Shrimp Farming Research Articles

Strain-specific responses of Penaeus vannamei to two Enterococcus faecium strains supplementation: A trade-off between growth and immunity

Probiotic properties are highly species- or even strain- specific. Strain-specific responses of growth performance, non-specific immunity, disease resistance, and intestinal microbiota in Penaeus vannamei to two Enterococcus faecium strains supplementation were investigated in this study. Basal diet (control, CON) was supplemented with E. faecium HK and LYB at the dose of 1 × 1010 CFU / kg (HK group) and 1 × 1011 CFU / kg (LYB group), respectively. The results indicated that the HK and LYB groups exhibited significant enhancements in growth performance, non-specific immunity, and disease resistance of shrimp against Vibrio parahaemolyticus compared to the control (P < 0.05). However, the specific growth rate of shrimp in the LYB group was significantly better than that in the HK group (P < 0.05). Furthermore, the HK group showed significant increases in phenoloxidase, total nitric oxide synthase activities, lysozyme content in the serum, as well as the relative expression levels of proPO, LGBP, Imd, Relish, and eIF4E2 genes in the hepatopancreas compared to the LYB group (P < 0.05). These results suggested the strain HK exhibited better non-specific immunity efficiency while the strain LYB exerted better growth enhancement in shrimp. Dietary both of strain HK and LYB significantly altered microbial community structure (P < 0.05), and the strain HK significantly improved intestinal microbial diversity in shrimp. The relative abundance of Rubritaleaceae and Rhodobacteraceae were significantly increased, whereas those of facultative anaerobes and potential pathogens (i.e., Vibrionaceae, Flavobacteriaceae and Erysipelotrichaceae, etc.) were reduced in response to dietary supplementation of E. faecium HK and LYB. Furthermore, dietary both of strain HK and LYB could promote intestinal microbial community stability by increasing average connectivity, cooperation interactions, the number of generalists within the network. When growth performance and intestinal microbial homeostasis of shrimp are considered, E. faecium LYB might be better than the strain HK in shrimp farming.

Distribution and Management of Residual Antibiotics in the Litopenaeus vannamei Shrimp Farming Environment: Recommendations for Effective Control

This study specifically focused on Litopenaeus vannamei and examined the distribution of residual antibiotics in various components of shrimp ponds throughout an aquaculture cycle. The findings revealed that aquaculture feed served as the primary source of antibiotics, continuously introducing them into the ponds throughout the entire production cycle. A multimedia distribution model for antibiotics in the ponds was established based on the principle of mass balance. The distribution characteristics of six antibiotics with higher levels in the feed, namely, sulfamethoxazole (SMX), norfloxacin (NOF), levofloxacin (LEOF), tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC), were investigated in the pond water, sediment, and shrimp. At the end of the cultivation period, the total antibiotic residues accounted for 65~80% in various media, with the sediment containing 50~60% of the distribution proportion (p &lt; 0.01), which was identified as the primary reservoir for most antibiotics, with LEOF and NOF accounting for the highest proportions (45.78% and 50.29%, respectively). Based on the model’s findings and the allowable daily dosage of antibiotics, recommendations were made for the effective control of antibiotic residues in shrimp farming management. To address the significant net loss of sulfonamides (SAs) and tetracyclines (TCs) in aquaculture production, it is crucial to carefully regulate their dosages and administration methods. Implementing eco-friendly additives and regularly cleaning surface sediments can aid in reducing antibiotic residue levels in various environmental media, thereby mitigating the environmental impact on aquaculture production activities.

Valorization of the treatment of antibiotic and organic contents generated from an in-situ-RAS-like shrimp farming pond by using graphene-quantum-dots deposited graphitic carbon nitride photocatalysts

In this study, we investigated the possibility of a photocatalytic system that uses graphene-quantum-dot (GQD)-deposited graphitic carbon nitride (g-C3N4) to treat tetracycline (TC) and other organic compounds generated from an in-situ-recirculatory-aquaculture-system (RAS)-like shrimp farming pond. GQDs were successfully deposited on the exfoliated g-C3N4 base through a hydrothermal treatment. The results showed that the incorporation of GQDs into the g-C3N4 enhanced its porosity without aggregating its mesoporous structure. The GQDs-deposited g-C3N4 photocatalysts revealed sheet-like structures with nanopores on their surface that facilitate photocatalysis. More than 90% of the TC was removed by the photocatalysts under UV-LED irradiation. Low loadings of GQDs over g-C3N4 resulted in a faster and more effective photocatalysis of TC, mainly driven by.O2- radicals. The photocatalysts were also applicable in the degradation of organic compounds with 27% of the total organic compounds (TOC) being removed from the wastewater of a RAS-like shrimp farming pond.

Mengikis Ketergantungan: Dampak Program Pemberdayaan Terhadap Kehidupan Sosial Ekonomi Masyarakat Desa Sungai Pasir Kabupaten Sukamara

The life of the fishing community in Sungai Pasir Village depends on the Fisherman Boss (Juragan Kampung), which makes the fishing community unable to live independently, until an empowerment programme through Vaname Shrimp farming for fishing communities in Sungai Pasir Village emerged. This research aims to analyse the community empowerment approach applied and the impact of the empowerment programme through vaname shrimp farming on the socio-economic life of the Sungai Pasir Village community. The theory used in this research is the theory of community empowerment (Jim lfe). The research approach used is qualitative, with a case study research type. Data collection used participant observation, in-depth interviews and documentation. Data was analysed using data reduction, data presentation and conclusion drawing. The results show that the vaname shrimp empowerment programme in Sungai Pasir Village has an impact on the socio-economic life of the community. The impacts are: the opening of employment opportunities for the community; a change in the profession of the community from fishermen to pond farmers; the emergence of community independence; increased community awareness to save; and, the birth of small micro businesses. The community conducts vaname shrimp farming activities in groups of 25 members. The group is called "Mina Barokah" and is responsible for the cultivation of vaname shrimp from seedling stocking to harvesting. By providing resources, opportunities and knowledge to the community, the local government has empowered the community through vaname shrimp farming, increasing their income and independence.

Mangrove Nursery as Environmental Recovery Efforts in Aquaculture Pond Area, Utan Sub-District, Sumbawa

Geographically, the Utan sub-district is located in the coastal region of Sumbawa Regency, with abundant fisheries and marine potential. One of the potentials in the Utan sub-district is shrimp farming. Meanwhile, the management of natural resources in coastal forest areas so far tends to be less improved; this is due to various reasons, such as the lack of public awareness of the importance of coastal greenery and maintenance of existing coastal forests. Through the mangrove nursery program as an effort to restore the environment in the pond cultivation area, in Utan District, Sumbawa, it is hoped that it can raise awareness and the community's active role in the importance of a healthy environment. The results show that his community service succeeded in forming mangrove farmer groups, fostering mangrove farmer groups by conducting periodic education, and building mangrove nurseries. This mangrove nursery is managed directly by a group of mangrove farmers and has succeeded in producing 2,500-4,000 mangrove seedlings and successfully marketing them. In conclusion, this community service activity was successfully carried out and proved to improve farmers' welfare around the ponds. In addition, with this mangrove nursery, the community can contribute to the planting process so that a lot of carbon is absorbed in the atmosphere so that the air quality in the Sumbawa environment is of high quality. This means that the economy, society, and environment will be sustainable.

SOSIALISASI PENINGKATAN KUALITAS PRODUKTIVITAS PANEN UDANG MELALUI PENGONTROLAN KADAR AIR BERBASIS IOT DI DESA KUALA CEURAPE

Pond water quality is the main factor for the survival and productivity of shrimp farming. Physical parameters such as temperature, salinity and water turbidity are the main indicators of pond water quality. Poor water quality can reduce appetite, growth rate, and increase the risk of disease in shrimp. To overcome this problem, an effective monitoring and control system is needed. The method used in implementing this community service activity covering observation, design and socialization of the use of IoT-based automatic water content control devices. The results showed that the device is effective in helping fishermen controlling water levels automatically, increasing efficiency and effectiveness. The technology used includes the Arduino Uno microcontroller, ultrasonic sensor, RTC, LCD, relay module, motor driver, and DC motor. This activity is expected to provide new knowledge for fishermen in increasing shrimp productivity and quality through automatic control of pond water.

Detection of white spot syndrome virus in seston from a coastal ecosystem and a shrimp farm in the Gulf of California

Three molecular assays were used to detect and quantify white spot syndrome virus (WSSV) in DNA extracted from seston size-fractioned (0.02, 0.2, 1.2, and 20 μm) samples collected from a coastal lagoon and an adjacent shrimp farm. From 107 DNA extracts, only two from one sample tested positive for WSSV with nested PCR in the 1.2 and 20 μm fractions. These results were confirmed by a semi-quantitative (IQ2000TM WSSV Detection and Prevention System) and a quantitative (IQREALTM WSSV Quantitative System) detection system based, based, respectively, on nested PCR and real-time PCR. A first viral load reference value (6.54 × 104 WSSV copies/mL) was established in a seston size fraction (1.2−20 μm). The results suggest that WSSV could be associated with both resuspension of fine clays and silts, and nanoplankton and organic colloids during infectious events.

A Comparison of Resources Usage for Two White-Leg Shrimp (Penaeus vannamei) Farming Systems (Earthen Pond System and Round Tank System)

Shrimp farming plays an important role in providing nutritious food and generating livelihoods for many millions of people worldwide. Asia is the biggest producer of shrimp contributing nearly 80% of the global shrimp aquaculture production. Black tiger shrimp (Penaeus monodon) is the main brackish water aquaculture species in Sri Lanka before 2018. White-leg shrimp (Penaeus vannamei) was a new species that was introduced in 2018 expecting a rapid increase in production in the country. Shrimp farming is classified into several categories: extensive, semi-intensive, intensive, and super-intensive based on the intensity of management practices such as stocking density, supply of feed and fertilizer, and management of water qualities. The round tank system is round-shaped and is a type of lined pond that uses an impermeable geomembrane for the retention of water. It belongs to the super-intensive category. The earthen pond is a water body that is basically enclosed by the earth. It belongs to the intensive category. The purpose of this study was to assess the amounts of land, water, and energy required per ton of harvested shrimp in two different production systems and identify the most sustainable system that is used minimum natural resources. The round tank system is located in the Erukkalampiddy area in the Mannar district, Sri Lanka. The earthen pond system is located in the Maikkulama area in the Puttalam district, Sri Lanka. Data on water usage, electricity usage, land area usage, and weight of harvested shrimp were collected during two cycles of production from August 2021 to May 2022. The t-tests were performed to compare resource usages. Land usage of the earthen pond system (950.00 m2/t shrimp, 1266.67 m2/t shrimp) is significantly greater than the round tank system (190.77 m2/t shrimp, 139.33 m2/t shrimp). Water usage of the earthen pond system (950.00 m3/t shrimp, 1266.67 m3/t shrimp) is significantly greater than the round tank system (190.77 m3/t shrimp, 139.33 m3/t shrimp). Energy usage of the round tank system (473.84 kWh/t shrimp, 591.46 kWh/t shrimp) is significantly greater than the earthen pond system (119.91 kWh/t shrimp, 154.78 kWh/t shrimp). It concludes that less land and water resources and high energy usage are required for a round tank system compared to an earthen pond system. Although establishing a round tank system will need more capital, compared to that of an earthen pond system, it is evident that the round tanksystem is more environmentally sustainable. &#x0D; Keywords: Shrimp farming, Round tank system, Earthen pond system, White-leg shrimp (Penaeus vannamei)

Mangrove Biodiversity Conservation and Aquaculture Practices in Sri Lanka: An Overview

The tropical island of Sri Lanka is endowed with a diverse and resourceful coastal area of 1,700 km coastline and 152,000 ha of highly productive 82 lagoons and 93,075ha of 45 estuary ecosystems. Around 33% of the population in coastal areas is engaged in fishing as the main income source, which contributes to around 1.10% of the national GDP. The objective of the review was to provide an overview of the present status of Sri Lankan coastal aquaculture, mangrove coverage, and conservation status. Mangroves are ecologically and economically important ecosystems providing the best nursery grounds for both blackish and marine species, covering only 0.24% of Sri Lanka‘s total land area. In addition, as the most carbon-rich forests in the tropics, mangroves provide a wide range of ecosystem services and biodiversity conservation. Currently, Sri Lankan mangroves are estimated to cover 160 km2 and are distributed mainly in Jaffna, Kalpitiya, Batticaloa, Rekawa, and Trincomalee. Including endangered species such as Sonneratia apetala, Ceriops decandra, and Lumnitzera littorea, there are 21 true mangrove species, and 24 mangrove associate species can be found. However, mangrove ecosystems in Sri Lanka are progressively under threat due to coastal aquaculture practices, especially shrimp farming and development projects. Human settlements, overexploitation, and climatic variables such as coastal flooding, drought, rainfall, salinity changes, increased sea level, and sea surface temperature have significantly influenced coastal aquaculture and substantially damage the mangroves resulting in loss of mangrove biodiversity. Between 1980 and 2005, approximately 25% of mangrove habitats are estimated to have been destroyed. Recently, 1,000-1,200 hectares of mangroves have been established in 23 wetlands in Sri Lanka becoming leader of the mangrove conservation in Commonwealth countries. In conclusion, it is imperative to apply international standards for mangrove-based aquacultural practices, mangrove rehabilitation, and technical and management interventions. &#x0D; Keywords: Biodiversity, Coastal aquaculture, Coastal ecosystems, Mangroves

Performance of An Aerated Wastewater Stabilization Pond for the Treatment of Cultivation Wastewater of Pacific White Shrimp (Litopenaeus vannamei) Grow-out Ponds

Pacific white shrimp (Litopenaeus vannamei) is a major cultivated crustacean species whose aquaculture production has doubled in the last decade. The implementation of shrimp pond systems using closed or intensive methods is widely carried out. However, wastewater produced by intensive shrimp farming may cause environmental effects. This study is aimed to evaluate the feasibility of the aerated wastewater stabilization pond to treat the cultivation wastewater. The physicochemical parameters monitored were temperature, pH, salinity, ammonia, nitrite, nitrate and phosphate. In the case of this study, almost all physicochemical parameters of the water coming out of the aerated wastewater stabilization pond are suitable for use as input water for integrated multitrophic aquaculture (IMTA). Temperature, pH, salinity, nitrite, nitrate, and phosphate were 27.1°C to 32.2°C, 7.86 to 8.79, 30 ppt to 34 ppt, 0.003 mg/L to 0.068 mg/L, and 0.19 mg/L to 1.31 mg/L, respectively. Only ammonia concentration significantly fluctuated in the range of 0.44 mg/L to 12 mg/L.

Land Cover Change Detection Using Geo-Spatial Technologies: A Spatio-Temporal Study on Muthurajawela Marsh-Negombo Lagoon Wetland Complex

&#x0D; Biodiversity conservation and management encompass protecting Earth’s life diversity including species and ecosystems. Conservation efforts involve protecting endangered species and maintaining healthy ecosystems. Muthurajawela Wetland is one of the listed Ramsar sites of Sri Lanka which contains a rich biodiversity and productive ecosystem. Currently, this valuable landscape undergoes a radical change of its form over decades. Therefore, this study aimed to examine land cover changes in this wetland complex over three decades using satellite imagery. For in-depth change detection analysis, both pre-classification and post-classification land cover/use methods were used to assess changes from 1997 to 2023. The study of the Muthurajawela marsh- Negombo lagoon wetland complex used per-classification methods like Normalized Difference Vegetation/Water Indices (NDVI/NDWI) to identify vegetation and water bodies. The Maximum Likelihood Supervised Classification (MLSC) technique categorized the land cover into classes, water, marshland, settlements, vegetation, and barren land. To ensure accuracy, statistical methods such as Confusion Matrix was applied for each land cover class. Furthermore, a detailed post- classification analysis was conducted through Thematic Change Detection, which compared historical changes in land classes to their current status. Thematic Change analysis helped to assess and visualize the changes in each land class over time in relation to the present conditions on the ground. Change detection analysis illustrated that, about 46% land cover of total study has been converted from one land class to another over 3 decades. In 1997, highland vegetation of agriculture, forests, and marshy areas covered 41% of total land while Built-up areas comprised 18% of the land, with agriculture being more prevalent than construction. By 2023, there have been significant changes. Built-up areas make up 38% of the land due to the development of settlements, construction activities and the Katunayake highway project. The study shows a decrease in vegetation and marshland to 6%, possibly due to deforestation. In 2023, bare lands increased due to land reclamation and garbage dumping in the wetland complex. 90% of deep-water areas converted into shallow water. 28.35 km2 of deep-water bodies degraded. Prawn farming also contributed to mangrove destruction in the Negombo lagoon. The study emphasizes the need for sustainable management of valuable ecosystems and eco-friendly human approaches to mitigate wetland degradation.&#x0D; &#x0D; Keywords: Change detection, Land cover, Muthurajawela marsh, Negombo Lagoon, Wetland

Analysis of IoT-LoRa to Improve LoRa Performance for Vaname Shrimp Farming Monitoring System

Analysis of IoT-LoRa to Improve LoRa Performance for Vaname Shrimp Farming Monitoring System

Biometry, Growth, and Recruitment Pattern of a Commercially Important Nereid polychaete, Namalycastis fauveli, from the East Coast of Bangladesh

Certain benthic polychaetes, such as species within the genus Namalycastis, are employed in the diet of gravid shrimps in aquaculture due to their amino acids and highly unsaturated fatty acid content, enhancing the quality of gravid shrimp. Despite its importance in the rapidly developing shrimp culture industry, the population parameters of this economically valuable species are unknown. Therefore, the present study examines the population parameters of Namalycastis fauveli to assess its occurrence, growth, recruitment, exploitation level, and stock status in Bangladesh. Monthly samplings of N. fauveli and environmental variables were collected from five sites of the Cox’s Bazar coast using a square-shaped mud corer with a 0.093 m2 (or 1.0 ft2) mouth opening from August 2020 to July 2021 to measure or estimate. Within the 8.0–30.0 cm depth range of the intertidal zone, polychaete samples were collected from the sediment. The results showed negative allometric growth (b &lt; 3), but there was a significant L–W relationship (p &lt; 0.05, r2 = 0.43 to 0.94). The estimated L∝, K, and ϕ were 22.05 cm, 0.99 year−1, and 2.69, respectively, while total mortality (Z) was 4.56 year−1. It was calculated that the fishing mortality and capture probability proportionally increased with the total length at a certain age. Recruitment mostly occurred in October and March, and temperature had a greater impact than salinity. The evaluated exploitation level (E = 0.57) indicated that the stock was overexploited. Thus, the above results provide some valuable information for shrimp farmers and stakeholders, as well as for policymakers in the move towards restoration, species conservation, and efficient management of N. fauveli natural stocks.

Comparative Analysis of the Culture of Pink Shrimp Farfantepenaeus brasiliensis and Pacific White Shrimp Litopenaeus vannamei in Biofloc System

Shrimp farming in the Biofloc Technology System (BFT) is already considered an alternative to the traditional culture. The bioflocs maintain the water quality and can be used as a food supplement for shrimp. The Pacific white shrimp Litopenaeus vannamei forms the basis for most of the production in BFT. However, its culture is limited by the low temperatures. Thus, the BFT culture potential of native species, such as the pink shrimp Farfantepenaeus brasiliensis, should be considered. The present study aimed to compare the cultures of F. brasiliensis and L. vannamei in the grow-out phase in the BFT system. The experiment comprised two treatments: (FB), grown out of F. brasiliensis, and (LV), grown out of L. vannamei. The study lasted 70 days and was conducted at the Marine Station of Aquaculture at the Federal University of Rio Grande, Rio Grande do Sul State, Brazil. The stocking density was 100 shrimp/m² for both species. The shrimp were fed twice a day with commercial food. The physicochemical parameters of the water were monitored throughout the experimental period. The results showed that all physicochemical parameters of the water remained within the tolerated limits for both species. However, during the growth phase in the BFT, it was observed that the L. vannamei shrimp showed a better zootechnical performance than F. brasiliensis. The results indicate that L. vannamei has a higher capacity to catch bioflocs as supplementary food, demonstrating a better response of that species to the BFT system in the grow-out phase compared to F. brasiliensis.

THE INFLUENCE OF TRAINING AND COMPENSATION ON EMPLOYEE PERFORMANCE IN WILD TIGER PRAWN FARMS IN TANGGAMUS

Human resources play a crucial role in the success of a company. Therefore, it is essential for companies to provide effective training and fair compensation to enhance employee performance and ensure the smooth functioning of the organization. The objective of this study is to examine the impact of training and compensation on employee performance in windu alam tiger prawn farm. The research sample consisted of 30 employees, and the entire population was included using Non-Probability Saturation sampling technique. Data collection was done through a questionnaire system, and the analysis was conducted using multiple linear regression with the assistance of SPSS version 25. Various tests such as validity, reliability, normality, multicollinearity, and heteroscedasticity were performed to analyze the data. The hypothesis testing included simultaneous, partial, and R2 determination coefficient tests. The findings revealed that Training (X1) has a positive influence on Employee Performance (Y), and Compensation (X2) also has a positive impact on Employee Performance (Y). Moreover, the study concluded that both Training and Compensation have a positive effect on employee performance. This research holds both theoretical and practical implications, contributing to the field of human resource management and providing valuable insights for companies in making informed decisions.

Phytochemical analysis and antibacterial activity of palm waste extract against Vibrio harveyi and Vibrio parahaemolyticus.

Vibrio harveyi and Vibrio parahaemolyticus are species of the Vibrio genus that often cause disease and mass mortality in crustaceans. If not handled quickly and appropriately, these diseases can cause considerable losses to farmers. Therefore, it is necessary to find a solution with safe and environmentally friendly disease prevention technology using natural ingredients, among others from plants, namely oil palm. Some parts of oil palm, namely leaves, fronds, fibres and oil palm pulp, which are palm waste, contain antibacterial compounds. This study aimed to assess the antibacterial activity of palm waste extracts, namely pulp, leaves, fronds and fibres using n-hexane, ethyl acetate, chloroform, ethanol and water maceration solvents against pathogenic bacteria V. harveyi and V. parahaemolyticus, and identify active compounds contained in palm waste. The results of the research are expected to produce innovative and sustainable solutions to control diseases in shrimp farming, contribute to the development of a sustainable fishing industry and open up the potential for utilizing palm waste as a value-added resource in the field of aquatic health. The results of observations on antibacterial activity tests and identifying the content of palm waste extract compounds were analysed descriptively displayed in the form of figures, tables and graphs. The results showed that palm waste extracts (pulp, leaves, fronds and fibres) with ethyl acetate and ethanol maceration solvents had very strong antibacterial potential, namely 20.14 ± 0.31 mm-25.52 ± 1.42 mm on V. harveyi bacteria and 20.41 ± 0.55 mm-25.00 ± 0.51 mm on V. parahaemolyticus bacteria. Palm extracts with n-hexane (>20 mm) and chloroform solvents generally have strong category antibacterial potential (10-20 mm), and palm extracts in water solvents have medium category potential (5-10 mm) against V. harveyi and V. parahemolyticus bacteria. The results of phytochemical tests on palm waste extracts with ethyl acetate and ethanol maceration solvents contain bioactive compounds of flavonoids, saponins, polyphenols and alkaloid tannins, steroids and triterpenoids. Palm extracts with n-hexane and chloroform solvents generally contain saponins, alkaloids, steroids and triterpenoids, while palm waste extracts with water solvents contain saponins.

A Case Study on Current Disease Threats Faced by Vannamei Shrimp Farmers in South-East India

A Case Study on Current Disease Threats Faced by Vannamei Shrimp Farmers in South-East India

Unveiling Vannamei Shrimp Farming's Impact on Water Pollution in Wonocoyo Village

Unveiling Vannamei Shrimp Farming's Impact on Water Pollution in Wonocoyo Village

Microalgae Inoculation Significantly Shapes the Structure, Alters the Assembly Process, and Enhances the Stability of Bacterial Communities in Shrimp-Rearing Water.

Intensive shrimp farming may lead to adverse environmental consequences due to discharged water effluent. Inoculation of microalgae can moderate the adverse effect of shrimp-farming water. However, how bacterial communities with different lifestyles (free-living (FL) and particle-attached (PA)) respond to microalgal inoculation is unclear. In the present study, we investigated the effects of two microalgae (Nannochloropsis oculata and Thalassiosira weissflogii) alone or in combination in regulating microbial communities in shrimp-farmed water and their potential applications. PERMANOVA revealed significant differences among treatments in terms of time and lifestyle. Community diversity analysis showed that PA bacteria responded more sensitively to different microalgal treatments than FL bacteria. Redundancy analysis (RDA) indicated that the bacterial community was majorly influenced by environmental factors, compared to microalgal direct influence. Moreover, the neutral model analysis and the average variation degree (AVD) index indicated that the addition of microalgae affected the bacterial community structure and stability during the stochastic process, and the PA bacterial community was the most stable with the addition of T. weissflogii. Therefore, the present study revealed the effects of microalgae and nutrient salts on bacterial communities in shrimp aquaculture water by adding microalgae to control the process of community change. This study is important for understanding the microbial community assembly and interpreting complex interactions among zoo-, phyto-, and bacterioplankton in shrimp aquaculture ecosystems. Additionally, these findings may contribute to the sustainable development of shrimp aquaculture and ecosystem conservation.

Defining desired genetic gains for Pacific white shrimp (Litopenaeus vannamei) breeding objective using participatory approaches.

The objective of this study was to define desired genetic gains from economically important traits of Pacific white shrimp (Litopenaeus vannamei) using participatory approaches. Two questionnaires were sent out to 100 Pacific white shrimp farmers in all five Iranian shrimp farming provinces. Questionnaire A (Q-A) includes management factors and farming environments. Moreover, in this questionnaire, farmers were asked to rank the fourth most important traits in shrimp among 10 economic traits in the list for genetic improvement. In questionnaire B (Q-B), priorities of the four traits with the highest value were obtained using pairwise comparison. The results showed that the four most important traits were white spot syndrome virus resistance (WSSV), growth rate before 4 months (GR), acute hepatopancreatic necrosis disease resistance (AHPND), and female total weight at ablation (FTW). Medians of the best individual preference values were WSSV (0.222), GR (0.173), AHPND (0.157), and FTW (0.053). Most disagreements were found between the social group preference values in the commercial products and water salinity categories. Desired genetic gains were 1.71%, 1.57%, 0.53% and 0.31% for GR, AHPND, WSSV and FTW, respectively. This study highlighted that despite environmental and management differences, participatory approaches can achieve desired genetic results for Pacific white shrimp breeding programme.