Swamp Eel Research Articles

In-vitro evaluation of the antifungal activities of eel skin mucus from Asian swamp eel (Monopterus albus)

Discovery and development of new drugs from marine and freshwater animal remain one of the most challenging areas in recent marine sciences field. Thus, the object of current study to examine the antifungal activity of Asian swamp eel (Monopterus albus) skin mucus. Eel skin mucus aqueous and methanol extracts were prepared with different extract concentrations from 0.49 to 1000 μg/mL against fungus pathogens i.e. Aspergillus niger and Microsporum gypseum. The antifungal assay conducted using well diffusion method. The results showed a dose dependent decrease the fungal growth, at 100µl/well, the inhibition zone of methanol extract against M. gypseum (25.7±0.75) mm, while the aqueous one was (23.3±0.16) mm Whereas eel skin mucus methanol and aqueous extracts showed lower inhibition zone against Aspergillus niger at the same concentration which was (11.1±0.59) mm and (9.0±0.15) mm respectively. The methanol extract showed the highest inhibitory activity against M. gypseum because M. gypseum infect the upper layers of the skin and eel skin mucus protect eels from infections. The results were statistically significant with p < 0.001. In conclusion, the present study carried out to reveal the antifungal activities of eel skin mucus which might be use as a source of antifungal agent.

Renal acid excretion contributes to acid-base regulation during hypercapnia in air-exposed swamp eel (Monopterus albus).

The swamp eel (Monopterus albus) uses its buccal cavity to air breathe, while the gills are strongly reduced. It burrows into mud during the dry season, is highly tolerant of air exposure, and experiences severe hypoxia both in its natural habitat and in aquaculture. To study the ability of M. albus to compensate for respiratory acidosis, we implanted catheters to sample both arterial blood and urine during hypercapnia (4% CO2) in either water or air, or during whole-animal air exposure. These hypercapnic challenges caused an immediate reduction in arterial pH, followed by progressive compensation through a marked elevation of plasma HCO3- over the course of 72 h. There was no appreciable rise in urinary acid excretion in fish exposed to hypercapnia in water, although urine pH was reduced and ammonia excretion did increase. In the air-exposed fish, however, hypercapnia was attended by a large elevation of ammonia in the urine and a large rise in titratable acid excretion. The time course of the increased renal acid excretion overlapped with the time period required to elevate plasma HCO3-, and we estimate that the renal compensation contributed significantly to whole-body acid-base compensation.

Nghiên cứu thay thế bột cá bằng bột đậu nành chế biến thức ăn cho lươn (Monopterus albus)

This study is aimed to evaluate the effects of replacing protein fish meal (FM) by different levels of protein defatted soybean meal (SBM) in practical diets for Asian swamp eel, Monopterus albus fingerlings of initial mean weight 7.2 g ind-1. Six iso-nitrogenous (45% crude protein) and iso-energetic (18.5 KJ g-1) diets were formulated by replacing 20%, 30%, 40%, 50% and 60% of protein FM by SBM and control diet only used protein FM (0% SBM). After 8 experimental weeks, the results showed weight gain (WG), FCR, protein efficiency ratio (PER) decreased with the increasing of dietary SBM protein levels. However, there were not significant differences (p>0.05) among treatments 0%, 20%, and 30% SBM protein. Survival rate was not significant differences (p>0.05) among treatments. Hepatosomatic index (HSI), body lipid and ash content were reduced from dietary 40% SBM protein levels. The results of this study showed that protein SBM is an acceptable ingredient to supply 30% of protein without causing reduction on growth performance and feed utilization of eel fingerling.

Effects of Housefly Maggot Meal and Earthworms on Growth and Immunity of the Asian Swamp Eel Monopterus albus (Zuiew)

Fly larvae (maggot meal) and earthworms are promising potential replacements for increasingly expensive and unsustainable fishmeal. Apart from being a good protein source, fly larvae also contain substances with immunostimulant capacity, however the impact of their inclusion in feed on the immune system remains only partially understood. To address this, we studied the effects of four diets with varying levels of earthworm (40-70%) and maggot meal (0-30%) on growth and immunocompetence of juvenile Asian swamp eels Monopterus albus (fish n = 480, duration = 40 days). Maggot meal inclusion resulted in a significantly (P<0.05) higher total protein, glutamic pyruvic transaminase activity, anti-oxidizing enzyme and lysozyme activity, and significantly lower triglycerides, in the blood serum. Bacterial (Aeromonas hydrophila) challenge test results showed that adding maggot meal to the feed improved survival rate and immunocompetence at all three tested inclusion ratios. The strongest positive impact on most studied parameters (including 50% higher survival and 21.4% higher immunocompetence) was observed in the 20% inclusion group. As positive effects were slightly lower at the 30% level, the optimal combination of the two ingredients was 20% maggot meal and 50% earthworms

Are all bony fishes oxygen regulators? Evidence for oxygen regulation in a putative oxygen conformer, the swamp eel Synbranchus marmoratus.

This study investigated the oxygen consumption of the putative oxygen conformer marbled swamp eel Synbranchus marmoratus during progressive hypoxia. Earlier studies have not reached an agreement on whether S. marmoratus is a conformer or a regulator. Our results support the view that S. marmoratus is an oxygen regulator, like most bony fishes.

Effects of different stocking densities on growth performance of Asian swamp eel Monopterus albus, water quality and plant growth of watercress Nasturtium officinale in an aquaponic recirculating system

This study was conducted to determine the effect of different stocking densities on growth rate of Asian swamp eel (Monopterus albus), growth of watercress (Nasturtium officinale) in a floating-draft aquaponic recirculating system. Two factorial experiment designs consist of three different swamp eel (16.67 ± 3.48 g/individual) densities of 100, 180 and 260 individuals/m2 (8.4, 15.0 and 21.7 kg/m3, respectively) integrated with hydroponic trough of watercress (SEW) or without watercress (swamp eel only, SE). Watercress seeds were put into styrofoam, floating rack (80 heads/m2). Swamp eels were fed 2 times per day with commercial pellet (42% protein). The experiment was run for 65 days with two cycles of watercress. Statistical analysis by Two-way ANOVA showed that there is no significant difference (P > .05) in growth performance of swamp eel at different stocking densities between the SEW and SE systems. However, statistical analysis by One way ANOVA showed that there is a significant difference (P < .05) on weight gain (WG) and daily weight gain of animals among the SEW treatments. The highest WG was 32.78 ± 2.09 g/ind. and 41.71 ± 9.05 g/ind. for treatment of 180 inds./m2 at the SEW and SE, respectively. The average survival rate of animal in all treatments was above 80% and was not significant difference among the treatments. The lowest FCR (2.15 ± 0.94) were found in treatment 180 inds./m2 of the SEW. Production of watercress was low in all treatments, the highest biomass (507.81 ± 91.01 g/m2) was recorded for treatment 180 inds./m2 of the SEW. Nutrient accumulation was relatively high at higher stocking densities of swamp eel and was higher in the SE system compared to the SEW system. Total ammonia nitrogen (TAN) concentrations in the SE treatments were ranging from 2.61 ± 1.81 mg/L (120 ind./m2) to 5.77 ± 3.19 mg/L (260 ind./m2). Whereas, the TAN levels in the SEW treatments were only ranging from 1.94 ± 1.44 to 5.35 ± 0.36 mg/L and even lower in hydroponic trough (1.3–3.15 mg/L). Similarly, nitrate‑nitrogen level was high in the SE treatments (1.43 ± 1.36–2.36 ± 1.43 mg/L) and lower in the SEW treatments (0.89 ± 1.36–1.42 ± 1.34 mg/L). Generally, swamp eel farming combined with hydroponic trough was feasible in handling water quality and required little water change in contrast to SE treatments which required as much as 1 water change a day. This study found that the stocking density of 180 inds./m2 seems to be the most effective density for growth, survival of swamp eel as well as nutrient accumulation in the SEW. The results of this study provide an important information as to how aquaculture of swamp eel may be expanded in the Mekong Delta without destroying the environment by releasing nutrient rich effluent from growing chambers.

Disinfection effect of povidone-iodine in aquaculture water of swamp eel (Monopterus albus).

The swamp eel (Monopterus albus) is an important commercial farmed fish species in China. However, it is susceptible to Aeromonas hydrophila infections, resulting in high mortality and considerable economic loss. Povidone-iodine (PVP-I) is a widely used chemical disinfectant in aquaculture, which can decrease the occurrence of diseases and improve the survival. However, environmental organic matter could affect the bactericidal effectiveness of PVP-I, and the efficacy of PVP-I in aquaculture water is still unknown. In this paper, disinfection assays were conducted to evaluate the effectiveness of PVP-I against the A. hydrophila in different types of water. We found that the effective germicidal concentration of PVP-I in outdoor aquaculture water was 25 ppm for 12 h. In indoor aquaculture water with 105 CFU/mL bacteria, 10 ppm and 20 ppm of PVP-I could kill 99% and 100% of the bacteria, respectively. The minimal germicidal concentration of PVP-I in Luria-Bertani broth was 4,000 ppm. Available iodine content assay in LB solutions confirmed that the organic substance had negative impact on the effectiveness of PVP-I, which was consistent with the different efficacy of PVP-I in different water samples. Acute toxicity tests showed that the 24 h-LC50 of PVP-I to swamp eel was 173.82 ppm, which was much higher than the germicidal concentrations in outdoor and indoor aquaculture water, indicating its safety and effectivity to control the A. hydrophila. The results indicated PVP-I can be helpful for preventing the transmission of A. hydrophila in swamp eel aquaculture.

Molecular characterization and expression analysis of Asian swamp eel (Monopterus albus) CXC chemokine receptor (CXCR) 1a, CXCR1b, CXCR2, CXCR3a, CXCR3b, and CXCR4 after bacteria and poly I:C challenge

The CXC chemokine receptors (CXCRs) play critical roles in innate and adaptive immune systems. In this study, six Asian swamp eel (Monopterus albus) CXCRs (MaCXCR1–4) were identified and their molecular characterization and expression patterns were analyzed. The open reading frames (ORFs) of MaCXCR1a, MaCXCR1b, MaCXCR2, MaCXCR3a, MaCXCR3b, and MaCXCR4 were 1074 bp (base pairs), 1080 bp, 1125 bp, 1146 bp, 1083 bp, and 1140 bp, and encoded proteins of 357 aa (amino acids), 359 aa, 374 aa, 381 aa, 360 aa, and 379 aa, respectively. All these CXCRs have seven conserved transmembrane domains and four cysteines (with the exception of MaCXCR3b). Multiple sequence alignment revealed that the MaCXCRs possess a typical G-protein receptor family 1 signature and a DRY motif. There are also one to four potential N-glycosylation sites in the extracellular regions of the MaCXCRs, mainly distributed in the N-terminus and extracellular hydrophilic loop (ECL) 2 region. Phylogenetic analysis demonstrated that the MaCXCRs were clustered together with homologous proteins from other fish. Taken together with the amino acid identity and similarity analysis, these results suggested that the MaCXCRs are conserved with other homologous genes, in which CXCR4 is more conserved than CXCR1–3. The MaCXCRs loci showed conserved synteny among teleost fish, and we found that human CXCR1 shares a common ancestor with fish CXCR1a. MaCXCRs were constitutively expressed in a wide range of tissues (especially in immune-related tissues) with different expression levels, suggesting that the MaCXCRs have different roles in un-stimulated tissues, and may play vital roles under normal conditions. MaCXCRs showed different fold changes in the spleen after Aeromonas veronii and polyinosinic-polycytidylic acid (poly I:C) challenge, which suggested that MaCXCR1a and MaCXCR3a have longer antiviral activities compared with their antibacterial functions, and that MaCXCR1b possesses stronger antiviral than antibacterial activity. MaCXCR4 may play vital roles during bacterial and viral infection; however, MaCXCR2 has relatively small effect in antibacterial and antiviral responses. The differential responses of these genes to bacteria and poly I:C implied the differences in the mechanisms of defense against viruses and bacteria.

Review about the importance of skin mucus from asian swamp eel (Monopterus albus)

Review about the importance of skin mucus from asian swamp eel (Monopterus albus)

Melanocortin-4 receptor in swamp eel (Monopterus albus): Cloning, tissue distribution, and pharmacology

Melanocortin-4 receptor (MC4R) plays critical roles in the regulation of various physiological processes, such as energy homeostasis, reproduction and sexual function, cardiovascular function, and other functions in mammals. Although the functions of the MC4R in fish have not been extensively studied, the importance of MC4R in regulation of piscine energy expenditure and sexual functions is emerging. Swamp eel (Monopterus albus) is an economically and evolutionarily important fish widely distributed in tropics and subtropics. We cloned swamp eel mc4r (mamc4r), consisting of a 981 bp open reading frame encoding a protein of 326 amino acids. The sequence of maMC4R was homologous to those of several teleost MC4Rs. Phylogenetic and chromosomal synteny analyses showed that maMC4R was closely related to piscine MC4Rs. qRT-PCR revealed that mc4r transcripts were highly expressed in brain and gonads of swamp eel. The maMC4R was further demonstrated to be a functional receptor by pharmacological studies. Four agonists, α-melanocyte stimulating hormone (α-MSH), β-MSH, [Nle4, D-Phe7]-α-MSH (NDP-MSH), and adrenocorticotropin, could bind to maMC4R and induce intracellular cAMP production dose-dependently. Small molecule agonist THIQ allosterically bound to maMC4R and exerted its effect. Similar to other fish MC4Rs, maMC4R also exhibited significantly increased basal activity compared with that of human MC4R. The high basal activity of maMC4R could be decreased by inverse agonist ML00253764, suggesting that maMC4R was indeed constitutively active. The availability of maMC4R and its pharmacological characteristics will facilitate the investigation of its function in regulating diverse physiological processes in swamp eel.

Oxidative stress and inflammatory responses in the liver of swamp eel (Monopterus albus) exposed to carbon tetrachloride

“Liver and gall syndrome” disease often caused dramatic economic losses in swamp eel (Monopterus albus) which is one of the most economically important freshwater aquaculture fish in China. Carbon tetrachloride (CCl4)-induced liver injury model has been evidenced as a useful method to screen the hepatoprotective agents to study and prevent this disease in fish. Therefore, in order to provide a better research platform for prevention and treatment liver diseases in swamp eel, we evaluated the hepatotoxicity effects of CCl4 on swamp eel based on the acute toxicity and biochemical responses of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), lactate dehydrogenase (LDH), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA), as well as mRNA expression levels of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO). The 96 h LD50 value of CCl4 in swamp eel was 2.54 g/kg. Sublethal levels of CCl4 induced time-depended liver injury in swamp eel, evidenced by the significant increases of serum GPT, GOT and LDH levels at the first 48 h injection, but restoration after 96 h injection. CCl4 led to oxidative stress, supported by the enhanced of MDA contents, and decreased of SOD and CAT activities. Moreover, CCl4 caused hepatic inflammatory reaction, evidenced by the significant changes of the transcription of COX and 5-LO genes in liver tissues. Overall, our results suggested that lipid peroxidation, antioxidant enzymes and COX and 5-LO pathways are important mechanisms involved in CCl4-induced liver injury, and could be used as the effective biomarkers of CCl4-induced liver injury model to screen the hepatoprotective agents in swamp eel.

Review about the Factors Effect on Asian Swamp Eel (Monopterus albus)

Review about the Factors Effect on Asian Swamp Eel (Monopterus albus)

The Growth Performance and Nutrient Quality of Asian Swamp Eel Monopterus albus in Central Java Indonesia in a Freshwater Aquaculture System with Different Feeds

ABSTRACTThe Asian swamp eel (Monopterus albus) is a high protein content fish with delicious taste that can survive for 6–8 months. The growth performance and nutrient quality of Asian swamp eels in a freshwater aquaculture system in Central Java, Indonesia was studied using a completely randomized design. Golden snails, snails, silkworms, and earthworms were the feeding treatments at 5% of total body weight. The test animals weighed 5.68 ± 0.35 g after a 60-day culture, and the density was 36 eels/m2. Providing different types of feed had significant effects (P < 0.05) on relative growth rate (RGR), feed intake, and survival rate (SR) but did not significantly affect the protein efficiency ratio (P > 0.05). The best final weight, RGR, and SR results were 11.80 g, 2.64%, and 80.95% during a 60-day culture with silkworms used as feed. The nutrient quality in a similar treatment found with the best proximate composition was 76.90% protein, 3.24% fat, 25.19% palmitic acid, 15.41% oleic acid, 15.9% glutamic acid, 8.2% isoleucine, and 8.9% lysine.

Molecular Cloning and Expression of Major Histocompatibility Complex Class Iα Gene of Swamp Eel (Monopterus albus)

Major histocompatibility complex (MHC) plays an important role in the immune response of vertebrates. In this study, we isolated MHC class Iα gene from swamp eel (Monopterus albus) by rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR). In order to study the function of MHC Iα in swamp eel, tissue distribution and immune response of the MHC Iα after bacterial challenge were analyzed. All the characteristic features of MHC Iα chain structure were identified by the deduced amino acid sequence, including the leader peptide, α1, α2, and α3 domains, connecting peptide, transmembrane and cytoplasmic regions, conserved cysteines, and N-glycosylation site. The deduced amino acid sequence of the MHC Iα shares 27.3% to 69.6% similarity with those of other vertebrates. Quantitative real-time PCR (qRT-PCR) demonstrated that MHC Iα gene was ubiquitously expressed in ten tissues, comparatively higher in immune related tissues, including the liver and intestine. Challenge of M. albus with the extracellular pathogen, Aeromonas hydrophila, resulted in a significant increase in the expression of MHC Iα within 72 h after infection and these high levels were maintained for 72 h in kidneys, spleen, and skin, whereas in the intestine and liver, it was found first in the form of up-regulated and then down-regulated gene. These results demonstrated that MHC Iα gene played an important role in response to bacterial infection in M.albus.

Acid-base regulation in the air-breathing swamp eel (Monopterus albus) at different temperatures.

Vertebrates reduce arterial blood pH (pHa) when body temperature increases. In water breathers, this response occurs primarily by reducing plasma HCO3- levels with small changes in the partial pressure of CO2 (PCO2 ). In contrast, air breathers mediate the decrease in pHa by increasing arterial PCO2 (PaCO2 ) at constant plasma HCO3- by reducing lung ventilation relative to metabolic CO2 production. Much less is known about bimodal breathers, which utilize both water and air. Here, we characterized the influence of temperature on arterial acid-base balance and intracellular pH (pHi) in the bimodal-breathing swamp eel, Monopterus albus This teleost uses the buccopharyngeal cavity for gas exchange and has very reduced gills. When exposed to ecologically relevant temperatures (20, 25, 30 and 35°C) for 24 and 48 h, pHa decreased by -0.025 pH units (U)°C-1 in association with an increase in PaCO2 , but without changes in plasma [HCO3-]. pHi was also reduced with increased temperature. The slope of pHi of liver and muscle was -0.014 and -0.019 U °C-1, while the heart muscle showed a smaller reduction (-0.008 U °C-1). When exposed to hypercapnia (7 or 14 mmHg) at either 25 or 35°C, M. albus elevated plasma [HCO3-] and therefore seemed to defend the new pHa set-point, demonstrating an adjusted control of acid-base balance with temperature. Overall, the effects of temperature on acid-base balance in M. albus resemble those in air-breathing amniotes, and we discuss the possibility that this pattern of acid-base balance results from a progressive transition in CO2 excretion from water to air as temperature rises.

Ảnh hưởng của nồng độ CO2 cao trong nước lên cân bằng acid và base của lươn đồng, Monopterus albus (Zuiew, 1973)

The study was conducted to investigate the variability of parameter in water with different stages as well as to determine the effect of high CO2 on the acid-base regulation of the eel. The field survey was measuring CO2 levels in 9 swamp eel grow-out tanks. The results showed that the partials pressure of CO2 in water was 9.5 mmHg and 28 mmHg in the middle and harvest of culture cycle (9 months), respectively. The laboratory experiment was conducted with 3 treatments including control, 14 and 30 mmHg CO2. Blood was sampled at 0, 3, 6, 24, 48, and 72-h. Blood pH decreased during the first 24-h and completely recovered after 72-h with value of 7.4±0.04 at the treatment of 14 mmHg CO2. In contrast, partial pressure of CO2 in the blood and plasma HCO3- increased significantly at the treatments of 14 and 30 mmHg CO2 during hypercapnic exposure compared to the control group (p

Photographs of Wading Bird Depredation Update Invasion Extent of Monopterus albus (Asian Swamp Eel)

Several anecdotes exist of wading birds depredating invasive Monopterus albus (Asian Swamp Eel) in waterways of the conterminous US. We present photographic evidence of 4 different wading bird species depredating adult Asian Swamp Eels in Georgia and Florida herein. Photographs taken by wildlife enthusiasts could provide a means for early detection of the Asian Swamp Eel and other aquatic species that are challenging to detect in waterways.

Morphometrics and Genetic Diversity COI Gene of Swamp Eel (Monopterus albus) from Four Population in West Java

Swamp eel ( Monopterus albus ) is an economically important freshwater fish which has the potential to sustainable development. This species is considered as one of the taxonomically problematic spesies due to its complex characters and similar morphology to Monopterus cuchia and Monopterus javanensis that often lead to taxonomic dilemmas. Taxonomic certainty is an essential basis information in sustainable fisheries management, studies on morphometric characters, and genetic variability is a method which commonly used for species or stock identification. This study was aimed to validate the taxonomy certainty and evaluate the kinship of swamp eel from four populations (Indramayu, Subang, Tasikmalaya, and Garut distrik) in West Java. Morphometric analysis was conducted by measurement of 19 characters, whereas genetic analysis was conducted using PCR-Sequencing method of COI gene. The results from stepwise discriminant analysis showed that 7 morphometric characters ratio were powerful to classified the populations and the first two discriminant functions accounted 84.2% of the total variability. Genetic diversity indicated by alignment 14 sekuen of COI gene showed there were 11 haplotypes from 109 variable sites. Results of cluster and phylogenetic tree analysis indicated that swamp eel from four research populations were grouped into two major clusters. The first cluster consists of Indramayu and Subang population, the second cluster consists of Tasikmalaya and Garut population. This cluster is an evidence that swamp eel from West Java possesed morphometric and genetic diversity among populations and lead to assumption that at least there were two cryptic species from M. albus in West Java.

Comparative genomic insights into the taxonomy ofEdwardsiella tardaisolated from different hosts: Marine, freshwater and migratory fish

Edwardsiella tarda, a Gram-negative member of the family Enterobacteriaceae, has been isolated from many animal species worldwide, especially fish species. Its broad host range indicates the diversity in taxonomy, which attracted the attention of many researchers. Here, we added genome of E. tarda strain isolated from freshwater fish to comparative genomics study for the first time. We sequenced and assembled the genome of E. tarda ASE201307 which was isolated from freshwater Asian swamp eel. ASE201307 genome contained a single circular chromosome of 3.68M with G+C 57.09% content. Comparative genomics including SNP calling, synteny block, Core/Pan genes analysis and phylogeny analysis was conducted among ASE201307 and other Edwardsiella strains isolated from different fish species. Results of SNP analysis and synteny block demonstrated the close relative of ASE201307, FL95.01 and DT which were all isolated from freshwater fish. In further analysis heat map of dispensable genes and phylogenetic tree, all E. tarda strains were divided into two groups. One was isolated from freshwater fish and the other was isolated from marine/migratory fish. Based on all studies above, we proposed the living environment of hosts as a new taxonomic character and divided E. tarda isolated from diseased fish into freshwater group and marine/migratory group.

Genetic variability and performance of Asian swamp eel Monopterus albus (Zuiew, 1793) from West Java cultured in saline water medium

&lt;p class="Pa3"&gt;&lt;strong&gt;ABSTRACT &lt;/strong&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p class="Pa5"&gt;Asian swamp eel &lt;em&gt;Monopterus albus &lt;/em&gt;(Zuiew, 1793) is freshwater fish species which is prospective for domestic and export markets. The production is limited depend on the catches of natural population. The cultivation of eel has been carried out to increase the production for sustainability. This study was conducted to evaluate the genetic variability and performance of Asian swamp eel from West Java and its potential cultivation in water based media with salinity. Three populations from West Java were collected of different altitudes from Sukabumi (673 m asl), Cianjur (429 m asl), Karawang (51 m asl) sized 19–26.5 cm and weighed 4.95–11.4 g. The cultivation was performed during 30 days in water media without substrate at salinity 6 ppt with density of 1 kg/m2 and maintenance at container 50×30×30 cm completed with shelter pipe of ¾ inches diameter and 20 cm length, height of water 10 cm and water exchange 100% every day, fed at satiation using &lt;em&gt;Tubificidae &lt;/em&gt;once a day. Genetically, all of the populations showed low heterozygosity at 1.19–1.23% and genetic distance 0.01–0.04. Asian swamp eel adapted better at water salinity 6 ppt which indicated by low mesure of osmotic gradient and blood glucose. Asian swamp eel from Karawang showed superior at survival rate (90%) and daily growth rate (1.42/day).&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p class="Pa5"&gt;Keywords: Asian swamp eel, &lt;em&gt;Monopterus albus&lt;/em&gt;, cultivation, genetic variability, salinity&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p class="Pa3"&gt;&lt;strong&gt;ABSTRAK &lt;/strong&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p class="Pa5"&gt;Belut sawah &lt;em&gt;Monopterus albus &lt;/em&gt;(Zuiew, 1793) merupakan komoditas ikan air tawar potensial di pasar domestik maupun ekspor, namun produksinya masih mengandalkan hasil tangkapan dari alam karena budidaya belum berkembang. Penelitian ini bertujuan untuk mengevaluasi keragaman genetik dan keragaan belut sawah asal Jawa Barat dan potensinya untuk dikembangkan dengan teknik budidaya di air bersalinitas tanpa lumpur. Tiga populasi belut sawah dikoleksi dari lokasi di Jawa Barat dengan ketinggian berbeda yaitu Sukabumi (673 m dpl), Cianjur (429 m dpl), Karawang (51 m dpl). Sumber genetik belut berukuran 19–26,5 cm dan bobot berkisar 4,95–11,4 g dipelihara selama 30 hari dalam media air tanpa substrat bersalinitas 6 ppt. Wadah pemeliharaan berukuran 50×30×30 cm dilengkapi shelter pipa paralon diameter ¾ inci dan panjang 20 cm serta ketinggian air 10 cm. Padat penebaran ikan 1 kg/m2 (20 ekor/wadah), serta pergantian air 100% dilakukan setiap hari dan pemberian pakan berupa Tubificidae secara &lt;em&gt;at satiation &lt;/em&gt;satu kali sehari. Secara genetik ketiga populasi menunjukkan tingkat heterosigositas yang rendah yaitu berkisar 0,19–0,23 % dan jarak genetik 0,01–0,04. Belut sawah menunjukkan respons adaptasi yang baik dalam media air tanpa substrat pada salinitas 6 ppt berdasarkan indikator beban osmotik dan kadar glukosa yang rendah. Belut sawah asal Karawang unggul pada laju pertumbuhan harian (1,42/hari) dan kelangsungan hidup (90 %).&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;Kata kunci: belut sawah &lt;em&gt;Monopterus albus&lt;/em&gt;, budidaya, keragaman genetik, salinitas&lt;/p&gt;