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.
