Volume 77, Issue 2, 2025

Permanent URI for this collectionhttps://hdl.handle.net/10524/83019

Browse

Now showing 1 - 20 of 21

Assessment of Indigenous Feed Ingredients on Growth and Feed Utilization Efficiency in Juvenile Milkfish (Chanos chanos Forsskål, 1775)
(2025) Macusi, Edison D.; Sales, Anthony C.; Jimenez, John Edward M.; Vender, Ethel Kate E.; Bongas, Henzel P.; Macusi, Erna S.; Andam, Michael B.
This study aimed to assess the feasibility of utilizing indigenous feed ingredients for milkfish (Chanos chanos Forsskål 1775) aquaculture. Nine different feed treatments were tested: taro, golden apple snail, azolla plant, blood meal, cacao pod, banana stem, copra meal, soybean meal, and a control. We used 15 juvenile milkfish (initial weights=6.4-7.4 g; initial lengths=5.3-5.7 cm) cultured in 80 L tanks and replicated three times to assess their growth and feed utilization. After 60 days of culture, copra meal and Azolla attained 23.0 g and 21.8 g, which were higher compared to the other treatments. This was followed by taro (18.9 g), bloodmeal (18.4 g), golden apple snail (18.2 g), control (18.2 g), cacao pod (18.2 g), soybean treatments (17.5 g), and lastly banana stem (16.1 g). Comparison of the initial length and weight of the treatments versus their final values during the 60 days of culture showed differences (length: t=20.0, p=0.0001, df=16; weight: t=16.5, p=0.0001, df=16) but none between the nine treatments (p\>0.05). In terms of average daily weight gain, copra meal gained faster (0.34 g), followed by Azolla (0.24 g), and then the control (0.22 g) and bloodmeal (0.19 g) with banana stem the last (0.15 g). While in terms of feed conversion ratio (FCR), copra meal (1.1), azolla (1.3), taro (1.5) and the control (1.5) had the lowest FCR values; banana stem (1.9) and soybean meal treatments (2.0) had the highest. Fulton's condition factor showed that these four treatments (taro=1; Azolla=1.2; copra meal=1.2; control=1.2) were closest to 1, signifying a healthy condition. The gonadosomatic index (GSI=0.005) and hepatosomatic index (HSI=0.03) values were consistent in the various treatments, showing no adverse effects suffered during the period of culture. The alternative feeds can be used in milkfish aquaculture to reduce the cost of operation.
Effects of Aquaculture Substrate on Key Aquaculture Environmental Parameters, Growth Performance, and Physiological Responses in Babylonia areolata
(2025) Zhou, Cheng; Zhao, Wang; Yang, Rui; Huang, Junhua; Qin, Haipeng; Ma, Zhenhua; Wang, Xiaoyu
To enhance the aquaculture environment of Babylonia areolata, this study evaluated five substrates—small ceramsite, medium ceramsite, large ceramsite, quartz sand, and river sand (control)—on water quality, growth, survival, digestive enzyme activity, and antioxidant capacity in juvenile B. areolata. Results demonstrated that small ceramsite achieved optimal performance in water quality maintenance, survival rate (92.4 ± 3.1%), and growth rate (specific growth rate: 1.85 ± 0.12%/day). Small ceramsite significantly enhanced lipase (18.7 ± 1.2 U/mg protein) and trypsin (23.4 ± 1.5 U/mg protein) activities in hepatopancreas compared to control (p < 0.05). In contrast, large ceramsite exhibited lower digestive enzyme activity than control (p < 0.05). Glutathione peroxidase (GSH-PX) activity in large ceramsite groups declined significantly (p < 0.05), while lysozyme activity in hepatopancreas surpassed that in foot and mantle across all substrates. Conversely, acidic phosphatase (ACP) activity in mantle and hepatopancreas under large ceramsite was significantly lower than in foot tissues (p < 0.05). Substrate type critically influences growth, immune function, and antioxidant capacity in B. areolata. Small ceramsite outperformed others by improving water quality, enhancing survival, and accelerating growth, while simultaneously boosting digestive and antioxidant enzyme activities. These findings suggest small ceramsite as the optimal substrate for B. areolata aquaculture, offering a strategy to optimize rearing conditions, improve economic efficiency, and promote mollusk health.
Strengthening the Resilience of Aquaculture Competitiveness in EU Economies: An empirical analysis
(2025) Alsaleh, Mohd; Abdul-Rahim, A.S.
The European Union (EU27) faces significant challenges in enhancing the global competitiveness of its aquaculture market, such as stagnant production, high production costs, competition from cheaper imports, focus on sustainability, and consumer preferences. Thus, the main goal of this research is to explore how factors related to global competitiveness influenced the growth of the aquaculture sector in the EU27 from 1990 to 2023. The methods of ordinary least squares (OLS), two-stage least squares (2SLS), and robust least squares (RLS) estimations were used to address the endogeneity problem to arrive at the most important results. The effect sizes indicate that the system of innovation and human capital have a greater influence on the development of the aquaculture sector in the highly developed EU14 countries compared to the developing EU13 nations. The exact outcomes of the applied methods, however, demonstrate that the aquaculture market's expansion in EU13 developing nations is more influenced by market size, institutional quality, and economic growth compared to EU14 members. This study recommends that the EU27 region emphasize policy adjustments to balance sustainability with competitiveness, which includes streamlining regulations, improving access to financing, and fostering innovation in aquaculture technologies.
Development and Utilization of Transcriptome SSR Markers in Procambarus clarkii
(2025) Zeng, Dan; Zhang, Yunsheng; Du, Min; Shao, Liye; Xia, Hu; Han, Qing
To accelerate the research process of molecular marker-assisted breeding in Procambarus clarkii, this study conducted transcriptome sequencing of P. clarkii muscle tissue using the Illumina NovaSeq platform. Microsatellites (SSRs) were analyzed for distribution and sequence characteristics using MIcroSAtellite (MISA), and genetic diversity was studied in seven cultured populations. The results showed that the sequencing yielded between 9.9 to 12.7 Gb of clean data, and after assembly, produced between 52,244 to 83,367 contigs, identifying a total of 11,304 SSR loci. The SSRs were predominantly dinucleotide and trinucleotide repeats, accounting for 33% and 27% of the total loci, respectively. The average observed heterozygosity (Ho) across the seven different regional aquaculture populations ranged from 0.374 to 0.502, while the average expected heterozygosity (He) ranged from 0.502 to 0.604. The average polymorphic information content (PIC) for the populations was greater than 0.450, indicating substantial genetic variability. According to Nei's genetic distance, an Unweighted Pair Group Method with Arithmetic Mean (UPGMA) cluster tree divided the seven different regional aquaculture populations into two major clades: one comprising Yunnan (YN) and Qianjiang (QJ) and the other comprising the remaining five populations. The study found that 93.52% of the variation originated within populations, with only 6.48% of genetic variation attributable to differences between populations. These results lay a foundation for further assessment of the genetic diversity of P. clarkii, innovative utilization of germplasm resources, and in-depth studies into its molecular genetics and evolutionary mechanisms.
Research on ecological-economic value equilibrium path of aquatic products from trust perspective
(2025) Dai, Yunyun; Wang, Zhixiao; Liu, Qiyao; Pan, Yuting; Yang, Hong
Eco-aquatic products have two important attributes: food safety and eco-friendliness. However, in China, the market price of most eco-aquatic products is not significantly different from that of ordinary aquatic products, which fails to fully realize their ecological value and high quality. This paper analyzed the path of realizing the ecological value and economic value of aquatic products from the perspective of trust. Through the analysis of three cases of Suzhou Haimei Family Farm, Suzhou Pinwei Aquatic Products Company, and Jiangsu Yunian Agriculture and Forestry Ecological Development Company, this paper showed how to improve consumer trust through community participation, social network and government endorsement, aimed at maximizing the value of ecological aquatic products. The case analysis demonstrates that adhering to the concept of ecological priority and sustainable development, building regional or product brand, maintaining brand image, and innovating diversified business strategies can effectively promote the development of aquaculture industry to a healthier and more environmentally friendly direction, and achieve a win-win situation of economic and ecological benefits.
Research on the resilience level of fishery economy in coastal areas of China
(2025) Chen, Yingjie; Ma, Teng; Xu, Shiwei; Zhao, Yu; Deng, Zhikang
Multiple risks such as environmental pollution, market risk, and extreme weather pose severe challenges to fishery production, fishermen 's lives and property, and the sustainable development of fishery. Improving the resilience of fishery economy is an inevitable requirement for coping with fishery production risks and achieving high-quality development of fishery economy. Therefore, based on the three dimensions of resistance and recovery ability, adaptation and adjustment ability, innovation and transformation ability, this study constructs a comprehensive index evaluation system of fishery economic resilience, and uses entropy method and Theil index method to measure the level of fishery economic resilience and regional differences in coastal areas of China from 2016 to 2023. The conclusions are as follows: (1) From 2016 to 2023, the level of fishery economic resilience in coastal areas of China showed a fluctuating growth trend of 'first decline and then rise', with an average value of 0.2566. (2) There are significant differences in the level of fishery resilience in different coastal areas. From 2016 to 2023, Shandong Province had the highest level of fishery economic resilience (0.5226), and Hainan Province had the lowest level of fishery economic resilience (0.0751). The eastern marine economic circle has the highest fishery economic resilience (0.2713), followed by the southern marine economic circle (0.2650), and the northern marine economic circle has the lowest fishery economic resilience (0.2371). (4) The regional differences in the level of fishery economic resilience in coastal areas of China mainly come from inter-group differences, with a contribution rate of 68.36 %. The difference in the level of fishery economic resilience between the three major marine economic circles has gradually become the most important factor affecting the difference in the level of fishery economic resilience in China.
Identification and characterization of pathogenic Aeromonas hydrophila isolated from clinically diseased Chinese rice-field eel, Monopterus albus
(2025) Jiang, Jingwen; Xue, Mingyang; Liu, Wenzhi; Jiang, Nan; Zhou, Yong; Liu, Yisha; Li, Mengmeng; Zhong, Qiwang; Fan, Yuding
Aeromonas hydrophila is recognized as a prevalent pathogenic bacterium in aquaculture. An outbreak of a disease characterized by a high mortality rate has been reported at a Chinese rice-field fish farm (Monopterus albus) located in Hubei Province. This study isolated a causative A. hydrophila strain (YFI-C1) in diseased Monopterus albus through bacterial isolation and subsequent morphological, physiological, biochemical, evolutionary and molecular biology analysis. Ten virulence genes, including those that encode cytotoxic enterotoxins (act and alt), a quorum sensing-controlled virulence factor (LuxS), a temperature-sensitive protease (eprCAI), serine proteinase (ser), haemolysin-aerolysin (aeraA), nuclease (nuc), hemolysin (hlyA), lipase (lip), flagellin (fla) have been shown to be responsible for YFI-C1's pathogenicity. An artificial infection was utilized to evaluate the pathogenicity of YFI-C1, with a median lethal dose (LD50) of 1 × 106 colony forming units (CFU)/mL. The Kirby-Bauer test was used to measure YFI-C1's sensitivity to ten antibiotics. According to the findings, YFI-C1 was resistant to Cefothiophene but extremely susceptible to six antibiotics: Ciprofloxacin, Trimethoprim-sulfamethoxazole, Doxycycline, Enrofloxacin, Compound sulfamethoxazoles, and Flufenicol. The results of this study offer valuable insights for future research on bacterial disease prevention and treatment in Monopterus albus.
Effects of dietary marine red yeast on growth performance, digestive enzyme activities, antioxidant capacity, and immunity response of white-spotted conger (Conger myriaster)
(2025) Wang, Yuyu; An, Meiling; Shen, Hengxia; Chen, Tong; Li, Yuanyuan; Guo, Jianjun; Dong, Yanjun; Teng, Fuhai; Wang, Junxia; Hu, Ming
This study aimed to investigate the effects of marine red yeast (MRY) on growth performance, digestive enzyme activities, serum biochemistry, antioxidant capacity, immunological indices, and expression of immune-related genes in white-spotted conger (Conger myriaster). Four diets were supplemented with varying levels of MRY (0%, 0.5%, 1.0%, and 1.5%, designated as MRY0, MRY0.5, MRY1, and MRY1.5, respectively). Fish (average weight, 46.27 g) were divided into 12 net cages, with 3 cages per diet. The fish were fed diets twice daily for 56 days. Results indicated that dietary supplementation of MRY had no significant effects on growth and digestive enzyme activities (P\>0.05). Fish fed diets MRY1 and MRY1.5 had lower serum alanine aminotransferase (ALT) content than the MRY0 and MRY0.5 groups (P<0.05). Serum glucose (GLU) content showed an increasing trend with increasing MRY levels, and the MRY1.5 group had the highest value (P<0.05), while cholesterol (TC) and triglyceride (TG) levels exhibited an opposite trend, and fish-fed diet MRY1 had lowest values (P<0.05). Fish fed diet MRY0.5 had significantly higher hepatic glutathione peroxidase (GSH-Px) activity than those fed diets MRY0 and MRY1.5 (P<0.05). Hepatic total superoxide dismutase (T-SOD) and serum alkaline phosphatase (ALP) activities increased with the increase of dietary MRY level (P<0.05). Fish fed diet MRY1.5 exhibited significantly lower relative expression of heat shock protein 70 (HSP70) in the liver than fish fed diets MRY0 and MRY0.5 (P<0.05), and no significant difference was found in the relative expression of HSP90 in the liver among all groups (P\>0.05). In conclusion, 1%--1.5% MRY could be applied as a feed additive to effectively enhance the immune response of white-spotted conger.
Cyclophilin A in Megalobrama amblycephala: Molecular characterization and expression analysis in response to Aeromonas hydrophila challenge
(2025) Lu, Juanjuan; Xia, Hu; Gong, Yanan; Chen, Fuyan; Bu, Jianchao; Yang, Pinhong
Cyclophilin A (CypA) is a cell’s primary receptor of Cyclosporin A (CsA). It is essential for biodiversity and plays an important role in the immune system. In this study, the full-length cDNA sequence (GenBank ID: PV256473) of Megalobrama amblycephala CypA was acquired by PCR and RACE technology. The complete cDNA sequence of M. amblycephala CypA is 901 bp. The lengths of the 5′ untranslated region (UTR), the 3′ untranslated region, and the open reading frame (ORF) are 77 bp, 329 bp, and 495 bp, respectively. It encodes a total of 164 amino acids. The theoretical isoelectric point of M. amblycephala CypA is 8.6, and the relative molecular weight is 17.43 KDa. According to homologous sequence retrieval in GenBank, the similarity between CypA amino acid sequence of M. amblycephala and other fish was Cyprinus carpio (94.51%), Ctenopharynodon idellus (92.07%), Carassius gibelio (92.07%), Labeo rohita (92.07%), Danio rerio (91.46%), and Onychostoma macrolepis (91.46%). ESyPred3D predicted that the CypA of M. amblycephala contained 8 β-pleated sheets and double α-helixes, which might form the active central region of CypA. MEGA 5.1 software was used for multiple sequence comparison analysis, and the adjacency method constructed the genetic phylogenetic tree. It was found that the CypA gene of M. amblycephala was clustered into one branch of Cyprinidae fish CypA, and CypA of M. amblycephala was closely related to CypA of Cyprinus carpio. Expressions of CypA in different tissues of M. amblycephala were detected through qPCR; it was found that the expression level of the CypA gene was highest in the head kidney, followed by liver, kidney, and spleen. The M. amblycephala was immersed in Aeromonas hydrophila for infection; it was found that expression levels of CypA in head kidney, liver, gills, and intestines first increased, then decreased in the first 72 h of infection. Specifically, the expression levels reached a peak at 6h in the head kidney, at 12 h in the liver and gills, and at 24h in the intestines. It indicated that the expression of M. amblycephala CypA gene could be significantly induced after A. hydrophila infection—expression levels of CypA in the head kidney peak earlier than in the liver and intestines. Moreover, the relative expression level of CypA in the head kidney at peak (15.02-fold) is significantly higher than that in the liver (6.89-fold), intestines (9.92-fold), and gills (7.42-fold). It is suggested that CypA might play an essential role in the head kidney of M. amblycephala in defense against bacterial infection.
Monthly variations in reproductive indices, egg quality, and larval survival of broodstock snubnose pompano (Trachinotus blochii)
(2025) Ngo, Manh V.; Le, Hoang M.
This study evaluated the monthly variations in reproductive indices, egg quality, and larval survival of broodstock snubnose pompano (Trachinotus blochii) reared under captivity conditions from January to December. The parameters assessed included gonadal maturation rate, fecundity, egg diameter, egg buoyancy rate, fatty acid composition (SFA, MUFA, PUFA, and HUFA) in egg, fertilization rate, hatching rate, and 3-day larval survival rate. The results showed that May, July, November, and December were the most favorable periods regarding reproductive performance and egg quality, with maturation rates exceeding 70% and hatching rates surpassing 90%. Notably, July recorded the highest fecundity (107,454 eggs/kg female), and larval survival peaked at nearly 60% during this month. These findings highlight the significant influence of time and environmental factors on reproductive success and seed quality. Analyses revealed a strong relationship between egg quality and larval survival, with the nutrient content of eggs, particularly long-chain polyunsaturated fatty acids such as DHA and EPA. Therefore, the study recommends proactively developing seasonally aligned spawning schedules and providing targeted nutritional supplementation to broodstock during maturation to enhance sustainable seed production efficiency for this high-value marine species.
Effects of PS-MPs on growth, immunity, antioxidant capacity and amino acid metabolism in common carp (Cyprinus carpio)
(2025) Li, Pengcheng; Chen, Weijun; Chen, Deshan; Xie, Pengfei; Han, Lei; Yang, Feng; Sun, Ping
To explore the toxic effects of polystyrene microplastics (PS-MPs) on common carp (Cyprinus carpio), 0 µg/L, 50 µg/L, 100 µg/L, and 200 µg/L PS-MPs were designated as the control group (CK) and low, medium, and high concentration groups, respectively. Each group had 3 replicates and was exposed to PS-MPs for 15 days. The results showed that, compared with the control group, the weight gain rate and hepatopancreas somatic indices were significantly decreased in 100 and 200 μg/L PS-MPs groups, the visceral index was significantly decreased in 50 and 100 μg/L PS-MPs groups. In comparison to CK, experimental groups (50-200 µg/L PS-MPs) significantly decreased activity levels of acid phosphatase, alkaline phosphatase, and peroxidase while significantly increased activity levels of lysozyme, catalase, and superoxide dismutase. In addition, the malondialdehyde contents of the experimental carp increased significantly in 50 and 100 µg/L PS-MPs groups compared to CK. For hepatic amino acid contents, methionine, threonine, leucine, and isoleucine contents of the hepatopancreas of carp in PS-MPs groups were significantly lower than the control group. Correlation analysis showed that amino acids in the liver closely associated with fish growth, immune, and antioxidant-related indicators. In conclusion, PS-MPs above 50 µg/L in the water body could significantly affect normal growth, weaken the activity of hepatopancreatic immunity-related enzymes and antioxidant capacity, and disturb the balance of amino acid metabolism in common carp. The findings provide valuable insights into optimizing feeding strategies, contribute to more sustainable aquaculture practices, and support the development of policies in aquatic ecosystems.
Molecular Characterization and Functional Analyses of IGFALS in the Chinese Soft-Shelled Turtle (Pelodiscus sinensis)
(2025) Zhu, Yulei; Li, Lin; Tu, Yangyang; Chen, Xincheng; Chen, Mengying; Yan, Feng; Zeng, Dan
The insulin-like growth factor (IGF) system plays a crucial role in the regulation of development, reproduction, and growth. Within this system, the IGF acid-labile subunit (IGFALS) plays a pivotal role in modulating IGF activity by stabilizing circulating IGF complexes. In this study, two IGFALS gene transcripts, named IGFALSX1 and IGFALSX2, were identified for the first time in the Chinese soft-shelled turtle (Pelodiscus sinensis). The cDNA sequences of IGFALSX1 and IGFALSX2 were 2,452 bp and 2,520 bp, respectively, encoding 617 and 616 amino acids (AAs). The IGFALS gene was expressed in all tissues of P. sinensis, with particularly high expression in the liver, gonads, and lungs, and marked sexual dimorphism observed in the liver. Short-term stimulation of juvenile P. sinensis with sex steroids led to significant changes in IGFALS expression in the livers of both male and female individuals, suggesting its potential involvement in steroid-mediated growth modulation. These observations collectively indicate that IGFALS may function as a key molecular mediator in the steroid-responsive growth regulatory pathway of P. sinensis.
Analysis of the influence of two kinds of shell characteristics on the total weight and soft tissue weight of the clam Cyclina sinensis
(2025) Ge, Hongxing; Zhao, Chen; Xie, Yong; Dong, Zhiguo
To reveal the influence of shell traits between two shell colors on the body and soft tissue weight of the clam Cyclina sinensis, a total of 1000 individuals (500 with white shells and 500 with purple shells) were randomly selected to analyze the effects of shell length, shell height, shell width, ligament length, and shell weight on the body and soft tissue weight. The results indicated that the shell traits of the clam were significantly correlated with the total weight and the soft tissue weight at an extremely significant level (P < 0.01). Shell height was the main determinant of total body weight and soft tissue weight in the white shell group and the mixed group. Shell length is the main characteristic that determines the total weight and soft tissue weight of the purple shell. The optimal multiple regression equations with total weight and soft tissue weight as dependent variables and other characteristics as independent variables were established for the two shell color groups of C. sinensis. The results provided a theoretical basis for the breeding and production of the clam.
Nutrition composition of different size of male largemouth bass (Micropterus salmoides) and its implications for food processing industry
(2025) Xie, Quansen; Cai, Jiaying; Liu, Yiran; Zhang, Zhihua; Wang, Miao; Yang, Mingjian; Xing, Haochun
To understand the basic nutritional composition and enhance the application of largemouth bass (Micropterus salmoides), the nutritional quality of muscle and skin of largemouth bass with body weight of 450.10±1.11g, 650.31±1.20 g, and 850.10±1.13 g was analyzed. Results showed that the skin and muscle of fish with a body weight of 650.31±1.20 g were most suitable for processing and comprehensive utilization. Glycine had the lowest percentage, while glutamic acid was the most prevalent amino acid connected to umami. Total amino acid (TAA), essential amino acid (EAA), and D-aspartic acid (DAA) levels first increased and then decreased as the body weight increased. Largemouth bass of an intermediate size exhibited the highest levels of TAA and DAA, and superior amino acid balance and had the highest nutritional value among the three groups. The most common necessary minerals were Na, Mg, and K. The skin had higher concentrations of these elements than muscle, and their amounts rose and reduced in proportion to body weight. Our results demonstrated that the male largemouth bass with a body weight of 650.31±1.20 g had the muscle with the highest nutritional quality and the greatest application potential.
Study on the Approval Criteria for Fishing Vessel Main Engine Power Control Based on Main Engine Power Calculation Methods
(2025) Lyu, Chao; Shi, Yihe; Liu, Shuang
This study examines the challenges of accurately reviewing and approving the main engine power of multipurpose motorized fishing vessels. It summarizes theoretical estimation methods and examines the impact of various power estimation techniques through example calculations. The effective power method was used to estimate main engine power, and the performance of the fitted equations and auditing methods was evaluated. The results show that there are significant differences in the accuracy of the different auditing methods, with differences as high as 45%. The error of the fitted equation method is below 15%, while the Japanese effective horsepower estimation method has the smallest error of about 10%.
Impact of Acute Hypoxia Stress on the Antioxidant Capacity and Tissue Damage of Penaeus monodon
(2025) Qi, Xinyu; Wang, Jieyi; Zhou, Falin; Shi, Jianzhi; Ding, Yangyang; Li, Yundong; Yang, Qibin; Jiang, Song
This experiment was conducted to examine the effects of acute hypoxia stress on Penaeus monodon, specifically focusing on its antioxidant capacity and tissue damage. The study aimed to understand how acute hypoxia stress influences these physiological parameters in P. monodon. Hepatopancreas and gill tissues were sampled at three distinct dissolved oxygen (DO) levels: a normoxic condition of 6 mg·L⁻¹, a hypoxic condition of 2 mg·L⁻¹, and an acute hypoxic condition of 1 mg·L⁻¹. Tissue collections were performed after exposure periods of 2 hours and 4 hours, respectively, to assess the effects of varying oxygen concentrations over time. The activities of immune enzymes (ACP, AKP) and antioxidant enzymes (T-AOC, T-SOD, MDA) were measured, and the hepatopancreas and gill tissues were examined through sectioning. The results showed that under hypoxic stress, the activity level of the experimental shrimp increased, the movement of the eye stalk was rapid, and the antennae and abdomen were significantly curved. AKP activity initially increased in response to stress but decreased over prolonged hypoxia exposure. ACP activity decreased with prolonged hypoxia but showed some recovery over time. T-AOC and MDA activities decreased with prolonged hypoxia exposure. T-SOD activity showed an increasing trend but decreased under excessive hypoxia. Different degrees of damage were observed in the hepatopancreas and gill tissues under hypoxia stress. The study indicates that hypoxia stress affects the activity of immune and antioxidant enzymes in P. monodon, causing tissue damage to the hepatopancreas and gills. These findings help elucidate the response mechanism of P. monodon to hypoxia stress and provide a reference for the healthy aquaculture of this species.
Environmental Impacts of Aquaculture in the Philippines
(2025) Tahiluddin, Albaris B.; Bornales, Jonald C.; Limbaro, Gindol Rey A.; Paudac, Mohammad Al-Thanie U.; Amarille, Randell Keith; Sirad, Naima R.; Kabirun, Mariam C.; Ujing, Romar A.; Gonzaga-Torino, Floriefe M.; Sabdani, Mardiya H.; Bacla-an, Ramonito E.; Hairal, Moh. Abdul-jan S.; Magcanta-Mortos, Maria Lyn M.; Esguerra, Jonhniel P.
Aquaculture is one of the fastest-growing industries globally, hailed as a crucial source of aquatic food for human consumption. In the Philippines, a nation with a significant stake in global aquaculture, this sector not only supports food security and provides livelihoods but also boosts the national economy by generating valuable export revenue. However, the rapid expansion of aquaculture in the country has sparked concerns, particularly regarding its environmental footprint. This work critically reviews the environmental impacts of aquaculture in the Philippines by reviewing available literature published from 1918 up to the present on the environmental impacts of Philippine aquaculture using relevant keywords from databases like Scopus, Web of Science, PubMed, Google Scholar, and ResearchGate, and some Philippine government databases like the Philippine Statistics Authority and Bureau of Fisheries and Aquatic Resources. While aquaculture plays a key role in ensuring food security, sustaining livelihoods, and supporting the country’s economic growth, it has also been linked to several environmental issues. These include the destruction of mangrove habitats, degradation of seagrass ecosystems, sediment disruption, water pollution, and declining water quality. Moreover, the presence of antibiotic-resistant genes and residues in farmed species, alongside the introduction of non-native species, has triggered biodiversity imbalances and ecosystem degradation. This review underscores the urgent need for mitigation strategies to address these environmental impacts and proposes actionable solutions. Looking ahead, the future of Philippine aquaculture will depend on how well it balances growth with sustainability, ensuring the sector's continued contribution to the economy and the environment.
Evaluating the culturing performance of two-skinned mud crabs (Scylla paramamosain) using intermolt and mature crabs in various eyestalk ablation and gender conditions
(2025) Le, Vu H.; Huang, Ting C.; Nguyen, Bac V.; Tien, Ly H.; Doan, Diep X.
A thorough investigation into the effects of crustacean eyestalk ablation across different genders is crucial for optimizing aquaculture practices. This research was conducted from June to September 2023, with two separate experiments to assess how eyestalk removal and the gender of mud crabs (Scylla paramamosain) affected the performance of raising double-skinned crabs using intermolt and mature crabs. Both experiments utilized a completely randomized design with three replications in rectangular tanks (a bottom area of 0.3 m²). Crabs were divided into four eyestalk ablation groups (no ablation, right ablation, left ablation, and bilateral ablation) in experiment 1, while experiment 2 focused on right eyestalk ablation crabs and categorized them into three gender groups (males, females, and mixed-sex). The animals were stocked at a density of 20 individuals m⁻² and were fed trash fish at a rate of 5% of their wet body weight throughout the experiments. The results showed that eyestalk ablation did not significantly affect overall yields. However, it improved the specific growth rate (SGR), the time needed to form double-skinned crabs (duration), and the feed conversion ratio (FCR). The right ablation group showed the most notable improvements. The bilateral ablation group showed improvements in FCR but had the fewest benefits in SGR, duration, and survival rate (SR). Additionally, gender factors had a minor effect on duration, with the shortest time recorded for the female group. Both male and mixed-sex groups showed improvements in FCR but experienced a decline in SR, with a significant reduction in the male group. Based on these findings, it is recommended that right eyestalk ablation in intermolt and mature female mud crabs is the most effective strategy for producing double-skinned crabs under the conditions studied.
An Improved Active Disturbance Rejection Control Method for a Deep-Sea Aquaculture Vessel
(2025) Lyu, Chao; Zhao, Si-Dong; Liu, Shuang
To address the challenges of accurately modeling the motion of deep-sea aquaculture vessels under the combined effects of dynamic disturbances from the external environment and coupled disturbances from the liquid levels within the aquaculture tanks, as well as the performance limitations of traditional Active Disturbance Rejection Control (ADRC), this study proposes an improved Active Disturbance Rejection Control strategy based on the ADRC structure, and applies it to the design of the controller for the dynamic positioning system of aquaculture vessels. Furthermore, to tackle the issues of numerous uncertain parameters and tuning difficulties inherent in ADRC, an Improved Whale Optimization Algorithm (IWOA) is introduced for parameter tuning. The optimization algorithm incorporates a chaotic optimization strategy and an improved adaptive inertia weight ω with nonlinear characteristics, which simplifies the complex process of constructing an adaptive function in the Grey Wolf Optimization (GWO) algorithm and addresses the slow global search speed and poor local optimization ability of the traditional Whale Optimization Algorithm (WOA). The final Simulink simulation results demonstrate that the ADRC controller designed with IWOA outperforms traditional WOA, GWO, and Genetic Algorithm-optimized ADRC controllers in terms of control effectiveness and disturbance rejection capability, improved the dynamic positioning control performance of aquaculture vessels.
Optimization of multi-trophic aquaculture systems for Penaeus monodon through the introduction of Mugil cephalus, Scylla serrata, and Microecological Agents
(2025) Lin, Changhong; Zhang, Bo; Qiu, Lihua; Zhang, Bo; Yan, Lulu; Zhao, Chao
The mixed aquaculture model, developed based on the ecological principles of species' living characteristics, habits, and different requirements for matter and energy of different ecological niches, has been proven to be an environmentally efficient and low-carbon type of aquaculture. Based on this concept, the present study aims to establish an effective regulation of aquaculture water quality by determining a reasonable fish-shrimp-crab ratio and combining the use of microbial agents. The research initially establishes a multi-trophic integrated aquaculture model of shrimp-fish-crab and develops the microecological regulation of water quality in multi-trophic level aquaculture ponds. In this study, the experimental ponds were divided into one control group (shrimp) and three experimental groups (different species ratio combinations of shrimp, sea mullet and mangrove crab), each comprising three ponds, and subjected to a 60-day cultivation period. Water quality parameters such as total nitrogen, total phosphorus, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, active phosphorus, and chemical oxygen demand (COD) were monitored bi-weekly. Results showed significant reductions in these metrics within the experimental groups compared to the control group. Specifically, group 3 demonstrated the most substantial decreases, with a maximum reduction range of 32.54% to 60.09%. Shrimp growth and survival rates were notably influenced by the mixed culture system, with group 3 exhibiting the highest final yield and significant improvement in average body weight. Furthermore, introducing Sea mullet and mangrove crabs into the pond system proved beneficial for water quality and shrimp productivity. The optimal co-culture scheme was determined to be 0.90 Sea mullet/m², 0.45 mangrove crabs/m², and 75 shrimp/m². Additionally, the use of microecological agents like Bacillus subtilis, Bacillus licheniformis, and Saccharomyces cerevisiae further enhanced the farming environment. The optimal application scheme in the experimental ratio plan was: Bacillus subtilis applied at a concentration of 5.0×10^8 CFU/m³ with a frequency of once every 10 days; Bacillus licheniformis applied at a concentration of 1.0×10^8 CFU/m³ also every 10 days; and Saccharomyces cerevisiae administered at a concentration of 2.0×10^8 CFU/m³, with the same 10-day interval. This will promote the development of a sustainable and efficient integrated aquaculture model for Penaeus monodon, providing theoretical support and practical foundation for its application.

Browse

Recent Submissions