Volume 76, Issue 2, 2024

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https://hdl.handle.net/10524/76165

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Comparative analysis of the structural and compositional change of spotted sea bass (Lateolabrax maculatus) gut microflora following Aeromonas veronii infection and the effects of Lactobacillus plantarum on these changes
(2024) Lin, Changhong; Qiu, Lihua; Zhang, Bo; Wang, Pengfei; Zhang, Bo; Yan, Lulu; Zhao, Chao
Growing evidence suggests a close relationship between gut microbiota and infectious diseases. However, the specific role of gut microbiota in host-pathogen interactions during aquaculture-related infections remains poorly understood. This study investigated the diversity and composition of gut microbiota communities in Aeromonas veronii-infected Lateolabrax maculatus using high-throughput sequencing. The results revealed significant changes in the structure and composition of L. maculatus gut microbiota after A. veronii infection. Over time, Bacteroidetes and Firmicutes decreased significantly, while Proteobacteria increased significantly after A. veronii infection. Most intestinal bacteria showed a decline in abundance over time, with probiotics (such as Lactobacillus) experiencing a significant decrease and pathogens (such as Aeromonas) showing a significant increase. Conversely, no differences were observed in the structure and composition of gut microbiota between healthy L. maculatus and those infected with A. veronii after treatment with Lactobacillus plantarum; no changes in relative abundances of other bacterial phyla or genera except for Aeromonas. Furthermore, intestinal flora's structural diversity and composition differed significantly from untreated L. maculatus infected with A. veronii. These findings suggest alterations in the structure and composition of gut microbiota following A. veronii infection. L. plantarum can maintain a dynamic balance within the intestinal flora, reducing the potential risk of pathogen infections.
Rice-fish symbiosis improves the muscle nutrition and intestinal flora diversity of tilapia
(2024) Zhu, Yuanming; Ji, Yan; Zhou, Xuan; He, Xianlin; Xue, Xiaoshu; Zhang, Jiaqi; Tang, Hongyu; Zhou, Ya; Zhang, Chi
Rice-fish symbiosis is an ecological farming model that can improve fish's muscle nutrient profile and intestinal flora. We investigated the effect of rice-fish symbiosis on tilapia's intestinal flora and muscle nutrients. We used 16S rDNA technology to analyze the intestinal flora of tilapia in pond culture and rice-fish symbiosis. Furthermore, spearman correlation analysis was performed on tilapia intestinal flora and muscle nutrients. The results showed that the contents of Valine, Phenylalanine, and Docosahexaenoic acid were significantly higher in the rice-fish symbiosis than those in the pond culture (p<0.05). Intestinal flora analysis showed that the diversity in rice-fish symbiosis was significantly higher than in pond culture (p<0.05). Meanwhile, the abundance of Brevundimonas, Pseudomonas, and Ralstonia in rice-fish symbiosis was significantly higher than those in pond culture (p<0.05), but Pirellulaceae unclassified and Cyanobium_PCC-6307 were opposite. The number of 8 predictive functional tilapia genes in the rice-fish symbiosis was higher than in the pond culture. Correlation analysis showed that the abundance of Ralstonia was positively correlated with the contents of Valine, Phenylalanine, and Docosahexaenoic acid, respectively. Our study shows that the rice-fish symbiosis could improve muscle nutrient profile and intestinal flora diversity in tilapia. This study will help to improve the rice-fish symbiosis model and provide a scientific basis for ecological aquaculture and healthy fish production.
Fish Welfare – A Case Study: Reviling for the first-time side effects of vaccination in European sea bass (Dicentrarchus labrax) and barramundi (Lates calcarifer) in the Israeli fish farming
(2024) Smirnov, Margarita; Hershko, Hanna; Ron, Tetsuzan B
Vaccination is an effective way to control many infectious diseases in fish. Israeli fish farming has successfully used two vaccines over the last 30 years and has no problem with the side effects of vaccination. However, after introducing new species, a new problem emerged: these fish, after vaccination, demonstrated peritoneal lesions such as granulomas. At the same time, the fish did not show retarded growth or suffering during the fattening period. This study was conducted to establish the connection between vaccination and the appearance of granulomas. Evidence drawn from this research work and comparing vaccinated and non-vaccinated fish confirms that intraperitoneal granulomas do not impact the growth, performance, or fish fillet quality at harvest.
Isolation of Lactobacillus plantarum CMT1 from shrimp intestine and its effects on growth and survival of the whiteleg shrimp, Litopeneaus vannamei
(2024) Phan, Thi Cam Tu; Nguyen, Thi Thu; Nguyen, Thi Kim Lien; Huynh, Truong Giang; Tran, Thi Thanh Hien
Probiotics are widely applied in aquaculture, which can improve the growth, survival and health of aquatic animals. The aim of this study was to isolate and evaluate a Lactobacillus strain from the intestine of healthy whiteleg shrimp, Litopenaeus vannamei. A total of 20 Lactobacillus isolates showed rod-shaped morphology, gram-positive, non-motile, non-spore forming, and catalase and oxidase negative. Among the isolates, strain CMT1 exhibited the highest antibacterial activity against Vibrio parahaemolyticus and extracellular enzyme activity, which was selected and identified as Lactobacillus plantarum CMT1 based on 16S rDNA gene sequencing. This strain was also chosen to evaluate its effects on growth and survival of the whiteleg shrimp as a feed supplement. Four different diets were prepared, including the control (a commercial diet without L. plantarum CMT1) and three different concentrations of L. plantarum CMT1, viz. T1 (10^6 CFU kg diet^-1), T2 (10^7 CFU kg diet^-1), and T3 (10^8 CFU kg diet^-1). After a 56-day feeding trial, the growth parameters in the T3 group had the highest values and showed a significant difference compared to the other groups. The survival rates of shrimp fed T2 and T3 diets were significantly higher than those in the control diet (p < 0.05). The lowest FCR value was recorded in the T3 group and showed a significant difference compared to the control group (p < 0.05). In addition, Lactobacillus counts in T2 and T3 groups increased significantly from day 28, which indicated that L. plantarum CMT1 could sustain its population in the intestine of shrimp. However, the total Vibrio sp. count in the T2 and T3 groups was significantly lower than that in the control group (p < 0.05). In conclusion, L. plantarum CMT1 could be used as a potential probiotic for shrimp aquaculture, and the recommended level of the probiotic strain CMT1 is 10^8 CFU kg diet^-1.
Behavioral characteristics and transcriptome analysis of Mizuhopecten yessoensis in response to Neptunea arthritica cumingii predation during laboratory bottom-sowing culture
(2024) Liu, Yang; Li, Danyang; Tian, Ying; Mao, Junxia; Wang, Xubo; Hao, Zhenlin
In this study, we investigated the effects of predation by the whelk Neptunea arthritica cumingii on the culture and survival of scallops (Mizuhopecten yessoensis) during bottom culture. The behavioral characteristics of three sizes (small, medium, and large) of scallops were assessed in response to exposure to N. cumingii. We also measured the activities of superoxide dismutase, catalase, arginine kinase, and octopine dehydrogenase in the gill, adductor muscle, and mantle tissues of scallops before and after exposure to predation. We found that scallops escaped from N. cumingii predation by continuous shell closure or movement. The shell closure force increased with the scallop size, and scallops of the same size that were stimulated by the presence of N. cumingii closed their shells more frequently than control scallops. The shell closure ability of scallops of all sizes decreased as the duration of the experiment continued. The enzyme activities in the three scallop tissues changed significantly after continuous stimulation, and the trend was particularly obvious for the enzyme activities in the adductor muscles of medium-sized scallops. Transcriptome analysis of the adductor muscles from medium-sized scallops detected 405 differentially expressed genes (172 upregulated and 233 downregulated), where the expression levels of RYK, APC, BAMBI, WNT16, CACYBP, and RUVBL1 changed after stimulation by N. cumingii. The sequencing results were verified by quantitative real-time PCR. We hypothesize these genes may be related to muscle movement and regulation in M. yessoensis after stimulation.
Analysis of bacterial community of Labidochromis caeruleus reared in RAS with various feeds
(2024) Ha, Chengxu; Wang, Yunzhong; Yang, Cuihua; Jin, Peng; Ren, Yi
The electric yellow cichlid (Labidochromis caeruleus), renowned for its exceptional ornamental value, enjoys widespread popularity among aquarium enthusiasts and holds significant economic value in the market. This study employed high-throughput sequencing technology to analyze the microorganisms in the circulating water of the electric yellow cichlid cultivated with six different types of feeds. Statistical results showed that the compound feed group exhibited the highest specific growth and mass gain rates. In contrast, the water flea and brine shrimp groups showed lower rankings with significant differences. 51,084 to 64,626 effective sequences were obtained and clustered into 127 to 848 operational taxonomic units (OTUs). The research findings indicate a remarkable bacterial diversity in the breeding environment of electric yellow cichlids with higher levels in the water flea and brine shrimp groups, and the lowest level in the compound feed group; the dominant bacterial phyla in all six experimental groups include Proteobacteria, Actinobacteria, Parcubacteria, and Cyanobacteria; Comparative analysis using the COGs database revealed significant differences (P<0.05) in the metabolic pathways of 24 functional microbial genes among the experimental groups.
Improved breeding and seed production of climbing perch (Anabas testudineus) in controlled tanks and cage systems
(2024) Choresca, Casiano H.; Taberna, Princess P.; Pedroso, Fiona L.; Magbanua, Faith Loraine T.; Oclos, Maria Theresa T.; Danting, Ma. Jodecel C.
The climbing perch (Anabas testudineus) is a valuable fish species with significant potential for aquaculture. However, a low survival rate was observed at its early development stages, requiring an optimized protocol for sustainable aquaculture production. This paper presents an improved breeding and seed production technology for climbing perch. Mature climbing perch were induced to spawn using salmon gonadotropin-releasing hormone analog (sGnRHa) at a dose of 30 µg/kg-1 body weight of the breeder. The female broodfish spawn 9–10 hours after hormone injection. Developmental stages were defined based on the morphological features of the embryos from the first cleavage to the hatching stage. The first cleavage began at approximately 18–20 minutes after fertilization. Newly hatched larvae were observed within 18–20 h at 30°C, having an average larval size of 0.389±0.042 mm (total length). Successful breeding entails a selection of suitable algal species, an optimal aquaculture environment, regular feeding rates, consistent monitoring of larval development, and effective management of water quality. Survival rates from the larval stage to fry were achieved at 84.69% and 77.60%, respectively, while the survival rate to the fingerlings stage was 72.51%. Therefore, by implementing an optimized protocol, aquaculture practitioners can maximize the production potential of climbing perch while ensuring sustainable cultivation practices. The findings from this research contribute to the advancement of climbing perch aquaculture by providing valuable insights for the successful cultivation and increased economic profitability of A. testudineus species in hatchery productions.
Dietary supplementation of Astragalus fermentation products improves the growth performance, immunological characteristics, and disease resistance of crucian carp (Carassius auratus)
(2024) Shi, Lisha; Xue, Mingyang; Xing, Yangyang; Xu, Chen; Jiang, Nan; Fan, Yuding; Chen, Jianwu; Liu, Wei; Wu, Yeying; Wu, Minglin; Zeng, Lingbing; Zhou, Yong
The fermentation products of Astragalus have been acknowledged for their ability to enhance immune functions. This study assessed the impact of incorporating Astragalus, fermented with Lactobacillus plantarum and Bacillus coagulans, on crucian carp's growth, disease resistance, and immunological characteristics. The experimental groups were fed with common feed (C), C + Astragalus (A), A + Lactobacillus plantarum (AL), A + Bacillus coagulans (AB), and AL + Bacillus coagulans (ALB). The fermented products were mixed with common feed at a 1:99 ratio, and crucian carp were fed 2% of their body weight for four weeks, with sampling conducted on days 3, 7, 14, 21, and 28. Disease resistance was evaluated using Aeromonas hydrophila (A. hydrophila) at a concentration of 0.2 mL (1.0×10^7 CFU/mL). The final weights in the AL, AB, and ALB groups significantly increased compared to the C group. The ALB group exhibited elevated serum albumin levels, alkaline phosphatase, intestinal lipase, protease enzyme, C3, and IgM gene expression compared to the C group. At the same time, alanine aminotransferase, aspartate aminotransferase, and glucose contents were significantly reduced. The survival rate significantly increased in all experimental groups after treatment with A. hydrophila. In conclusion, Astragalus products fermented with Lactobacillus plantarum and Bacillus coagulans could effectively improve crucian carp's growth, disease resistance, and immune response.
Mannan oligosaccharide improves antioxidant capacity, non-specific immunity and protection against Vibrio disease and Typhoon stress in Trachinotus ovatus juveniles
(2024) Chen, Zihan; Wu, Yue; Cai, Yan; Chen, Xin; Zhou, Yongcai; Cao, Zhenjie; Li, Jianlong; Wang, Shifeng
This study examined the impact of varying doses of mannan oligosaccharide (MOS) supplementation on antioxidant defense, non-specific immunity, resistance to typhoon stress, and resistance to disease in Trachinotus ovatus. Fish groups C, M1, M2, and M3 were fed 1%, 0.3%, 0.6%, and 1% MOS-supplemented feed, respectively. On the 28th and 56th day of the feeding trial, samples from all groups were taken to measure the antioxidant and non-specific immunity parameters and challenged with Vibrio harvey. On the 32nd day, a typhoon hit the experimental site, and the survival rates of all groups were calculated. Results showed that on the 28th day, groups M2 and M3 showed considerably higher levels of antioxidant abilities (T-AOC), and groups M1 and M2 showed significantly enhanced non-specific immunity (AKP, LZM, and TP) levels than those of group C (p < 0.05). All MOS groups had significantly lower cumulative mortality following the challenge test and typhoon stress than the control group (p < 0.05). On the 56th day, groups M2 and M3 showed significantly enhanced antioxidant ability (CAT) compared to the control group. Only one non-specific immunity parameter increased significantly in groups M2 and M3 (p < 0.05). After the challenge test, only group M3 exhibited a significantly declined cumulative mortality rate compared to the control groups (p < 0.05). In summary, supplementation of MOS at dose 0.6% (M2) for 28 days showed the best overall improving effects on the antioxidant capacity, non-specific immunity, disease resistance, and typhoon stress resistance in T. ovatus juveniles.
Effects of dietary β-sitosterol supplementation on growth performance, antioxidant ability, and disease resistance in largemouth bass Micropterus salmoides
(2024) Xing, Yangyang; Zhang, Liping; Xue, Mingyang; Liu, Wei; Jiang, Nan; Li, Yiqun; Chen, Jianwu; Fan, Yuding; Zhou, Yong; Meng, Yan
β-sitosterol, as the most abundant phytosterol, has been shown to exert multiple biological roles in in vitro and in vivo animal studies. Largemouth bass (Micropterus salmoides) is an economical freshwater-farmed species widely cultivated in China due to its nutritious and delicious meat. This study investigated the effects of dietary β-sitosterol supplementation on largemouth bass farming. In the study, largemouth bass were fed with five levels of β-sitosterol (0, 20, 40, 80, and 160 mg/kg) supplementation in a commercial feed for four weeks. The growth performance, antioxidant ability, intestinal structure, immune-related gene expression, and resistance to pathogens such as Aeromonas hydrophila and largemouth bass virus (LMBRaV) were detected. The results revealed that β-sitosterol supplementation in feed increased the weight gain rate of largemouth bass, with 40 mg/kg supplementation displaying the best effect. The serum biochemical indices all showed an increase, including glucose and alkaline phosphatase. The intestinal villus length and muscularis propria thickness also increased, accompanied by elevated digestive enzyme activities, which promoted digestion and absorption of nutrients. Meanwhile, the levels of total cholesterol, aspartate aminotransferase, and alanine aminotransferase in serum decreased, indicating reduced liver damage. In addition, β-sitosterol supplementation effectively enhanced the antioxidant capacity of largemouth bass by decreasing malondialdehyde and elevating superoxide dismutase. Immune-related gene expression also changed. Pathogen infection tests revealed that β-sitosterol supplementation in feed had a certain protective effect against infection in largemouth bass, with the protection rate against A. hydrophila being higher than LMBRaV. The 40 mg/kg β-sitosterol supplementation group exhibited the best results. Collectively, the results revealed that the β-sitosterol can promote growth, improve enzyme activity, stimulate intestinal digestion, increase immune gene expression, and induce disease resistance in largemouth bass, with the optimal supplementation dosage being 40 mg/kg. β-sitosterol might be an excellent feed additive in aquaculture.
Identification of Acinetobacter schindleri isolated from Chinese giant salamanders (Andrias davidianus)
(2024) Wang, Cheng; Xie, Yixing; Deng, Zhiyong; Yuan, Huanyan; Tian, Mingzhu; Mao, Pan; Zhou, Yong; Wei, Ying
At a particular aquaculture facility in Zhangjiajie in China, the Chinese giant salamander (Andrias davidianus) exhibited analogous clinical manifestations, culminating in sequential mortalities. This study used rigorous aseptic sampling methods to isolate bacteria from the affected liver of salamanders to determine the causative agent behind the decline in amphibians. A bacterial pathogen was isolated from diseased A. davidianus, and the strain was named DN-3. This isolate was subjected to bacterial identification, antibiotic susceptibility assays, reinfection experiments, and biochemical profiling. The isolated bacterial strain was definitively identified as Acinetobacter schindleri using 16S rRNA sequence analysis and biochemical identification. Antibiotic susceptibility testing revealed that this isolate was susceptible to neomycin, macrolides, doxycycline, piperacillin, nitrofurantoin, and carbenicillin. Subsequent reinfection assays, in which varying concentrations of the bacterial inoculum were administered to healthy salamanders, confirmed that the pathogen elicited varying degrees of morbidity or mortality within an eight-day observation period. The median lethal dose (LD50) of A. schindleri DN-3 for A. davidianus was calculated to be 6.25×104 CFU/mL. This result supports the significant pathogenicity of the strain for A. davidianus. The findings of this study provide empirical insights into the clinical management and epidemiological control of diseases affecting A. davidianus.
A First Look at Genetic Diversity of Metapenaeus ensis Populations in Tam Giang – Cau Hai Lagoon, Vietnam
(2024) Xuan Huy, Nguyen; Ty, Nguyen; Giang, Tran Van; Phuong, Tran Vinh
This study investigates the genetic diversity and population structure of the greasyback shrimp, Metapenaeus ensis (De Haan, 1844), within the Tam Giang – Cau Hai lagoon, Vietnam, by analyzing mtCOI genes from 91 individuals collected across four populations in nine sampling locations. High genetic diversity was found, with 34 unique haplotypes and 38 genetic variations identified. Most genetic variation occurred within populations (AMOVA), suggesting high gene flow. Low and non-significant Fst values and close genetic distances confirmed minimal differentiation among populations. These findings provide the first insights into M. ensis population genetics in this lagoon, informing conservation and management efforts. Understanding genetic diversity is crucial for sustainable management and conservation of marine species. This research aids in understanding population resilience, potential impacts of overfishing, and may assist in developing sustainable harvest strategies of this economically important shrimp species.
Length-weight relationships and biometry analysis of saddled seabream, Oblada melanurus (Linnaeus, 1758) in İzmir Bay (Central Aegean Sea of Türkiye)
(2024) Kara, Ali; Bayhan, Bahar; Taylan, Burcu; Babaoğlu, Ali Özcan
The present study presents length-weight, length-length, length-girth relationships, and biometry of male and female specimens of saddled seabream, Oblada melanurus(Linnaeus, 1758), in the Turkish Aegean Sea. The length-length and length-weight relationships were calculated by measuring 516 individuals. The total length values of all male and female O. melanurus specimens were in the range of 17.2-30.7 and 18.5-30.0 cm, respectively, and the mean values were 21.84±2.04 and 22.44±2.12 cm, respectively. The length-weight relationships were W=0.0110TL^3.057 for males, W=0.0114TL^3.043 for females, and W=0.0089TL^3.122 for all the specimens. The results denoted a high correlation (r²=0.966; p<0.001) in the length-length relationships. Furthermore, 287 individuals (105 females and 182 males) were examined for length-girth relationships and biometric analyses. Ten morphometric characters were analyzed to analyze biometry. In conclusion, no statistically significant differences were determined in morphology between the sexes (p<0.05).
Cercariae from snails in rice fields and canal supplying water directly to Trichopodus microlepis fish cultured in earthen ponds in Binh Chanh district, Ho Chi Minh City, Vietnam.
(2024) Thien, Pham C.; Manh, Ho T.; Quyen, Duong T.; Xuan, Nguyen T.L.; Lan, Nguyen T.; Hung, Nguyen M.
Snails are the first intermediate host in the life cycle of trematodes. Previous research found that Trichopodus microlepis fish, cultured in earthen ponds in Tan Nhut Commune, Binh Chanh District, Ho Chi Minh City, Vietnam had a high infection rate with metacercariae of Centrocestus formosanus and Procevorum sp. It is necessary to investigate whether habitats supplying water to the ponds may contribute to the transmission by carrying intermediate hosts and/or cercariae into these ponds or not. A study of cercariae and snail composition in rice fields and canal supplying water directly to these Trichopodus microlepis ponds was carried out with six samplings in the years 2022 and 2023. A total of 1,151 snails were collected, and nine snail species belonging to 8 genera and 6 families were identified. Three snail species in both rice fields and canal were infected with trematode (cercariae stage) including Bithynia siamensis, Lymnaea viridis and Indoplanorbis exustus. The overall prevalence in the dry season (25.9%) was significantly higher than in the wet season (10.6%) (P<0.05). Three cercariae morphotypes were recovered from snails: xiphidio (in all three snails), echinostome (in Lymnaea viridis and Indoplanorbis exustus), and pleurolophocercous in Bithynia siamensis. This finding shows that Bithynia siamensis is one of the infected sources for Trichopodus microlepis fish cultured in ponds, as pleurolophocercous is also the cercariae in the family of Heterophyidae (including Centrocestus formosanus and Procevorum sp.). Further research should be done to clarify the transmission of fish-borne zoonotic diseases to cultured Trichopodus microlepis in other habitats including the actual fishponds, and sources of trematodes in order to produce Trichopodus microlepis free of metacercariae, contributing to clean aquaculture development and safe food for local people in the area.
Construction and reflections on the disease prevention and control system of aquatic organisms based on management perspective
(2024) Li, Cai-Yun; Li, Xiao-Ai; Li, Li; Lou, Yi-Chun; Yu, Cheng-Song; Xu, Hui-Ping; Xu, Tao
Disease prevention and control are a crucial aspect of fishery management, as they ensure the sustainability of aquacultural systems. With a specific focus on Shandong Province, China, this study outlines the occurrence of diseases in aquatic organisms. It summarizes dynamics that drive disease prevention and control and supports technology, work mode, and emergency prevention and control. In addition, this study also delves into the role of epidemic prevention and control institutions, the upgrading of the social service of disease prevention systems, and insufficient technical support for new species and models. Overall, the findings outlined in this study are intended to achieve the following aims: enhance organizational management of disease prevention and control, standardize the implementation of social services, improve research into prevention and control technologies, and highlight the importance of information technology in disease prevention and control. Based on practical aquaculture production, our aim is to comprehensively analyze the situation of the construction of a disease prevention and control system, strengthen guidance on epidemic prevention technologies, establish a robust animal epidemic prevention system, and propose development strategies, serving as a reference for competent authorities to enhance the disease prevention and control of aquatic organisms.
Threatened fishes of the world: Schizothorax (Racoma) biddulphi (Günther, 1876) (Cyprinidae)
(2024) Wang, C.X.; Serekbol, Gulden; Hu, L.H.; Yang, L.T.; Huo, B.; Song, Y.; Chen, S.A
In order to study the individual biology of endemic fish in China, lay a foundation for the conservation of its germplasm resources, and consolidate the basic biological data of endemic fish in the world. According to the ethical code and fishing permit, 21 samples of Schizothorax (Racoma) biddulphi (Günther, 1876) were collected from the Muzati River in Tarim River system from 2021 to 2022, and their morphological characteristics, age identification and anatomical observation were analyzed by classical biological methods. S. biddulphi has a long body, a conical head, a pointed snout and a lower mouth. Requires 2 pairs. The scales are small and neatly arranged; Bare or scaly chest; The lateral line scale is slightly larger. The lateral line is complete. The correlation equation between body length and body weight is: W = 4.148 × 10^-5L^2.791. There were 5 kinds of age identification materials: 15⁺ for lapillus and asteriscus, 14⁺ for vertebra, 11⁺ for opercular bone, and 9⁺ for anal scale. The peritoneal wall of S. biddulphi is black; The tooth type is 2·3·5-5·3·2; The gill harrow was 11\~13 for laymen and 15\~18 for experts. Diphysocyte; Gallbladder oval; The number of vertebrae is 4+42-43+1, and the number of ribs is 23 or 24. S. biddulphi is a special species in the Tarim River system, and its evolutionary adaptation is closely related to the uplift of the Qinghai-Tibet Plateau.
Evaluation of earthworm meal (Eudrilus eugeniae) as fish meal replacement in juvenile Mangrove Crab (Scylla serrata) diet
(2024) Genodepa, Melanie P.; Apines-Amar, Mary Jane S.
Two feeding trials were conducted to evaluate the performance of the earthworm (Eudrilus eugeniae) meal (vermimeal) as a replacement for fish meal in the diet of juvenile mangrove crab (Scylla serrata) in terms of growth, feed efficiency, intermolt duration, carapace width increment, molting success, survival, and incidence of cannibalism. Four experimental diets were formulated with 0, 25, 50, and 75% fish meal protein replaced with earthworm meal protein, designated as D0, D25, D50, and D75, respectively. In the first feeding trial, the experimental diets were fed to crablets with an initial average weight of 0.09±0.007g. Each replicate comprised ten (10) crablets individually stocked in 750ml-capacity plastic containers randomly distributed in a static water bath. Final weight gain, feed efficiency and survival were measured after the 5^th^ molt. In the second feeding trial, 150 crablets with an average weight of 0.07±0.002g were stocked at 30 crablets each in five (5) replicate tanks. Survival and incidence of cannibalism were monitored daily until the end of the culture period of 30 days. The first study showed that the growth of mangrove crab juveniles fed the diet with up to 50% of the fish meal protein replaced by the earthworm meal protein was statistically comparable to the control group. The survival of crablets in the second feeding trial was highest in D25 (33%), followed by D50 (29%), D0 (18%), and lowest in the group fed with D75 (13%). Overall, earthworm meal (Eudrilus eugeniae) can replace as much as 50% of the fish meal protein in juvenile mangrove crab (Scylla serrata) diet without negative effects on growth, carapace width increment, feed efficiency, intermolt duration, molting success, survival, and cannibalism.
Establishing a fish repository at Ege University Faculty of Fisheries (1965-2023): A Journey on a long and challenging road to becoming a museum
(2024) Bayhan, Bahar; Akalın, Sencer; Akçınar, Salim C.; Taylan, Burcu; Kaya, Murat; Taşkavak, Ertan; Özaydın, Okan; Sever, Tuncay M.; Salman, Alp; Gürkan, Şule; İlhan, Dilek; Uygun, Orçin; Altay, Burak
This study examined preserved marine fish specimens collected from numerous field surveys conducted along Türkiye's Black Sea, Marmara, Aegean, and Mediterranean coasts since 1965. Our review and categorization of these materials revealed that the specimens belong to 360 species from 131 families. Current data shows that the museum collection includes 20 species of cartilaginous fish and 8 species of bony fish listed as endangered on the IUCN Red List, alongside 54 non-native fish species. Prepared according to museum standards by Ege University Fisheries Faculty's Scientific Material (ESFM), this collection of Turkish marine fish constitutes 66% of all Turkish marine fish fauna. This makes it the largest and oldest marine fish collection in Türkiye. Considering Türkiye's maritime borders with neighboring countries, this collection is significant nationally and globally. Given the diverse marine fish species in Turkish seas over the past half-century, this preserved material is a vital reference for local and foreign ichthyologists. If organized and transformed into a visitable museum, this extensive collection could raise awareness about the diversity of marine fish species in our seas. As a result, we have established the " biological repository of Turkish Marine Fish Department" in the Faculty Museum, now known as the Fisheries Faculty's Scientific Material (ESFM) at Ege University. We present the fish in the collection as a species list.
Phylogenetic relationships analysis of the family Scombridae (Actinopterygii, Scombriformes)
(2024) Zeng, Xinru; Cui, Mengyao; Yu, Haoyu; Pan, Xiaoyuan; Zheng, Pingzhong; Wei, Fen
Scombridae is a family of pelagic marine fishes that comprises 16 genera and 51 species. This family has been of significant commercial importance throughout history; however, the phylogenetic relationships within the Scombridae have been disputed due to the unclear taxonomic boundaries of the suborder Scombroidei, which includes six families, including Scombridae. Despite this, only a limited number of studies have been conducted on the Scombridae. In our study, eight species covering five genera of the Scombridae were selected, and one nuclear (ITS) and three mitochondrial DNA markers (CO1, Cytb, and D-loop) were used to amplify gene fragments. Additionally, we included homologous sequences from other Scombridae fishes obtained from GenBank. Our analysis constructed phylogenetic relationships of 48 Scombridae species in 14 genera. The results demonstrated that the three phylogenetic trees (NJ, ML, and BI) exhibited similar topologies, containing three major clades. One major clade indicated that Grammatorcynus bilineatus and Grammatorcynus bicarinatus did not cluster with other species in the Scombridae; another clade comprised the genera Scomber and Rastrelliger; the third clade consists of the remaining Scombridae species. Notably, the study showed that Gasterochismatinae and Scombrinae were not sister groups; Allothunnus (tribe Thunnini) and Cybiosarda (tribe Sardini) clustered into a clade, suggesting that Sardini and Thunnini were non-monophyletic. Overall, this research enhances the understanding of phylogenetic relationships within the Scombridae and provides basic information to aid further research.
Copper toxicity in juvenile largemouth bass (Micropterus salmoides): acute toxicity bioassay and oxidative stress response in gut and kidney
(2024) Zhang, Junhao; Zhao, Na; Meng, Zihao; You, Mengkang; Wang, Ke; Dai, Songlin; Zhang, Zhenyang; Huang, Yuchao; Chen, Weijun; Gao, Shiyang
Aquaculture intensification has resulted in serious disease outbreaks in largemouth bass production. Compounds containing copper (Cu) are widely used as therapeutic agents in aquaculture. Currently, Cu misuse has been a severe issue in largemouth bass farming. However, few investigations have been performed on Cu toxicity in largemouth bass so far. In this study, an acute and a chronic toxicity test was carried out to determine the toxicity and the recommended dose of waterborne Cu in largemouth bass. In the acute toxicity bioassay, fish (2.58 ± 0.03 g) were exposed to 0 (control), 3, 6, 9, 18, or 30 mg/L Cu, and the results showed that the 96-h LC~50~ of waterborne Cu was 12.78 mg/L. Then a 30-day chronic toxicity test containing six treatments (i.e., 0, 51.3, 164, 513, 1640, and 5130 μg/L Cu) was conducted to investigate the influence of Cu on intestinal and renal health in terms of oxidative stress in juvenile largemouth bass (2.69 ± 0.02 g). The results showed that Cu concentrations at and above 51.3 μg/L significantly increased the malondialdehyde contents (in the intestine) and simultaneously decreased total superoxide dismutase activity levels (in the intestine and kidney), glutathione peroxidase activity levels (in the kidney), and reduced glutathione contents (in the kidney), compared to control. In contrast to control, fish exposed to high Cu concentrations (at and above 1640 μg/L) demonstrated lower catalase activity levels in the intestine and kidney. Based on the findings in the study, waterborne Cu content for largemouth bass farming was recommended to be less than 51.3 μg/L.

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