of the Oncorhynchus mykiss. Samples weighted 18±3 gr and exposure to CuSo44 for a week. Physicochemical properties of water were 14±2 oC temperature, 7-8 pH, and 270 mg/l Caco3. Total red blood cells, total leukocyte count, hemoglobin, mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), hematocrit, lymphocyte, neutrophil, eosinophil, and monocyte were measured by routine laboratory methods. Analysis of hematological parameters showed that, CuSo4 stimulated White blood cells, Lymphocytes, Hemoglobin, Neutrophil, Hematocrit, MCH, MCHC and MCV and did not any effect on Monocyte and Eosinophil. In conclusion, this study showed that hematological parameters of O. mykiss are suitable indicators to verify the existence of copper in water resources.

Due to an increase of the human population on Earth, log of pollutants to water resources has increased and this caused the more restriction of water resources for human. Limited availability of fresh water resources, especially in the Middle East that have arid and semi-arid climate increases the importance of water recycling. The main problem in many conventional wastewater treatment systems is their high content of nitrogen and phosphorus effluent, which affect the potential for reuse wastewater effluent. Solutions that today are considered in this context is the bioremediation of these substances from sewage. In the present study, for the first time, we evaluated the performance of a BIODROF system that in this system the algal biofilm are added to its bacterial part for bioremediation of nitrogen and phosphorus content from domestic wastewater. Our results showed a higher uptake of ammonia, nitrite, nitrate and phosphate compared to similar studies. The uptake efficiency for ammonia, nitrate, nitrite and phosphate was at least up to 96% of their initial concentration. Finally, we can say that the symbiosis of algae and bacteria with favorable conditions for gas exchange in Biodrof system could be a good reason for the better performance of our system compared to similar systems.

Zaribar Lake is a little shallow lake in Kurdistan province of Iran and it is faced to eutrophication.The study of phytoplankton biomass-nutrient relations is important in eutrophication management and there are many empirical models to predict phytoplankton biomass (chlorophyll a) based on nutrient (nitrogen and phosphorous) amounts in the lake. Evaluation of these empirical models and comparing the results with the real chlorophyll of the lake can be determine the proper model to simplifying future study and helps eutrophication management of the lake by giving useful information about chlorophyll-nutrient relations. Hence, sampling to an analysis of nitrogen, phosphorous and chlorophyll was carried out by select 6 sampling sites every two months from September 2010 to July 2011. Results showed that the models cannot predict current amounts of the chlorophyll and predicted amounts of chlorophyll based on nutrient are much more than the real chlorophyll a. Therefor the growth of phytoplankton (chlorophyll a) is limited by another factor such as light and common eutrophication control methods, that are based on limitation of external nutrient loading, are not practical and effective to the lake Zribar. In addition, there should be a new adapted model contained light limiting variable.

Petroleum hydrocarbons pollution is one of the problems in the environment due to petroleum industry processes. Biological methods are novel routs to defend against them. In this research, the effect of light intensities on biodegradation of naphthalene and the physiological responses of cyanobacterium Schizothrix vaginata is investigated. In this order, studied cyanobacterium transfered to liquid medium, after isolation in the solid BG11 medium. Following transferred to a liquid medium the alga was treated with naphthalene %0.05. OD, dry weight, chlorophyll, and phycobiliproteins were measured spectrophotometrically and naphthalene degradation was studied by gas chromatography (GC). Data obtained from physiological analysis were evaluated by historical data pathway via Design Expert software. According to the results, the maximum chlorophyll and phycobiliproteins contents belonged to 5000 lux. The reduction percent of Naphtalene also enhanced with increasing of light intensity and achieved its maximum in 3th hour. Dry weight reduced under naphthalene treatment by time, indicated negative effect of this pollutant on studied cyanobacterium. The obtained results suggest that microbial biodegradation of pollutants can be used to clean up contaminated environments. Biotreatment of wastes using living organisms is an environmentally friendly, relatively simple and cost-effective alternative to physico-chemical processes.

Streptococcus iniae is the most causative agent of economic losses in fish farms in Iran. In this study, antibacterial effects of the essential oils of Eryngium campestre, Pimpinella affinis, Zataria multiflora Boiss, Bunium persicum and Allium sativum on S. iniae, the causative agent of zoonotic disease was investigated. The disc diffusion method, Minimum Bacteriocidal Concentration (MBC) and determination of minimum inhibitory concentration (MIC) of the essential oils against S. iniae were employed to determination of antibacterial effects of essential oils and streptomycin were used as standard. The MBC of essential of E. campestre, P. affinis, Z. multiflora, B. persicum and A. sativum were 1, >1, 0.25, 0.12 and 0.5 (mg/ml), respectively, MIC of these essential was 0.5, 0.5, 0.06, 0.06 and 0.12 (mg/ml) respectively, and diameter of zone of inhibition were 27.3±1.7, 22.8±1.1, 32.8±1.3, 17±0.4 and 18.5±0.7 (mm) were, respectively, against S. iniae. Results of the present study demonstrated that the essential oils of B. persicum Z. multiflora and A. sativum were appropriate antifungal agents against S. iniae. As a result of this study using these herbal essential oils were suitable alternative than common antibiotics to treatment infections caused by S. iniae, the causative agent of zoonotic disease.

This study evaluates the influence of marshmallow extract administration (Althaea officinalis L.) at 0.0 (control), 2.5, 5, and 10 g on the activity of certain hepatopancreatic enzymes such as α-amylase, lipase and trypsin in common carp (Cyprinus carpio) during 60 days. Feeding the fish with diets enriched with marshmallow extract had no effects on the satiety index and hepatic index in these fish. α-Amylase and lipase significantly decreased (P<0.05) in fish fed 10 g marshmallow extract compared with the control group. Although amylase was significantly (P<0.05) elevated on day 30 in the fish fed with 5 g marshmallow extract, trypsin level indicated a significant decrease (P<0.05). Administration of marshmallow extract decreased pancreatic lipase on day 30 of the experiment. No significant change (P>0.05) was observed in pancreatic trypsin in the control or experimental groups on day 60, but the level of pancreatic α-amylase was higher in fish fed with 2.5 g marshmallow extract compared with the control group. In conclusion, the increase of pancreatic α-amylase may be attributed to the polysaccharide compounds found in marshmallow extract. Finally, marshmallow extract may decrease lipase but it does not affect trypsin level.

A killifish species Aphanius ginaonis occurs in Geno hot spring is one of the unique fish species that could successfully survive and acclimated to the high temperature of hot springs. In this study, we investigated the effects of Geno's cyanobacteria extracts on growth, survival and morphology of gill tissue in Aphanius dispar exposed to normal temperature and long-term thermal stress. For this purpose, 228 fish divided in four treatments including control (25°C), thermal (40-37°C), cyanobacteria control and cyanobacteria thermal. Our results showed significant affects of prolonged thermal stress in all growth parameters of A. dispar. At the end of the experiment at day 44, most of the growth parameters significantly decreased compared to the control group. The results showed that growth factors, including specific growth rate (SGR), weight gain (WG) and food conversion rate (FCR) in the control and the control – cyanobacteria groups were significantly higher than those of thermal and thermal- cyanobacteria treatments (p<0.05). The survival rate of fish in control and control - cyanobacteria treatments was 100%, whereas survival rate significantly reduced in thermal and thermal - cyanobacteria treatments (p<0.05). Fish kept at 37-40°C showed changes in gill tissue included blood congestion of primary lamellae and shortened secondary lamellae. In normal temperature, cyanobacteria caused blood congestion of primary lamellae, but in thermal stress, severe pathological changes observed. The conclusion can be drawn that at the thermal environment of hot spring, cyanobacteria extracted from Geno hot spring reduced the physiological functions of fish and could not modulate thermal tolerance in Aphanius fish.

This study was conducted to evaluate the effects of different levels of Mentha piperita extract on growth factors, body composition, intestinal bacteria and survival rate of Oncorhynchus mykiss in challenging with Yersinia ruckeri. For this purpose, four groups of fish with mean weight of 32.2±0.12 g were raised for 8 weeks in Vniro tanks, 80 fish to each tank and feeding with different levels of M. piperita (with concentrations of % 0, % 1, % 2.0 and % 3.0, 3 replicates for each treatment). At the end of the trial, growth factors, intestinal bacteria and survival rate of fish in challenging with Y. ruckeri were determined in different groups. Results showed that O. mykiss fed on a diet supplemented with 3% M. piperita had significantly higher growth factors, lactic acid bacteria, and survival rate compared to other treatments (P<0.05). Although, the study of body composition showed no significant difference between different treatments (P>0.05). Based on the results, using of M. piperita extract, especially at the level of 3% can improve the growth performance and survival rate of O. mykissmykiss in challenging with Y. ruckeri and was recommended in the diet.

The present study was aimed to identify thermophilic cyanobacterial of Chah-ahmad hot springs located in Hormozgan province. Sampling was done based on water resource condition, Water physicochemical analysis was performed due to their dramatic effects on species distribution. Thermophilic samples collected at different temperature gradients were fixed in 4% formaldehyde to minimize changes in phytoplankton. The taxonomic determination was carried out using artificial keys presented in some valid publications. Semi-permanent slides of each isolate were prepared and morphometric study is done using light microscopy. The vegetative and reproductive characters such as shape, color and size of the cell, colony, thallus and trichomes, shape, size and color of vegetative cells, apical cell shape, presence of sheaths and some other morphological were used in the taxonomic determination. Results showed the highest level of diversity was achieved at lower temperatures. Jaaginema angustissimum, Jaaginema pseudogeminatum and Jaaginema metaphyticum were present in all temperature gradients and well adapted to temperature gradients. CCA analysis was done in order to explore the relationship between the species composition in individual spring and physic-chemical parameters as environmental variables. According to the result indicated species are well separated along some parameter such pH, Do, temperature, Ca, Na, K, No3, Po4, So4.

In the present study, the levels of the hypoxia-inducible factors (hif-1, hif-2) transcripts were evaluated during development of an ancient fish species, Beluga sturgeon (Huso huso) in a normal oxygen environment. The transcripts of hif-1, hif-2 were detected in all developmental time-points of H. huso from embryos to juvenile fish. Changes in normalized hif-1, hif-2 mRNA expression by using the RPL6 over development was statistically significant over time (P<0.05). Our results revealed that the mRNA expression of hifs was low during embryonic development and then upregulated significantly in the time of hatch and early larval time-points whereas, in the late larval development and juvenile stage started to decline. The upregulation of hif-1, hif-2 transcripts at the time of hatch and during yolk sac fry development of H. huso is likely tied to the role of hifs in organogenesis and angiogenesis.

The main idea of this research was to evaluat the effects of concentration and time of exposure the Cypermethrin Toxin on the gill tissue of Black Fish (Capoeta damascina). In order to do this research, the Black Fishes that where used gathered from Kordan River of Karaj and their average weight was 150 gr and their average length was 12 cm. the fish used in 4 treatments (0.25, 0.5, 0.75 mg/lit and a control group) and 3 replication that exposed to lethal doses of Cypermethrin toxin. Sampling of fish gill was conducted in the first, 5th and 10th day of the experiment. In this study injuries such as hyperplasia of gill secondary lamella apical cells, epithelial lifting secondary lamella, mucous cell hyperplasia in primary lamella, fusion, shortening the secondary lamella, and aneurism were observed with different severity in various treatments. The results showed that with increasing toxin concentration and time of exposure fishes to the toxic, more injured fishes gill tissue.

Determination of sex and gonadal development of Siberian sturgeon (Acipenser baerii) by using endoscopy as a new and less aggressive method for sturgeon conservation is the aim of this study. the gonadal development status of 23 Siberian sturgeons (7 years) by using endoscopy and histology for confirmation investigated in Shahid Dr. Beheshti Sturgeon Fish Propagation and Rearing Complex, located in Guilan, Iran. The system consists of a 7.5 mm, 30°, 22 cm long cytoscope sheath, fiber-optic light, halogen cold light source (150 W, #30801, Gima, Gessate, MI, Italy) and video camera installed on laptop. The results showed 52% female and 48% male identified by endoscopy which histology studies confirmed it, so the accuracy of sex identification was 100%. Our results suggest that endoscopy is an efficient technique for sex identification as well as the determination of gonadal development stages in Siberian sturgeon. Correct performing of this method in sex identification and gonadal development stages can help conserving of this valuable fish and economy of our country.

The aim of this study was to record the length-weight relationship and condition factor of A. maculatus from Persian Gulf coastal waters. The specimens were collected on a monthly basis from April to March 2013. Overal 766 specimens were caught. Size and weight of collected fish ranged between 13.2-48 cm and 31.2-1820 gr. The Condition of the growth fish was all metrically negative with b value<3.0 (w=0.03 L2.72) respectivly. Condition factor was estimated at 0.95. This study provides basic information for fishery biologists and managers.

Rising trend of production and use of nanoparticles can lead to the possibility of their release into aquatic environments. Therefore, knowing toxic effects of these materials on aquatic organisms is of great importance. The objective of this research was to study the acute toxicity of colloidal silver nanoparticles (CAgNPs) through determining the lethal concentrations in the euryhaline teleost, Aphanius dispar. Toxicology experiments were conducted for 96 h in freshwater according to the OCED 203 standard protocol. Fish mortality was recorded every 24 h after exposure to concentrations of CAgNPs 0, 5, 10, 20, 30, 40 and 50. The actual concentration of silver in each aquarium was measured by atomic absorption and based on the actual concentration; data on mortality were analyzed using the US EPA Probit analysis program. Based on the results, the estimated 96h LC50 of CAgNPs was 10.631 mg/L. Accordingly, the tested CAgNPs should be classified according to GHS (Globally Harmonized System of Classification and Labeling of Chemicals) as “category acute 3” for Aphanius dispar; this means that presence of CAgNPs in the environment of this fish is detrimental and, therefore, its release into the aquatic ecosystem should be carefully considered.

This study aimed to the first report of Saw-belly, Hemiculter leucisculus from the Zarinehrud River and investigation of its morphometric and meristic characteristics, length-weight and length-length relationships. A total of 77 saw-belly specimens were caught on September 2013 from the Zarinehrud River. Twenty-one morphometric and 10 meristic characters were examined. The total length and weight ranges were 66-142 mm and 1.7-30.27 g, respectively. The parameter b of 3, indicating its isometric growth pattern. Regarding the observed species diversity and presence of 6 other exotic fish species in this River, the saw-belly has probably introduced to this river with commercially cyprinid species from the Caspian Sea basin.