Volume 77, Issue 1, 2025

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https://hdl.handle.net/10524/81137

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The Efficacy of Vermicompost in Optimizing Water Quality and Plankton Production in Cemented Aquaculture Ponds
(2025) Kebede, Wondwosen D.; Natarajan, Pavanasam; Worku, Shiferaw
Aquaculture is vital for global food security, yet cemented ponds often face challenges related to poor water quality and low natural productivity owing to the absence of bottom soil. This study investigates the use of vermicompost, a nutrient-rich organic fertilizer, to enhance water quality and increase plankton production in aquaculture systems. The experimental design involved four cemented tanks: a control (Without fertilizer) and three treatments with varying vermicompost application rates (5,000, 10,000, and 15,000 kg/ha/yr). Assessments of water quality parameters—including dissolved oxygen, pH, and ammonia levels—were conducted, along with sampling of plankton abundance and species composition. Results indicated improvements in water quality, particularly in DO levels, with the highest rates observed in the treatment receiving 15,000 kg/ha/yr vermicompost. Additionally, plankton diversity (Diversity index) and abundance increased with higher vermicompost applications, notably enhancing phytoplankton groups, particularly Chlorophyta, while maintaining stable zooplankton populations. These findings suggest that vermicompost is a promising sustainable alternative to chemical fertilizers, effectively improving water quality and fostering a healthier aquatic ecosystem, thereby supporting aquaculture productivity. Future research should explore the long-term effects of vermicompost in various aquaculture settings.
Hesperetin inhibits Siniperca chuatsi rhabdovirus replication by reducing mitochondrial apoptosis in EPC cells
(2025) Ma, Yu-Zhen; Sun, Shuang-Shuang; Ma, Shi-Wei; Zhou, Guang-Zhou
Hesperetin is one of the natural dihydroflavonoid widely extracted from various plants, and a large number of studies have demonstrated that hesperetin has a wide range of biological activities. In this study, we explored its antiviral function against Siniperca chuatsi rhabdovirus (SCRV), one strain of important fish viral viruses, resulting in multiple transmissions and devastating damage in aquaculture. Experiments were performed to confirm that hesperetin could effectively delay the occurrence of cytopathic effects (CPEs) in epithelioma papulosum cyprinid cells (EPC), and inhibit SCRV replication by microscopy observation and viral titer assay, respectively. Time-of-addition assay showed that the best inhibitory effect of hesperetin was achieved by blocking SCRV invasion into cells. In addition, qRT-PCR and western blot analysis confirmed that hesperetin could significantly inhibit the expression of SCRV nucleoprotein. Flow cytometry analysis showed that hesperetin could reduce SCRV-inducing apoptosis of EPC cells after annexin V-FITC/PI double staining and immunofluorence microscopy observation after JC-1 incubation. Down-regulation of caspase-3 and caspase-9 enzymatic activity after hesperetin treatment indicated that it might protect cells from SCRV infection by decreasing mitochondrial intrinsic apoptosis in infected cells. After hesperetin treatment, a decrease in ROS and an increase in mitochondrial membrane potential (MMP) in SCRV-infected EPC cells further confirmed the inhibition of the apoptotic pathway mediated by hesperetin. Thus, our present study indicated that hesperetin possessed antiviral ability against SCRV, suggesting its candidate role for potential effective control of fish rhabdovirus spreading.
Non-fishmeal based, and Selected Indigenous Raw Materials as Cost-Effective Feeds for Milkfish Aquaculture
(2025) Macusi, Edison D.; Sales, Anthony C.; Vender, Kate E.; Jimenez, Edward M.; Bongas, Henzel P.; Macusi, Erna S.; Andam, Michael B.
This study aimed to find alternative feeds or supplementary feeds that can perform similarly to the existing commercial feeds thereby reducing farmer expense and cutting down their cost of production and increasing their profitability on Milkfish (Chanos chanos Forsskål, 1775) aquaculture. The formulations for the study included four grow-out treatments mainly: control (commercial feed), taro+control (powdered Colocasia esculenta+commercial fish feed), bloodmeal (formulated fish feed based on bloodmeal), banana stem+control (chopped banana stem+commercial fish feed). The result of the study showed no significant differences between feed treatments from the 6^th^ week onwards, whether with weight (MS=0.130, df=3, F=1.14, p=0.333) or total length of the treatments (MS=0.008, df=3, F=0.40, p=0.75). The FCR ratio showed bloodmeal (1.60) as the lowest, followed by the control (1.65), and taro+commercial (1.71), and then banana stem+commercial (2.18). In terms of weight gain, fish from the bloodmeal treatment gained the highest (236.97 g), followed by control (223.33 g), then taro (217.67 g), and banana stem (196.99 g). As a result, we find that any of the tested treatments can serve as an alternative feed to using purely commercial fish feeds. Cost-benefit analysis showed that a better gross profit margin of 42% and cost-benefit ratio of 1.37 was observed in taro+commercial feed diet. The experiment showed that the taro, Blood meal, and banana stem can be used as an alternative feed component for sustainable milkfish farming.
Effects of compound Chinese herbal medicine on growth performances, non-specific immunity and digestive enzyme activity of dongtingking crucian carp（Carassius auratus indigentiaus）
(2025) Ding, Cheng; Xia, Hu; Gong, Yanan; Zhang, Yunsheng; Ning, Yan; Fang, Yixing; Chen, Fuyan; Bu, Jianchao; Yu, Jia; Xiang, Guangqing; Huang, Jiezhen; Yang, Pinhong
This study investigates the effects of compound Chinese herbal medicine (CCHM) on growth performances, antioxidation activities, immune-related enzymes, and digestive enzymes of dongtingking crucian carp (Carassius auratus indigentiaus). Lycium barbarum L., Panax ginseng C.A. Mey, Astragalus membranaceus and Phragmites communis Trin were ground and prepared into CCHM at the ratio of 4.5:3:1.5:1. The one-factor experiments were designed, in which different gradients of CCHM (0%, 1%, 2% and 4%) were added to basal feeds for C. auratus indigentiaus, which were fed for 90 d. The weight gain rate (WGR) and specific growth rate (SGR) in the experimental groups with CCHM addition were significantly higher than those of the control group (0%, without CCHM), the feed coefficient (FCR) was significantly lower in the experimental groups compared to the control group. In the experimental group with 4% of CCHM, WGR, and SGR of C. auratus indigentiaus were the highest (73.87±7.20 % and 0.63±0.15 %, respectively), while the FCR was the lowest (0.24±0.07 %). In the experimental group with 1% CCHM, the spleen index (SPI) increased significantly. However, the SPI of experimental groups, with 2% and 4% CCHM, showed no significant difference from that of the control group. The hepatosomatic index (HSI) of both experimental groups, with 2% and 4% of CCHM, was lower than that of the control group. However, there was no significant difference between the experimental group, which had 1% CCHM, and the control group. Activities of immune-related enzymes like lysozyme, acid phosphatase, and alkaline phosphatase (AKP) in the experimental groups with 1%, 2%, and 4% of CCHM were all higher than those of the control group. The lysozyme activity reached the highest in the experimental group with 1% of CCHM, the alkaline phosphatase (AKP) activity reached the peak in the experimental group with 2% of CCHM, and the acid phosphatase activity reached the highest in the experimental group with 2% of CCHM. Activities of antioxidant-related enzymes like catalase and glutathione peroxidase (GSH-PX) in C. auratus indigentiaus were all higher than those of the control group and reached the highest in the experimental group with 1% of CCHM. The total superoxide dismutase activity was highest in the experimental group with 4% of CCHM. Activities of intestinal digestive enzymes such as lipase, amylase, and trypsin in the experimental groups with 1%, 2%, and 4% of CCHM were higher than in the control group. Specifically, lipase and amylase activities were highest in the experimental group, with 1% of CCHM. In comparison, trypsin activity reaches the highest in the experimental group with 4% of CCHM. The results of this study show that adding CCHM into feed can increase the activity of immune-related enzymes and antioxidant-related enzymes in the serum of C. auratus indigentiaus, improve the activity of intestinal digestive enzymes, and promote growth. The appropriate CCHM content in basal feed for C. auratus indigentiaus is 1%.
Effects of water quality on the hatching of rapa whelk (Rapana venosa) eggs and larvae
(2025) Jia, Menghao; Cai, Linxuan; Li, Wenjia; Tian, Ying; Hao, Zhenlin
To detect the effects of water quality factors on the hatching of Rapana venosa eggs, the eggs were exposed to controlled conditions with different concentrations of ammonia nitrogen and nitrite and different pH values respectively, for 60 days. The hatching rate, larval release time, and initial larvae sizes after hatching were documented and analyzed. Egg capsules had 100% mortality at pH ranges of 6.0-7.00 and 9.00-10.00, and the mortality rate was relatively low between pH of 7.50-8.50. With an increase in pH within this range, mortality decreased. Larval release times were also significantly affected by pH. Within the pH range of 7.50-8.50, the shortest larval release occurred at a pH of 8.5 and the longest at a pH of 7.5. Ammonia nitrogen had significant effects on larval body length and length to width ratio, with larval length increasing with decreasing ammonia nitrogen concentrations, whereas the ratio of length to width increased with decreasing ammonia nitrogen concentrations. Nitrite concentration had significant effects on the larval body length and ratio of length to width. In addition, pH had significant effects on larval body width and the length to width ratio. With increasing pH, larval body width decreased, whereas the ratio of length to width increased. This study explores the optimal growth conditions for the Rapana venosa, providing theoretical guidance for its industrial aquaculture and the conservation of wild resources.
Effects of Adding Purslane (Portulaca oleracea) as a Source of Omega-3 Fatty Acids on Muscle Composition, Fatty Acid Profile, and Productive Performance in Tilapia (Oreochromis niloticus)
(2025) Díaz-Vázquez, I.E.; Cuevas-Rodríguez, B.L.; Zavala-Leal, O.I.; Cuevas-Rodríguez, E.O.; Arámbul-Muñoz, E.; Sánchez-Magaña, L.M.; Valdez-González, Francisco J.
This study evaluated the effect of diets enriched with purslane flour (P. oleracea) on production variables, muscle composition, and fatty acid profile in Nile tilapia. Four isonitrogenous and isolipidic diets were prepared, incorporating 0% (CTRL), 5% (V-5), 10% (V-10), and 15% (V-15) of P. oleracea flour. Trials were conducted in triplicate with an initial average weight (2.93±0.17 g), and the fish were fed the experimental diets for 60 days. The inclusion of 100 g/kg of purslane significantly increased (p\<0.05) the lipid content in the fillet. However, at 150 g/kg, protein content decreased (p\<0.05), while levels of 20:5 n-3 (EPA) (3.27%) and 22:6 n-3 (DHA) (4.14%) in the tilapia fillet increased (p\<0.05), with a 100% survival rate reported in all treatments. The results demonstrate that up to 100 g/kg of purslane flour can be included in diets for Nile tilapia without negatively affecting productive performance, and up to 150 g/kg when the objective is to improve the nutritional quality of the tilapia fillet.
Identification of multifunctionality of glutamate dehydrogenase gene (CsGDH) and development of SNPs associated with ammonia nitrogen tolerance in clam Cyclina sinensis
(2025) Ge, Hongxing; Hu, Jidong; Ni, Qian; Xia, Chenyu; Dong, Zhiguo; LI, Zhen
The full length of the CsGDH gene was 1683 bp, with an open reading frame (ORF) of 1176 bp, encoding 391 amino acids. The predicted CsGDH protein contained the conserved ELFV_dehydrog (IPR006096) functional domain at 98 aa-387 aa. Exposed to ammonia nitrogen, the transcript level of CsGDH mRNA in the hepatopancreas showed a decreasing trend, then increasing and finally decreasing. Association analysis for ammonia nitrogen tolerance traits was performed, and seven SNPs (264bp A/G, 435bp A/G, 504bp A/T, 582bp C/T, 648bp C/T, 933bp C/T, and 969bp A/G) located in the region of ORF were screened for ammonia nitrogen tolerance in the CsGDH. The two SNPs mutations of 504bp A/T and 582bp C/T were significantly associated with ammonia nitrogen tolerance (P<0.05). The above findings suggest that the CsGDH gene can be used as one of the candidate marker genes to improve ammonia nitrogen tolerant of the clam Cyclina sinensis.
Analysis of the genetic diversity of different populations of Pinctada maxima from China
(2025) Fang, Wei; Chen, Mingqiang; Zhao, Wang; Wang, Yu; Ma, Zhenhua
This study aims to analyze the genetic diversity and differences among wild populations of Pinctada maxima, providing a foundational reference for the enhancement and optimization of its germplasm. In this study, we developed SSR primers based on simplified genome sequencing and screened 10 pairs using fluorescent PCR amplification to assess the genetic diversity of wild populations of P. maxima from Danzhou (DZ), Nansha (NS), and Xuwen (XW), China. Additionally, we investigated the genetic richness and the degree of differentiation among the populations. The results indicated that the number of alleles (Na) detected by the 10 SSR primer pairs ranged from 8 to 17 across the three P. maxima populations, with a total of 130 alleles. The polymorphic information content (PIC) varied from 0.769 to 0.865, with an average of 0.8531. All ten pairs of SSR primers exhibited high levels of polymorphism. The observed heterozygosity (Ho) among the three P. maxima populations ranged from 0.1333 to 1.000, with an average of 0.7884. The expected heterozygosity (He) ranged from 0.6333 to 0.8755, with an average of 0.7815. The mean values of Hardy-Weinberg equilibrium indices (F) ranged from -0.032 to 0.058, indicating that all populations were approximately in Hardy-Weinberg equilibrium, with the F values for DZ and XW populations being negative, suggesting a heterozygote deficit. The mean Fst value for the three P. maxima populations was 0.098, and molecular ANOVA revealed that 10% of the genetic differentiation occurred between populations, while 90% arose from individual variation. The average gene flow (Nm) between populations was 2.804, suggesting that genetic drift did not dominate the changes in population genetic structure. Among the three populations, the genetic distance between the DZ and XW populations was the smallest (0.3352), while the NS and DZ populations exhibited the greatest genetic distance (0.6462). UPGMA clustering analysis based on genetic distances revealed that the three P. maxima populations could be divided into two major groups, with the DZ and XW populations clustering independently into one group. Significant genetic differentiation and high genetic diversity were observed among the three P. maxima populations, although heterozygous deletions were present. Therefore, during the breeding process of P. maxima, the genetic diversity of the offspring can be enhanced by introducing these three populations, each with distinct genetic backgrounds from different marine regions and distant phylogenetic affinities, as parent stock.
Effects of neuroendocrine on the immune and metabolic functions of Litopenaeus vannamei under high nitrite conditions
(2025) Li, Yuquan; Hao, Pengyuan; Song, Xuan; Zhang, Long; Wang, Xiaofan; Wang, Zhongkai; Liu, Fei; Wang, Renjie; Cui, Yanting
In recent years, nitrite toxicity has become a significant concern in shrimp aquaculture, affecting cultured species' health and productivity. Herein, we investigated the impacts of nitrite on the immune and metabolic functions of Litopenaeus vannamei and assessed the impacts of eyestalk hormone on these parameters when shrimp were cultured under high nitrite conditions. After exposure of L. vannamei to nitrite-N at 0, 2.5, 5, 7.5, 10 mg/L, and unilateral eyestalk-ablated shrimp only to nitrite-N at 10 mg/L for 48 h, phenoloxidase (PO) activity, antibacterial activity, bacteriolytic activity, oxyhemocyanin, lactate, and glucose contents were measured. Oxyhemocyanin levels decreased as the nitrite-N concentrations increased, while lactate and glucose levels increased. This indicated that conversion from aerobic to anaerobic respiratory metabolism is exacerbated by hypoxia-induced nitrite stress to ensure that readily metabolizable energy stores are available to meet increased energy demand. The decrease in PO levels, antibacterial activity, and bacteriolytic activity in the hemolymph indicated that the physiological and immunological responses of L. vannamei was impaired by subjection to nitrite-N. Under the same nitrite-N conditions, eyestalk ablation caused a remarkable decrease in glucose, lactate, and PO levels, compared with those detected in the non-ablated eyestalk group. These findings suggest that the eyestalk hormone in L. vannamei increases metabolic and immune responses as a protective mechanism against nitrite-N stress.
The use of supplementary feed with ethanol extract of Syzygium nervosum leaf to prevent acute hepancreatic necrosis (AHPND) in white shrimp (Litopenaeus vannamei)
(2025) Truong, Hoa T.; Ho, Tung T.; Tran, Ha N.; Tran, Van Q. K.; Hoang, Manh N.
This study evaluated the effects of supplementing shrimp diets with an ethanol extract of Syzygium nervosum leaf on growth performance, survival rate, immune parameters, and resistance to AHPND in white shrimp (L. vannamei). Shrimp juveniles (weighing 1.05 ± 0.04 g) were fed diets supplemented with varying concentrations of S. nervosum leaf extract, including 12.5 g/kg (NT1), 25.0 g/kg (NT2), 37.5 g/kg (NT3), and a control diet without S. nervosum leaf extract (DC). After 28 days of feeding, the shrimp were challenged with Vibrio parahaemolyticus. The results showed no significant differences in growth performance and feed conversion ratio between the experimental groups and the control group (p>0.05). However, the survival rates of shrimp in the supplemented groups (93.4-94.1%) were significantly higher than those in the control group (90.0%) (p<0.05). Furthermore, shrimp in the experimental groups exhibited higher total haemocyte counts, phenoloxidase activity, and lysozyme activity than the control (p<0.05). After 14 days of being challenged with V. parahaemolyticus, the cumulative mortality of shrimp in the supplemented groups was significantly lower than that of the control group (p<0.05). The study recommends supplementing shrimp diets with S. nervosum leaf extract at a concentration of 12.5 g/kg as the optimal level for practical application in white shrimp farming.
Preliminary study on the absorption of nitrogen and phosphorus by five species of macroalgae
(2025) Zhang, Wenwen; Ni, Yan; Wang, Jiangyong; Zhou, Wenchuan; Chen, Suwen; Li, Ting; Li, Tao
In the experiment, Caulerpa lentillifera, Caulerpa sertularioides, Caulerpa serrulata, Halymenia microcarpa and Chaetomorpha valida were employed. The seawater utilized was high in phosphate and nitrogen, and the macroalgae were cultured for 72 hours. We assessed the capacity of five different species of macroalgae to remove nitrogen and phosphorus from seawater by examining changes in the concentrations of ammonia nitrogen, nitrate nitrogen and active phosphorus. The results of the experiment demonstrated that five different types of macroalgae had noticeable removal effects on nitrogen and phosphorus. Caulerpa sertularioides had the best removal effect on ammonia nitrogen, with an absorption efficiency of 96.4%. Caulerpa lentillifera and Caulerpa serrulata had the best removal efficiency of nitrate nitrogen, with an absorption efficiency of 95.5%. Chaetomorpha valida had the best removal effect on active phosphorus, with an absorption efficiency of 78.4%.
Hematological profile of red drum Sciaenops ocellatus (Linnaeus, 1766) under natural and commercial feed nutritional conditions
(2025) Huu Quyet, Do; Tan Dung, Pham; Le Na, Nguyen Thi; Bich Dung, Mai; Mai Huong, Nguyen Thi; Phi Vuong, Tuong
This study was conducted to evaluate the effect of natural and commercial feeds on the hematological characteristics of red drum Sciaenops ocellatus. At different durations up to 30 days of feeding, blood samples were collected from the caudal vein. Biochemical analyses were conducted, and blood smears were prepared and stained with Giemsa. The results showed that the number of erythrocytes fluctuated from 2.07 to 6.32 × 10^6^/μL, the percentage of leukocytes was about 0.34 to 4.80%, and platelets ranged from 0.14 to 4.49% compared to the number of erythrocytes. Pearson correlation (r) between the cell morphological parameters, such as the erythrocyte length and width, with the length, width and area of the nuclei of erythrocytes was not greater than 0.30, while in the group of fish consuming natural feed, the correlation coefficient between cell length and width with the area were 0.57 and 0.52 respectively. In both groups of fish, we found many types of morphological disorders of erythrocytes associated with the cell membrane, and disorders associated with the cell nucleus were expressed at a low level. In addition, the study results also provided biochemical data of red drum such as glucose (1.8 – 22.4 mmol/L), urea (0.6 – 1.7 mmol/L), creatinine (12.1 – 43.2 µmol/L), triglyceride (2.5 – 10.7 mmol/L), AST (4.7 – 68.9 U/L), ALT (0.3 – 6.1 U/L) and protein (21.0 – 49.2 g/L). Overall, these findings contribute to understanding the health and physiological responses of red drum, offering valuable data for optimizing feeding strategies in aquaculture.
A comparative analysis of the transcriptome in skeletal muscle of different growth stages in the Chinese Giant Salamander (Andrias davidianus)
(2025) Wei, Zihui; Zhang, Weichuan; Chen, Hongyu; Fei, Di; Cao, Zhiyuan; Yan, Yujie; Wan, Yixiang; Huang, Yong
To understand the molecular mechanisms underlying its growth in Chinese giant salamander (CGS), transcriptome analysis of the skeletal muscle from five different growth stages at year 0.5 (0.5Y), year 1 (1Y), year 2 (2Y), year 3 (3Y), and year 4 (4Y) were performed. Five libraries were constructed, resulting in the identification of 59,850 unigenes in skeletal muscle by assembly. Unigenes exhibited a length distribution ranging from 201 to 96,350 bp, with an average length of 346 bp. Totally, 20,328 (33.96%) unigenes were successfully annotated to the Nr, TF, Swiss-Prot, Pfam, eggNOG, GO, and KEGG databases. Among these unigenes, 15,467 were found to contain SSRs loci, representing 25.84% of the total unigenes. The average inter-locus distance for SSR was determined to be 3,134 bp. A total of 696 differentially expressed genes (DEGs) with co-expression were identified. Furthermore, it was found that 13 myosin heavy chain family genes are involved in the muscle regulation of CGS. Of them, six DEGs were confirmed for their accuracy by real-time qPCR. GO enrichment showed that DEGs were associated with cytoplasm, nucleus, ATP binding, and metal ion binding in terms of biological processes. KEGG enrichments showed that DEGs were enriched to 275 signaling pathways including cardiac muscle contraction, RNA transport, AMPK signaling pathway, regulation of actin cytoskeleton, calcium signaling pathway, Glycolysis/Gluconeogenesis. Our results contribute to improve and enrich the annotation information of CGS transcriptome, and also provide theoretical basis and data support for the further exploration and verification of related gene functions for elucidating molecular regulatory mechanism behind growth differences between individuals of CGS.
Threatened fishes of the world: Diptychus maculatus and Aspiorhynchus laticeps
(2025) Hu, Linghui; Han, Aizhi; Song, Yong; Yang, Liting; Serekbol, Gulden; Liu, Jiaxuan; Huo, Bin; Ren, Daoquan; Wang, Chengxin; Chen, Shengao
In order to deeply analyze the individual biological characteristics of unique fish in China, lay a solid foundation for the effective protection of its germplasm resources, and further enrich and consolidate the basic biological data system of endemic fish in the world. According to the ethical norms and fishing licenses, 5 samples of Diptychus maculatus and 3 samples of Aspiorhynchus laticeps were collected from the Tarim River system in Baicheng County from 2023 to 2024. The morphological characteristics, age identification and anatomical observation of the two fishes were analyzed by classical biological methods. Both fish belong to Cypriniformes, Cyprinidae, Schizothoracinae. D. maculatus has a long body, a conical head, and a lower mouth with a pair of fish whiskers. The mouth is slightly blunt and arcuate, and the lateral line is complete. A. laticeps has a long, slightly flattened body, a round abdomen, and a large head that is flattened at the front. It also has a pair of fish whiskers located at the corners of the mouth. Age identification materials: D. maculatus lapillus 6+, asteriscus 6+, vertebra 6+, anal scales 6+, opercular bone 5+, A. laticeps lapillus 7+, asteriscus 7+, vertebra 7+, anal scales 7+, opercular bone 7+. The peritoneal wall of D. maculatus is black or brown the tooth type was 3·4-4·3; the external behavior of gill rakers was 8-13; and the internal behavior was 12-16. A. laticeps pharynx teeth 3 lines, tooth type is 2·3·5-5·3·2; the external behavior of gill rakers was 11-13; and the internal behavior was 15-18. D. maculatus and A. laticeps are special species distributed in the Tarim River system. Their evolutionary adaptation is closely related to the uplift of the Qinghai-Tibet Plateau. This study provides important data for better understanding the individual biological characteristics of these two endangered fish species and lays the foundation for their germplasm resource conservation.
Quercetin inhibits largemouth bass rhabdovirus infection by enhancing the immune response in Micropterus salmoides
(2025) Xue, Mingyang; Jiang, Yangyang; Xu, Chen; Huang, Zhenyu; Jiang, Nan; Li, Yiqun; Meng, Yan; Fan, Yuding; Zhou, Yong
The Largemouth bass Rhabdovirus (LMBRaV) is a highly virulent pathogen that results in substantial mortality rates and economic losses within the largemouth bass (Micropterus salmoides) aquaculture industry. The utilization of medicinal plant extracts has emerged as a promising strategy for combating aquatic animal diseases. In this study, we aimed to evaluate the anti-LMBRaV properties effects of nine plant-derived compounds utilizing EPC cells and largemouth bass. Among them, quercetin demonstrated a notable inhibitory effect on LMBRaV replication in EPC, with a reduction of 93.6% at 20 mg/L. Quercetin exerts its anti-LMBRaV properties on cells may result from its ability to inhibit viral entry, mitigate nuclear damage, and inactivate the virus directly. In vivo experiments showed that the preventive protection rate of quercetin against LMBRaV infection in largemouth bass reached 57.7%, and decreased LMBRaV viral loads in liver, spleen and kidney. Moreover, quercetin appeared to induce the expression of several immune-related genes, including interferon (IFN), and major histocompatibility complex 1 (MHC-1), myxovirus resistance 1 (MX1), and nuclear factor erythroid 2-related factor 2 (Nrf2), suggesting its potential for immunoregulation. Furthermore, quercetin mitigated the pathological alterations in the immune organs of largemouth bass infected with LMBRaV. In summary, quercetin shows promise as an immunomodulatory agent against LMBRaV infections in largemouth bass.
Effects of walnut (Juglans regia) green peel extract on growth performance and challenge to enteric redmouth disease (Yersinia ruckeri) in rainbow trout (Oncorhynchus mykiss)
(2025) Karadaş, Filiz; Gültepe, Nejdet
This study aimed to investigate the effects of walnut (Juglans regia) green peel extract on growth performance parameters growth performance and challenge to enteric redmouth disease (Yersinia ruckeri) in rainbow trout (Oncorhynchus mykiss). The triplicate experimental study was performed for 105 days to evaluate the effect of 1, 2, and 4 mg kg^-1^ of walnut green peel extract (WPE). Although there was no significant difference in growth performance between the groups, the growth performance and survival rate of the extract-added groups were slightly better than the control group. Some blood parameters such as mid-range cells (MID), platelet (PLT), platelet distribution width (PDW), procalcitonin (PCT), platelet large cell ratio (P-LCR), and cholesterol (CHOL) values significantly improved in walnut green peel extract-added groups. Phagocytic activity (PA), lysozyme activity (LA), and myeloperoxidase activity (MPO) were significantly increased between all groups compared with the untreated group. Although respiratory burst activity (RBA) increased, no significant difference existed between groups. As a result, it was determined that although walnut green peel extract does not directly affect growth performance, it can be used as a feed additive with its immunomodulatory aspect.
Effects of Dietary Protein and Lipid Levels on Growth, Feed Utilization, and Body Composition of Tire Track Eel (Mastacembelus favus) Fingerlings
(2025) Loan, Phan P.; Thanh Phuong, Nguyen
This study aimed to determine the optimal protein and lipid levels for tire track eel (Mastacembelus favus) fingerlings. Nine test diets comprised three protein levels (40, 45, and 50%) and three lipid levels (6, 9, and 12%). The experiment was conducted in triplicate for 56 days. The initial sizes of fish varied from 3 to 5 g. There were significant interaction effects between protein and lipid levels on final body weight, weight gain, and feed conversion ratio. The dietary protein levels affected weight gain and daily weight gain, while the dietary lipid levels affected length gain. The protein-sparing effect of lipids did not occur in the fingerling stage. Daily feed intake was affected by dietary protein levels but not lipid levels. Feed conversion ratios were lower with increased lipid levels; the lowest value was found at the protein level of 45%. The protein efficiency rates of fish were improved with increased dietary protein levels but were reduced with increased dietary lipids. Increasing dietary lipid levels of the fish resulted in higher body lipid deposition. Survival rates were high and were not affected by the experimental diets. The optimal levels of dietary protein and lipid for growth performance and feed utilization of the Mastacembelus favus fingerlings were 40% and 9%, respectively.
A Comparative Bibliometric Analysis of Chinese and Foreign Articles in Fisheries Cooperation Research
(2025) Wei, Jipeng; Zhao, Junpeng; Huang, Shuolin; Tian, Xinluan; Chai, Yuan
As a highly globalized sector, fisheries play a pivotal role in ensuring global food security, providing high-quality protein, and promoting socio-economic development. Due to its dependence on marine resources, the fisheries industry chain values close international resource sharing and cooperation that help facilitate sustainable utilization of fisheries resources, promote regional and international economic growth, maintain eco-balance, and address global challenges. This paper leverages 1253 articles from Web of Science (WOS) core collection data and 828 articles from China Knowledge Network (CNKI) journal literature as data sources to analyze the publication volume, author and research institution cooperation network, co-occurrence of Chinese and English keywords, citation clustering, and burst detection in this field from 1991 to 2022. This study finds that although a relatively stable publication growth trend has been observed in fisheries cooperation research, the fragmentation of collaboration networks indicates a lack of strong research partnerships. By conducting an in-depth analysis of the underlying factors and proposing policy recommendations, we aim to promote future international cooperation and research innovation in this field.
Dietary incorporation of Bacillus subtilis, enhances growth performance, survival rate, gametogenesis and intestinal health, in zebrafish (Danio rerio)
(2025) Dede, Kemal; Cek, Sehriban
This study assessed the probiotic effects of dietary supplementation with Bacillus subtilis HBB 493® on growth, survival, gametogenesis, and intestinal health of Zebrafish (Danio rerio). 600 juveniles were divided into five experimental groups namely: Control group I (0.0 cfu/g), group II (6.5x10⁹ cfu/g), group III (1.3x10¹⁰ cfu/g), group IV (2.6x10¹⁰ cfu/g) and group V(3.9x10¹⁰ cfu/g). Each treatment and control had three replicates, while each replicate had 40 fish. The duration of the experiment was 100 days. At the termination of the experiment, gonads, and intestine were histologically assessed. Growth parameters, in the fish fed 3.9x10^10^ cfu/g were significantly different from those observed in the control, group II, and group III B. subtilis fed groups (P<0.05), and group V was the best. There were no significant differences in the survival rate between treatment groups including control (P>0.05). The histological observations of the gonads reveal differences among the fish fed different levels of B. subtilis. Fish fed diets II, III, IV and V had more developed gonads compared to those on diets without B. subtilis. The status of villus and goblet cells was used to assess the intestinal health of the fish fed diets supplemented with B. subtilis. Villus and goblet cells were intact in all the different levels of B. subtilis supplemented groups. The present study suggested that the dietary supplementation of 3.9x10¹⁰ cfu/g probiotic B. subtilis should be used for the enhancement of growth parameters, survival rate, gametogenesis and intestinal health in ornamental zebrafish.
Supplementation of Yellow River carp diet with lutein and ferrous fumarate: Growth performance, digestive enzyme activity, skin pigmentation, and intestinal microbiota
(2025) Ren, Hongtao; Cao, Xiang; Guo, Xiangzhi; Yuan, Peng
In this study, the effect of the diet with lutein and ferrous fumarate on Yellow River carp (Cyprinus carpio) was studied, aiming to evaluate skin pigmentation, intestinal digestive enzymes, intestinal microbial diversity, and growth performance. Three experimental diets, including a control group, a lutein group (150mg/kg lutein), and a lutein and ferrous fumarate mixture group (150mg/kg lutein and 100mg/kg ferrous fumarate), were designed. The carp (N=135; 25.0±2.0g) were fed with experimental diets for 42 days. The results showed that the intestosomatic index (ISI) and viscerosomatic index (VSI) of the carp fed with lutein and ferrous fumarate were increased, accompanied by significant changes in body color, with the higher value of blue (b), color difference (ΔE) and chroma (Ch) compared with control group (P <0.05). Meanwhile, the higher activity of amylase, lipase, and trypsin were observed in the mixture group (P<0.05). High-throughput sequencing and Venn diagrams revealed that lutein or ferrous fumarate has obvious effects on the intestinal microbiota community of carp. The abundance of Actinobacteria and Flavobacterium was significantly increased in the carp fed with the mixture group compared with the control group. In conclusion, the addition of lutein and ferrous fumarate to the feed can change the skin pigmentation and intestinal microbial composition of Yellow River carp, thereby enhancing the coloring effect and digestive function of the fish. These findings provide valuable insights for optimizing feed formulation and aquaculture management, which can contribute to the improvement of the quality and farming efficiency of Yellow River carp.

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