Larval Extracts Research Articles

Assesment of Hypoderma infestation in a wild population of Cervus elaphus from mountains Atlantic ecosystems in southwestern Europe (Spain)

Hypodermosis in Cervus elaphus was studied in the Riaño Regional Hunting Reserve, Province of León, north-western Spain. One hundred and ten red deer were examined for the presence of warble fly larvae. They were analyzed by PCR analysis of the COI region of mt-DNA and identified as Hypoderma actaeon. The prevalence of larvae was 42.7% with a mean intensity of 12.5 ± 18 (range 1–80) warbles/deer infested. The distribution of larvae in the infested animals showed an aggregated/overdispersed pattern (aggregation index = 25.84), where the larvae are not randomly or uniformly distributed, but strongly aggregated among their hosts. Larvae were found in all three states. First and second-instars were observed mainly in the autumn until the end of winter (November-March) and third-instars in late winter until mid-spring (March–May). The adult animals and the males had a higher prevalence than the young and the females, finding statistically significant differences only according to the sex of the animals. Seasonal variations were observed in the prevalence with the highest number of infested animals in winter and autumn, but not in terms of the mean intensity of parasites. Additionally, we assessed the presence of anti-Hypoderma antibodies in serum by means of indirect ELISA tests, using a crude larval extract (CLE) and a purified fraction the hypodermin C (HyC) obtained from first instars of Spanish isolates of Hypoderma lineatum (cattle). These findings confirm that H. actaeon is widely distributed in northern Spain, and provide new information about its chronobiology in mountainous Atlantic ecosystems from southwestern Europe.

Characterized extracts of the tropical red seaweed Acanthophora spicifera protect Ostrea edulis larvae against Vibrio coralliilyticus

Vibriosis is one of the most common bacterial diseases affecting bivalve mollusk hatcheries, especially during their early life stages, leading to high mortality rates and significant economic losses worldwide. Bivalves are more susceptible to diseases because they are filter-feeding organisms capable of accumulating a wide diversity of microorganisms, antibiotic residues, and other contaminants present in the marine environment. In the present study, we evaluated the in vitro and in vivo bioactivity of the aqueous and ethanolic (10, 25, 50, 75, and 100%) extracts of the tropical red seaweed Acanthophora spicifera against Vibrio coralliilyticus which affects the larvae of the European oyster Ostrea edulis. The aqueous extract displayed 43.1% inhibition of V. coralliilyticus growth at 100 mg/L after 46 h (regrowth performance). During the toxicity test, O. edulis larvae showed a survival rate of 91.1 ± 5.8% and 84.6 ± 5.2% at aqueous extract concentrations of 1 and 5 mg/L, respectively. In the challenge test with V. coralliilyticus at a cell density of 105 cells/mL, the aqueous and 10, 25, and 50% ethanol (v/v) extracts at 1 mg/mL resulted in significantly higher survival rates (99.2 ± 1.0%, 93.3 ± 8.8%, 96.5 ± 0.9%, and 95.8 ± 1.9%, respectively) at 48 h post-challenge compared to only 0.6 ± 1.1% for the larvae challenged with Vibrio without seaweed extract (positive control). Chemical characterization of aqueous and 25% ethanol extracts, showing the highest bioactivity based on the challenge test, revealed the presence of succinic acid and the heterosides floridoside and digeneaside as major components in both extracts. This is the first report of the presence of digeneaside in A. spicifera. These findings suggest that aqueous and 25% ethanolic extracts from Acanthophora spicifera provide a natural alternative for disease management in O. edulis hatcheries.

Insights into the mechanism of action of the chlorophyll derivative 13-2-hydroxypheophytine a on reducing neutral lipid reserves in zebrafish larvae and mice adipocytes

Obesity is a worldwide epidemic and natural products may hold promise in its treatment. The chlorophyll derivative 13-2-hydroxypheophytine (hpa) was isolated in a screen with zebrafish larvae to identify lipid reducing molecules from cyanobacteria. However, the mechanisms underlying the lipid-reducing effects of hpa in zebrafish larvae remain poorly understood. Thus, investigating the mechanism of action of hpa and validation in other model organisms such as mice represents important initial steps.In this study, we identified 14 protein targets of hpa in zebrafish larvae by thermal proteome profiling, and selected two targets (malate dehydrogenase and pyruvate kinase) involved in cellular metabolism for further validation by enzymatic measurements. Our findings revealed a dose-dependent inhibition of pyruvate kinase by hpa exposure using protein extracts of zebrafish larvae in vitro, and in exposure experiments from 3 to 5 days post fertilization in vivo. Analysis of untargeted metabolomics of zebrafish larvae detected 940 mass peaks (66 increased, 129 decreased) and revealed that hpa induced the formation of various phospholipid species (phosphoinositol, phosphoethanolamine, phosphatidic acid). Inter-species validation showed that brown adipocytes exposed to hpa significantly reduced the size of lipid droplets, increased maximal mitochondrial respiratory capacity, and the expression of PPARy during adipocyte differentiation.In line with our data, previous work described that reduced pyruvate kinase activity lowered hepatic lipid content via reduced pyruvate and citrate, and improved mitochondrial function via phospholipids. Thus, our data provide new insights into the molecular mechanism underlying the lipid reducing activities of hpa in zebrafish larvae, and species overlapping functions in reduction of lipids.

Performance of black soldier fly larvae (Hermetia illucens, l.) on different feed substrates

Abstract The study assessed the nutrient composition of Sesbania grandiflora (SG) and Moringa oleifera (MO) leaves, and agro-industrial by-products, including soybean waste (SBW), wheat pollard (WP), rice bran (RB), and milk-extracted coconut meat (MECM) to determine the potential of these resources as feed substrates for rearing black soldier fly larvae (BSFL). Developmental studies of BSFL were conducted for three weeks with four replicates for each substrate. The nutrient composition and growth performance data were collected until half of the larvae had transformed into prepupae. The crude protein (CP) content of BSFL ranged from 26 to 57 g/100 g on a dry matter (DM) basis. The CP levels of larvae declined significantly () as the development time progressed. The ether extract (EE) or crude fat levels of larvae ranged between 6 and 55 g/100 g DM and were significantly () different between substrates. In all samples, larval amino acid profiles were characterised by high levels of glutamic acid (4.08 g/100 g DM) and leucine (2.48 g/100 g DM). The SBW-fed larvae showed a shorter development time (12.75 ± 0.25 days); the longest was MECM-fed larvae (28.5 ± 0.29 days). Larvae on the higher protein feed (SG, MO, and SBW) had the highest feed reduction and larval yield compared to the lower protein group (WP, RB, and MECM). The study demonstrated that BSFL can thrive on a range of substrates where all six feedstuffs (SG, MO, SBW, WP, RB, and MECM) have the potential to be employed in mass production of BSFL with high nutritional values. The selection of a good quality substrate for BSFL production is critical since the substrate’s nutrient composition influences the development and nutrient composition of the larvae.

Evaluation of the Antibacterial Activity of Chrysomya albiceps Larval Extract and its Synergistic Effects with Antibiotics

Evaluation of the Antibacterial Activity of Chrysomya albiceps Larval Extract and its Synergistic Effects with Antibiotics

Antioxidant, anti-inflammatory, anti-adipogenesis activities and proximate composition of Hermetia illucens larvae reared on food waste enriched with different wastes.

The use of insects as a food source is not a new idea, but it has gained momentum in recent years due to the need for sustainable protein source in livestock feedstuffs and for more environmentally friendly organic waste treatment. In the case of black soldier fly larvae, Hermetia illucens, research has focused on their ability to convert organic waste into usable nutrients and their potential as a protein source for animal and human consumption. In this study, black soldier fly larvae were reared on raw food waste (FW) mixed with garlic peel waste (G) and hydronic growth media waste (H) and the proximate composition and bioactive potential of black soldier fly larvae extract (SFL) were compared. Analysis showed that protein content of SFL fed with G was 4.21% higher and lipid content was 9.93% lower than FW. Similar results were obtained for SFL fed with H. Antioxidant activity of SFL-G was higher than that of SFL-FW and SFL-H. SFL-G treatment exhibited enhanced anti-inflammatory and anti-adipogenesis activities as well compared to SFL-FW. Current results suggested that feeding black soldier fly larvae with food waste added with garlic peel and hydroponic growth media waste resulted in increased nutritional value, polyphenol content and bioactivity for SFLs. In this context, garlic peel waste-added food waste was suggested a promising substrate for black soldier fly larvae to obtain high-quality protein source with enhanced antioxidant, anti-inflammatory and anti-adipogenic potential.

Vacuum extraction: an effective larval sampling method for spotted-wing drosophila in small fruit crops.

Detecting and sampling the pest for pest management, either through enumerating their life stages or by quantifying the crop damage, is the cornerstone in deploying integrated pest management. Currently, for spotted-wing drosophila, Drosophila suzukii Matsumura, larval extraction from the fruit samples involves immersing the fruits in hot water, salt, or sugar solution. We are introducing a novel, fast, and effective larval sampling technique where D. suzukii larvae can be extracted from infested fruits by subjecting the fruit samples to vacuum pressure. We optimized the vacuum pressure and vacuum duration for larval extraction from blueberries by testing a range of vacuum pressures and durations. A vacuum pressure of -98 kPa for 60 min resulted in the maximum larval recovery of the small, medium, and large larvae from blueberries. A 30-min incubation at -98 kPa also yielded similar results. Larval extraction at -98 kPa for 60 min on average recovered 61, 70, and 83% of larvae from 2, 4, and 6-day incubated fruit samples, respectively. The fruit sample size (37, 149, and 298 g) did not affect the larval extraction efficacy. Additionally, comparing larval extraction efficacy at -98 kPa with the salt and sugar extraction, incubated for 10, 30, and 60 min, suggests that vacuum extraction is comparable to or more efficient than the salt and sugar methods in extracting larvae from the infested blueberries. Overall, our results indicate that vacuum sampling is a promising method for detecting D. suzukii larval infestation in small fruit crops.

Aqueous extract of Protaetia brevitarsis larvae increases mTOR-mediated growth rate in zebrafish larvae

Objective: To evaluate the effects of an aqueous extract of Protaetia brevitarsis (AEPB) on the growth of zebrafish and preosteoblast MC3T3-E1 cells. Methods: The effects of AEPB on the linear growth and the expression of growth-related genes in zebrafish and MC3T3-E1 cells were assessed using various molecular techniques. Furthermore, the involvement of the mammalian target of rapamycin (mTOR) pathway in AEPB-induced growth was investigated by employing the mTOR inhibitor rapamycin. Results: AEPB administration led to a significant and dose-dependent increase in zebrafish larvae growth over time. Additionally, AEPB treatment upregulated the expression of growth hormone-1 (GH-1), insulin-like growth factor-1 (IGF-1), growth hormone receptor-1 (GHR-1), and cholecystokinin-a (CCKA) in zebrafish. Similarly, AEPB stimulated the expression and release of IGF-1 and accelerated mTOR expression in MC3T3-E1 cells. In addition, rapamycin hindered AEPB-induced linear growth in zebrafish larvae and suppressed the expression of growth-promoting genes by inhibiting mTOR activation. Conclusions: AEPB shows growth-promoting effects by upregulating growth-related genes and activating the mTOR signaling pathway. Further investigations are warranted to elucidate its mechanisms of action and explore its potential application in the development of growth-enhancing supplements for various purposes.

Optimization of extraction factor and nutritional characterization of black soldier fly larvae oil via subcritical butane extraction

This study aimed to optimize the subcritical butane extraction of black soldier fly larvae (Hermetia illucens) using response surface methodology (RSM) and evaluate the nutritional properties of oil (BSFLO) and meal (BSFLM) products. A Box-Behnken design was conducted to reveal the effects of temperature (25–65 °C), extraction time (20–60 min) and number of extractions (1–5 times) on oil yield. Results showed that oil yield was significantly affected by number of extractions as well as the interaction of extraction time and number of extractions. The optimal conditions were 35 °C, 50 min/time and 5 times with the extraction yield of 31.19% (dry basis). Nutritional properties indicated that subcritical butane extraction did not change the fatty acids composition of BSFLO and amino acids composition of BSFLM. The total amino acid of BSFLM produced by subcritical butane extraction was enhanced due to the more lipid was separated. However, the nitrogen solubility index and protein dispersibility index of BSFLM decreased, which may negatively affect the protein utilization. To conclude, subcritical butane extraction provided an available and promising method for further processing of black soldier fly larvae.

Antibiosis interaction of black soldier flies (Hermetia illucens) (Diptera: Stratiomyidae) with house fly (Musca domestica) (Diptera: Muscidae).

Black soldier fly (Hermetia illucens (Linnaeus, 1758)) larvae inhibit oviposition of house fly (Musca domestica Linnaeus, 1758) by releasing a semiochemical, although in some situations, inhibition is only partial. We hypothesized that there is a certain period in the life cycle of black soldier fly when it can cause antibiosis of the house fly. Choice and non-choice tests were used to separately examine the effectiveness of each developmental stage of black soldier fly (egg, larval (phase I, II, and III), prepupal and pupal stages) and crude extract of larvae on house fly oviposition. Tests using each developmental stage were compared with controls lacking black soldier fly. The effects of black soldier fly on the number of newly hatched house fly larvae were evaluated and there was a significant difference between the test and control in the number of eggs laid by house fly for all phases of the black soldier fly larval stage. Strong inhibition was found in some black soldier fly larval phases. Significant differences in the numbers of house fly eggs oviposited in food containers treated with crude extract were found when compared with a control, confirming that chemicals from black soldier fly larvae resulted in inhibition of oviposition of house fly. The results from experiment also indicated that chemicals from black soldier larvae influenced the number of house fly larvae newly hatched from eggs.

Wash Deployment and Geo-helminth Ova Dispersion in Primary Schools in Akure North and Owo Local Government Areas, Ondo State, Nigeria

Soil-Transmitted Helminths (geo-helminths) are intestinal parasites causing human infections that are soil-borne. The study assessed the level of soil contamination with geo-helminths ova and also evaluated the level of compliance to WASH policies in some selected public and private schools in Akure North and Owo Local Government Areas of Ondo state, respectively. The study was conducted in the major districts of the two towns.
 Methods
 Soil samples were collected from three (3) different locations within each school premise: Toilet areas, classroom and playground. Assessment sheets were used to evaluate data on indicators of compliance to WASH interventions. Modified Baemann’s culture technique was used in the extraction of geo-helminths larvae and sedimentation techniques were used in the concentration and isolation of geo-helminths eggs. The significant difference in soil contamination between public and private schools was obtained using statistical analysis.
 Result
 Of the 162 soil samples examined from each local government area, Akure North had the highest number of contaminated samples, n=116 (71.61%), while Owo local government had the least, n =88 (54.32%). Four (4) different geo-helminth species were identified; Hookworm, Ascaris lumbricoides, Strongyloides stercoralis, and Trichuris trichiura. The most occurring parasites seen in Akure North were hookworm larvae (67.83%), Strongyloides stercoralis (67.83%), hookworm ova (11.25%) and ova of Ascaris lumbricoides (7.56%). Likewise, Hookworm larvae had the highest level of occurrence (51.67%), while Trichuris trichiura was the least occurring (0.77%) in Owo local government area. Public schools had the higher parasite count 668/780 (85.64%), while private schools had the lesser parasite count, 112 /780 (14.36%).
 Conclusion
 The study revealed poor deployment of WASH in the schools, and children were predisposed to geo-helminths infections due to the high level of contamination, particularly in the public schools.

In vitro antibacterial activity and synergetic effect of crude extract of the Wohlfahrtia nuba (Diptera: Sarcophagidae) flesh fly larvae

Multidrug-resistant pathogens have become ubiquitous, and effective treatment alternatives are urgently required. Maggot therapy is a promising agent that is being studied to overcome antibiotic-resistant pathogens. This study evaluated the antibacterial activity of the larvae extract of the Wohlfahrtia nuba (wiedmann) (Diptera: Sarcophagidae) flesh fly on the growth of five pathogenic bacterial species (methicillin-sensitive Staphylococcus aureus [ATCC 29213], methicillin-resistant Staphylococcus aureus [ATCC BAA-1680], Pseudomonas aeruginosa [ATCC 27853], Escherichia coli [ATCC 25922], and Salmonella typhi [ATCC 19430]) in vitro by using different techniques. Resazurin-based turbidimetric assay demonstrated that the W. nuba maggot exosecretion (ES) was potent against all the bacterial species tested, and according to the determined minimum inhibitory concentration (MIC) for each bacterium, gram-negative bacteria were more sensitive than gram-positive bacteria. Additionally, colony-forming unit assay showed that maggot ES was able to inhibit bacterial growth rate for all bacterial species tested, where the highest bacterial reduction was observed with methicillin-sensitive S. aureus (MSSA) followed by S. typhi. Moreover, maggot ES was shown to be concentration-dependent, where 100 μL of ES at 200 mg/mL was bactericidal towards methicillin-resistant S. aureus (MRSA) and P. aeruginosa compared with 100 μL at the MIC of the ES. Moreover, based on the result of agar disc diffusion assay, maggot extract was more efficient against P. aeruginosa and E. coli than the remaining reference strains tested. Furthermore, the combination between regular antibiotics with maggot ES at different concentrations indicated that ES acts synergistically with the tested antibiotics against the five bacterial models.

Cross-generation pheromonal communication drives Drosophila oviposition site choice

In a heterogeneous and changing environment, oviposition site selection strongly affects the survival and fitness of the offspring.1,2 Similarly, competition between larvae affects their prospects.3 However, little is known about the involvement of pheromones in regulating these processes.4,5,6,7,8 Here, we show that mated females of Drosophila melanogaster prefer to lay eggs on substrates containing extracts of conspecific larvae. After analyzing these extracts chemically, we test each compound in an oviposition assay and find that mated females display a dose-dependent preference to lay eggs on substrates spiked with (Z)-9-octadecenoic acid ethyl ester (OE). This egg-laying preference relies on gustatory receptor Gr32a and tarsal sensory neurons expressing this receptor. The concentration of OE also regulates larval place choice in a dose-dependent manner. Physiologically, OE activates female tarsal Gr32a+ neurons. In conclusion, our results reveal a cross-generation communication strategy essential for oviposition site selection and regulation of larval density.

Effect of feeding a diet containing housefly (Musca domestica) larvae extracts on growth performance in broiler chickens

Insects like housefly (Musca domestica L.) are future feed resources for economic animals because insects can improve growth performance by promoting the immune function and gut microbial balance. However, little is known about research reports on housefly larvae extracts containing an antibacterial peptide. This study investigated the effect of feeding diets supplemented with housefly larvae extract (HLE) containing antibacterial peptides on the growth performance of broiler chickens. Nine hundred broilers (Ross 308) were fed diets containing HLE for 35 days. Treatment groups consisted of CON (control without HLE), PC (positive control, 8 ppm of avilamycin), HLE50 (diet containing 50 ppm of HLE), HLE100 (diet containing 100 ppm of HLE), HLE150 (diet containing 150 ppm of HLE), and HLE200 (diet containing 200 ppm of HLE). Body weight gain and feed conversion ratio were significantly (P < 0.05) increased in HLE150 and HLE200 groups compared to those in the CON group. Spleen weights were higher in HLE150 and HLE200 groups than in the CON group. Caecal bifidobacteria and Lactobacillus counts were significantly (P < 0.05) higher in HLE150 and HLE200 groups whereas E. coli and coliform bacteria counts were higher in the CON group. Caecal acetic acid, propionic acid, and total short-chain fatty acid levels were significantly (P < 0.05) higher in HLE150 and HLE200 groups than in the CON group. These results show that feeding diets containing 150 ppm of HLE containing antimicrobial peptides could replace antibiotics to improve the growth performance of broiler chickens.

Relative efficiency of methods to estimate cabbage stem flea beetle (Psylliodes chrysocephala) larval infestation in oilseed rape (Brassica napus).

The cabbage stem flea beetle (CSFB; Psylliodes chrysocephala) is an important pest of winter oilseed rape (OSR) crops in Europe. Damage is caused by adults feeding on young leaves and by larvae mining in the leaves and stems. The most common method to estimate the severity of CSFB larval infestation is by plant dissection, which is time consuming and labour intensive. Two alternative methods have been proposed: extraction of larvae from desiccating plants and counting the percentage of leaves with scars left by larvae on plant petioles. These methods are easy to implement and less time consuming than plant dissection but have not been properly validated. OSR plants were sampled in five different experiments and the two alternative methods tested; assessment of the total number of scars per plant as a predictor of the number of larvae was also tested. The number of larvae remaining in plants following various periods of desiccation was checked via plant dissection. We found that the desiccation method is efficient, giving reliable results after 7 days (76% of the total larvae extracted) with good accuracy in estimating the number of larvae per plant (±0.38 larvae per plant). The total number of scars also gives a reliable estimation of the number of larvae (r=0.76, accuracy of ±1.01 larvae per plant). OSR plant desiccation and the total number of scars per plant are reliable methods to estimate CSFB larval infestation and will facilitate monitoring of this cryptic pest stage. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A Relaxin-Like Gonad-Stimulating Peptide Appears in the Early Development of the Starfish Patiria pectinifera.

Relaxin-like gonad-stimulating peptide (RGP) is a hormone with gonadotropin-like activity in starfish. This study revealed that spawning inducing activity was detected in an extract of brachiolaria larvae of Patiria pectinifera. Spawning inducing activity in the extract was due to P. pectinifera RGP (PpeRGP), not 1-methyladenine. The expression of PpeRGP mRNA was also found in brachiolaria. Immunohistochemical observation with specific antibodies for PpeRGP showed that PpeRGP was distributed in the peripheral adhesive papilla of the brachiolaria arms. In contrast, PpeRGP was not detected in the adult rudiment or ciliary band regions, which are present in the neural system. These findings strongly suggest that RGP exists in the larvae before metamorphosis. Because gonads are not developed in starfish larvae, it seems likely that RGP plays another role other than gonadotropic action in the early development of starfish.

Effects of edible insect extracts on the antioxidant, physiochemical, and microbial properties of Tteokgalbi during refrigerated storage

In this study, Tteokgalbi, a meat product, was prepared with edible insect larvae extracts and its antioxidant, physiochemical, and microbial properties were evaluated during refrigerated storage. Tteokgalbi prepared with 2% A. dichotoma and 2% P. brevitarsis showed the highest radical-scavenging activity and metal-chelating activity, but the lowest thiobarbituric acid reactive substance (TBARS) value, among the treatments (P < 0.05). In addition, those antioxidant activities were the lowest and the TBARS value was the highest in control Tteokgalbi (P < 0.05) during all storage days. Tteokgalbi prepared with 2% A. dichotoma showed the highest brownness index, pH, and cooking yield, but the lowest shear force value (P < 0.05). During all storage days, the total aerobic bacteria level did not differ significantly among the treatments. In conclusion, A. dichotoma extracts (2%) were effective as antioxidants, inhibiting lipid oxidation, and improving the quality properties of Tteokgalbi, without negatively affecting microbial counts. These results confirmed that the edible insect extracts have industrial value as a food additive.

Quantitation of Glutamine Synthetase 1 Activity in Drosophila melanogaster.

Protocols to assay the activity of glutamine synthetase (GS) are presented as they have been used in our laboratory to correlate the expression levels of the gene encoding Drosophila GS1 gene, the GS1 protein levels, and its activity in extracts of larvae and heads from Drosophila melanogaster. The assays are based on the glutamine synthetase-catalyzed formation of γ-glutamylhydroxylamine in the presence of ATP, L-glutamate, and hydroxylamine, in which hydroxylamine substitutes for ammonia in the reaction. Formation of γ-glutamylhydroxylamine is monitored spectrophotometrically in discontinuous assays upon complex formation with FeCl3. Fixed-time assays and those based on monitoring the time-course of product formation at different reaction times are described. The protocols can be adapted to quantify glutamine synthetase activity on biological materials other than Drosophila.

Lipid Extraction of Black Soldier Fly Larva Using Aqueous Enzymatic and Soxhlet Method

This study aimed to explore the efficacy of lipid extraction methods on black solider fly larvae (BSFL) which is a potential sustainable source of biodiesel. The raw fat content of BSFL in exam was 29.6% on dry matter basis, which is comparable to other studies. Both aqueous enzymatic method and Soxhlet method are effective in BSFL lipid extraction at levels around 80%. The lipid quality from aqueous enzymatic method is superior in addition to other merits such as mild, easy and fast. Further research is recommended to scale up its potential as bioenergy alternatives.

EFEKTIFITAS EKSTRAK MANGROVE Rhizophora apiculata (Tomlinson, 1986) DALAM MENGHAMBAT Vibrio parahaemolyticus PENYEBAB PENYAKIT PADA UDANG VANAME Litopenaeus vannamei (Boone, 1931)

Vaname (L. vannamei ) shrimp cultivation is currently experiencing problems, one of which is disease caused by Vibrio bacteria, especially V. parahaemolyticus. This type of vibrio is the cause of white feces disease and AHPND in shrimp. Disease control due to Vibrio can be done by utilizing plants that have active compounds as natural antibacterials that are environmentally friendly. Mangrove plants have several active compounds that have great potential as antibacterial. This study aimed to examine some parts of the mangrove plant R. apiculata in inhibiting the activity of V. parahaemolyticus. Three parts of the mangrove plant, namely: roots, stems, and leaves were extracted using methanol. The three extracts were tested for their antibacterial activity against V. parahaemolyticus by several tests such as phytochemical, sensitivity, zone of inhibition, best dose, and toxicity tests. The test results showed that R. apiculata mangrove stem extract had the greatest ability to inhibit V. parahaemolyticus with an effectiveness value of 15.85% with the best dose of 200 mg/L. Toxicity testing using vaname shrimp larvae extract showed that mangrove stems were non-toxic with an LC50 value of 2,155.5 mg/L.Keywords: White feces disease, AHPND, active compounds, extracts, antibacterials