A 32-year-old man was attacked by flies while camping around Khorram Abad, Lorestan Province, western Iran. Pruritic dermatitis with marked edema and considerable discomfort appeared mainly on the lower legs. The flies were identified as Simulium. Simuliids are tiny bloodsucking flies, popularly known as blackflies or buffalo flies, belonging to the dipterous, family Simulidae. They are occurred worldwide, breed in fast-flowing streams, and are a major animal pest.

After report of animal death and sever dermal damages by one kind of insect in Arasbaran area, specimens of the insect are collected on cows and buffaloes during spring of 1998. Preliminary study on collected specimens in research center of natural resources and animal affairs of east Azarbaijan indicated that, they were belong to Simulium genus of blackflies (Fam. Simuliidae). For complementary identification 11 females of them sent to department of zoology in comennius university of Slovaakia. According to L. Jedlicka studies most of specimens were Simulium margaritae (Rubtsov 1958). Accidents and death in the cause of blackflies happen merely by collectively attack and sever blood sucking of them probably, therefore don't interfere any pathogen in it. Prevalence of simulids and accidents of them are reported for the first time of Arasbaran and Iran.

Species diversity of macrobenthos in Fusheh River, in Guilan Province, North Iran was studied and biological indices developed based on macroinvertebrates were used to evaluate the health status of the river. Macrobenthos sampling in the river was carried out at 4 stations on a monthly basis beginning from May to December 2016 using a Sorber sampler (mesh size of 300 μm and surface area of 900 cm2) with three repetitions. The sampled macrobenthos were preserved in 96% ethanol and transported to the laboratory for identification. A total of 4928 individuals from two phyla of Arthropoda and Annelida, three classes of insects (Insecta), crustaceans (Crustacea) and Clitellata as well as 8 orders (including Ephemeroptera, Trichoptera, Plecoptera, Diptera, Coleoptera and Haplotaxida) along with 25 families and 31 genera were identified. The most abundant genera were Simulium sp. (35.84-46.65%), Hydropsychae sp. (15.79-33.36%) and Baetis sp. (7.87-17.66%). Parameters of total abundance, EPT richness, EPT percentage and EPT/CHIR ratio were also calculated. The EPT richness showed a significant difference in monthly samplings (p<0.05). The presence of species sensitive to pollution such as Perla sp., Isoperla sp., Chloroperla sp., Oligoneuriella sp., Heptagenia sp., Rithrogena sp., Epeorus sp., Rhyacophila sp. and Philorus sp. belonging to orders Trichoptera, Plecoptera and Ephemeroptera exhibits both the good quality of river water and the desirability of species and genera as natural food for the river fish species.

This research has been conducted in Tonekabon River in 1996. 190 fish samples were take from diferent age groups of 0+, 1+, 2, 3+, 4+. Results indicated that the most highest and lowest abondant were %63, %5.7 in Dohezar and intersection of Dohezar and Cehezar respectively. Maximum body length and weight were 175mm and 84.5g in Dohezar respectively. Minimum body length and weight were 27mm and 0.39 g in Cehezar, respectively. Highest abundant belonged to 2 years age group with 112.3mm average length. Sex ratio was 1:1.4 (female to male). Condition factor of male and female were almost equal (1.268 and 1.257 respectively). Highest feeding intensity was in spring and the lowest was in autumn. Main preys were Simulium, Plecoptera and Ephemeroptera. Growth was positive alometric. Absolute fecundity ranged between 168-379 with an average of 268 eggs.

The diet of Tinca tinea in Lahijan Amirkelayeh Lagoon was in studied in four seasons of 2001. Fishes were caught by gillnet, common haul science, castnet and dipent. Fishes were biometry, age determination' necropsy and intestine contents were recognized after catch. According to obtained results from 178 Amirkelayeh lagoon Tinea tinea 1+ - 7 + age groups, average total length, weight, relative length gut, index of fullness and fullton's condition factor were  respectively 26.3 cm, 382.5 gr, 0.72,187.2 and 1573.1. Natural diet of Tinea tinea indud,  17 groupsoflive foods like odonata, snail, water plant, trichoptera, chironomidae, hemiptera, ephemeroptera, Perea fluviatilis, diptera, gammarus, tubifex, plant seed, simulium, water bug, water tick, zeoplankton and phytoplankton during sampling in 2001. In this fed foods, ahytoplankton, snail and hemiptera had highest frequency percentage (68.53%, 65.7% and 34%) and water tick, water bug, trichoptera, ephemeroptera, diptera and Perea fluviatilis had lowest frequency percentage (each with 1.1%). There for, according to obtained information, Tinea tinea is a phytoplanktonvores, zeoplanktonvores, bentosvores, plantovores and carnivores. That by account of this food habitis and also relative length gut, we should say that Tinea tinea is an omnivores. Meanwhile, Tinca tinca food habits and food factors were dependent of season, age and sex changes. Key word: Amirkelayeh lagoon, Tinea tinea, Natural diet. Over 87% (ranged from 87.7 to 112 %). The within laboratory relative standard deviations [RSDr] were less than 16.6% (ranged from 4.3 to 16.6%). Subsequently 47 samples of shrimp were collected from the southern provinces of Iran and were analyzed for the presence of and aflatoxins B1 , B2, G1, and G2. Aflatoxin B2 contamination only detected in one sample at a level of 1.71 ppb. Such a low contamination level may pose a negligible risk to human health.

Karaj River as one of the most important water sources of Tehran city, has special importance. This study consisted of diversity and distribution of Macro benthos on Karaj River that was conducted during years 2014-2015. It was started in fall 2014 and it was finished in summer 2015. In the mentioned area, the total of five study stations were selected based on environmental impact, Macrobenthos fauna samples were taken by Quadrat with dimensions of 50 × 50 cm such that were repeated 5 times at each station with seasonal frequency. Samples were fixed with 4% formalin, were separated in a lab, and then identified and counted. In surveys conducted, 23 genuses from 21 families and 5 orders of Macrobenthos were identified. The results show the station 4 in winter season had most abundance (1067) and the station 5 in spring season had the less abundance (254) of specimen. Insecta had the most abundance (88.8 % of total) and Malacostraca had the less abundance (0.1 % of total) between five classes were identified on Karaj River. The genera of the Simulim with the number of 879 per square meter the highest abundance and The genuses of the Asellus and Atherix With the number of 1 per square meter the lowest among the species had been identified. During this study the average of the Shannon-Wiener diversity index was calculated 1.73, Simpson dominance species was calculated 0.74 and Margalef richness species was calculated 3.31. According to the biological values of Hilsenhoff (HFBI), the water quality status of Karaj River at stations 2 and 3 were evaluated excellent, at stations 5 was evaluated very well and at stations 1 and 4 were evaluated well. Overall according to the results, it was determined that aquatic insects constitute the dominant population of the benthic fauna in Karaj River. In winter season the classes: Insecta, Turbellaria, Gastropoda, Malacostraca and Clitellata had the greatest density and diversity compared to other seasons.

Introduction: The study of the structure of aquatic communities in aquatic ecosystems has a special place in the ecological studies of aquatic organisms. Among the important and common macrobenthic indices, we can mention uni-variate and multi-variate ecological indices, which having different advantages and disadvantages, are still used in various studies in riverian waters. In recent years, studies using biodiversity index and bioindices, especially the Helsinhof index, were used to assessment of the water quality of the Karaj River. Assuming that there is agreement between the ecological indices of the region, the present study evaluated the degree of agreement between the quality statuses results obtained from different ecological indices in the Karaj River. Materials and Methods: In this study, we sampled macrobenthic fauna using a sorber sampler in nine stations during 2017-2018, seasonally. After separating and identifying macrobenthos, Shannon's index, EPT, ASPT, BMWP and HFBI were calculated. Then the ecological status of the stations was classified based on these indices. The percentage of stations whose ecological status was acceptable or unacceptable, as well as the compatibility level between these five indices in the study area, were calculated. To determine the similar tendency of the different indices in the classification of stations, the degree of correlation between them was determined using a non-parametric test. SPSS23 and Excel software were used for statistical analysis and Primer6 was used to determine biodiversity index. ShapiroWilk test was used to check the normal distribution of the data. In order to determine the significant difference between the desired data, one-way ANOVA and Kruskal-Wallis tests were used at the significance level of p<0. 05. ArcGIS 10. 3 and Terrset 17. 3 software were used to prepare maps using the IDW method. Results: In terms of abundance, the Shironomide family was dominant. Baetis, Tubifex, Micrasema, Rhithrogena, Eporus, Hydropsyche, Leptophlebiidae, and Simulium made up 83% of the samples. The values of H', EPT, ASPT, BMWP and HFBI were calculated (12. 2±, 0. 65), (5. 6±, 2. 8), (3. 9±, 1), (48. 8±, 23. 34) and (4. 6±, 1), respectively. The relative agreement in the results obtained from the five studied indices was seen in 67% of the stations with unacceptable quality in the case that 22% of the river stations showed complete agreement and 11% of the stations showed disagreement. The statistical analysis shows that there is a significant agreement between the results of the ecological status obtained from EPT with ASPT, BMWP and Shannon, if they are different with HFBI index. Also, based on the results of the correlation between the classification of the ecological quality obtained from the bioindices (positive and strong correlation between the EPT and the Shannon and BMWP), it indicates the similar direction of these indices in the classification of the stations. Discussion: There are structural and population changes of macrobenthos in aquatic ecosystems due to natural factors and human activities. Due to the lack of complete agreement between the assessment results of the five indices in this study, in order to use biological indices in each region for environmental management, there is a need to simultaneously use indices. Also, it is important to check the agreement between different indices and choose the appropriate ecological index. As a result, using each of these indices alone and without considering the above considerations can lead to wrong results. Based on the results of the present study, the Helsinhof index (HFBI) can be introduced as a more suitable index than other studied indices to assess the ecological status of the Karaj River.