Iranian Journal of Fisheries Sciences
Volume:23 Issue: 1, Jan 2024

The assemblage structure of bottom associated fishes across the northern coast of the Persian Gulf has received little attention. The present study was conducted in the waters more than 10 m. of northeast coasts of the Persian Gulf. The autumn data of a bottom trawl survey targeting demersal fishes were used to describe the assemblage structures and their response to environmental variables. A total of 165 and 145 demersal fish species were sampled in 2014 and 2016, respectively. The assemblages were dominated by bony fishes, prevailed by Gilded goatfish (Upeneus doriae), followed by batoid fishes, prevailed by the Arabian banded whipray (Maculabatis randalli), and sharks, prevailed by Whitecheek shark (Carcharhinus dussumieri). The results indicated a reduction in the species richness over the two-year periods in the studied area. The highest species richness was observed at depths of 20 to 30 meters, with a downward trend to shallower and deeper waters. The BEST routine showed that temperature, EC, salinity and pH best described the distribution pattern of bottom-associated fishes in both years. Additionally, CCA analysis demonstrated three bathymetrical assemblage structures for bottom-associated fishes in the studied area. Among different environmental variables, the depth seems to be a major one distinguishing the communities.

Recently, the use of nanoliposome and coated systems has received much attention due to their unique properties for more effective delivery of antibacterial agents. The phenolic extract was co-encapsulated into nanoliposomes and a polyelectrolyte delivery system was obtained by the sequential deposition of positive chitosan (CH) and negative sodium alginate (AL) onto the surface of anionic nanoliposomes (NLs). Phlorotannin compounds were identified by HPLC and the properties of nanoliposomes were evaluated. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of NLs/extracts against acne-related bacteria were determined. The identified compounds of the extract were phloroglucinol, bieckol, dieckol, phlorofucofuroeckol A, and eckol. The mean particle size, zeta potential, and polydispersity index of NLs were 19.77 nm, -13.3 mV, and 0.212, respectively. NLs efficiency on days 0 and 60, at 4°C, was 91.22 and 67.16%, respectively. Release of NLs at pH 3 was higher than at pH 5 and 7. The MIC and MBC values of NLs, AL-CH-NLs, and CH-NLs against all studied bacteria are lower than the extracts. The MIC and MBC activity of the nanoliposomes and coated nanoliposomes decreased over time. The results suggested that NLs, especially CH-NLs and AL-CH-NLs, can be considered an effective carrier system for phenolic compounds.

The present investigation aimed to study the anatomical characteristics of Virgularia gustaviana (Herklots, 1863) from the Strait of Hormuz in the northwest of the Persian Gulf. In this regard, 25 sea pens, which were identified as V. gustaviana (Herklots, 1863), were collected from the intertidal zone of the Suru and Bandar Abbas coasts (the northeast of the Persian Gulf). The samples were fixed in the alcohol formalin glacial acetic (AFA) fixative for a week and were then studied using a stereomicroscope. According to the results, the body of V. gustavia anatomically consisted of two main parts (rachis and peduncle), both of which originate from a primary polyp. The rachis was the upper part of the body with leaf-like leaves. The peduncle, with a smooth, straightforward structure, was the lower part of the body. The caudal part of the peduncle was bubble-like. A mineralized axis was observed at the center along the body, surrounded by mesenteric septa. Although all sea pens share the same basic anatomical structure, colony shape varies considerably in different species in terms of evolution.

Acute hepatopancreatic necrosis disease (AHPND), caused by Vibrio spp., is a new farmed penaeid shrimp bacterial disease. Several strains of Vibrio parahaemolyticus were identified as the etiological agent of AHPND. Probiotics are low-cost, non-pathogenic, and largely non-toxic source that have antibacterial functions and applications. According to the outbreak of AHPND in the south of Iran, it is necessary to conduct a meta-analysis to determine the effect of the bacterial strains in different studies on AHPND. The present meta-analysis was conducted to summarize the current evidence on the effects of probiotics on AHPND under laboratory conditions. The objectives of this meta-analysis were to quantitatively review the responses of shrimp to probiotic interventions to determine the effect of different treatment on reducing mortality during the outbreak of AHPND and evaluating the specific growth rate (SGR) and feed conversion ratio (FCR). According to the results, probiotic administration via water & feed and, via water more than spray on, or mix to feed, have been affected on survival rate (SR) to prevention of AHPND, and mono-strain probiotics were better than multi-strain probiotic in order to decrease mortality. To study design to evaluate the effects of probiotic on SR, SGR and FCR, longer experiments (60 days) are better, for evaluating the effect of the probiotics, and mono-strain probiotics increased SR more than multi-strain probiotics, after challenge with V. parahaemolyticus. gram positive and spore-forming bacteria showed greater improvement in SGR and FCR, but greater improvement in SR were observed in gram positive and non-spore forming bacteria.

This study was aimed to evaluate the single and combined effects of sodium diformate as an acidifier and bacilli probiotics (Bacillus subtilis and B. licheniformis) on some immunological, oxidative stress and biochemical responses in juvenile Salmo trutta caspius for 60 days. Hundred juvenile fish weighing 12.6±1.4 g was divided into 4 different treatments, including control, 0.4 g B. subtilis+B. licheniformis /kg diet, 0.5 g sodium diformate/kg diet and their combination (0.4 g B. subtilis + B. licheniformis+0.5 g sodium diformate/kg diet). Blood samples (9 fish/treatment) were withdrawn at two different time intervals (days 30 and 60). Results showed that bacilli probiotics treatment led to significant increases in the serum lysozyme and complement activities (ACH50) at days 30 and 60, and sodium diformate only increased this parameter at day 30 as compared with the control one. The ACH50 indicated a significant decrease following sodium diformate treatment at the same time. Serum bactericidal activity was declined following either acidifier or probiotic treatment. Serum catalase activity was elevated in all treatments, either significant or insignificant as compared with control. Serum malondialdehyde (MDA) was not changed significantly during 30 days of the experiment. On the contrary, bacilli probiotics and sodium diformate led to increase and decrease in MDA, respectively. Our data suggest that sodium diformate applied here was much more successful in improving the fish health status rather than bacilli probiotics. Combined treatment revealed a mid-level of responses except for ACH50, in which a higher level was observed.

The aim of this investigation is to evaluate the effects of Artemia urmiana metanauplii enriched with a premix extract of brown macroalgae including Padina australis, Sargassum ilicifolium, and Stoechospermum marginatum (macroalgae premix extract; MPE) on growth performance, survival, carcass quality traits, and antioxidant properties of Litopenaeus vannamei (PL15). A total of 1200 PL1(19±0.97 mg) were randomly divided into 4 groups (100 individuals in each group (in triplicate)). The control group was fed only with non-enriched metanauplii (MPE0) and other groups were fed with metanauplii enriched with 200 (MPE200), 400 (MPE400), and 600 (MPE600) mg L-1 for 15 days. Our findings revealed that the highest specific growth ratio (SGR), percentage weight gain (WG), protein efficiency ratio (PER) and dry matter were recorded in the group fed with MPE600-enriched metanauplii. The feed conversion ratio (FCR) in the group fed with MPE600 was less than in other experimental treatments (p<0.05). The highest levels of polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid(ARA), total sterols, and total amino acid content were observed in the shrimp fed with metanauplii enriched with MPE600 (p<0.05). The phenol, flavonoid, superoxide dismutase (SOD), and catalase (CAT) contents were increased by increasing levels of MPE in themetanauplii diet (p<0.05). This study demonstrates the positive effect of metanauplii enrichment with 600 mg L-1MPE on growth performance, carcass quality, and antioxidant properties of L.vannamei.

The high volume of plastic waste, especially microplastics (MPs), has caused a global concern in the last decades. The present study aims to investigate the presence of MPs in two zooplankton groups in the southwest of the Caspian Sea due to the importance of zooplankton populations in the bottom levels of the marine food pyramid and the probability of their transfer to the human food chain. The samples were collected from four stations over one year (2020-2021) using 100 μm plankton nets. After separation and assessment of MP particles, fragments and fibers were the predominant forms of MPs. Analysis of 5123 Acartia tonsa and 1528 Pleopis polyphemoides, resulted in 38 (22 fragments and 16 fibers) and 28 (15 fragments and 11 fibers) MPs, respectively, and 42 MPs (24 fragments and 17 fibers) in the seawater. The average size of the ingested pieces in the zooplankton communities was in the range of 35-46.5 μm and 56.25 μm in the seawater in four stations. The most commonly observed colors in A. tonsa were orange and white, and black in P. polyphemoides and seawater. The samples were also inspected using FTIR-ATR method and confirmed the presence of polymeric compounds and the probable types of polyester, polyethylene, and polyethylene terephthalate in the zooplankton and seawater samples at all stations. Since seafood is an important source of nutrients in coastal areas, the polymers present in the zooplankton's bodies can transfer to higher trophic levels, including humans.

The pickhandle barracuda, Sphyraena jello Cuvier, 1829, is the most common species of Barracuda in Oman Waters but its basic biological information is still absent, hence this study was conducted. A total of 662 individuals were sampled in the Dhofar region along the southwest coast of Oman in the Arabian Sea from June 2021 to May 2022. The length-weight relationship for combined sexes was W=0.0151 TL2.7221. The average monthly values of the gonado-somatic index and the percentage of different maturity stages of gonads for males and females indicated that S. jello spawns throughout the year, with spawning peaking from June to August. The length at first maturity was estimated at 71.9 cm TL for males and 74.0 cm TL for females and the age at first maturity was 4.1 and 4.3 years, respectively. The determination of age derived from the sectioned otolith reading revealed that the age of the studied fish varied from one to 24 years with the dominant age of 3 years old. The longevity of S. jello was calculated at 27 years old. The values of growth parameters in von Bertalanffy growth function for combined sexes were estimated as: L∞=161.18 cm, K=0.119 уr-1 and to= -0.88. The present study indicates that S. jello is a long-lived species with slow growth rate, so it is vulnerable to overfishing. Further monitoring studies of S. jello are needed to develop scientifically sound and effective management measures for their fishery.

This paper aims to investigate the biological and cytotoxic characteristics of venoms extracted from Rhopilema nomadica and Chrysaora hysoscella jellyfish collected from the Persian Gulf. The cytotoxic effect of the venoms is surveyed on human fibroblast skin cells (HU02) using the The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Moreover, the protein molecular weight was determined and the toxicity test (LD50) of venoms were explored on BALB/c mice. The R. nomadica venom possessed a higher protein concentration with the lowest molecular weight protein via SDS-PAGE (12.5 %) along with more peaks obtained by HPLC. In addition, the results of both LD50 and MTT are affected by the venom characteristics. Besides, intravenously and intraperitoneally LD50 were 1.26 and 2.35 for C. hysesella and 0.65 IV and 1.6 IP for R. nomadica, respectively, suggesting that R. nomadica venom was more lethal. The results of the MTT assay on Hu02 fibroblast cells for 24 h revealed that R. nomadica had more lethal effects on skin cells compared to C. hysoscella. Escherichia coli, whereas methicillin-resistant Staphylococcus aureus had no antibacterial activities in the presence of both R. nomadica and C. hysoscella venoms. Meanwhile, the venoms had antibacterial effects on Pseudomonas aeruginosa and S. aureus, which were still weak compared to the other reported species. Overall, R. nomadica venom was more lethal in the case of mice and human skin cells and likely with more symptoms in prey. Finally, considering the relatively high viability of different bacteria in diverse dilutions of venom, it seems that victims not only should face dermal injuries and possible scars caused by direct stings but also the presence of venomous protein on the dermal tissue may provide a cultivation medium for different kind of bacteria.

Iran’s marine catches are mostly captured by the small-scale fisheries (SSF) section, which is inherently difficult to manage. Socio-economic data is a key component of a community-based management approach to achieving sustainable SSF. A socio-economic survey was conducted to evaluate the profitability of small-pelagic purse seine fisheries in the northern Persian Gulf from 2020-2021. The study area covered three main fishing grounds of Sardine and Anchovy in the northern Persian Gulf.  Data were collected by random sampling technique, using 104 standard questionnaire forms. The results showed that 104,000 tons of fish were landed by 348 purse seiners in 2020, which supports ~96% of the fisherman’s household income. In total, 3811 fishers were engaged on the pair-boat purse seiners with an average (±SD) age of 32.1±11.6 years. In terms of literacy, ~52% of fishers had secondary and high school education. On average, the number of engaged crew per vessel was 9.7 people, and each crew worked 843 hours per year which is 42% of national FTE. Total variable costs for purse seine fleet were 6.57 million Euro, of which personnel costs 47.5%, energy costs 32.5%, operational costs 7.8%, maintenance costs 7%, commercial costs 5%, and fixed costs 0.2%. The value of total investment (vessels and gears) was estimated at 9.77 million Euros, which is close to the total revenue of 10.46 million Euros in 2020. The purse seine fleet consumed 17.2 million liters fuel in 2020, their energy efficiency was calculated at 0.165 for 1 ton landed fish. This study showed that the purse seine fishery in the northern Persian Gulf, which utilized 0.93 of its capacity, is a livelihood-oriented activity. Therefore, it is recommended that the fisheries management approach is aimed at ensuring sustainable exploitation and employment stability.