نشریه اکوبیولوژی تالاب
سال هشتم شماره 4 (پیاپی 30، زمستان 1395)

The fish gill is the main organ of respiratory gas exchange and also plays dominant roles in osmotic regulation, acid-base balance, and excretion of nitrogenous wastes. Fish gill show one of the most complex vascular structure but some anatomical differences can be observed among various species of the fish. Vascular corrosion casting coupled with scanning electron microscopy is a standard method, which allows three-dimensional visualization with good resolution of the micro vessels and fine capillaries of organs. IN the present study, the gill fine vascular structure (arterio arterial pathway) of silver carp (Hypophthalmicthys molitrix) was studied by using the vascular corrosion cast technique with scanning electron microscopy (SEM). According to the results, the general pathway of blood flow of this fish was like the other teleost but showed some differences in the gill vasculature details. Probably, the smaller interconnected Ampulla and the longer vascular channel with more branches of vessels of silver carp gill, was relating to the low oxygen demand and metabolism rate of Hypophthalmicthys molitrix.

In this study the effects of substrate and hydraulic retention times of 1, 3, 5 and 10 days on lead removal efficiency in horizontal subsurface constructed wetland under crop the common reed were evaluated. The results showed that the removal efficiency increased with increasing hydraulic retention time so observed significant difference at 5% level in sand substrate among hydraulic retention times 1, 3 and 5days in average removal efficiency of lead but there was no significant differences between retention times 5 and 10days and in the fine and medium gravel substrate between retention times of 1 and 3day was significant different at 5% but there was observed a significant difference at 5% level among retention times 3, 5 and 10 days, So the best hydraulic retention time was obtained in the sand, Fine and medium substrates respectively 5, 3 and 3 days with maximum efficiency of 88.51, 81.53 and 80.35 percent. The analysis results also showed that the substrate had a significant effect at 5% level on the lead removal efficiency in retention time 3 and 5 days so that sand substrate had higher efficiency than the other two substrates; therefor can be concluded the sand substrate has more effect to intensify in the physical, chemical and biological effective processes on removal of lead synthetic wastewater.

Due to the lack information about morphological and genetic characteristic of B. mesopotamicus a study with the goal of providing this information for the first time in Iran. In the fall 2012, three populations of Barilius mesopotamicus in the Tigris basin were studied and compared. For this purpose, samples from Seimare, Changouleh and Siah-gav rivers were collected and their 29 morphometric characters were measured by a digital caliper and 7 meristic characteristics were counted under a stereomicroscopy. The morphological differences between the studied populations were analyzed using principal component (PCA) and canonical variables analysis (CVA). In addition, to compare the genetic and phylogenetic relationships of these populations, their Cyt b gene sequences were used. Based on the results, Changouleh and Seimare rivers populations showed significant differences with Siah-gav one in terms of morphological features. Based on the Maximum likelihood and Bayesian methods, the studied populations were not genetically differentiated from each other and therefore were clustered in a single clad. In general, it can be concluded that the morphological differences of the studied populations can be as result of environmental factors, and the role of genetic factors is limited.

Analysis of the structure and future trends of climate parameters in sensitive area and vulnerable to environmental threats, particularly inland lakes Iran is very important. Therefore, in this study to investigate the effects of global warming on the pattern and structure of thermal equilibrium Lakes basin washstand, Bakhtegan and Maharlou daily average temperature is simulated. In this regard, the first air circulation over the period 2015 to 2050 model data base EH5OM data was extracted. The base of the general circulation of the atmosphere and ocean data model, under scenario A1B, the international climate change made. The base of the general circulation of the atmosphere and ocean data model, under scenario A1B, the international climate change made. Downscaling them in the fourth edition model was then RegCM4. The average daily temperature in small scales with size 0.27 × 0.27 degrees latitude those areas with approximate dimensions of 30 × 30 km area covered by the mining deals. The temperature of the monthly, quarterly and yearly basin, interpolation and relevant maps were drawn. Also, after a variable Mathematical reference temperature by applying trigonometric fractal structure on temperature data to evaluate the results of fractal geometry was classic. The results showed a temperature of 21-16° zone around the three lakes in the case study watershed based on the highest average annual temperature of the lake in the coming decades Maharlou and lowest lake is Tashk. Lake Maharlou in all entitled to a higher temperature than is the Maharlou Lake in all seasons; the temperature is higher than the other lakes. Zones where average temperatures and seasonal patterns, although the temperatures are different, but in terms of the spatial patterns of the structure are relatively similar and equally enjoyed. The trend shows that the average daily temperature, this parameter follows the fractal structure, which reflects the dynamics of the indices in the coming decades of the Equilibrium to Disequilibrium.

Amirkelaye international wetland, with an area of 935 acres is located in Gilan province. Agricultural runoffs, water withdraws for agricultural purpose and plants growing, especially submerged and marginal plants are of the main threatening factors in this wetland which reduce its surface and therefore it is necessary to determine the trophy status in the case of adverse circumstances, the reclamation measures can be done for it. The research was made from autumn 1392 to summer 1393 in order to check the status of Amirkelaye wetland trophy. Sampling was done from 6 stations during four seasons, and in which trophic state index (TSI) was examined using 4 parameters: total phosphorus (TP), total nitrogen (TN), the depth of Secchi disk (SD) and chlorophyll (chl-a). According to TSI index, Amirkelaye wetland is in the most critical state in the terms of SD parameter compared to TP, TN and chl-A parameters and in a better state in terms of chl-A parameter compared to TP, TN, and SD parameters. According to the statistical analysis, the average amount of total nitrogen in winter and summer was lowest and highest, respectively. The average amount of phosphate was observed as highest and lowest in winter and autumn, respectively. Average amount of chlorophyll A was highest in summer, but the other three seasons together in terms of the amount of chlorophyll A were not significantly different (P> 0.05). Average depth of Secchi disk was found the lowest and highest in summer and winter, respectively. Using Duncan statistical test, none of the variables of chlorophyll A, total nitrogen, total phosphorus and depth of Secchi disk at various stations were significantly different (P> 0.05). The results showed that in the autumn and winter, Amirkelaye wetland was in the Mesotrophic state and in the spring due to agricultural runoffs entering was in acute Mesotrophic state. In the summer, due to increased agricultural runoffs entering and the hot weather, it was in the Eutrophic state.

The objectives of this study were to determine concentrations of lead and zinc in the kidney, liver and muscle of mallard (Anas platyrhynchos) from Fereydunkenar wetland. The study was conducted between November and December 2015. The determination of Pb and Zn in mallard tissues was carried out using a graphite furnace atomic absorption spectrometer, (Thermo, Model 97GFS). Mean concentrations of Pb in kidney, liver and muscle of mallard were measured 2.95, 1.71 and 0.62 mg/kg, respectively. Also, mean concentrations of Zn in kidney, liver and muscle of mallard were observed 13.8, 20.96 and 8.69 mg/kg, respectively. The distribution patterns of Pb in tissues follow the order: kidney>liver>muscle, while Zn follow the sequence: liver>kidney>muscle. The results indicated that there were positive correlations (r = 0.688, P< 0.05) between liver and muscle in Zn. Zn levels in the kidney and muscle of mallard were below the maximum permissible limit of FAO/WHO (2015), but concentration of Zn in the liver of mallard was above the permissible limit proposed by FAO/WHO (2015). In this study, the mean concentrations of Pb in liver, kidney and muscle were higher than FAO/WHO (2015). The concentrations of Pb reported in the study are alarming and require proper management.

Bioassay Artemia toxicity is one of the common methods in marine Nano ecotoxicology to predicting the negative impacts of the release of nanomaterials. Due to the increasing in production and applications of silver nanoparticles in the various industrial areas, in this study, we evaluated the toxicity of chemical and biogenic silver nanoparticles using the aqueous extract of brown seaweed Sargassum boveanum and assessment their effects on the sensitivity of different developmental stages of Artemia fransiscana, (Nauplius and adult). For this purpose, the OECD standard method was used. The number of 30 artemia nauplii and 10 adults were placed in each well of 24-well plates and 6-well plates respectively, and for testing the toxicity were exposed to an additive serial concentration of biosynthetic and chemical silver nanoparticles (each concentration in 3 repetitions). Mortality in each group at the times of 12, 24, 36 and 48 hours after exposure to silver nanoparticles were recorded and analyzed via Probit software. The result showed that not only the toxicity of these two types of silver nanoparticles on artemia nauplii and adult increased in a dose-dependent manner, but also their toxicity increased along with the duration of exposure time. The toxicity if these nanoparticles were significantly different (P <0.05). So that after 48 hours, the LC50 value of chemical AgNPs in the artemia nauplii was 31.8 mg/l, while 48h LC50 for biosynthesis AgNPs produced by seaweed was 141.1 mg/l. While the concentration of the chemical AgNPs in adults artemia during exposure was 47 mg/l and for biosynthesis form of AgNPs was 132.5 mg/l, were assessed. Comparison of the toxicity result in both of Nauplius and adult stages of artemia showed that the chemical form of AgNPs was more toxic potential (up to 5 times in nauplii) than a biosynthetic form of AgNPs (up to 3 times in adult). It seems, the sensitivity of artemia nauplius to chemical silver nanoparticles more than to mature stage, but compared to biosynthesis form produced by algae is less than adult stage. This research recommends the development and replacing the green approach in the production of nanoparticles to prevent future environmental risks.

Chlorella is a green and photosynthetic algae that are very important in the aquaculture industry. Conway is very wealthy more than TMRL and wastewater has many nutrients such as nitrate and phosphate. Therefore, To perform this test growth of microalgae chlorella in 2 types Conway and TMRL in 3 types waters (marine water, sterile wastewater and no sterile wastewater). Culture mediums that were cultured with contain 6 treatments and every which 3 tautology. Microalgae commutated daily and accounted equal condition (temperature: 250C, salting: 5 ppt, lighting rage: 2500 lax, lighting period: 16:8). The results showed that there is a significant difference between the 3 treatments. Maximize density was TMRL treatments in sterile wastewater and minimize density was no sterile wastewater. The results showed that marine water is grown rather than other treatment, whereas TMRL in sterile wastewater grown rather than Conway, so, given that sewage has many nutrients such as nitrate and phosphate, can cause growth of many algae as well as wastewater treatment.