فصلنامه محیط زیست جانوری
سال سیزدهم شماره 4 (زمستان 1400)

Most of the vertebrate species populations affected by the main threatening factors like habitat destruction and fragmentation are experiencing rapid and worse destruction and decrease. Identification of potential and suitable habitats trough modeling tools and methods as well as survey on population relationship and contacts through genetic studies, provides needed knowledge and understanding to define the conservation status and needs for different species. For these purpose, Maximum Entropy (Maxent) and mitochondrial cytb sequencing with 704 bp were deployed. Based on the results, northern part of Iran followed by Semnan, Tehran, Qom and Alborz provinces, as well as western part including Khuzestan consisted the most suitable habitats for the species. Haplotype diversity of h= 0.894 as the main index, showed high genetic diversity for the populations of the species in Iran. Populations of Stripped Hyena, in Iran, are losing their main and suitable habitats due to habitats destruction and degradation, illegal hunting and lack of proper genetic connections. Decreasing populations and worse conservation status of the species convince us to prepare and conduct urgent conservation actions to prevent more loss. The study, using the habitat modeling and genetic surveys, as well as data gained from the field works, gives new vision on the conservation actions needed to protect stripped hyena in Iran

Awareness of the factors affecting the habitat desirability of species and also the distribution of desirable habitats are essential issues in planning for dynamic and sustainable management and conservation of species which consequently might lead to balance in ecological relationships of habitat. Regarding  the lack of field research on the ecological status of the Porcupine (Hystrix indica)  and its unique characteristics in morphological, behavioral and its effects on the sustainability of the ecological status of the country's habitats, in this research we are trying to  model the habitat of this species as the  largest rodent species in the country from October 2017 to December  2018, during 30 rounds of accurate field monitoring in Khojir National Park to determine the most important habitat variables affecting species distribution. In this study, 130 points of presence were recorded by GPS based on direct and indirect indices obtained from species activity. MaxEnt method was used to model the habitat suitability of Hystrix indica. The AUC value was 0.9, which indicates a good accuracy of Maximum entropy's model. The results showed that the type of vegetation, geographical direction, altitude, slope and distance from the road have the greatest impact on the presence and activity of the species, respectively. The results of this research can be used as an efficient tool to identify the factors affecting the presence of the species and also help to the proper management of Porcupine in the study area and other habitats of this species.

Iran’s mouflons (Ovis orientalis) populations have been declined in western regions because of poaching and habitat destruction and categorized as vulnerable in IUCN red list, this population as ancestors of domestic sheep (Ovis aries) breeds all around the world has an international importance. In this study, genetic diversity and structure of mouflons in the north-west of Iran (West Azerbaijan, East Azerbaijan, Kurdistan, Markazi, Hamedan and Qazvin) identified and compared with the domestic breeds via whole genome sequencing and BeadChip Ovine SNP 50K Data. Number of SNPs all over the genome, genetic load and inbreeding coefficient based on whole genome data, as well as expected heterozygosity and inbreeding coefficient as genetic diversity parameters based on c BeadChip data have been compared between wild and domestic groups. Number of discriminator SNPs as the most important parameters showed impressive difference and was calculated about 24 million for wilds and 20 million for domestics. According to the findings of nucleotide diversity for the whole genome, genetic diversity based on complete genome data was higher in the wild group than in the domestic group. Based on the results of this study, mouflon (Ovis orientalis) with high levels of genetic diversity as genetic resources for domestic breeds of all domestic sheep in the world are of vital value and should be given priority in conservation programs.

Throughout the world, roads have a significant devastating impact on natural habitats wildlife, indicating that roads serve as one of the major factors contributing to global biodiversity loss. Expansion of road networks in Khorasan Razavi Province, within and around protected areas, has led to an increase in road casualties, especially carnivores’ road mortalities. The present study aimed to delineate the hotspots of carnivores’ vehicle collisions on the roads located inside and around of the protected areas, investigate the time patterns for the carnivores’ road casualties, and prioritize hotspots of road casualties in the Khorasan Razavi Province. For this purpose, road casualties of carnivores in this province were evaluated between 2011 to 2020. The results showed that a total of 199 carnivores belonging to 11 species of the Canidae, Hyaenidae, Mustelidae and Felidae have died due to vehicle collisions during our study period. The highest numbers of mortalities, in this study, were recorded for the common fox (25.8%), golden jackal (20.7%), grey wolf (14.15%), hyena (13.6%), and wildcat (10.1%), respectively, making a total of 167 cases of recorded collisions (84.34%). The results of this study showed that the majority of road mortalities for these species occurred during autumn, winter, summer, and spring, respectively. Our results also revealed a total of eight hotspots of road mortalities in this province that are mainly situated across the northern, central, and western parts of this province.

When the needs and behaviors of wildlife affect humans or the behavior of wildlife negatively affects the needs of wildlife, the conflict between humans and wildlife occurs. The purpose of current study is to investigate the conflict between human and wildlife in rural and urban environments in Robat Karim. For this purpose, it was used purposive sampling method, 45 academics, health department, environment department, municipality (municipal services, transportation and waste management unit), environmental NGOs, agricultural and livestock activists and Indigenous guys were selected and interviewed in an unstructured form. Then, by using inductive qualitative content analysis, the findings of the interview were interpreted and classified. Thus, using the open coding method, the first meanings extracted from the interviews are "concepts"; Categorization of concepts, "subcodes"; and subcategory categorization, "main codes" were extracted. From the open coding results, 4 main categories were obtained. Main category 1 pointed to damage to garden facilities and destruction of agricultural products, main category 2 pointed to inflict economic losses and create fear and panic among the villagers, main category 3 pointed to damage and cause severe livestock casualties and main category 4 pointed to disrupt discipline and The tranquility of the urban environment and the transmission of pathogens have been emphasized. In general, public media, forming an environmental committee in the city governorate, forming NGOs with the aim of holding training courses, cooperation of the city environmental organization with the municipality to collect stray dogs and sterilize them, cooperation of relevant organizations with the health network organization to vaccinate stray dogs to reduce epidemics illnesses, insuring gardens (facilities and products), insuring livestock (sheep and goats) are approaches to mitigate human-wildlife conflict.

This study was conducted to evaluate some of the clinical parameters following field anesthesia in Caspian ponies. Twelve healthy Caspian ponies of both sexes was contributed in this study. The ponies were premedicated with Xylazine (2 mg/kg). The study was continued in five groups including: Propofol (group1), Acepromazine- Ketamine (group 2), Diazepam-Ketamine (group 3), Midazolam-Ketamine (group 4) and Sodium thiopental 5% (group 5). The drug or combinations were administered 10 minutes after sedation. Heart and respiratory rate, induction time, duration of surgical anesthesia, recovery time and standing time were measured. Considerable sedation without excitement was achieved following premedication. The results revealed presence of significant difference (P≥0.05) in the induction time, and standing time between propofol and other protocols. In comparison to other groups, heart rate significantly increased in group 1. In group 1 and 5 respiratory rate decreased relationship to others. It was found that 2, 3 and 4 groups provided stress- free induction, easily controlled anesthesia, good analgesia and muscle relaxation. According to the results of this study, suitable surgical anesthesia was obtained in Ketamine combinations. It is recommended that Propofol and Sodium thiopental are used for light anesthesia. Considering the results of the present study, these protocols are recommended for field anesthesia in Caspian pony.

This study was conducted to register and introduce the biometric indicators of the Zel sheep on some flock of stockbreeder who were inhabit Mazandaran villages. The live weight, body biometric, milk and its composition, and fleece of 200 ewes and 20 rams was recorded during one year randomly. Based on results of ewe biometric traits, these values were recorded; live weight 33.8±4.78 kg, chest circumference 82.6±7.01 cm, body length 41.4±3.76 cm, body height 63.8±4.69 cm, and tail 24.5±4.02 cm. the values of milk daily quantity, fat, protein, and lactose were 700±170.3, 4.3±1.56, 4.9±0.59, and 4.7±0.49 respectively. The recorded traits of ewe fleece weight, staple, diameter and efficiency were; 1700±0.30 gr, 10±2.33 cm, 34.7±2.68 mic, and 64.2±5.78 percent. The lambs birth weight, weaning weight, and daily gain weight to weaning for male and female mean, were 2.9 kg, 13.100 kg, and 130 gr respectively. The live weight, chest circumference, body length, body height, and tail length of Rams were 6505 kg, 88, 50.5, 65.4 and 22 cm respectively.

The main purpose of this study is to estimate the relative emphasis on production and reproductive traits of growth and longevity in dairy herds of Pars Animal Husbandry Company. This study was conducted using a bioeconomic model and by determining the economic value and relative importance of each of these traits in the breeding programs of dairy cattle breeding system of Pars Livestock Company in Ardabil province. The first step in the development of breeding goals is to determine the economic coefficients for the traits that are considered as breeding goals. The economic value of a trait indicates the contribution of the genetic growth of a trait in improving the economic efficiency of the production system. In order to study the effects of change in input values on the model response, sensitivity test was used. Also, for comparing different attributes, the relative emphasis of each attribute was calculated. The annual profit of each productive cattle in this research was reported to be 5529076.86 9 Rials. Attributes can be divided into several categories in terms of the type of effects on revenues and expenses. A group of traits increase the income and cost of the production unit as well as the profit compared to the baseline (initial amount) by increasing their average. Most of the production traits including milk production, fat production, weight gain after weaning, adult body weight, and survival rate before and after weaning were in this category. However, with an increase of one unit in daily weight gain before weaning, income and expenses have increased compared to the base amount, but the profit has decreased. In the other category were traits whose average increase was both a decrease in income and a decrease in costs, which led to a decrease in profit, which included the traits of production life and the calving interval in this group. The traits of the third group had no effect on income, but as the average increased, the unit costs of production increased, resulting in a decrease in annual profits, which included age at first calving. The fourth category also includes an attribute that has no effect on cost and with the increase of unit income has caused profitability, which is the attribute of milk fat in this category. The results also showed that the highest relative importance or emphasis was related to milk production with a value of 45.01% and the lowest was related to the calving interval of 4.17%.However, in terms of the relative importance of traits in each category, in the group of production traits, milk production and milk fat had the highest relative importance. In the group of survival and survival traits, the priority of survival rate after weaning, survival rate before weaning and production life, as well as in the reproductive group, age at first calving and calving interval were the highest relative importance, respectively. In the group of growth traits, adult body weight, weight gain after weaning and weight gain before weaning, respectively, had the highest relative importance. Sensitivity test results also showed that the effect of fluctuations of production factors on economic values of traits are not the same. and some traits are more stable.

Livestock industry as one of the sub-sectors of agriculture in the world has a significant growth and its entrepreneurship in job creation, value creation, human nutrition, human and community health and in general its irreplaceable role in the economy has always attracted the attention of governments. In our country, despite the protections defined in the laws, this industry is still in a tight spot due to the lack of infrastructure, lack of coherent and sustainable management, superficiality of basic and macro issues and lack of prioritization in planning, and has faced activists with some ambiguity about the future. While with the current investments, capacities and potentials and existing facilities, it is possible to lead the curve to more growth and excellence by reforming the infrastructure, facilities and credit support from the government and culture building. Therefore, proper planning in this area requires strategic and forward-looking decisions. For this purpose, Future Study approach was used to formulate future scenarios for the livestock industry in Khorasan Razavi province and the critical uncertainty method, which is one of the common techniques for extracting key factors, was used. In the next step, DEMATEL method was used to determine the interactions of key indicators. The scenarios of the present study were developed based on two macro-policies of government and climate which are scenario 1, scenario 2, scenario 3 and scenario 4. Finally, Using the Moora method, the most probable scenario, which is scenario 4, was determined, in which both the amount of precipitation is reduced and the government's macro-policies do not move towards optimism and productivity.

This study was conducted to investigat the effect of different levels of addition of lactobacillus plantarum inoculant of common reed silage and also to compare this silage with corn silage in a compeletly randomized design with 8 treatments and 4 replication. Treatments included of common reed silage without inoculation, common reed silage with bacterial inoculation (2.5 mg/kg DM) and other treatments were inoculants silages with addition bacteria in 25, 50, 75 and 100 percent above of commercial amount, respectively and corn silage with or without bacterial inoculation (2.5 and 0 mg/kg DM). Inoculated common reed silage and corn silage were ensiled in laboratory silos (2-L- plastic jars). At the end of ensilage duration and sampeling of silge, laboratory analysis included pH, DM, CP, IVDMD, IVOMD and VFA's of silages were down. Results of this experiment indicated that inoculants of common reed silage with different levels of lactobacillus bacteria had significant effect on pH, ash and In vitro digestibility (p<0.05) but did not influence CP and VFA's (p>0.05). Inoculation of corn silage did not influence pH, CP, In vitro digestibility, propionic acid and butyric acid (p>0.05) but it had significant effect on ash and acetic acid of silages (p<0.05). According to results of experiment and considering studied factors and the inoculation influences on In vitro digestibility, pH and VFA's, it seems that bacterial inoculation of common reed silage with 75 percent above of standard level had the best results and this addition level is recommended.

Heavy metals are dangerous for living organisms and are causing many problems. These metals can enter the food chain in different ways and cause severe illness and sometimes fatal, so it is crucial to monitor the pollution of heavy metals. Among the human various sources of landfills, where the possibility of heavy metals in them are great, and these elements are then absorbed through the food chain, monitoring of these elements is essential in these areas seems. The aim of this study was to investigate the level of toxic metals contamination in landfill Angeli Si of Babol city using bird feathers and leachate. Therefore, to achieve this objective in the study area, a feathers of black kite birds, because food diet and Gathering place, with leachate to measurement heavy metals concentration, were sampled and prepared. The metals concentration was determined using the ICP instrument and Mercury Analyzer AMA 254 for Hg. The results showed that Cd and Hg have the concentration highest (11.5 mg/kg) and lowest (4 mg/kg) respectively in bird feathers. General the pattern of heavy elements distribution in the bird, are the following: Cd> Pb> As> Hg.

To investigating the role of Avibacterium paragalinarum (AP) in the development of Swollen head syndrome (SHS) in commercial and traditional layers in Isfahan province, 23 laying hen farms with signs of head swelling and mortality were sampled from the suborbital sinus. In addition, swabs were prepared from 20 traditional and commercial laying hen farms with respiratory symptoms and SHS. Samples were cultured on specific media for isolation Escherichia coli (E. coli) and AP and approved by biochemical examination. After genome extraction, AP was detected with specific primers. Microbiological results showed that out of 23 samples, 14 samples (60.86%) were infected with AP and 21 samples (91.3%) were infected with E. coli. The results of direct detection of AP in suborbital sinus swabs that prepared from 23 dead laying hens with coryza symptoms showed the amplification of 500 bp fragment in 19 samples of suborbital sinus swabs (82.6%). Also, the rate of infection in live birds was less than the dead hens. It seems that the sampling site can play role in the rate of infection and possibly the occurrence of false negatives. Therefore, due to the high frequency of AP infection in hens with SHS, it seems that a regular and public vaccination program should be applied to control Avibacterium paragalinarum in laying hens.

Respiratory diseases cause significant damage to the poultry industry worldwide. In recent years, infection with Ornithobacterium rhinotracheal bacterium (ORT) has been reported frequently from different parts of the world, including Iran. The aim of current study was to isolate the causative agent and reveal the antibiotic susceptibility to common antibiotics. in Markazi province. In this study, twenty poultry farms reported with respiratory signs clinically were conducted to collect 231 samples including Lung, trachea and infraorbital sinus swaps from sick and dead birds in Markazi province during 2016-2017.The samples were cultured on blood agar medium with 5% sheep blood containing Gentamicin and Polymyxin B and then incubated with 7.5% CO2at 37 °C for 48 to 72 hours. The bacteria identification was carried out using biochemical and PCR tests. The antimicrobial susceptibility of the isolates to 15 common antibiotics which used in poultry farms was determined by Kirby &Bauer method as well. Fifteen ORT isolates out of the 20 farms (75%) were collected using biochemical and PCR methods. The results showed that the isolates were resistant to Enrofloxacin, Erythromycin, Penicillin, Amoxicillin, Colistin and Lincomycin completely(100%). These isolates also were mostly sensitive to Nitrofurantoin. The results of this study indicated that 15 out of 20 examined poultry farms in Markazi province had been infected with the Ornithobacterium rhinotracheale (ORT) and were highly resistant to common antibiotics.

The present experiment was performed to investigate the effects of two sources of DL-methionine and L-methionine on the performance, characteristics of internal organs and blood factors of broilers. A total of 400 one-day-old male broilers of Ross 308 strain were divided into 8 treatments and 5 replications (10 birds per replication) in a completely randomized design. Experimental treatments included 1, 2, 3, 4 (basic diet + 25, 50, 75, 100% DL-methionine) and 5, 6, 7, 8 (basic diet + 25, 50, 75, 100% L-methionine). The results showed that in the L-methionine groups, the improvement in performance was related to 75 and 100%, but in the DL-methionine groups, the improvement was seen only in the amount of 100% (P<0.05). The percentage of internal organs in none of the treatments was significantly different (P>0.05). Differences in different sources and levels of methionine had no significant effect on blood factors in broilers (P>0.05). The results of this experiment showed that 75% of the recommended L-methionine of Ross 308 can have a similar result in terms of performance with 100% of the recommended DL-methionine.

An experiment was conducted to investigate the effect of different levels of alfalfa extract (polysavone), a natural extract of alfalfa, on growth performance, gut characteristics, and some blood parameters in broiler chickens. A total of 200 one-day-old Ross 308 male broiler chicks were assigned to 5 experimental treatments, with 4 replications and 10 birds in each replication with a completely randomized design. The polysavone was used in 4 levels (0, 2, 4, 8, and 12% of feed). The results showed that polysavone had no adverse effects on the average daily gain, average daily feed intake, and European Broiler Index. The addition of polysavone (4, 8, and 12%) to the diet significantly increased relative weight of bursa and spleen but decreased triglycerides concentration in serum (P<0.05). Increasing of dietary polysavone levels (8 and 12%) caused a significantly decrease in abdominal fat (P<0.05). Also, total cholesterol concentration was reduced (P<0.05) in broilers fed on diet with 12% polysavone. Relative weights and lengths of duodenum, jejunum, and ileum, relative weights of thymus, crop, gizzard, and proventriculus, as well as serum glucose concentration were not affected by experimental treatments. The results of this research indicated that polysavone may decrease abdominal fat deposition and enhance immunity without showing an adverse effect on the performance of broiler chicken.

An experiment was conducted to investigate the effect of two inorganic and organic forms of manganese on performance, egg quality and resources of manganese of body`s in older laying hens. 250 Leghorn laying hens (w 36) with 80 weeks of age were divided into 5 treatments and 5 replications in a completely randomized design. Treatments were: control (without manganese supplement), treatments containing 100% manganese sulfate (diet 1), 75% manganese sulfate and 25% organic manganese chelated (diet 2), 50% manganese sulfate and 50% organic chelated (diet 3) 25% sulfate Manganese and 75% organic chelated (diet 4). The results showed that there was a significant increase in feed intake, laying percen, egg weight and egg mass between diets 3 and 4 with control treatment (P <0.05). Also, egg weight in diets 1 and 2 increased significantly compared to basal diet. Feed conversion ratios in diets 3 and 4 showed a significant decrease (P<0.05). No significant difference in egg quality traits was observed between experimental treatments (P>0.05). Tibial manganese increased significantly in diets 2, 3 and 4 compared to basal diet (P<0.05). Yolk and egg shell manganese concentrations increased in diets 1, 3 and 4 compared to basal diet (P<0.05). Experimental treatments significantly increased serum and liver concentrations of manganese (P<0.05). Increased manganese bioavailability could be a reason for more uptake of manganese in the diet, which improved the production performance of older laying hens.

Knowledge of studying energy consumption in production operations is a useful method for determining energy-consuming areas, which are determined by analyzing the amount of energy consumed in production operations. The required information was collected through a questionnaire and face-to-face interviews with broiler breeders in Diwandarreh city. The total input energy was estimated to be 250574.01 MJ for 1000 chickens. Energy indices including energy ratio, energy efficiency and specific energy for poultry farming were 0.11, 0.1 Kg/MJ and 96.48 MJ/Kg, respectively, and the total input energy amounted to 250990.01. In this study, the total production cost of 1000 chickens in Diwandarreh city was about 108.83 million Rials, of which about 102.25 million Rials belonged to the variable cost of production and about 6.58 million Rials belonged to the constant cost. The benefit-to-cost ratio index was also estimated as 1.19. Finally, the total efficiencies for chicken meat and chicken manure were 23.87 and 14.8 kg per million Rials, respectively. The results of input sensitivity analysis showed that the elasticity of chicken inputs, gas fuel, manpower, corn, soybean, minerals, fatty acid, dicalcium phosphate, and disinfection having coefficients of 0.17, 0.35, 0.03, 0.18, 0.2, 0.72, 0.54, and 0.26 were positive and less than one. The amount of MP (final productivity) of these was calculated as 1.3, 0.009, 09.05, 0.07, 0.05, 9.45, 0.35, 0.95, 0.02 and 25.97 respectively.

In the present study, it has been tried to investigate the climate change effect between current and 2050 on three critically endangered lizards in Iran. For this purpose, three species has been selected Phrynocephalus horvathi, Eremias pleskei, Darevskia kopetdaghica that distributed in northwestern and northeastern part of Iran. Ecological niche modeling indicated that current distribution range of all three species is relatively smaller than predicted models, but during 30 years ahead (till 2050) these suitable areas will be decreased about 50% for E. pleskei and 30% for Ph. horvathi or more than 50% for D. kopetdaghica. Minimum temperature of coldest month and coldest quarter are the most important factors for this variation. Increasing the global warming for next 30 years (till 2050) will change the temperature in different seasons and this event may have direct effect on the lizards that categorized as cold blood animals. Conservation management and evaluation the protected areas can prevent the extinction of animals in face of climate change effects. However, increasing the public awareness about the importance of biodiversity conservation is essential.

The role of aquatic animals in human nutrition has been considered with the increasing population of the world, and it is necessary to pay attention to increasing its shelf life and changing its taste. In this project, by adding garlic, grape and tomato extracts to coated fish fillets, in order to change the taste of fish, a comparison is made to increase the shelf life in the freezer through the chemical index of total volatile bases on the base of titration, Trimethyl amine, Tiobarbitoric acid were evaluated with Spectrophotometer and also Sensory evaluation was performed in terms of smell, appearance and taste. First, the fish was filleted and washed, then the fish coating mixture was prepared by increasing the extract of garlic, tomato and garlic by 6% of weight to wheat flour, salt and sodium carbonate, and a sample was prepared as a control without extract. Then the prepared mixture was mixed with water in a ratio of 1: 1.5. The fish was immersed in this mixture and remained in this mixture for 5 minutes, then it was kept in the freezer to check the shelf life at -18 ° C and the quality changes during 6 months were examined. The amount of volatile bases respectively in the samples containing garlic, grapes and tomatoes, 21.52, 23.73, 26.5 were lower compared to the control 35.73. Trimethylamine respectively 1.114, 1.165, 1.424 compared to the control 2.508, they had lower values. Thiobarbiotric acid also respectively 0.55, 0.37 and 0.8 were close to or less than the control value.So the shelf life of the products were in garlic, grape and tomato respectively. In sensory evaluation, the highest points for taste, smell and appearance were related to garlic, tomato and grape, respectively, and this process continued during 6 months of storage in the freezer.

This study aimed to investigate the effect of replacing a commercial feed with different ratios of earthworm meal (0 (Control), 5, 10, and 15%) on growth parameters and skin pigmentation in Oscar fry. For this purpose, the experiment was performed in a completely randomized design with four treatments and three replicates. One hundred and twenty of Oscar fry with an initial average weight of 4.32±0.35g were dispersed into 12 aquaria. The stocking density was 10 fingerlings per aquarium. After 8 weeks, three fish from each treatment were randomly selected to measure the studied characteristics. The highest final weight (18.31±0.49 g), specific growth rate (2.51±0.11 %/day), survival rate (100 %), and the best food conversion ratio FCR (1.74±0.14) were observed in the fish fed with 5% earthworm meal compared to others (p<0.05). Total carotenoid at all treatments was significantly higher than the control group (p<0.05). The mean level of a* and b* factors in treatments replacing with 5 and 10% of earthworm meal was significantly higher than the control group (p<0.05); While, L* factors in mentioned levels (5 and 10%) was significantly lower than the control group (p<0.05). In conclusion, the results of this study showed that replacing the commercial feed with earthworm meal at 5% had positive effects on growth parameters and skin pigmentation factors in Oscar fry.

This study conducted to analyses time series data of stingrays catch per unit effort (CPUE (kg/day) data from 2007 to 2018 from fishing grounds of the Persian Gulf and the Oman Gulf. Data from sea surface temperature, chlorophyll a, evaporation, wind speed, rainfall and air temperature were also considered in the analysis. In order to investigate ecological status, regression models, neural networks and decision tree used to analyses data. According to the results, biomass of the stingrays stock showed different status in various parts of the water body and results revealed that stingrays stock significantly related with wind speed and sea surface water in Khuzestan waters, chlorophyll a in Bushehr waters, air temperature in Hormozgan waters and sea surface temperature in Sistan and Balouchestan waters. Technically, temperature was the constant significant coefficient in all parts of the study area. To sum up, effect of climate change on stingray’s biomass was sensible according to the results of this study and was vary between study sites.

The present study was designed to investigate the interaction effect of acute and subacute ammonia toxication in different salinity levels (0, 4, 8 and 12 g/l) on some hematological factors and oxidative enzymes in Nile tilapia (Oreochromis niloticus). To investigate the interactions, 360 fish (57.32±16.7 g) were randomly divided into 12 treatment groups (each with three replicates). At the end of the experiment (96 hour), hemoglobin, hematocrit, red blood cell count, catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) were measured. According to the results, LC50- 96 hours of NH3 was 0.86 mg/l. The results showed that hematocrit, hemoglobin, glutathione, superoxide dismutase and catalase decreased in treatment of acute ammonia poisoning and 0 salinity and treatment of subacute poisoning and 0 salinity compared to treatment 1 (control) (P<0.05). The results showed that increasing salinity levels in treatments improved catalase and superoxide dismutase levels. In general, the results indicate that ammonia poisoning maybe by producing free radicals has weakened the antioxidant system of fish. Also ammonia toxicity effects were decreased with increasing water salinity, which reduced oxidative stress enzymes.

Sterlet is one of the most valuable species of sturgeon that its population has declined in recent years. The bioball acts as a biological filter, which is a site for bacteria that can remove ammonia. This study was done for evaluation the effect of bioballs on physical and chemical parameters of water, growth performance, survival percentage and improvement of hemological and immunological factors and stress reduction of Sterlet in Dr. Keyvan Fisheries and Marine Technology Research Center of Chamkhaleh during 8 weeks. For this purpose, 150 Sterlet with initial weight of 120 gr were distributed in 15 fiberglass tanks that their capacity was 500 liters. 4 treatments including treatment 1 opened with bioball system, treatment 2 opened without bioball system, treatment 3 closed with bioball system and treatment 4 closed without bioball system were selected in 3 replications. During the experiment, physical and chemical parameters of water, hemological and immunological parameters, stress and growth performance were measured. Among growth indices, there was an increase in FCR, SGR, BWI and %BWI in treatments 1 and 3, which was significantly different from control treatments (P<0.05). Also, treatment 1 in terms of hemological factors, and treatments 1 and 3 in terms of immunological and stress indices were better. There was the lowest number of white blood cells and neutrophils and the highest number of red blood cells, hematocrit and MCV in treatment 1. The highest amount of total immunoglobulin and the lowest values of cortisol, lactate and glucose were observed in treatments 1 and 3. These results had significant difference with control treatments (P<0.05). Treatment 1 had better values than other treatments in terms of physical and chemical factors and pH, NO3, NH3, NH4 and TAN values were significantly different (P<0.05). In addition, treatment 3 had the highest bacterial count compared to other treatments (P<0.05). Therefore, treatments 1 and 3 can be selected as the best treatment based on their performance. Because they improved the conditions and increased the efficiency of system. Their existence improves living conditions, even if they are not directly used by aquatic animals.

In this study the antiparasatic effect of three herbal extract Lawsonia inermis, Satureja khuzestanica and Citrullus colocynthis on  Ichthyophthirius multifiliis were investigated. Firstly, the hydro alcoholic extract of plants was prepared according to maceration method. Then theront and tomont stages of parasite isolated from heavily infected rainbow trout and were exposed to serial increasing two-fold dilution of each extract. Immobilized (dead) parasites were recorded every 4 hours for 12 hours in each dilution and 12 h LD50 of each extract calculated using probite method. Malachite green used as positive control. Results showed that 12h LD50 of L. inermis, S. khuzestanica and C. colocynthis and Malachite on parasite tomont were 4.68, 2.32, 5.21 and 0.24 mg/l respectively; meanwhile 12 h LD50 of mentioned extract on theront were 0.57, 0.45, 2.37 and 0.121 respectively. According to results it can be concluded that Although L. inermis, and S. khuzestanica showed mild anti parasitic effects against Ichthyophthirious; these effect was insignificant compare to therapeutics such as malachite green. These extracts can be used as a complementary treatment along with chemical treatment.

Sturgeon is one of the most valuable aquatic species in the world and is of great commercial and economic importance. Monogenean trematode Diclybothrium armatum is one of the parasites which is specific to its host and after invading the host, causes symptoms such as respiratory system disorders, multiple gill injuries, decreased mobility, surface swimming, swallowing air bubbles near the water surface, and persistent losses occur in Siberian sturgeon. The aim of the present study was to investigate the causes of losses in Siberian sturgeon farms of sturgeon farms in Qom and Mazandaran provinces. In this study, 20 Siberian sturgeons with a size of 80 to 90 cm during the months of May and September 2016 from sturgeon farms were referred to the aquatic animal clinic of the faculty of veterinary medicine, university of Tehran and in terms of characteristics and appearance, were examined and monitored. In the initial macroscopic examinations, a number of parasites were visible in the gills of Siberian sturgeon with the naked eye, but there was no sign of the presence of parasitic pathogens in the gills of starry sturgeon and beluga fish. Then, in order to better investigate the parasitic infections, a wet smear was prepared from the gill tissue of fish and carefully examined under a light microscope. Based on the available diagnostic keys, the presence of Diclybothrium armatum monogenic parasites in the gills of Siberian sturgeon was confirmed. In order to treat the infected fish, a salt bath (to increase the salinity of water) was prescribed at a rate of 20 g / l for 7 days (1 hour daily).

The present study was conducted in six stations in the eastern coasts of Sistan and Baluchestan province by underwater counting method in two seasons (the per monsoon and the Post monsoon) and depths less than 5 meters and depths of 5 to 10 meters, in the period of 2019. During different sampling stages, 201 Holothuria leucospilota (Brandt, 1835) sea cucumbers were caught by a diver in the sampling area, and total length and total weight data were measured and recorded. Range of the total length was between 6-43 cm and the average 23±6 cm and the total weight was between 228-788 g and the average 284±164 g. Length-weight relationship of total H. leucospilota species were W= 18.09 L ^ 1.73 (R2 = 0.72, N = 201) and the value of b Length-weight relationship indicating their allometric growth. The sea cucumbers total density was significantly between different stations (P<0.05). The population density of black sea cucumber species at the per monsoon and the post monsoon seasons were not significant (P>0.05). In this study, the estimated density of H. leucospilota populations below 10 meters in the east of Sistan and Baluchestan province has changed from 142 to 120 per hectare and it seems that the population of sea cucumber in the eastern part of the province can be exploited.

The decrease of energy resources in the world and the increase of its demand has led Human to extract oil and gas even in the depths of the seas; Therefore, paying attention to environmental management of energy consumption is an undeniable necessity. The study area is the South Pars gas field, which is located on the joint border line between Iran and Qatar. The first step in implementing risk management is to identify the risk. The present study used the results of risk assessments of previous years, HAZOP reports and through interviews with some experts in the field of oil and gas extraction from the sea. Contaminants were extracted and the required information for each agent, including the probability of risk occurrence, the severity of the risk effect and the degree of risk control were determined. Then a risk map was prepared and finally the risk rating was done. The results showed that 6 factors have the highest intensity of risk impact, which are also in the group of risks with an emergency nature. These factors include Low Pressure Flaring, Operation of wells, Operation of the platform, Supply and transmission, Crane activity on the platform and Helicopter activity on the platform. In the results of the present study, it was found that Low Pressure Flaring has the highest intensity of risk impact, which is also one of the emergency risks. The Flaring process can produce sulfur compounds that will have detrimental effects on human health, the environment and air quality.

This research was carried out based on ecological monitoring of the Caspian Sea in depth of 30 meters project during 2018-2019. Sampling from the bed sediments of the southern Caspian Sea in 8 transects including Astara, Anzali, Sefidrood, Tonekabon, Nowshahr, Babolsar, Amirabad and Turkmen was done by a cat sampler. Sampling was done seasonally. The aim of this study was to investigate the species diversity, density and biomass and local distribution of different macrobenthos species. A total of 16 species were identified, belonging to 7 families which of Polychaeta, Crustacea and Bivalvia were found. In addition, Oligochaeta have been identified. The polychaeta comprised 59% of the total macrobenthos density. In contrast, Cerastoderma glaucum, although the frequency was 6.3% of the total density of macrobenthos, but comprised 59.9% of the total biomass. The results showed that the diversity indices had the highest value in spring and the lowest in summer. Polychaeta had the highest local distribution (100%) and Malacostraca Pterocuma sowinskyi and Cardiophila baeri had the lowest (8.2%). The lowest and highest mean (±SE) densities were recorded in winter and spring with 408±81.1 ind.m-2 and 1225±246.2 ind.m-2, respectively. In conclusion, the increase in biomass of bivalve molluscs versus the decrease in density can be due to the large size and having oyster shell and the increase in diversity indices in spring can be due to the presence of different species for reproduction after wintering period which is consistent with the density of macrobenthos in the spring.

Biotic indexes are an effective tool for measuring the water quality of rivers and lakes. In this study, the effect of fish pond effluent on water quality and validation of three common biotic indexes EPT, BMWP, and HFBI in Baliqlu river of Ardabil province was investigated. A sampling of invertebrates communities was done seasonally from the summer of 2018 for one year with the help of a Sorber sampling device with dimensions of (40 * 40 cm) and in three replications.10582 samples from 10 orders and 14 families were identified. The highest frequency was related to the order of Ephemeroptera and then Diptera, which belonged to the Baetidae and then Chironomidae family, respectively. Shannon-Wiener (H)(1.20) diversity, uniformity (exp(H)/S)(0.83), Simpson (1-D)(0.66), and dominance (D)(0.33) indices were used to study the diversity of macro-invertebrate communities. The results of determining the correlation of environmental parameters with the distribution of macrobenthos and environmental factors with each other by Detrended Correspondence Analysis (DCA) in PAST software (version 3.25) showed that the environmental parameters of nitrate and phosphate were positively correlated with Chironomidae and Tipulidae families. Based on the Helsinhoff(HFBI) biotic index, the water quality of the Baliqlu River in the third station with severe pollution (HFBI = 8.24), based on the EPT, water quality in the third station is poor (EPT = 9.5) and the BMWP biotic index reflects poor results. The water quality of Baliqlu River in all stations was in a poor quality class. The validation results of the three indicators used, showing that the BMWP, unlike other indicators, has a relatively poorer performance in the Baliqlu River and in the quality assessments of our country's rivers, it is better to use a combination of several biological indicators.

This study was aimed to investigate whether bee colonies can use the starch and how the Protexin can influence the feed consumption, hive population and mortality at farm and cage conditions. For this purpose, 36 hives were randomly allocated into six different groups and fed with one of the experimental treatments as the first experiment. The control group have only received sugar syrup, the 2nd group received sugar syrup supplemented with one g/L of Protexin (P), the 3rd group received sugar syrup supplemented with 10% of the starch (S10), the 4th group fed with sugar syrup supplemented with 20% of the starch (S20), the 5th group received sugar syrup supplemented with 10% starch and 1g/L of the Protoxin (S10P) and the 6th group fed with sugar syrup supplemented with 20% of starch and 1g/L of the Protoxin (S20P). In the second experiment, the newly emerged bees were kept in a cage and incubated for 21 days. After hatching they were also fed with the above-mentioned experimental treatments. At the end of both experiments, feed intake hive adult and larvae population were evaluated before and after overwintering. In the 2nd experiment the consumption of sugar syrup, sugar paste and the rate of bee losses during the cage storage period. The results of 1st experiment showed that the group S20P1 has the higher egg production and feed intake when compared to the other groups (P≤0.05). Moreover, the feed intake of S20P and S10P was statistically higher than S20 and S10 respectively (P≤0.05). The sugar consumption of S10P and S20P was statistically higher than control (P≤0.05) but have not significant differences with other the groups (P≥0.05). Cumulative consumption of sugar syrup was higher in S10P and S20P groups than the control group (P≤0.05). Honey bee losses in the third week and cumulative mortality (total losses in the first to third weeks) were the lowest in the S20P group compared to S20 group (P≤0.05). It is concluded that, the use of Protexin improves feed intake and reduces bee mortality.

The study of Queen and male ants (Hymenoptera: Formicidae) in Iran is very limited and scattered in comparison with the ants of the world. The present study has investigated the stations in eastern part of Isfahan Province during three seasons of spring, summer and autumn of 1398 in order to confirm the presence and nativeness of the species in Iran. So far a comprehensive study on winged ants has not been conducted in Iran. In the present study, a total of  15 Queen and 6 male ants from 18 species have been collected and detected by manual and traping methods. Except for the queen of Tapinoma karavaievi, the winged ants of other species were identified for the first time from Iran. All the species have been identified using valid keys and were introduced as native species of Iran. The identified species are:Camponotus adenensis, Cataglyphis bicolor, Cataglyphis foreli, Cataglyphis niger, Cataglyphis nodus, Formica clara, Plagiolepis pygmaea, Lepisiota dolabella, Crematogaster (Cr.)n.sp., Messor ebeninus, Pheidole cicatricosa, Pheidole fervens, Pheidole pallidula, Tetramorium caespitum, Tetramorium chefketi, Tetramorium impurum, Tapinoma karavaievi, Tapinoma simroti.

Crabs family Macrophthalmidae play the importanat ecological role in food web of mangroves. In this study, using MaxEnt modeling technique, recent and future distributions of the crab M. sulcatus were modelled. The records on species distribution were obtained from the open-access databases, literatures and collections of museums. Depth and sea surface temperature (SST) were the most important drivers of distribution of mangrove crab. In present model, the most suitable environments were depths of less than 32.34 m, mean SST 27.82°C, salinity 40.11-44.02 (ppm), current velocity of 0.04m-1, and in future models, coastal area with depth less 44.33 m, SST between 28.86°C, salinity 38.77 (ppm), and current velocity between 0.01m-1. Future models showed that distribution of species will be contracted in response to climate change and it will be observed the expanding the low suitable environments from 23.52 to 27.27 percent and the decresing median suitable environments from 38.23 to 33.33 percent in future. In summary, the outputs of MaxEnt model present the vulnerability of mangrove crabs to climate change in future, in regards to the contraction of future distribtion and how they may response to change in climatic conditions through the contraction their distribution .

Some reproductive characteristics of the non native oriental river prawn Macrobrachium nipponense were monthly studied in Anzali Wetland. Totally more than 2,500 prawns were caught and examined during this period, with maximum and minimum lengths of 97 and 10.05 mm and weight of 0.02 to 13 g, respectively. The average length of shrimp was 45.7±14.3 mm and the mean weight was 1.4±1.376 g. The sex ratio of females to males was 1.1±0.4 on average, which during the peak spawning months, this ratio is more inclined to females. Examining some of the reproductive factors of 244 ovigerous females within the length of 38 to 92.7 mm with an average length of 56.8±8.2 mm showed that the most frequent length and weight classes were 50 to 60 mm in length and 2 to 3 grams in weight, respectively. The minimum oviposition length was 38 mm. Total fecundity was observed 75 to 4146 oval eggs with short diameter 0.35 to 0.8 mm and long diameter 0.5 to 1.0 millimeters. The number of eggs hatched by shrimp was linearly correlated with total length and weight of shrimp. Reproductive efficiency ranged from 0.01 to 0.19. Although its fecundity is lower than other economical species of Macrobrachium, other characteristics such as reasonable reproductive output and long reproduction period can make them suitable option in aquaculture.

This study aimed to investigate the status of Pirenella cingulata in the coastal areas of mangrove forests in the Hara Biosphere Reserve in the Persian Gulf. Seasonal sampling was conducted from winter of 2019 to autumn of 2019 using a metal quadrat with dimensions of 25x25 cm in three areas on Qeshm Island and two areas in Bandar Khamir in the low tide. At each sampling station, Environmental parameters including (temperature, salinity, dissolved oxygen and pH), the total organic matter and sediment grain size were also measured. Environmental parameters showed significant differences between seasons. While no significant difference was between different sampling areas. In contrast, sediment grain size differed only between different regions. The total organic matter showed a significant difference between seasons and the sampling areas, Abundance and biomass (wet- weight) of P. cingulata did not show significant differences between different regions and seasons. However, the lowest abundance and biomass were recorded in autumn and the highest abundance and biomass were recorded in spring and winter, respectively. According to the Kendall correlation coefficient, there was no correlation between the abundance and biomass of this species with other environmental parameters, which indicates that seasonal and regional changes do not affect this species. Given that this species is one of the most abundant gastropods in mangrove forests, the results of the present study help to better understand the status of this species and its effects on mangrove ecosystems.

This study aimed to measure the concentrations of lead and cadmium in the muscle tissue of Solen dactylus oyster in Tiab and Sirik areas located in Hormozgan province. To conduct this research, in the summer of 2018, 30 Solen dactylus oysters were collected from each of the mentioned areas and then bioassay operations were performed in the laboratory. Atomic absorption spectrophotometry was used to measure the concentration of lead and cadmium. Atomic absorption spectrophotometry was used to measure the concentration of lead and cadmium. The recorded results for the mean concentrations of lead and cadmium showed that there is a significant difference between Tiab and Siric stations (p≤0.05), And the highest mean concentrations of lead and cadmium were observed in oyster muscle tissue of knife handle, lead (0.761±0.065) and cadmium (0.506 ± 0.75) in the samples of Tiab station, respectively. The results show that factors such as the habitat of Solen dactylus affect the accumulation of heavy metals lead and cadmium, so that Tiab station shows higher pollution than Sirik station. On the other hand, the amount of these heavy metals in the oyster tissue of the knife handle at Tiab station is higher than the standard of the World Health Organization (WHO) and also in the Sirik region, the concentration of lead is lower and the concentration of cadmium is higher than the WHO. It turns out that the consumption of knife oysters both as shrimp food and by humans should be accompanied by health considerations.

Snails are a subcategory of Gastropods and are important pests of orchards and fields that cause a lot of damage to farmers annually. The aim of this study was to identify the types of farm and garden snails in the west of Gilan province and to investigate the distribution of their species. Snails were sampled from 32 stations in 8 areas of western Gilan province. Snails were identified based on morphometric characteristics using valid identification keys by stereomicroscope. Based on the results obtained in this study, from a total of 1161 snails were collected from 13 species from five families, 6 species of terrestrial snails including Caucasotachea atrolabiata, Xeropicta derbentina, Helicella candeharica, Helicella krynickii in Family Helicidae, Goniodiscus rotundatus in Family Discidae, Pomatias rivular in Family Pomatidae, and 7 species aquatic snails including Planorbis planorbis, Planorbis intermixtus,  Planorbis carinatus in Family Planorbidae, Pseudonapeus latilabris, Subzebrinus sp., Luchuena sp., Jaminia isseliana in Family Enidae were identified. C. atrolabiata was reported with the highest frequency (60%), This species causes a lot of damage to citrus trees in the north of the country. In the diverse vegetation of Gilan province, due to suitable climatic conditions, valuable animal reserves are found, among which the number and variety of different species of snails is significant.

Among the most frequently found groups of mollusks are freshwater gastropods that play a substantial role in the health of aquatic and terrestrial ecosystems and also in the health of human communities because they are the intermediate hosts of some parasites such as trematodes and nematodes. Consequently, it is very important to know their morphology and study their ecology, which the present research addresses. For this purpose, specimens of freshwater gastropods were taken from 52 stations in East Azerbaijan, Ardabil and West Azerbaijan Provinces during 2015-2020. They were mostly collected by hand and, if possible, transferred to the laboratory after photographing them and recording their habitat characteristics together with their sympatric species that were found. To identify the species more accurately, shell characteristics and reproductive organs were studied. Among the 288 studied specimens, 11 species belonging to nine genera and six families were observed, and 55 % of the species (six spp.) were reported for the first time from this region. The greatest species diversity was found in the Radix genus of the Lymnaeidrae family. The dominant species found in most of the studied stations were Radix bactriana (٪26), Physella acuta (٪19) and Stenochlaena palustris (٪12.8).

The growing demand for medicinal leeches around the world has increased the need for new leech resources. In order to determine the appropriate blood for sexual intercourse and the amount of cocoon production in oriental leech. For this purpose, 120 leeches with an average age of one week and an average weight of 0.1±0.04 in 2 treatments (feeding on goat and sheep blood) and each treatment with 3 repetitions were divided into 10-liter containers. To feed the leeches, the blood needed from the slaughterhouse was prepared and to prevent blood clotting, a blood vessel was taken and added to the blood of sodium heparin. To feed the leeches, the blood reached a temperature of 37 to 38 °c. For the first 48 hours after feeding to prevent loss and control of ammonia, container water was changed twice a day at a rate of 70%. Re-feeding was performed one month after the previous feeding and in 6 steps. In order to find out the sexuality of leeches, at the end of stages 5 and 6 of feeding, two leeches were randomly selected and described from each treatment. The results showed that the number of cocoons and larvae in goat-fed blood was significantly higher than in sheep-fed blood (p<0.05). The survival of goat-fed leeches was higher than that of sheep-fed blood, but there was no statistically significant difference. The results of this study indicate that leeches feed effectively on goat's blood.

Asteroidae, or starfish, have about 1900 extant species as one of the classes of phylum Echinodermata. Thirty specimens of starfishes were collected from the northern islands of the Persian Gulf for morphological identification, molecular analysis and phylogeny. The first starfish samples were distinguished morphologically then they were identified after DNA extraction by CTAB and Chelex 5% and its amplification based on 16S rRNA gene in molecular analysis. The phylogenetic relationships of asteroids were analyzed using maximum likelihood, maximum parsimony and Bayesian methods. The morphological and molecular identifications displayed 6 species of Luidia hardwicki, Astropecten indicus, Aquilonastra watersi, Aquilonastra iranica, Linckia laevigata and Pentaceraster mammillatus belonging to 5 genera and 2 families. Our results showed Luidia hardwicki and Astropecten indicus species were grouped with sequences of the same species from GenBank in separate clades. As Aquilonastra watersi and Pentaceraster mammillatus in 16S rRNA gene are reported for the first time so their sequences were placed in sister groups with Aquilonastra yairi and Pentaceraster cumingi, respectively. Since the species of Linckia laevigata species (orange-green morph) have been identified based on molecular analysis, this technique along with morphological studies can provide more complete results for Asteroids. The results of Asteroidae classifications at the genus and family levels indicated phylogenetic tree of mt 16S rRNA gene based on Bayesian method is consistent with previous phylogenetic results.

This study was performed to investigate the use of Spirulina platensis enriched with iron and zinc during the process of biosorption and its raw sample in the Quebec diet on the amino acid profile and the amount of these two elements in the Quebec muscle. 96 Quebec specimens are classified into eight groups. Treatments containing 0%, 1% and 4% are the result of enriched, raw and control algae that in each treatment tripilcate with 12 birds were applied. To perform the experiment, 2 birds were randomly selected from each treatment and beheading and filling were performed without water. Other indicators of meat and zinc, meat pH, moisture content, meat protein, histometry, colorimetry, Quebec amino acid profile have been studied and measured. The results showed that the amount of iron and zinc in different treatments were significantly different (P˂0.05). The highest amount of iron and zinc was measured in the treatment fed with enriched algae. The amino acids glutamic acid, glycine, serine, lysine, isoleucine and leucine were the highest. There was no significant difference in meat hardness in quail fed with spirulina algae enriched with iron and zinc in 1 and 4% diets. In general, the addition of essential elements of iron and zinc through the process of biosorption of algae in the diet of partridges had beneficial effects on increasing the quality factors of their meat.

Urmia lake is the largest natural habitat of a unique species of Artemia named Artemia urmiana. The lake has about 5000 km2 surface area when full, was recorded as biosphere reservoir by UNESCO in 1975. During last two decades, irregular development of agriculture (80%) and reduced precipitation (20%) have decreased decreased its surface area to about 1661 km2 in November 2018. This had either economical, social, environmental and pathogenic impacts on local people around Urmia lake or on Artemia population structure and its cysts. In this study, the effects of water withdrawal on the lake Artemia population was studied during 26 month period from April 2018 to May 2020. Eight sampling sites were selected in northern and southern parts of the lake. Samplings were performed monthly. Several physicochemical factors were determined such as water temperature, transparency, salinity, water level, Total Dissolved Solids (TDS) and Electric Conductivity (EC). Furthermore, Artemia life stages including Nauplius, meta Nauplius, juvenile and adult densities were determined. Statistical analysis was carried out by PAST software version 3.04. the results showed that reduced water level imposed decreased Artemia biomass and cysts density.

One of the main problems of the Caspian Sea is its biological pollution due to the entry of invasive species and their distribution. The bivalve Mytilaster lineatus is an invasive species that has been able to stabilize its position after entering the Caspian Sea. The objectives of this study were to investigate population dynamics, dispersion, morphometric characteristics, coverage percentage, frequency and longitudinal weight relationship of this species in the coasts of Gilan province. Seven stations along the coastal strip of Gilan province were selected and sampling from rocky, natural, and man-made beaches on a monthly basis during a year (April2019 to March 2020) was carried out by 15 x15 cadres. The results showed that the average annual salinity of water is 9.85 ± 2.97 per thousand, water temperature is 16.44 ±5.01° C, oxygen آب water solution is 9.88±9.75 mg / L have been. The mean and standard deviation of the number of samples in the squares were 324.05 ± 49.86 and the mean weight was 25.65 ± 44.59 and the mean shell length was 11.35± 0.68 mm and there were significant differences between different stations. The principal components test also showed that the salinity and oxygen of the water solution had the highest correlation with the frequency of this species. The maximum longitudinal frequency at 11 mm was also determined. The length-weight relationship of this species had a high correlation (r2=95). Comparison of different longitudinal groups showed that the larvae were more present from July to November and the adult group from April to September and a mixture of the two groups was seen from September to March.This longitudinal pattern indicates the reproduction of this species in summer and early autumn months in the southern Caspian basin.