Journal of Agricultural and Marine Sciences [JAMS]

3rd Marine Biotechnology Conference: Emerging Opportunities and Future Perspectives

Sergey Dobretsov — Tue, 17 Sep 2024 00:00:00 +0400

The Center of Excellence in Marine Biotechnology, Sultan Qaboos University had successfully organized the “Third GCC Marine Biotechnology Conference: Emerging opportunities and future perspectives”. This conference was held virtually from 8 to 9 December 2021. The main objectives of the conference were to share scientific results between researchers and promote marine biotechnology in the region. In total, 27 oral and 12 poster presentations were delivered during the conference. The conference had 40 participants from different countries. Professor Sergey Dobretsov was served as the chair of the conference. All papers in this volume are perceived.

Ectoparasite Fauna of Imported Ornamental Fishes in Oman

Gilha Yoon — Tue, 17 Sep 2024 00:00:00 +0400

The movement of live aquatic animals crossing international borders is a regular activity for economic, social, and public resource development. A survey was carried out to investigate the prevalence of parasites translocated with imported ornamental fishes. Exotic diseases from imported fish have a potential hazard of biosecurity. A sample of 138 imported ornamental fish originating from Thailand and Sri Lanka were collected from pet shops around Muscat governorate and examined for ectoparasites. Parasitological examination was based on a visual macro and microscopic examination of fish’s exterior. The findings of the current survey of imported ornamental fish revealed that 50.72% of the imported ornamental fish were infected by the one or more of ectoparasites species including Ichthyophthirius multifiliis, Dactylogyrus sp., Gyrodactylus sp., digenean metacercaria and Trichodina sp. Parasitic infection of the gills (55.795) was higher than the skin (42.75%). The most prevalent parasite in skin infection was Gyrodactylus sp. (14.49%) but this was absent from the gills which was dominated by digenean metacercaria (26.08%). The existence of such parasitic organisms could pose a threat to native fish populations and the aquaculture sector. It is recommended that a risk analysis method based on the detection and assessment of fish diseases found in live ornamental fish be established and used. Also, exotic pathogenic parasites, as well as their hosts, must be closely monitored to reduce the likelihood of infections being introduced into new areas.

Bioactive Compounds from Omani Soft Corals Belonging to Genera Sarcophyton and Sinularia

Bait-Maqbool, S.H. & Dobretsov, S — Tue, 17 Sep 2024 00:00:00 +0400

Soft corals are marine invertebrates belonging to the class Anthozoa and are rich in bioactive substances that provide their defense and protection from predators, pathogens, and other unfavorable organisms. Seven soft coral species belonging to the genera Sarcophyton and Sinularia were collected from Omani water and extracted and their antibacterial and antifungal properties were tested using the agar-disk diffusion method and a MicroResp technique. Potential compounds that were present in the species were characterized using GC-MS analysis. The results showed that the soft coral species have anti-bacterial activity against Gram-negative bacteria Pseudomonas putida and Pseudomonas tunicata. The GC-MS analysis found the presence of antibacterial, antifungal, antiviral, anticancer, antioxidant agents, agrochemicals, and medicine chemicals. Three novel compounds were found in a Sarcophyton sp. In addition, the compound Andrographolide found in a Sarcophyton sp. has been recently studied as an antiviral agent against SAR-CoV-2. Moreover, the compound Decosane which is found in Sinularia sp. has been used as an anti-parasitic agent against the female Anopheles mosquito to treat malaria in Pakistan. This study highlighted the importance of Omani soft corals as a source of novel bioactive compounds.

Marine Natural Products with Cytotoxic Properties against Epithelial Ovarian Cancer

I. A.I. A. Burney — Tue, 17 Sep 2024 00:00:00 +0400

Epithelial ovarian cancer (EOC) is a common gynecological cancer and a leading cause of death, especially because the tumors develop resistance to cisplatin. New compounds are needed to achieve better disease control and survival. We examined the cytotoxic effect of Gallic acid (GA), Hymenialdisine, and Malformin A1 (MA1) on human ovarian cancer cells. Cytotoxicity was tested using cisplatin-sensitive (A2780s) and cisplatin-resistant (A2780cp) ovarian cancer cell lines, and a normal ovarian tissue cell line (HOSE6-3) using AlamarBlue assay, Hoechst dye, and flow cytometry, and the genes and proteins of interest were assessed using western blot, and qRT-PCR. The IC50 of Hymenialdisine was 146.8 μM for A2780s cells and >300 μM for A2780cp cell lines. Both GA and MA1 decreased cell viability in a concentration-dependent manner. The IC50 of GA was 103 μM for A2780s cells, 189 μM for A2780cp cells and 262 μM for HOSE6-3 cell lines, for MA1 IC50 was 0.23 μM for A2780s and 0.34 μM for A2780cp. This was in comparison to IC50 of 31.4 μM and 76.9 μM, for A2780s cells, and A2780cp cells respectively for cisplatin. The combination of GA and MA1 with cisplatin revealed synergistic action, especially in A2780cp cell lines. The results suggest that both GA and MA1 may help overcome the resistance to cisplatin through the synergistic effect. Hence, the cytotoxic potential of GA and MA1 merit further investigation.

Potential of Microsatellite Markers for Genetic Assessment of Scalloped Spiny Lobster (Panulirus homarus) Populations in Al Sharqiyah Governorate and their Application in Specie’s Fishery Management

Huda Al-Brashdi — Tue, 17 Sep 2024 00:00:00 +0400

Spiny lobster is one of the highest-priced seafood worldwide. Its fishery contributes well to the country's income and is considered one of the important export items to other countries. However, its annual catch declined sharply. Studying the stock is important for proper fishery management because stock responds differently to overexploitation and adaptation, therefore different stocks need different conservation plan. In this study, the genetic diversity and population differentiation of 50 P. homarus (the most present spiny lobster subspecies in Oman) from two regions (Al-Ashkharah and Masirah) of Al Sharqyah governorate were studied using 49 microsatellite markers. The results showed that P. homarus from the two sites are genetically similar based on low Fst (0.009), AMOVA test (1% variation). In addition, they are admixed as it is shown by DAPC (Discriminate Analysis of Principal Component) and by the phylogenetic tree. In conclusion, P. homarus from the two sites can be considered as a single stock, therefore the same fishery management and conservation strategy can be used to manage the spiny lobster fishery in Al Sharqyah governorate. More studies with a larger sample size are necessary to support our findings.

Screening of probiotics from indigenous Omani natural products for potential use in the aquaculture industry

Gilha Yoon — Tue, 17 Sep 2024 00:00:00 +0400

Probiotics can enhance the growth performance and disease resistance of aquatic animals. Probiotics can influence digestive physiology through the secretion of exogenous digestive enzymes, facilitating the utilization of nutrients, and resulting in improvements in growth performance. The objectives of the present study were to reduce fish diseases, minimize the usage of antibiotics, and promote national policy on aquatic health management in Oman through enhancing immune stimulation mechanisms with probiotics from indigenous Omani products and finally to promote Oman’s aquaculture industry. Thirty-five kinds of edible products were screened. After the primary screening process, only 3 products contained appropriate amounts of probiotics, therefore the present study focused on 3 probiotics from Omani products, i.e., dried date, date vinegar, and camel milk. Gram staining, VITIK2, and DNA tests were used for the identification and characterization of bacterial strains. DNA sequence revealed that the bacteria isolated from dried dates were identified as Bacillus licheniformis. Those from date vinegar were identified as Bacillus vallismortis. A viability test with pepsin, pH 3 showed that the bacteria isolated from camel's milk (Bacillus stratospheric) had a greater tolerance at low pH followed by bacteria isolated from dried date (B. licheniformis). Thus, these can be used as a probiotic for aquatic organisms.

Sustainable Development in Oman Fisheries Industry: Status and Potential of Fishing Companies

Ashraf Mishrif — Tue, 17 Sep 2024 00:00:00 +0400

Our study examines the condition of sustainable development in Omani fisheries industry, with specific focus on the extent to which the fishing companies practice sustainable fishing that meets the objective of food security. We also detect, characterize, and analyze the compliance of the fishing companies with the principles of social, economic, and environmental sustainability. Using 55 completed questionnaires of 70 surveyed operating fishing companies, a multivariate general linear model was used to determine the impact of economic and environmental factors on achieving sustainability, and domestic demand of fisheries sector in Oman. Our results revealed that more than 63% of companies believed that sustainability is extremely important in the fisheries industry, and around 42% of the companies 'strongly agree' that Oman meets its domestic demand from its own harvest. The model displayed significant effects of the amount of production for local consumption, climate change adaptation, and water waste management on improving sustainability of the fisheries sector. Analysis also confirmed significant effects on the amount of production for local consumption, amount of production for export, and using technology to locate stock on enabling the country to meet its domestic demand through its own harvest. We conclude by arguing that our findings have important implications for managing production in terms of food security and safeguarding domestic consumption.

Histological Examination of Various Organs of Asian Seabass, Lates calcarifer after an Oral Inactivated Vaccine against Vibrio harveyi

Gilha Yoon — Tue, 17 Sep 2024 00:00:00 +0400

Disease outbreaks and consequential losses are a challenge to the aquaculture industry. Diseases in aquaculture are caused by pathogenic agencies, such as bacteria, viruses, and parasites. The use of vaccines is one approach for the control of infections in fish and in building immunity against them. The goal of the present study was to create an effective oral vaccination against V. harveyi in order to ensure the long-term viability of aquaculture operations in the Sultanate of Oman. At a commercial farm, the target bacterium was isolated from infected fish and identified from a pure strain. Bacteria were killed with formalin and cleaned with saline several times. The vaccine was mixed with commercial feed to provide an oral vaccination for fish. This vaccinated feed was given for four weeks, and the efficiency of vaccine was determined by a challenge test, which involved injecting live same species of bacteria into healthy fish. Histology samples were taken when the experiment was completed. Multivitamins and vaccination therapy helped the fish to develop faster and to survive for extended periods of time without any organ damages. The control fish, on the other hand, demonstrated an incapacity to resist bacteria and died as a result, with external and internal organ damage. Despite the positive findings of this study, more research is required.

Antibacterial Activity of Moroccan Saffron By-product Extracts against Clavibacter michiganensis subsp. michiganensis: The Causal Agent of Tomato’s Bacterial Canker

Mamouni Rachid — Tue, 17 Sep 2024 00:00:00 +0400

This study aimed to investigate the effect of Moroccan saffron (Crocus sativus) floral by-products on the causal agent of bacterial canker of tomato caused by Clavibacter Michiganesis subsp Michiganesis (CMM). This work intends to replace chemical treatment methods with ecological, safe, and less expensive methods using extracts of saffron by-products. The phytochemical screening and the antioxidant activity of saffron by-products were studied. Moreover, the antibacterial activity of ethanolic extracts of saffron by-products was determined using the agar well diffusion method. The minimum inhibitory concentrations (MIC) of the saffron by-product extracts were determined by the dilution method using 96-well microplates. The results showed that the ethanolic extracts of saffron by-products constitute a significant source of bioactive molecules endowed with antioxidant activity. Further, all the tested saffron extracts inhibited the bacterial growth of (CMM) with an inhibition zone diameter ranging from 3 to 31 mm. Thus, this study aimed to valorize the saffron by-products generated after the harvest of the stigmas, in the biological treatment of tomato diseases.

Assessing Food Safety Practices in the Era of COVID-19: A Cross-Sectional Analysis of Restaurant, Retail, and Hotel Sectors in Muscat Governorate, Oman

Mohammed Al-Khusaibi — Tue, 17 Sep 2024 00:00:00 +0400

This study evaluated the adherence of food retailers, restaurants and hotels in Muscat Governorate to the precautionary measures to control the spread of COVID-19. This study found that only 18% of hotels implemented a Food System Management System (FSMS) while no restaurant or retailer implemented any FSMS. The majority of food retailers (89%) and restaurants (96%) did not conduct COVID-19 measures assessment while the assessment was conducted by 53% of caterers. All caterers assessed visitors/suppliers on COVID-19 symptoms and 94% of them kept details in a record book, followed by 96 and 76 %, respectively in retailers and restaurants. Safety distancing measure, signs, barriers and one-way system were implemented by different food establishments at different percentages. Covid-19 pandemic resulted in several changes in the food hygiene-related practices, such as hands sanitizing, wearing gloves and wearing masks. In conclusion, the overall adherence level of the food establishments toward health and symptoms monitoring, physical distancing, and face mask wearing was relatively high. The Era resulted in the introduction of hygienic practices that have been always recommended in the food service sector.