Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are central regulators of teleost reproduction, yet their molecular characteristics in giant gourami (Osphronemus goramy), a key Indonesian aquaculture species, remain largely uncharacterized. This study cloned and analyzed the full-length β-subunit cDNAs of FSH (OgFSHβ) and LH (OgLHβ), encoding 126 and 142 amino acids, respectively. Both sequences exhibited conserved cysteine residues and canonical N-linked glycosylation motifs typical of vertebrate glycoprotein hormones. Phylogenetic comparison revealed highest similarity with Anabantoid fishes (85–94.2% for FSHβ; 84–85.8% for LHβ). Expression profiling demonstrated stage-specific regulation, with OgFSHβ predominating during vitellogenesis and OgLHβ increasing toward final maturation. Following LHRH-a administration (0.75 mL/kg), OgFSHβ was significantly upregulated at 24 h, whereas OgLHβ showed a limited transcriptional response. These findings provide the first molecular insight into gonadotropin regulation in giant gourami and support the optimization of hormonal induction strategies to improve broodstock performance and larval production.
Pond fertilization is a crucial factor in enhancing the productivity of inland aquatic resources. Organic fertilizers, such as vermicompost and biocompost derived from water hyacinth, promote the growth of algae and insects, which serve as essential food sources for fish. This study investigated the effects of water hyacinth vermicompost as a fertilization strategy in aquaculture, specifically examining its impact on fish growth compared to traditional fertilizers, such as triple superphosphate (TSP) and a combined fertilizer of TSP and urea. Water hyacinth, an invasive aquatic plant, was processed through vermicomposting to produce a nutrient-rich organic fertilizer. Over three months, from mid-November 2021 to mid-February 2022, various pond fertilization techniques and physicochemical parameters were examined in concrete ponds at the Batu Fish and Other Aquatic Life Research Center. Twelve concrete partitioned fish ponds, each measuring 6 m², were constructed and stocked with 18 Oreochromis niloticus fingerlings each, weighing approximately 7 grams, randomly sourced from Batu Fish and Other Aquatic Life Research Center. This pond was equally divided into four treatments with three replicates (4T x 3R). The growth performance of Oreochromis niloticus was measured every 15 days for 90 days in water-filled ponds treated with mixed fertilizer (a 1:1 ratio of triple superphosphate and urea), triple superphosphate (TSP) alone, vermicompost (VC) as a direct application fertilizer, and control ponds. ANOVA was employed to analyze the data, which included growth parameters such as weight gain and feed conversion ratio, and the overall fish health was inspected and monitored throughout the study. Results indicated that ponds treated with water hyacinth vermicompost achieved significantly higher fish growth rates compared to those receiving TSP, TSP combined with urea, and the control group at p<0.05. Specifically, the VC-treated pond recorded a final fish weight of 69.00±.78964 g, followed by mixed fertilizer (66.1917±.57309 g), TSP (63.144±.51088 g), and the control ponds (51.00±.82446 g). In the VC-treated pond, there was a high abundance of zooplankton, and high plankton production was observed in all treatments except in the control ponds. Water quality assessments showed that the use of vermicompost significantly improved the overall health of the pond. For example, dissolved oxygen (DO) levels increased, while ammonium (NH₄⁺) levels decreased, as ammonia could be absorbed by the available phytoplankton. The study recorded dissolved oxygen (DO) levels ranging from 8.06±1.09 mg/l in the control group to 8.7583±0.7 mg/l in the VC group. Consequently, the application of vermicompost released nutrients that fostered plankton production, which supported fish growth. Overall, Water hyacinth vermicompost is a viable, eco-friendly alternative to inorganic fertilizer for enhancing the productivity of semi-intensive Nile tilapia ponds.
Chitin (degree of deacetylation ~18.13%, average viscosity molecular weight ~79.128 g/mol), prepared from molted whiteleg shrimp shells, was used to synthesize a chitin selenoester-zinc (ChSe-Zn) complex via a heterogeneous reaction with ZnSO4 and SeO2 in an acid medium. The resulting complex was characterized by Ultraviolet-visible, X- ray diffraction, and Fourier-transform infrared spectroscopy. Dietary supplementation with the ChSe-Zn complex (25.1 g Zn/kg and 239 mg Se/kg) at ~42 mg Zn/kg and 0.4 mg Se/kg in whiteleg shrimp (Litopenaeus vannamei) significantly enhanced growth and antioxidant capacity compared with the control group, and showed comparable effects to the diet containing zinc proteinate and selenomethionine at the same Zn and Se concentrations. These results highlight the potential of the ChSe-Zn complex as a feed additive to enhance shrimp growth and antioxidant capacity, while utilizing molted shrimp shell waste and reducing reliance on other organic Zn and Se sources.
With the intensification of aquaculture, sustainable farming systems are essential for the rational use of water. This study compared four rearing systems for juvenile Oreochromis niloticus: biofilter-based recirculation, green water, biofloc, and a partial water-exchange control, evaluating their effects on water quality and growth performance. Ninety-six juveniles (2.48 g) were stocked in sixteen 100-L aerated aquaria (four replicates per system) and reared for 60 days under controlled temperature. Water-quality variables and growth indices were analyzed using one-way ANOVA (P<0.05). The recirculation system provided significantly higher water hardness and calcium concentration than the other systems, as well as higher alkalinity than the control and green water systems, while maintaining nitrogenous compounds within safe limits. Fish reared in the recirculation and biofloc systems exhibited greater final weight, weight gain, specific growth rate, and an improved feed-conversion ratio compared to the control. The green-water system produced intermediate and non-significant responses. Survival, morphometric indices, salinity stress tolerance, and skin color parameters did not differ among treatments. Overall, the recirculation and biofloc systems improved the performance of juvenile tilapia under intensive rearing conditions, with the recirculation system providing better physicochemical water conditions and buffering capacity, making it the most robust and culture-efficient option..
High early larval mortality hinders African catfish (Clarias gariepinus) aquaculture. This study aimed to identify novel indigenous Ethiopian probiotics to enhance larval growth and survival. Lactic Acid Bacteria (LAB) were isolated from African catfish and Nile tilapia, then screened in vitro for probiotic potential. Selected strains were evaluated in a catfish larval feeding, and associated pathogens and their antibiotic resistance patterns were also assessed. Lactobacillus was the dominant probiotic genus. In vitro, strains showed excellent acid/bile tolerance and broad-spectrum antimicrobial activity. Crucially, host-specific Lactobacillus spp. from African catfish remarkably improved larval growth and survival (up to 78.3%) compared to the control (56.5%) and non-host-specific probiotics. However, widespread resistance to key antibiotics (e.g., penicillin G, kanamycin) was found in both LAB and pathogenic isolates, including Staphylococcus aureus. These findings underscore the considerable potential of indigenous, host-specific probiotics for sustainable African catfish aquaculture, while highlighting the critical need to address emerging antibiotic resistance.
The grey mullet (Mugil cephalus) is a significant aquaculture species known for its rapid growth, versatility, and high market demand. However, nursery-stage mortality, slow development, and high production costs continue to limit its profitability, particularly in earthen pond systems. One of the most significant issues is a lack of standardized and cost-effective feeding and fertilization systems that may optimize natural food production, maintain appropriate water quality, and improve fry survival and growth. The current study examines how various fertilizers and feeding techniques affect the water quality, plankton quantity, growth performance, survival rate, certain blood parameters, and economic assessment of raising grey mullet (Mugil cephalus) fries in eastern ponds. For seven months, grey mullet fries weighing 0.35±0.02 g were planted in nine earthen ponds (1000 m2 each) at a pace of 50,000 seeds. Three treatments were studied in triplicate: organic fertilizer with aquafood (T1), inorganic fertilizer with aquafood (T2), and aquafood only (T3). The measured water parameters were determined to be within an optimal range during the study period, with significant (P<0.05) changes in pH and ammonia concentrations across treatments. When comparing T1 to the other treatments, phytoplankton and zooplankton numbers showed considerably (P<0.05) higher values. The findings also show that compared to other groups, T1 showed a highly significant (P<0.05) increase in final body weight, weight gain, daily gain weight rate, and specific growth rate. T1 had the highest survival rate (60%), followed by T2 (57%) and T3 (55%). Basic hematological measures such as hemoglobin concentration (Hb), red blood cell count (RBCs), and hematocrit (Ht) showed substantial (P<0.05) changes. Furthermore, T1 achieved the highest benefit-cost ratio of 1.42, while T2 and T3 achieved 1.32 and 1.26, respectively. This approach came to the conclusion that the optimal nursery pond management for improving grey mullet survival and growth as well as raising the financial returns was to use organic fertilizers with aquafeed as a feeding strategy.
Outbreaks of Aeromonas hydrophila cause major losses in African catfish (Clarias gariepinus) farming, while antibiotic raises resistance concerns. This study evaluated bacteriophages from a diseased catfish pond as local biocontrol agents. In vitro, phages reduced bacterial density by over 50% within 24 h (P<0.05). In vivo, phage treatment significantly improved survival compared with infected controls (P<0.05) and moderated hematological disruption. After infection, clinical signs were milder in phage-treated fish than in non-treated control. These results indicate that locally sourced phages can mitigate A. hydrophila infection and support future disease management in C. gariepinus aquaculture.
The effects of resin acids oil with carrier (RAC) in powder form, Progres®, supplementation on Litopenaeus vannamei growth performance, immune response, and disease resistance to severe Vibriosis, Vibrio parahaemolyticus AHPND were assessed. A completely randomized design (CRD) with three treatments of RAC supplemented—control 0, RAC350, and RAC700 ppm was applied to shrimp for 2 weeks. Juvenile white shrimp initial weights of 1.82±0.03 g., were created a random stocked 30 shrimp to each aquarium of 240 L with 15 ppt. saline water 120 L with total 810 shrimp. After 2 week feeding trial, shrimp were applied oral administration. The study found that short-term dietary RAC under normal condition, shrimp growth performance and survival rate were in the same range (P>0.05). The immunity of shrimp fed both treatments in term of lysozyme activity and superoxide dismutase activity was significantly increased (P<0.05). After stress condition, shrimp innate immunity significantly improved (P<0.05), and exhibited disease resistance against, Vibriosis count in both treatments decreased (P<0.05). The survival rate after challenge was low in Control and significantly high in both treatments (P<0.05). There were 66.67+5.77, 86.67+5.77 and 80.00+10.00%, respectively. Therefore, short-term dietary resin acid effects on improving immune response and resistance to Vibrio under stress conditions.
The Navicula species as a phytoplanktonic organism has attracted considerable research interest due to its simple cellular structure, remarkable photosynthetic efficiency, short life cycle, and resilience in extreme environmental conditions. This study aims to evaluate global research trends on Navicula using a scientometric approach to identify key applications and emerging opportunities. To understand how its roles have evolved across disciplines, we analyzed Scopus-indexed publications spanning two periods, namely 1873–2013 and 2014–2023. Our findings reveal a marked increase in publication volume, co-authorship networks, and international collaborations in the last decade. Thematically, early studies emphasized Navicula's role as a fouling organism, while more recent publications focus on antifouling strategies and material innovation. In taxonomy, early works relied on morphology-based identification with limited strain coverage, whereas current research addresses classification errors and cultivation challenges. In ecotoxicology, influential articles identify Navicula as a methanogen capable of accumulating methylated mercury and producing β-methylamino-L-alanine, raising human health concerns. Concurrently, its biochemical potential, particularly as a source of antioxidants and stigmasterol, has expanded its relevance to biomedical and nutraceutical fields. Together, these trends underscore the multidimensional importance of Navicula and point to promising directions for future interdisciplinary research.
This study evaluated long-term growth, survival, and health challenges during earthen-pond rearing of mangrove red snapper (Lutjanus argentimaculatus) from juveniles to broodstock potential over 24 months. Juvenile fish were stocked at 200 per ponds and cultured for 24 months. Growth (ADG, SGR), survival, and health assessments were recorded, and sick individuals were laboratory-tested for pathogens. Results showed that average total length reached 47.3 cm and weight 1,959.4 g. ADG was 2.50 g/day and SGR was 0.35%/day. Final survival ranged from 75.5% to 92.0% (mean 83.8%). Water quality remained within acceptable ranges. Meanwhile, infections (viral nervous necrosis) and Caligus sp. parasites emerged around 20–22 months, reduced feeding and survival, and prevented attainment of broodstock size (3–7 kg). While baseline growth and survival data were established, broodstock-size targets were not met. Future directions included nutritional optimization, enhanced health management, and strengthened biosecurity to improve broodstock yield.
As aquaculture based on commercial feed continues to grow substantially in Bangladesh, the study evaluated five widely used commercial fish feeds—Lili, One, Quality, Nabil, and ACI by analyzing their nutrient and heavy metal (Pb, Co, Cr, Cd, Ni) contents, and their impacts on the growth rate and muscle composition of four carp species: Catla catla, Hypophthalmichthys molitrix, Labeo rohita, and Cirrhinus cirrhosus. Proximate parameters and heavy metal contents of the feeds were analyzed using standard methods. A 90-day cage-based feeding trial was conducted to assess the growth and nutrient utilization of the fish, measuring mean weight gain (MWG), specific growth rate (SGR), survival rate, feed conversion ratio (FCR), and carcass nutrient composition. Although all the feeds exceeded allowable heavy metal concentrations, the ACI feed had lower heavy metal concentrations and higher protein content (23.63±0.32). Fish fed with ACI feed exhibited better MWG (288.44±4.81), SGR (0.82±0.01), and FCR (2.25±0.08), whereas fish fed with Nabil feed performed the poorest results. No significant difference was found in carcass nutrients among the fish, but those fed ACI feed exhibited relatively higher protein content. The study identified ACI feed as a superior commercial feed that enhances carp growth in the northwestern part of Bangladesh.
With about 750 km of coastline along the southern Caspian Sea, Iran holds substantial potential for coastal aquaculture. Overfishing and other anthropogenic pressures have caused a sharp decline in valuable fish stocks, prompting the government to explore cage fish farming as an alternative to reduce pressure on wild populations, ensure food security, and support local livelihoods. This review synthesizes national efforts, policies, and scientific studies on cage aquaculture in the southern Caspian Sea, highlighting the key factors behind its limited progress. Between 2018 and 2023, cage aquaculture in the southern Caspian produced nearly 1,940 tonnes, with 1,850 tonnes recorded across central coastal counties (Mazandaran) in the 2023–2024 period, while provincial and national datasets show a wider but uneven distribution of production. These figures suggest that less than half of the region`s estimated carrying capacity is currently utilized. Environmental concerns, economic instability, stakeholder conflicts, and insufficient legal and technical frameworks continue to constrain sustainable growth. Nevertheless, targeted adoption of eco-friendly technologies, strengthened governance, and community-based management could unlock substantial capacity and lead to resilient development of cage aquaculture in Iran`s Caspian region. This review integrates ecological, socio-economic, and policy perspectives to provide a forward-looking framework for sustainable aquaculture planning in the southern Caspian Sea.
Climate variability poses increasing challenges to hatchery performance by altering water quality and larval physiology. This study compared the seed quality of Nile tilapia (Oreochromis niloticus) produced in traditional ponds and Recirculatory Aquaculture Systems (RAS) under fluctuating climatic and water-quality conditions. RAS maintained stable conditions (temperature 28.1–29.4°C; DO 6.8–7.4 mg L⁻¹; ammonia≈ 0 mg L⁻¹) compared with pond system (temperature 27.2–32.5°C; DO 5.8–7.0 mg L⁻¹; ammonia 0.02–0.07 mg L⁻¹). Larvae reared in RAS showed higher length gain (2.94±0.658% vs. 1.19±0.207%), greater weight gain (7.24±1.37% vs. 7.04±0.81%), and improved specific growth rate (0.23±0.032% day⁻¹). Fulton`s condition factor was also superior in RAS (mean KF 1.97–2.15) compared with pond system (1.45–1.65). Morphometric traits, including total and caudal length, were significantly higher in RAS (P<0.001). PCA showed that water-quality variables contributed 42.5% of total variance. GHRH gene expression was markedly upregulated in RAS, indicating enhanced physiological performance. Overall, the stable and controlled environment in RAS improved larval quality, developmental progression, and molecular growth regulation, highlighting its potential as a climate-resilient and sustainable hatchery strategy for tilapia seed production.
Domestication of mud crab (Scylla paramamosain) is an important endeavor to support research and reduce the reliance on wild crab fisheries. Present study was conducted to evaluate growth and reproductive performance of domesticated mud crabs in the 1st (G1), 2nd (G2), and 3rd (G3) generations compared to those of wild crab (W) reared in grow-out ponds for 6 months. Results showed that there were significant differences in growth patterns between W and domesticated crabs, especially in G2-G3. The final carapace width and body weight of W were not significantly different from those of G1 but were significantly greater than those of G2 and G3. Furthermore, weight gain and specific growth rate of crabs significantly decreased in G2-G3 generations. W and G1 female brooders differed in reproductive performance only in hatching rate and total number of zoea I (Z1) produced, with W being higher than G1. G2 female brooders had lower to those from W regarding fecundity, hatching rate, total number of Z1 produced, and survival of Z1 at 1-day post-hatch. In addition, G2 had significantly lower values than G1 for total number of Z1 produced and the survivability of Z1 (P<0.05). The G3 female brooders were unsuccessful in breeding and larval hatching. These findings recommend selective breeding to improve reproductive success in G2 and G3 for sustainable mud crab aquaculture.
Research on gut microbiota has primarily focused on bacteria, though eukaryotic microorganisms also play important roles in their host. In fish, the suitability of fecal sampling methods for studying these gut microorganisms remains unclear. This study aimed to evaluate two fecal sampling methods, intestinal scraping and aquarium-bottom sampling, on the diversity and composition of gut microeukaryotes in Nile tilapia (Oreochromis niloticus), highlighting the importance of methodological choices in microeukaryotic studies. Results showed that intestinal scraping provides a more accurate representation of the stable, resident community, avoiding potential bias and emphasizing the critical importance of methodological choices in microeukaryotic research.
Water-meal (Wolffia globosa) was cultivated with NPK (15:15:15) fertilizer under three treatments with four replicates. The treatments consisted of NPK fertilizer applications at three different levels: 16 g/tank (CF1), 26 g/tank (CF2), and 36 g/tank (CF3), which were applied weekly. The water-meal was grown for 35 days, the biomass production was assessed, and the treatment with the highest mass production was harvested in order to determine the chemical composition and the amino acid profiles. The results showed that water-meal cultivated with NPK fertilizer at the rate of 26 g/tank (CF2) had exhibited the highest biomass production. There was a significant difference (P<0.05) compared to the CF1 treatment, while no significant difference (P0.05) was found when compared to the CF3 treatment. The water-meal that had been cultivated with the CF2 treatment exhibited high protein content (40.64±2.13%) and rich amino acid profiles. It contained 17 types of amino acid profiles, with 9 essential amino acids (EAA), and 8 non-essential amino acids (NEAA). Glutamic acid was the major amino acid, while leucine and lysine were the most abundant EAA. Our findings indicated that this cultivation system can be used to produce highly nutritious water-meal biomass for human consumption or animal feed.
This work evaluated the outcome of dietary ethanol (EE) and aqueous (AE) extracts of Terminalia catappa (Tropical almond) on growth, survival, oxidative stress, and resistance of Heterobranchus longifilis (Bagrid catfish) fingerlings to Pseudomonas aeruginosa. Five diets with different concentrations of T. catappa extracts (AL1, 0.0% extract; AL2, 0.5% EE; AL3, 1.0% EE; AL4, 0.5% AE and AL5, 1.0% AE) were formulated. Triplicate groups of H. longifilis (3.82±0.05 g) were fed diets at 3% body weight twice daily for 70 days. Results indicated that EE were richer in bioactive compounds including total phenolics, tannins, alkaloids, and flavonoids compared to AE. However, ethanol extracts negatively impacted feed intake and growth performance, particularly at higher concentration. Fish fed with aqueous extracts exhibited improved growth, higher hematocrit values, and enhanced antioxidant enzyme activity. Survival rates were highest in fish fed with aqueous extracts, particularly at 1.0% concentration. Fish fed with aqueous extracts showed increased resistance to Pseudomonas aeruginosa challenge, as evidenced by the higher relative percentage survival (RPS). These findings suggest that Terminalia catappa aqueous extracts can positively influence growth, health, and disease resistance of Heterobranchus longifilis. The study highlights the importance of considering extraction solvent when using plant-based extracts in aquaculture feed.
The use of natural feed additives presents an eco-friendly strategy to improve the performance and well-being of Nile Tilapia. A total of 180 juvenile Nile tilapia was randomly assigned to three treatment groups, each with three replicates (20 fish per replicate), and reared in glass aquaria. The groups were as follows: (1) control group, fed the basal diet; (2) probiotic group, fed the basal diet supplemented with 2 g/kg of Bacillus subtilis (2 × 10¹¹ CFU/kg); and (3) acidifier group, fed the basal diet supplemented with 5 g/kg of an organic acid blend. The organic acid and Bacillus subtilis supplementation boosted fingerlings` growth outcomes, protein retention and specific growth rate with superior nutrient digestibility unlike control group. In addition, fish fed the Bacillus subtilis fed groups displayed significant hematological benefits, such as lower serum cholesterol levels and increased high-density lipoprotein cholesterol (HDL-C) levels, distinguishing them from the other treatment groups. The administration of probiotics and acidifiers effectively strengthened the fish`s antioxidant system, reducing oxidative stress markers such as malondialdehyde (MDA) and enhancing enzymatic antioxidants including total antioxidant capacity (TAOC) besides superoxide dismutase (SOD) activity. Furthermore, the inclusion of probiotics and organic acidifiers enhanced the immune response, as reflected by increased serum IgM, lysozyme activity, phagocytic activity, and the upregulation of mucin-2 and interleukin-10 gene expression in the intestine. Concerning the intestinal microbiota, the Bacillus subtilis fortified group exhibited an increased lactobacilli DNA concentration unlike a decreased lactobacilli DNA concentration of Enterobacteriaceae. Overall, Bacillus and acidifier inclusion positively influenced performance, immune status, and gut bacterial composition, contributing to the economic viability of tilapia farming.
The giant gourami (Osphronemus goramy) is a freshwater fish with great potential for aquaculture production. This omnivorous fish tends to become herbivorous when it reaches adulthood. In this study, we initially conducted a preliminary study to determine which plants support the growth of giant gourami and choosing taro leaves (Colocasia esculenta) as additional phytogenic. The aim of this study was to determine the effect of adding taro leaves on the growth performance and gut microbial community of giant gouramis weighing 213±9.72 g. In this study, five groups of diets were formulated to replace 0%, 25%, 50%, 75% or 100% of commercial feed. The cultivation period lasted 16 weeks. Several parameters were observed, including absolute weight growth, specific growth rate, survival rate, haematology tests and gut bacterial community profiling using nanopore sequencing of the 16S rRNA gene. The results showed that replacing 25% of commercial feed with taro leaves produced the greatest weight gain in the fish (166.87±17.27 g), although there were no significant differences among the treatments. Microbiome analysis showed that the gut microbial community was dominated by the Firmicutes phylum, with a relative abundance of 91.25%. The most abundant genera were Clostridium, Paeniclostridium and Cellulosilyticum.
This study was designed to assess the histological and ultrastructural stages of the female sparid, zebra sea bream (Diplodus cervinus cervinus) sexual maturity, while publications that paid attention to the reproductive biology of this protandrous species is almost lacking. In the present study, it is suggested that oogenesis is classified into four stages: oogonia proliferation (the presence of oogonia is a typical feature of this stage), oocyte growth (is characterized by the formation of follicular layers around the oocyte. large nucleus and scattered nucleoli), vacuolization (is described by the appearance of marginal vacuoles) and final maturation (in which ovaries decreased in size, appeared with collapsed features, exhibited empty follicle and were provided with many blood vessels). D. cervinus cervinus is a partially ovipositing species having a multiple spawning character with asynchronous oocyte development. Transmission electron micrographs of the ripe oocyte demonstrated that it was characterized by the appearance of five ideal ovarian layers (theca, follicular epithelial, zona radiata externa, zona radiata interna and cortical alveoli). In teleost fish, eggs allow the entry of sperm from only a single site known as `the micropyle`, which is a narrow canal in the chorion of the egg. The morphology and classification of Diplodus micropyle were also investigated by scanning electron microscopy. During the spawning season, the full-grown Diplodus eggs collected from adult gravid females possess a single micropyle at the animal pole. This micropyle is a conical shaped with no pit, characterized by a tapering opening having only a deep, constricted canal. Several thickened annuli with little knobs strengthened the inside of the canal. In conclusion, this study provides a comprehension on the reproductive biology of D. cervinus cervinus which is important for the culture and sustainable seed production of this species.
