علوم زیستی دریا
Sahar Ahmadvand; Solmaz Shirali; Nasrin Sakhaei; Babak Doustshenas
Abstract
The Unionidae family is the most abundant family among freshwater bivalves which belongs to the Unionida order. Considering the nutritional, economic and environmental importance of bivalve molluscs, as well as the lack of information related to freshwater mussels of the Unionida order, especially the ...
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The Unionidae family is the most abundant family among freshwater bivalves which belongs to the Unionida order. Considering the nutritional, economic and environmental importance of bivalve molluscs, as well as the lack of information related to freshwater mussels of the Unionida order, especially the species belonging to the Unionidae family, as well as their global risk and concidering the importance of the ovary and the testis as an important organ of reproduction and survival and since histological studies are the most accurate method in determining the stages of the gonadal cycle, this research was conducted with the aim of investigating the histology of oogenesis and spermatogenesis in Unio tigridis of the Karun River. Sampling was done seasonally. For this purpose, the studied species after catching in every season were transferred to the histological laboratory, then they were biometrically identified using valid identification books and keys. After dissection, small pieces of gonads were separated and after tissue passage, they were examined histologically and histometrically. The results of the histological studies of the gonads showed that this species is often heterosexual. The results of the histological studies of gonads showed that out of 41 oysters in this study, there was only one hermaphrodite, and testicular and ovarian tissue were simultaneously observed in the gonad tissue. The ovary was asynchronous type because, at any time, all types of follicles in different stages of development (oogonia, previtellogenic oocytes, vitellogenic oocytes) were visible in the ovaries. The highest rate of development and maturation of both male and female gonads was observed in spring. It seems that the main breeding time of Unio tigridis species in the Karun River in the study area is in spring.
علوم زیستی دریا
Sanaz Ahmadi Falehi; Ahmad Savari; Nasrin Sakhaei; Faedeh Amini; Babak Doustshenas
Abstract
Planktonic crustaceans are of specific importance in energy transfer due to their location in the middle links of the food chain of aquatic ecosystems. Therefore, they directly affect the abundance and diversity of the higher categories of the food pyramid, especially stocks and fishery resources. In ...
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Planktonic crustaceans are of specific importance in energy transfer due to their location in the middle links of the food chain of aquatic ecosystems. Therefore, they directly affect the abundance and diversity of the higher categories of the food pyramid, especially stocks and fishery resources. In this study, the impact of a tidal cycle on the zooplanktonic Crustacean ecosystem in the estuarine Bahmanshir River (Northwestern Persian Gulf) was studied. Our samples were collected during the spring of 2018 by plankton net with mesh sizes of 100 μm. Samples were taken at 5 stations to have a tidal effect on the abundance of zooplankton, approximately from 8:00 to 18:00 every two hours. In general, 72 species belonging to 28 families related to 3 groups of crustaceans named Cirripedia, Cladocera, and Copeoda were observed. The highest percentage of relative abundance was related to Cladocera with 35%, which was caused by the abundance of Daphnia mendotae. The highest diversity (Shannon index = 2.71 ± 0.04) of copepods was revealed to be caused by the large number of species at station 5 (near the mouth of the Bahmanshir River). Most species among the families belong to the Acartiidae family, which has 10 species of Acartia. The results of PCA analysis showed that among environmental factors, salinity has a direct effect on the total density, density of Harpacticoida and Calanoida, in the first component. The tides appear to significantly affect the density and types of planktonic crustaceans during the mentioned springtime periods. Our results showed relatively strong influence of the tidal cycle on the spatial pattern of Copepod assemblages in the study area. This study may be useful for future biological monitoring and seawater salinity intrusion into rivers in the northwest of the Persian Gulf.
علوم غیرزیستی دریا
Yasaman Gandomi; Ahmad Savari; Babak Doustshenas; Saleh Arekhi
Abstract
The increasing application of remote sensing for mangrove mapping and monitoring is practical for sustainable management of the biological resources. The emergence of several vegetation indices (VIs) has certainly given significant impacts on mangrove and other forest mappings. In this study, four different ...
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The increasing application of remote sensing for mangrove mapping and monitoring is practical for sustainable management of the biological resources. The emergence of several vegetation indices (VIs) has certainly given significant impacts on mangrove and other forest mappings. In this study, four different vegetation indices including Normalized Different Vegetation Index (NDVI), Simple Ratio (SR), Soil Adjusted Vegetation Index (SAVI) and Triangular Vegetation Index (TVI) were compared to discover a suitable vegetation index for identifying mangrove area in Nayband bay, Boushehr, Iran and using landsat imagery with 30-m from 2012. Maximum Likelihood Classifier (MLC) was used to classify Mangrove and NonMangrove area. The results demonstrated that the best accuracy (96.85%) was from combination between 7 landsats spectral bands and some vegetation indices including NDVI and SAVI.
علوم زیستی دریا
Kobra Jalali; Babak Doustshenas; Ahmad Savari; Nasrin Sakhaei
Abstract
The transfer of alien and invasive species through the ballast water of vessels is one of the most important threats to aquatic ecosystems. This study aimed to investigate the ballast water of 10 vessels entering the export port of Majidiyeh Mahshahr in 2018. A sampling of zooplankton from each ...
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The transfer of alien and invasive species through the ballast water of vessels is one of the most important threats to aquatic ecosystems. This study aimed to investigate the ballast water of 10 vessels entering the export port of Majidiyeh Mahshahr in 2018. A sampling of zooplankton from each vessel was performed by filtering 100 litres of ballast water of each vessel using a plankton sampling net with 50 μm mesh with three replications. Simultaneously, environmental factors including dissolved oxygen, acidity, temperature, and salinity were measured with 3 replications in the ballast water of the vessels. The results of a one-way analysis of variance showed that there is a significant difference between the vessels entering the export port of Majidiyeh in terms of the average density of Copepods. The highest average density 3.2×104 ind/m-3 and the number of species (36 species) related to ARGO1 ship from Bandar Abbas and the lowest average density 1×104 and the lowest number of species (24 species) belonged to PRECIGIOUS and GUNISHLI from Fujairah, UAE, respectively. There was a significant positive correlation between the average density of Copepods with temperature and dissolved oxygen. In total, 3 orders, 20 families, 28 genera, and 56 species were identified. All identified species except Oithona davisae have been previously reported from the Persian Gulf. O. davisae species was found only on the CONSTANTINOS ship from the port of Fujairah, UAE. It is native to the coastal waters of East Asia, especially around Japan and China, and has been reported in the Black Sea, the central Mediterranean, and more recently in the Aegean Sea. This research can be important for assessing the potential risk of new invasive species as well as for improving the quantitative and quality management practices of ships' ballast water.
علوم زیستی دریا
Dariush Mohammadi kia; Ahmad Savari; Babk Dostshenas; Hossein Mohammad Asgari
Abstract
Plankton survey in coastal area of Southern Waters Qeshm was carried out in two season cold and warm and four stations (Parke Zeyton Beach, Soza Beach, Shibdraz Beach and Salakh Beach) during 2015 and 2016. In this study phytoplankton species belonging to 4 order Bacillariophyceae (Diatoms),Dinophyceae ...
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Plankton survey in coastal area of Southern Waters Qeshm was carried out in two season cold and warm and four stations (Parke Zeyton Beach, Soza Beach, Shibdraz Beach and Salakh Beach) during 2015 and 2016. In this study phytoplankton species belonging to 4 order Bacillariophyceae (Diatoms),Dinophyceae (Dinofellagelates), Chlorophyceae and Cyanophceae (blue-green algae) were identified. phytoplankton identification was done until genus and 31 ditoms, 11 from dinofllagelates, 6 from Chlorophyceae and 4 genus from cyanophyceae were identified.The mean (± SE) of density, biodiversity indices of Simpson,Pielo Shannon and Margalef were respectively 6705.72±63.9 Cell/L, 0.82±0.34,1.12±0.17 , 1.9±0.19, and 2.61±0.38 in season warm and 5666.13±53.2 Cell/L, 0.77±0.06, 1.12±0.11 , 1.9±0.17 and 2.26±0.43 in season cold.The seasonal similarity based on Sorensen's and Jaccard's coefficients were highest (0.97 and 0.88) for - two season warm and cold. In addition, there were significant correlation between Simpson and Shannon-Weiner diversity with salinity and PO4, and phytoplankton density with salinity and pH. A ccording to the results obtained can be concluded that both the area of ecological conditions in ranks are instead moderate. Also, phytoplankton of diversity and richness is good.
علوم زیستی دریا
Nasrin Sakhaei; Masomeh Sheyamizadeh; Babak Doustshenas; Ahmad Savari; Mohammad bagher Nabavi
Abstract
The purpose of this study was to identify and investigate the density and distribution of copepoda and cladosera and the structural analysis of their dominant species in the Arvand river by SEM (scaning electron microscope). Sampling was conducted with 50 μm mesh size plankton net at 6 stations and ...
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The purpose of this study was to identify and investigate the density and distribution of copepoda and cladosera and the structural analysis of their dominant species in the Arvand river by SEM (scaning electron microscope). Sampling was conducted with 50 μm mesh size plankton net at 6 stations and four times (in different seasons) with three reputation. The samples were detected by phase contrast microscopy and SEM. Totally 15 species of copepoda and 5 species of cladocera were identified in the river. The highest density of planktonic crustaceans including copepoda and cladocera with a mean density of 9481 and 3155 individuals per cubic meter was calculated in summer. These species, Acartia faoensis, Canthocalanus pauper, Subecalanus flemingeri, Labidocera acuta, which accounted for 61% of the total copepods abundance and 54% of the cladosera abundance were related to Moina macrocopa and Daphnia longisoina. The integrity of river were study using saprobic index which showed mesosaprobic-β (medium pollution) with mean 2.48 point.
علوم زیستی دریا
shafa hoveizavi; Babak Doustshenas; Gholamreza Eskandari; Ahmad Savari; Hossein Mohammadasgari
Abstract
The main purpose of this study was to describe and estimate the seasonal pattern of discard fish in the waters of the Persian Gulf coasts in Khuzestan. sampling was carried out Monthly by using fishing boats in the waters of Khuzestan province for one year in fishing areas of Lifeh, Boseif, Khure-mussa ...
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The main purpose of this study was to describe and estimate the seasonal pattern of discard fish in the waters of the Persian Gulf coasts in Khuzestan. sampling was carried out Monthly by using fishing boats in the waters of Khuzestan province for one year in fishing areas of Lifeh, Boseif, Khure-mussa and Bahrakan.Discard fish samples were included 61 species from 37 families, nearly 39 percent commercial and 61 percent of non- commercial species. Rayfish and catfish have been observed in most fishing nets. Average size of most species particularly bony fish were under 15 cm. The amount of discard fish per unit of fishing effort is not significantly different between seasons. The highest portion of the catch belongs to Rayfishes. Total discard fishes of gillnets were estimated 3162 tones. Total weight of commercial fishes with small size in trash fish was estimated 225 tones. The rate and proportion of discard fish in total catch of gillnet was estimated 0.23 and 0.31 respectively. Chondrichthyes with 12 species and 60% of gillnet catch has the highest percentage of discard fish of gillnet. A large number of commercial species with small size such as Otolithes ruber (Schneider, 1801), ( Scomberomorus commerson (Lacepede, 1801) and Scomberoides commersonnianus(Lacepede, 1801) could be due to the role of nursery grounds in Khuzestan coastal waters.
علوم زیستی دریا
Haleh Ali Abedi; Seied Mohammad Bagher Nabavi; Babak Dustshenas; Ahmad Savari; Mohammad Sharif Ranjbar
Abstract
To investigate some bioecological parameters of dolphins between Qeshm and Hengam Islands waters, the present field study was started on November 2014 and finished on may 2015. During this study morphological features of individuals, within dolphin groups, distribution and reproduction of the Indo-Pacific ...
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To investigate some bioecological parameters of dolphins between Qeshm and Hengam Islands waters, the present field study was started on November 2014 and finished on may 2015. During this study morphological features of individuals, within dolphin groups, distribution and reproduction of the Indo-Pacific Bottlenose dolphin (Tursiops aduncus) and their activities at the sea surface were registered using camera systems. At the same time a field questioner form was design to collect the local fisherman informations regarding to dolphins behaviors in the region. During this study one dolphin species namely Tursiops aduncus (Indo-Pacific Bottlenose Dolphin) was identified. The breeding period of Indo-Pacific Bottlenose dolphin was in spring season and a newborns were observed in April 2015. According to field observations, the mean number of Indo-pacific Bottlenose dolphin groups was 23/13±5/49 with 2 newborns in April 2015.Key words: Indo-pacific bottlenose dolphins, Bioecological parameters, Persian Gulf, Qeshm Island, Hengam Island.
masoumeh darabpour dezdarani
Abstract
Abstract: mudflats of the most important coastal habitats of the Persian Gulf to go and base are essential primary production. Variety of animal species to determine the biological and ecological health of an ecosystem of water is important. Class of ostracoda component of hard skin is shelled. To study ...
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Abstract: mudflats of the most important coastal habitats of the Persian Gulf to go and base are essential primary production. Variety of animal species to determine the biological and ecological health of an ecosystem of water is important. Class of ostracoda component of hard skin is shelled. To study the diversity and distribution of this species in the area seven stations were selected Bahrakan tidal beach. Sampling of sediment cores by the core 8/5cm2 from 5 cm surface sediments were performed. Environmental factors such as salinity, temperature, dissolved oxygen and turbidity was measured. Total organic carbon and grain size of total deposits each station respectively. Biological sediments at each station with 10% formalin were fixed, 63 mm sieve, then washed and stained with Rose Bengal and the organisms isolated were tetrachloride carbon. The density of organisms in the winter and summer were 10495 and 3565 individuals in the 10cm2, respectively. Finally, 29 species were identified. Cytheridae family was abundant. The highest value of Shannon’s diversity and brilluin index, Margalef index, Hill and Pielou’s evenness calculated in winter. The highest total organic carbon in winter and summer was 9.59 and 4.61, respectively. Sediment grain size showed that the region made of silt – clay and the highest percent of silt_ clay was in summer.
Nasrin Sakhaei; Ahmad Savari; Babak Dostshenas; Freshteh Saraji
Abstract
This research has been done on larval stage of two species of Epialtidae's Family on coastal waters of Hengam Island (The Persian Gulf) in 2011 . Sampling is done by plankton net with 300 μm mesh size by method of diagonal traction from bottom to surface in 6 station for a year from winter 2011 to ...
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This research has been done on larval stage of two species of Epialtidae's Family on coastal waters of Hengam Island (The Persian Gulf) in 2011 . Sampling is done by plankton net with 300 μm mesh size by method of diagonal traction from bottom to surface in 6 station for a year from winter 2011 to autumn 2012. This research is done based on morphological characteristics, such as overall shape and appendages of larvae in the lab by contrast phase inverted microscope of the first zoea larval stages of species Menaethuis monoceros and second zoea of Menaethiops nodulosus was studied. Larval species density studied at different stations and seasons were calculated. The highest average density respectively with 22/33 and 72/7 individual per m3 in the summer was calculated.
matin khaleghi
Volume 11, Issue 3 , November 2012, , Pages 81-90
Abstract
This research aimed to study the process of long and location changes of sea star(Astropecten hemprichi) and sea urchin(Diadema setosum) in the coast of Chabahar Gulf in the Oman Sea, IR. during November 2008 to September 2009. The area of study was at the farthest end of south east of Iran in province ...
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This research aimed to study the process of long and location changes of sea star(Astropecten hemprichi) and sea urchin(Diadema setosum) in the coast of Chabahar Gulf in the Oman Sea, IR. during November 2008 to September 2009. The area of study was at the farthest end of south east of Iran in province of Sistan and Balouchestan. Sampling was done bimonthly during low tide from 5 stations, using 1m×1m quadrating randomly. 1885 samples of Echinodermata were collected and studied. Results showed that 32 of them(1.6%) belong to A.hemprichi species and 28(1.4%) samples belong to D. setosum species. The samples then were counted and identified. Then the samples’ abundance, distribution and stability were investigated. The results show that the maximum abundance of A. hemprichi was occurred in September 2009 (1/92±0/76ind.m-2) and The maximum value for D. setosum was shown in November 2008 (3ind.m-2). Investigation of distribution and stability indicators may reveal that A. hemprichi and D. setosum were dispersed more randomly and they may be considered as the rare species .