Fish Culture Research Articles

Development of a Highly Permissive Mandarin Fish (Siniperca chuatsi) Kidney Cell Line for Mandarin Fish Ranavirus Using a Single-Cell Cloning Method.

Mandarin fish ranavirus (MRV) infection poses a substantial challenge to the mandarin fish culture industry as no effective preventive or therapeutic measures currently exist. The creation of a highly permissive cell line from a natural host is crucial for developing a vaccine for MRV and understanding its pathogenic mechanisms. In this research, the mandarin fish (Siniperca chuatsi) kidney cell line (SCK) was isolated from mandarin fish kidneys. Subsequently, SCK-a to SCK-g monoclonal cell lines were derived from the SCK cell population, distinguished by morphological variations. Notably, MRV infection induced an advanced cytopathic effect (CPE) in almost all cells of the SCK-f clone. Further tests showed that MRV achieved a peak viral titer of 1010.7 50% tissue culture infectious dose (TCID50)/mL and consistently exceeded 1010 TCID50/mL across nine passages in SCK-f cells. Electron microscopy verified the MRV virion integrity within SCK-f. In vivo experiments revealed that MRV infections led to cumulative mortality rates of 86.9% in mandarin fish and 88.9% in largemouth bass (Micropterus salmoides). Such results suggest that SCK-f is highly permissive to MRV. This study underscores the importance of cellular diversity in developing viral permissive cell lines. The SCK monoclonal cell line pool may offer potential for generating highly permissive cell lines for other mandarin fish viruses.

Evaluation of the green development efficiency of marine fish culture in China

Green development efficiency (GDE) is an important criterion for measuring the level of green development. GDE considers not only economic development efficiency but also environmental costs. In China, marine fish culture, as one of the pillar industries of mariculture, promotes green development and industrial transformation and upgradation. Based on data from the field surveys of marine fish farmers (2017–2019) and the China Fishery Statistical Yearbook (2018–2020), this study establishes an evaluation index system and uses the super-slack-based measure model (Super-SBM) to evaluate the GDE of marine fish culture. The results show that the average GDE of marine fish culture in China was 0.9529, which was in an inefficient state. As for culture species, golden pompano (Trachinotus ovatus) and cobia (Rachycentron canadum) were the two species farmed in an efficient state, with a GDE of 1.2107 and 1.0659, respectively. Regarding culture modes, green modes (offshore cage aquaculture, industrial recirculating aquaculture, and engineering pond aquaculture) were in an efficient state, with a GDE of 1.2310, 1.0827, and 1.0401, respectively. Traditional modes (industrial flow-through aquaculture, ordinary cage aquaculture, and ordinary pond aquaculture) were in an inefficient state, with their GDE being 0.9884, 0.8746, and 0.8248, respectively. Green modes have higher GDE than traditional modes. In contrast, the production and culture areas of green modes were less than those of traditional modes because the profits of the same species in green modes were lower than those in traditional modes. The results of this study present an objective assessment of the GDE of marine fish culture in China and provide valuable insights for analyzing the mechanisms to improve the GDE of marine fish culture.

PENDAMPINGAN PENERAPAN TEKNOLOGI SMART FISH FARM BUDIDAYA IKAN KOI PADA DINATA KOI FARM BADUNG

Dinata Koi Farm is a Koi fish cultivation business that has been started since 2018. The Koi fish cultivation business is carried out starting from breeding, sorting, growing and marketing Koi fish. The demand for Koi fish orders by customers is not proportional to the amount of production produced. The problem is that many fish die due to poor water quality, thereby reducing the number of Koi fish produced for market. Koi fish are very sensitive to increases in temperature and pH levels of pond water. Dinata Koi Farm has a problem, namely that it cannot continuously monitor the temperature and pH levels of the water, so sometimes handling the pond water quality becomes slow and the Koi fish die. Based on the problems faced by partners, the service team helped develop smart fish farming technology that can monitor Koi pond water quality in real time and automatically handle it if there is an increase in the temperature and pH levels of the pond water. . The approach methods that will be used in this activity include individual approaches and training. The components evaluated in this activity are the application of smart fish farm technology and increasing partners' knowledge in the use of information technology, especially smart fish farms.

Photosynthetic Bacteria as an Alternative Wastewater Treatment in Freshwater Aquarium Fish Set Up

Waste produced from aquaculture ultimately hampered the water quality and growth performance of species cultured. Therefore, the potential exploitation of photosynthetic bacteria (PSB) from aquaculture waste was investigated to treat the wastewater in the fish culture. In this study, the wastewater was collected from a fishpond and cultured in sunlight-exposed sterile bottles for 14 days. In the water additive experiment, five treatments (in a 30 cm3 aquarium) were prepared namely cultured PSB (T1), aquatic plant hornwort (T2), aquatic plant salvinia (T3), positive control (P), and negative control (N). Five individuals of Hyphessobrycon herbertaxelrodi (2.5±0.5 cm length) were placed in each treatment and reared for 30 days. Meanwhile, for the wastewater treatment, four treatments (in a 30 cm3 aquarium) were prepared namely wastewater from the hatchery fishpond (S1), wastewater from the hatchery fish tank (S2), positive control (P), and negative control (N). The results obtained indicate that T1 treatment significantly improved and maintained the water quality as compared to other treatments. The results showed the amount of ammonia and nitrite in S1 and S2 supplied with T1 for 30 days gradually decreased from day 1 until day 18. While zero amount of ammonia and nitrate was acquired from day 21 until day 30 of the wastewater experiment. The treatment with PSB showcased the bacteria's ability to utilize and absorb nutrients, thereby maintaining and improving water quality. The potential use of beneficial bacteria in the culture system can accelerate the nitrogen cycle for a sustainable way of wastewater management.

Aquaculture activities influencing the generation of geosmin and 2-methylisoborneol: a case study in the aquaculture regions of Hongze Lake, China.

Contamination by odor substances such as geosmin (GSM) and 2-methylisoborneol (2-MIB) was examined in the cultured water from aquaculture farming in the region of the Hongze Lake in 2022, and some factors influencing residual levels of them in the water were analyzed. Geographically, high concentrations of GSM were located mainly in the north and northeast culture areas of the lake, while those of 2-MIB were found in the northeast and southwest. Analysis of the water in the enclosure culture revealed significant differences in the concentrations of GSM and 2-MIB among the cultured species. The mean concentrations of GSM in culture water were ranked in the order: crab > the four major Chinese carps > silver and bighead carp, and silver and bighead carp > crab > the four major Chinese carps for 2-MIB. The concentration of GSM was significantly higher at 38.99 ± 18.93 ng/L in crab culture water compared to other fish culture water. Significant differences were observed in GSM concentrations between crab enclosure culture and pond culture, while 2-MIB levels were comparable. These findings suggest that cultural management practices significantly affect the generation of odor substances. The taste and odor (T&O) assessment revealed that the residual levels of GSM and 2-MIB in most samples were below the odor threshold concentrations (OTCs), although high levels of GSM and 2-MIB in all water bodies were at 30.9% and 27.5%, respectively. Compared with the corresponding data from other places and the regulation guidelines of Japan, USA, and China, the region in the Hongze Lake is generally classified as a slightly T&O area, capable of supporting the aquaculture production scale.

Penerapan Aplikasi “Aqua Hatch” Sebagai Media Analisa Kondisi dan Penjadwalan Pakan Pada Budidaya Ikan Koi di “Budi Daya Koi WIB”

The ornamental koi fish or nishikigoi is one of the ornamental fish that is in great demand because of its beautiful body shape and color, and is believed to bring profits by koi lovers in Indonesia. The ornamental koi fish commodity has succeeded in improving the community's economy and making it an alternative source of income besides rice. Farmers and koi cultivators in the area are formed in farming groups so that their production results are well organized even though the cultivation method used so far is still traditional. There are several difficulties experienced by farmers in analyzing the condition of fish in the koi fish ecosystem, scheduling feeding, and proper maintenance methods according to the type of koi fish. In an effort to increase the effectiveness of feed management, the "AQUA HATCH" application is proposed as a solution that can optimize the analysis of environmental conditions for Koi fish cultivation and develop appropriate feeding schedules. Through this technology, it is hoped that it can increase productivity, reduce the risk of disease, and minimize feed waste. The Koi fish farming environment is very dynamic, and factors such as water temperature, water quality, and meteorological conditions can influence the growth performance of the fish. By implementing the "AQUA HATCH" application, monitoring of these conditions can be done in real-time, enabling more timely decision making. In addition, this application will be equipped with an intelligent feed scheduling feature, considering aspects such as feed type, number of fish, and environmental conditions. Through this program, it is hoped that "WIB KOI Cultivation" can increase operational efficiency, optimizing resource use , and ultimately increase Koi fish production. Apart from that, this research is also directed at contributing to the development of technology in the field of fish cultivation, especially for business actors involved in cultivating Koi fish.

MENINGKATKAN PENDAPATAN DAN PEMENUHAN PANGAN MANDIRI DESA SUMBERREJA MELALUI AKUAPONIK

This community service activity aims to provide outreach and education regarding the application of aquaponics and cultivating catfish using materials available in the environment to the people of Sumbereja Village, Pebayuran District, Bekasi Regency. The majority of residents in this village are farmers and livestock breeders, so the implementation of aquaponics is expected to increase economic income and meet household needs. Aquaponics is an agricultural system that combines the cultivation of fish and vegetable plants by using fish waste as nutrients for plants. This system also functions as a dirt filter, maintaining water quality. Catfish were chosen as cultivated fish because they have high nutritional value. Apart from that, catfish is also suitable for consumption by various age groups. This activity involves socialization, making simple aquaponics, and practical training. As a result, participants became more aware of waste management and aquaponic technology. They are also enthusiastic about applying it in their homes. During the evaluation, some participants were even interested in trying to make liquid organic fertilizer from dry leaf waste and household waste. It is hoped that this activity can continue to be developed to increase residents' ability to utilize the resources around them, as well as improve environmental conditions and increase family income.

The community service journal

ABSTRACT
 
 The objective of the Student Work Program (KKM) activity is to enhance the capacity and skills of the Panamping Village community, Bandung sub-district, in managing the cultivation of Tilapia fish. The work program provides an opportunity for students to gain direct experience in the working world, allowing them to apply the theoretical knowledge acquired during their studies in a real working environment. This KKM activity is participated in by members of fish cultivation groups in the village who have a desire to improve their existing businesses. The challenges faced include the lack of knowledge and skills among the community regarding fish cultivation, especially in plastic ponds, and business planning. Additionally, there is a lack of implementation of good fish cultivation technologies, such as feeding practices, pre-stocking seedling management, all of which can affect fish growth. Moreover, there are no alternative fish rearing facilities, while the demand for tilapia fish is quite high. The method employed in this activity involves an approach that engages members of fish cultivation groups within the village. The implementation of the activity includes the direct provision of 2000 tilapia fish fingerlings. The results of this KKM activity have had a positive impact on the village.

Nelumbo nucifera synthesized selenium nanoparticles modulate the immune-antioxidants, biochemical indices, and pro/anti-inflammatory cytokines pathways in Oreochromis niloticus infected with Aeromonas veronii

Bacterial infection is considered one of the major issues in fish culturing that results in economic losses. Metal nanoparticles are a cutting-edge and effective disease management and preventive strategy because of their antibacterial ability. In this investigation, the selenium nanoparticles were prepared by a biological method using Nelumbo nucifera leaves extract. The in-vitro antibacterial activity of N. nucifera synthesized selenium nanoparticles (NN-SeNPs) was tested against Aeromonas veronii. A treatment assay was conducted on 210 Oreochromis niloticus (average body weight: 27 ± 2.00 g). A preliminary approach was conducted on 90 fish for determination of the therapeutic concentration of NN-SeNPs which was found to be 4 mg/L. Fish (n = 120) were categorized into four groups for 10 days; G1 (control) and G2 (NN-SeNPs) were non-challenged and treated with 0 and 4 mg/L NN-SeNPs, respectively. While, G3 and G4 were infected with 2 × 106 CFU/mL of A. veronii and treated with 0 and 4 mg/L NN-SeNPs, respectively. NN-SeNPs exhibited an inhibition zone against A. veronii with a diameter of 16 ± 1.25 mm. The A. veronii infection increased the hepato-renal biomarkers (alanine and aspartate aminotransferases and creatinine) than the control group. An oxidative stress was the consequence of A. veronii infection (higher malondialdehyde and hydrogen peroxide levels with lower glutathione peroxidase superoxide, dismutase, and catalase activity). A. veronii infection resulted in lower immunological biomarker values (immunoglobulin M, lysozyme, and complement 3) with higher expression of the inflammatory cytokines (interleukin-1β and tumor necrosis factor-ɑ) as well as lower expression of the anti-inflammatory cytokines (interleukin-10 and transforming growth factor-β). Therapeutic application with 4 mg/L NN-SeNPs prevented the disease progression; and modulated the hepato-renal function disruptions, oxidant-immune dysfunction, as well as the pro/anti-inflammatory cytokines pathway in the A. veronii-infected fish. These findings suggest that NN-SeNPs, employed as a water therapy, can safeguard fish from the harmful effects of A. veronii and serve as a promising antibacterial agent for sustainable aquaculture.

Deployment of in-silico analysis to reveal the antibacterial profiles of Allium sativum against Aeromonas hydrophila

The key challenges in aquaculture are the emergence of antimicrobial resistance in fish cultivation due to the frequent use of antibiotics. Over the past three decades, this led to a major threat in the persistence of multidrug-resistant bacteria. Aeromonas hydrophila is a Gram-negative bacterium, a common causative agent of motile bacterial septicemia in fisheries. Combining these two key factors of the presented narrative, the essential type II topoisomerase enzyme ‘DNA gyrase’ (encoded by the gyrA and gyrB genes) as a potential drug target in Aeromonas hydrophila was taken, retrieve its sequence from UniProtKB (Id-A0KKQ2), constructs the 3-D structure using SWISS-MODEL (in absence of the experimental structure), and performs an in-silico screening of selected drug-like compounds (25 antibacterial phytochemicals) most of which are bioactive compounds of A. sativum through molecular docking. Quercetin a derivative of A. sativum was observed as a more potent drug molecule than other studied molecules based on ligand binding energy as docking score −7.812, showed highly encouraging results, supported by a study using structural dynamics of the receptor-ligand complex for a duration of 100 ns by Molecular Dynamic Simulations and confirm binding stability with MM-GBSA calculations. This study also provides theoretical grounds for drug discovery against other pathogenic bacteria posing threats to the ecosystem. Switching to herbal products is the best way to combat the plurality of problems to avoid seen or unseen post-treatment side effects. Communicated by Ramaswamy H. Sarma

Study of obstacles of fish culture in Khartoum State (Omdurman, Khartoum and Khartoum north, case study)

The present study aimed to provide baseline information of fish culture status (obstacles) of Omdurman, Khartoum and Khartoum north in the Khartoum state in Sudan due to there is little or lack of information in this field. 30 owners of farm were questioned from Omdurman, Khartoum and Khartoum north, 10 farms for each location; Descriptive analysis was done for analyzing the raw data of the study by using Excel Microsoft Software 2007. Social data showed that male farm owners group was dominant in third sites 100%. Age groups of fishermen ranged between 20 to 60 years; where age group 31- 40 Khartoum north, age group 41- 50 was dominant in O mdurman and age group 51-60 year was dominant in Khartoum. Six educational categories were recorded where University education was dominant in the three locations 50%, 50% and 70% respectively; whereas, postgraduate was the second in the tow location: O mdurman and Khartoum 20% and the secondary education were the third in Khartoum 30%. all farm owners were married 100% in three sites; As regards to the farm owners other activities results showed that most of them were practicing other activities (farmers, business owner, officers and workers). Category of farmer was dominant 90% secondly business owner and officer 70% and 50% respectively. Data showed that the problems (Varanus niloticus, birds, marketing, fees and thefts) was dominant in three locations had the highest percentage 90%, 80%, 60%, 30% and 10% respectively. and according to production cost in three locations arranged: (feeds, workers, fingerlings, water and technical supervision) 50, and 70% and 40%, 50% and 70% and 30%, 40% and 50% and 10, 20 and 40% and 10, 20 and 30% respectively. Category of feeds dominant followed by workers and fingerlings, the best Method to obtain of information, the results showed that Bulletins was dominant in three sites 80%, 30% and 90%; whereas, field visits in three location was the second 60%, 90% and 0%, Radio programs in three location was the third 60%, 10% and 60% and the lowest percentage; Seminars and television 40%, 50% and 40%, and 30%, 0% and 0%. For the best location to obtain information results revealed that the General Director of Fisheries Ministry of Agriculture, Animal Resources and Irrigation - Khartoum State was dominant in the three locations 90%, 80% and 90%, whereas, Universities in three location was the second 40%, 20% and 0%, and the lowest percentage Central Research of fisheries 40%, 0% and 0%, and Internet 10%, 20% and30%. Also result showed most of the farm owners in three sites all them need to training courses in deferent programmers (Fish extinction, Fish feeding, Fish production and Fish marketing) according to this percentages 60%, 30% and 50%, and 30%, 10% and 50%, and 10%, 10% and 30%, and 10%, 0% and 20% respectively.

Runoff of foliar-applied natural fungicides in aquaponics: Implications for fish and nitrification

Aquaponics is a method of producing food in a sustainable manner through the integration of aquaculture and hydroponics, which allows simultaneous cultivation of fish and economic crops. The use of natural fungicides are crucial to the sustainable control of diseases in aquaponics. We assessed the potential impacts of natural fungicides, such as clove oil and lecithin, as well as a synthetic fungicide, tebuconazole, following foliar application in aquaponics. This study examined the runoff rates of the fungicides in decoupled aquaponics, and the subsequent effects of the runoffs on nitrification processes and Nile tilapia (Oreochromis niloticus). The runoffs of the foliar-applied fungicides, clove oil, lecithin, and tebuconazole, were detected in aquaponics water at a percentage runoff rate of 0.3 %, 2.3 %, and 0.3–0.8 % respectively. In the biofilter, lecithin altered the ammonium levels by increasing ammonium-nitrogen levels by 7 mg L-1, 6 h post application. Clove oil, on the other hand, showed no significant effect on ammonium, nitrite, and nitrate-nitrogen. Similarly, the toxicity test showed that eugenol had no significant effects on the hematological, biochemical and antioxidative activities of O. niloticus. Conversely, tebuconazole exhibited significant and persistent effects on various biochemical parameters, including lactate, albumin, and total protein, as well as hematological parameters like hemoglobin and MCH. The use of lecithin and tebuconazole should only be limited to decoupled aquaponics.

Profitability and factors affecting production of pond fish culture under NATP project in Tangail district of Bangladesh

Profitability and input use efficiency of pond fish culture was studied at farming systems Research and Development (FSRD) site, Atia, Tangail from July 2019 to June 2020. The average pond fish production was recorded at 2808 kg/ha/year with the highest yield from the medium farms (2940 kg/ha/year) and lowest yield from marginal farms (2624 kg/ha/year). The highest gross return (Tk 352,800/ha) was found with medium farmers followed by small farmers (Tk 343,200/ha). The benefit cost ratio was also recorded higher (2.08) in marginal and small farms. Considering the aggregate production function for all groups of farmers, it was found that inorganic fertilizer, organic fertilizer, feed and human labour were statistically significant in explaining the variation in pond fish output but the results varied with different farm categories. Since there was positive correlation between input use and production of fish, it is probable that an increase in application of inputs could increase production further.

Implementation of Control System and Simple Additive Weighting (SAW) Method in Smart Aquaponics for Photovoltaic Based Spinach and Tilapia Vegetables

Aquaponics currently uses sophisticated automatic control technology. This certainly makes it easier for spinach vegetable farmers. Farmers can also cultivate tilapia so they can make a profit from selling spinach and tilapia. Aquaponics has become a trend among society in improving the economy. So far, aquaponics in Sidopekso Village, Kraksaan District, Probolinggo Regency uses a manual system for watering, applying fertilizer and feeding tilapia. The number of tilapia fish affects the amount of feed given, and the size of the spinach leaves also affects the fertilizer provided and the vegetable watering system. This system uses fish ponds as a place to cultivate vegetables using pot media. This photovoltaic-based control system can be combined with an aquaponics system directly. This tool can automatically control watering, apply liquid fertilizer to spinach, feed fish, control the electrical power produced by photovoltaics to support all aquaponic controls. Apart from that, farmers can also find out information about the equipment on-off process for spinach and tilapia via telegram. Microcontroller and telegram can synchronize with each other on this tool. Smart aquaponics is a combination of fish cultivation and plant cultivation using a control system using photovoltaic as a generator of electrical power to save electricity caused by daily use of equipment. Spinach vegetables are harvested after 25 days in the aquaponics area, the pH and temperature of the plants affect the quality of the vegetables. On day 1 and every 7 days the water and fertilizer in the vegetable reservoir must be replaced. So that the quality of pH and temperature is good. This requires a control system to run the tool. The fish used were 30 fish aged 35 days. This is adjusted to the size of the pool, namely 100 x 200 cm. Fish that are 10 days old must be replaced with holding water and fish food. This also uses a control system so that it can make it easier for farmers to control the entire function of smart aquaponics properly

ANATOMICAL MORPHO INDEX PROFILE OF TILAPIA (Oreochromis niloticus) CULTIVATED IN THE MINA PADI POND SYSTEM

The morphological-anatomical index profile is a value of changes in morphology (outer shape) and anatomy (internal organs) as a basis for calculating fish growth. Fish Growth in terms of morphology includes length and weight, while in terms of anatomy can be seen from changes in gonad, liver, and visceral weight. The purpose of this study was to determine the value of the morpho-anatomical index of Nila Fish GIFT (Oreochromis niloticus) cultured in the POKDAKAN Mina Mandiri pond. This research was conducted in the Mina Mandiri Fish Cultivation Group (POKDAKAN) pond, Panembangan Village, Banyumas from September 23, 2021 – November 28, 2021. The method used in this study was a survey method where the data was processed and analyzed descriptively and compared with the literature related. The results of the morpho-anatomical index of Nila Fish GIFT included a hepatosomatic index (HI) of 0.31%, a viscerasomatic index (VI) of 14.09% and a gonadosomatic index (GI) of 2.61%. The fish condition factor value was 1.05557 and the length-weight relationship was 2.6, which is negative allometric

Monitoring of individual indicators of safety and quality of water and fish of Khadzhibey estuary

Water significantly influences the quality and safety of fish because it is the environment for the life and cultivation of fish. A study of hydrochemical and microbiological indicators of the water of Khadzhibey estuary was conducted; the content of heavy metals in it was determined. In the Khadzhibey estuary, from 2022 to 2023, the water acidity indicator was stable, did not exceed the established hygienic standards for fish farms, and was within the range of 7.6 ± 0.4–8.4 ± 0.3 mg/L, which completely meets the requirements for fish farming. The maximum salinity in the estuary is observed in summer and is 15 % higher compared to winter and spring indicators. The water type of the estuary is mixed with moderate mineralization. It was established that the zinc content in water samples from the estuary exceeds the maximum permissible concentration by 2.6 %. The content of Cadmium, Lead, Copper, and Mercury is constant and does not exceed the maximum allowable concentration for fish farms. An increase in zinc content in water is a stress factor and affects the quality of fish meat. The research results showed that the content of mesophilic aerobic and facultative anaerobic organisms does not exceed the maximum permissible level in muscle tissue cultures of common carp and round bull caught by commercial fishing from the Khadzhibey estuary. Escherichia coli bacteria, Staphylococcus aureus, Listeria monocytogenes, and pathogenic microorganisms were not detected in the samples of the fish subject to the study. According to the microbiological indicators of water and fish, common carp and Round goby caught by industrial fishing in the Khadzhibey estuary are safe and allowed for further consumption by humans and animals.

The Influence of Different Media on The Physiological Response of Nila Fish (Oreochormis nilaticus)

Nila fish (Oreochromis niloticus) is one of the leading commodities in freshwater fish cultivation in Indonesia is a freshwater fish commonly found in Indonesian waters. Media will be the main obstacle in cultivating tilapia on idle land (land that cannot be operated). Different water media influence the physiological responses of tilapia fish. The purpose of this activity is to determine the effect of differences in freshwater, brackish water and sea water media on the physiological response of tilapia fish. The parameters of this research are differences in water media, physical factors of the media, survival of tilapia fish, respiration rate of tilapia fish, mobility of tilapia fish, weight of tilapia fish and flexibility of tilapia scales. This study used quantitative methods with a completely randomized design (RAL). The collection technique makes observations. Data were analyzed using ANOVA with a significance level of 5%. The results of this study show that differences in the aquatic environment significantly affect the physiological response of tilapia. Where in sea water the fish mortality rate is quite high compared to fresh water and brackish water.

Diversity, Abundance, and Local Use of Fishes in Lake Danao, Ormoc City, Philippines

Lake Danao lies within the Lake Danao Natural Park in Ormoc City, Leyte, Philippines. The lake provides a habitat for various aquatic flora and faunal species. However, existing data on fish assemblage in Lake Danao is scarce and outdated. This study determined Lake Danao’s diversity, abundance, and local use of fish. With the help of local fishers, fish samples were collected from different parts of the lake twice a month for 14 months (March 2021 to June 2022). In addition, an ethnoicthyological survey was conducted to supplement the information on the provenance, endemism, and local use of the fish species in Lake Danao. This study recorded eight species of fish in Lake Danao, and only two are considered native (Anguilla marmorata and Clarias batrachus). Only five species were obtained from the fishers throughout the entire sampling period. On average, Glossogobius giuris was the most abundant species (95.96%), while Channa striata was the least (0.07%). The low Shannon-Weiner diversity index (mean = 0.19) and high Simpson’s dominance index (mean = 0.92) indicate low diversity and dominance of other species (e.g. G. giuris). No significant difference was observed in the diversity, dominance, and evenness of fishes between the sampling months. All of the fish species were used as alternative food sources. With the dominance of introduced species, local authorities are strongly encouraged to strictly regulate the entry, possession, and cultivation of exotic fish in Lake Danao and to continue the aquatic biodiversity assessment and monitoring in the area.

Effect of Different Natural Feeding (Blood Worm, Silk Worm, and Water Fleas) on The Growth of Betta Fish (Betta sp.)

One type of freshwater ornamental fish that is in great demand by the public is Betta fish (Betta sp.). The problem faced by Betta fish cultivation activity is inappropriate feed, for example feed with low protein content. Low protein causes slow growth in fish. This study aims to determine the effect of different natural feeds (silk worms, blood worms, water fleas, and controls) on the growth of Betta fish. The results showed that there was a significant effect (p<0.05) on the growth and specific growth rate of betta fish. However, there was no significant effect (p>0.05) of different natural feeding on the survival rate parameter. The highest result showed in treatment B (silk worm) with a weight value of 1.09 g, a length of 4.48 cm, and specific growth rate value of 1.77 ± 1.768. It can be concluded that silk worm is the best natural feeding for betta fish.

Study of Bawal Bintang fish (Trachinotus blochii) hatchery at the Lombok marine aquaculture, West Nusa Tenggara, Indonesia

Bawal Bintang fish (Tracinotus blochii) has high economic value, to meet both domestic and foreign consumption needs. Bawal Bintang fish cultivation has become a commercial business to be developed because of its relatively fast growth, relatively easy maintainance, and public interest in it. The objective of this study is to find out the hatchery techniques of Bawal Bintang Fish and the obstacles that arise in their hatchery at the Lombok Marine Cultivation Fisheries, West Nusa Tenggara. The method used was descriptive with data collection including primary data and secondary data. Data collection was done by means of active participation, observation, interviews, and literature study. Bawal Bintang fish hatchery technique began with tank preparation, spawning, egg distribution, and maintenance for 20-25 days. Bawal Bintang fish hatchery included feed management, water quality monitoring, and pest and disease control. After rearing the larvae for 20-25 days or reaching seedling size, then harvesting was carried out to transfer them to the nursery tank using the RAS system. The problem that arose in the hatchery of Bawal Bintang fish was the frequent occurrence of Bawal Bintang larvae that fell from a pond.