Mehdi Naderi Jolodar, Arefeh Sadat Mirhejazi,
Volume 8, Issue 3 (9-2019)
Abstract
Aims This study was conducted to determine the Exotic fish food strategy of rainbow trout escaped from cultivating cages located in the southern basin of the Caspian sea (Mazandaran).
Materials & Methods A total of 90 specimens of this species were collected during the period from September 2017 to may 2018 from bony fish from west to central coast of Mazandaran. Sample of fish were biomediated and the age was determined by scales and operclum.
Findings The relative frequency of food items were Balanus glandula , Clupeonella cultriventris , Cerastoderma lamarcki, Neogobius fluviatilis، Atherina caspia ،Chelon saliens ، Chinavia hilaris ، Taxiphyllum barbieri ، Rutilus kutum، Cumacea، Syngnathus caspius and Gasterosreus aculeatus respectively. The result showed that a wide range of food was more central than the west, the fullness index in the female was more than male and in age groups older than 2 + and 3 + is more than 1 + (P>0.05). The fullness index, especially in the spring, increased significantly, the presence of B.glandula more than C. cultriventris, but its relative importance was less than C. cultriventris (P> 0.05).
Conclusion This fish has a carnivorous behavior and uses a wide range of foods, so it is possible to compete with many species of Caspian sea fish such as Salmo caspius. The effects of the adaptations and behavioral, physiological and ecological mechanisms of C. cultriventri and B.glandula were more important in fish feeding.
Mehdi Ghodrati Shojaei, Ali Taheri Mirghaed, Melika Mashhadi Farahani, Nastaran Delfan, Maryam Weigt,
Volume 8, Issue 3 (9-2019)
Abstract
Aims: The aim of the current study was to determine the role of Avicennia marina’s primary production as well as other food sources in the diet of Longjaw thryssa, Thryssa setirostris (Broussonet, 1782) in an arid mangrove ecosystem using carbon stable isotopes of carbon (δ13C) and nitrogen (δ15N).
Material & Methods: We collected five potential food sources in the ecosystem including fresh and senescent leaves of Avicennia marina, particulate organic matter, microphytobenthos and sediment organic matter for further stable isotope analysis. Additionally, fishes were collected with a combination of set nets and seines. The muscle tissue (boneless and skinned, 5 g) was removed from the dorsum of fish.
Findings: Significant differences were found between carbon and nitrogen isotopes of different food sources (p < 0.05). Although, this was not significant for green and senescent leaves (p > 0.05). The average values of carbon and nitrogen isotopic ratios of T. setirostris were 15.93‰ and 13.01‰, respectively. The SIMMR model showed that the contribution of senescent and fresh leaves in the diet of T. setirostris was 15% and 10%, respectively.
Conclusion: The result of the current study emphasized a limited role for mangrove detritus in the diet of transient fishes in an arid mangrove ecosystem.
Parima Hajializadeh, Mohsen Safaei, Reza Naderloo, Mehdi Ghodrati Shojaei,
Volume 10, Issue 2 (4-2021)
Abstract
This study was conducted to determine the temporal and spatial distribution of Opusia indica in the Hara Biosphere Reserve in the Persian Gulf. Seasonal sampling (four seasons) was performed from winter 2019 to autumn 2019. Sampling was done in five regions and three habitats within each region using metal quadrats with dimensions of 25 × 25 cm. In each habitat, environmental parameters including temperature, salinity, dissolved oxygen, pH along with organic matter and grain size were measured. The results showed that the abundance and biomass of Opusia indica have decreasing trend with increasing habitat complexity. Seasonally, the highest abundance and biomass were observed in winter and autumn, respectively, and the lowest abundance and biomass were observed in spring. There was a significant difference between habitats and seasons (p <0.05). Salinity showed a significant difference between habitats but didn't have seasonal changes. While temperature didn't show a significant difference between habitats, but it had seasonal changes. There was a significant difference between dissolved oxygen levels and pH between habitats and seasons. Significant changes were observed between habitat and seasons in sediment grain size, while the amount of organic matter showed only differences between habitats. Also, analysis of Kendall correlation between environmental factors (temperature, salinity, dissolved oxygen and pH) with abundance and biomass showed that there was a significant correlation between these environmental factors but no significant correlation was observed between abundance and biomass with the amount of organic matter. The results help to better understand the situation of this species in the mangroves ecosystem.
Behzad Shokouh, Iman Sourinejad, Zahra Ghasemi,
Volume 12, Issue 1 (12-2022)
Abstract
The significance of mangrove species in the world is undeniable and planting artificial mangrove forests is a desirable solution to preserve mangroves. The mangroves provide us with superior ecological services and one of their main services is the bioremediation of heavy metals. Hence, this study aimed to assess the effects of artificial mangroves of Velayat Park of Bandar Abbas on the contamination, adsorption pattern and ecological risk of heavy metals in the sediment samples. Thirty samples were collected from two paralleled sampling sections included those without mangroves and containing mangroves. Each sampling area consisted of upper, middle and lower sections. After drying samples using an oven, the dried sediments were sieved by a 63-micrometer sieve and digested by nitric and hydrochloric acid mixture. The concentration of As, Cu, Fe, Ni, Pb, V, and Zn was determined using ICP. The studied factors suggested a high level of ecological risk for as and Pb and the highest risk was observed in the samples without mangroves and a lower risk was reported for samples containing mangroves. Comparing the results with sediment quality guidelines and other studies indicated a dangerous concentration of As. Pearson correlation coefficient values exhibited that artificial mangroves have significantly affected the adsorption pattern of heavy metals (p-Value < 0.05). The principal component analysis (PCA) showed that As and Pb are dominantly derived from oil products leakages and industrial sewages while Cu, Fe, Ni, V and Zn are predominantly derived from natural and geological sources.
Shiva Aghajari Khazaei, Reza Dehghani, Arash Haghshenas, Gholam Ali Akbarzadeh Chomachaei, Siamak Behzadi, Mohammad Darvishi,
Volume 12, Issue 3 (9-2023)
Abstract
The present study was conducted in order to obtain the necessary information on the diversity, abundance and distribution of macroinvertebrates, as well as to investigate the grazing status of batoid fishes (stingrays) from benthic macroinvertebrtes in coastal waters of Hormozgan province. For this purpose, sampling was done in the years 2017 and 2018 and once every year in the autumn season. At the end of the identification process, a number of 125 genus and 104 species belonging to 85 families, 31 classes, 9 orders, and 7 phyla were successfully identified. Results revealed that Malacostraca was the frequent order in the studied area. In order to investigate the possible relationship between composition and abundance of benthic macroinvertebrte and stingrays, CCA analysis was employed. Results of stomach content of stingrays revealed that in the diet of M. randall, crustacean (93.25 %IRI) has the highest amount. This pattern was the same for M. gerrardi and H. walga. However, in M. gerrardi, bivalvia were in the first place of importance (31.33 %IRI). Also, trophic level analysis was done for three species which shows all species are Mesopredators that place in the same level of food web. According to the mentioned cases, some benthic macroinvertebrates identified in this research have a significant relationship with the benthic fishes, which requires more studies to investigate their relationship.
Sedigh Azizi, Reza Naderloo, Adnan Shahdadi, Mohammad Sharif Ranjbar,
Volume 13, Issue 4 (11-2024)
Abstract
Mudflats are situated at the interface between land and sea, transitioning from submerged during high tide to exposed during low tide. For burrowing animals, especially crabs, mudflats serve not only as nesting sites but also as feeding grounds. This study aimed to examine the morphology and estimate the density, of the crab Leptochryseus kuwaitense using their burrows in the mudflats of Khor-Khoran during the winter 2023. For this purpose, the mudflat above the mangroves was divided into three zones: the upper intertidal (station one), the mid-intertidal (station two), and the lower intertidal (station three) zones. The results of the study showed that the number of burrows was higher in the mid-intertidal zone compared to the other two zones, likely due to higher moisture levels and less human pressure. The diameter of the burrow entrances increased from station one to station three, with a significant difference observed between station one and station three . The morphology and structure of the burrows in the lower intertidal zone were more complex, likely due to competition with other species.
Behzadi Siamak, Ali Salarpouri, Hadi Koohkan, Mohammad Darvishi, Sajjad Pourmozaffar, Freshteh Saraji,
Volume 13, Issue 4 (11-2024)
Abstract
The use of Artificial reefs(A.Rs) are one of the methods used to rehabilitation of fish stocks. This involves studying the grain size composition of bed sediments and Total Dissolved Solids (TDS), which are crucial components in terms of their location. For this purpose, three stations with three repetitions were selected in the eastern and western of Jask City Bay and the study was conducted in the summer and winter seasons of 2023.In the study of total suspended solids, the minimum value with the mean and standard deviation was 25.9±0.46(mg/lit)at the fourth station in the Eastern basin during winter 2023. The maximum value with the mean and deviation was 36.39±0.62( mg/lit )at the third station in the western basin during summer 2023. The analysis of sediment grain size in the stations revealed that the lowest and highest amounts of sand and silt were found in the western basin at 76.4% (third station, summer 2023) and 88.5% (second station, winter2023) respectively. Firstly, the strength of the substrate (grain size) is the most essential factor in establishing structures, which contributes to ecological and biological success. Considering the optimal range of this component stations, suggested as the suitable areas for installation of A.Rs, one area(Western of Jask City Bay) and two area(Eastern of Jask City Bay), respectively.
