Aquaculture Reports最新文献

{"title":"Effects of replacing Laminaria japonica with mixed seaweed meal on growth performance, digestive and metabolic enzyme activities, and immune function of the sea cucumber Apostichopus japonicus (Selenka)","authors":"Bin Xia ,&nbsp;Zhengyong Liu ,&nbsp;Qingfei Li,&nbsp;Dongxue Xu,&nbsp;Ji Liu,&nbsp;Jinghua Chen","doi":"10.1016/j.aqrep.2025.102789","DOIUrl":"10.1016/j.aqrep.2025.102789","url":null,"abstract":"<div><div><em>Laminaria japonica</em> is a widely cultivated and economically significant seaweed, commonly used as a primary feed ingredient in sea cucumber aquaculture due to its cost-effectiveness and high nutritional value. However, declining production and rising costs have prompted the exploration of alternative feed sources to support sustainable aquaculture practices. This study assessed the feasibility of substituting <em>L. japonica</em> with a mixed seaweed meal to enhance feed sustainability while sustaining the health and growth performance of <em>Apostichopus japonicus</em>. The control diet (P0) contained 70 % <em>L. japonica</em> meal, whereas experimental diets replaced it with a mixed seaweed blend (2:1:1:1 ratio of <em>Sargassum polycystum</em>, degummed <em>L. japonica</em>, <em>Ulva lactuca</em>, and <em>Enteromorpha prolifera</em>) at substitution levels of 25 %, 50 %, 75 %, and 100 % (P25-P100). Over an 84-day feeding trial, specific growth rate and protein efficiency ratio decreased significantly at substitution levels exceeding 25 %, with parallel reductions observed in intestinal trypsin and lipase activities. Hexokinase and succinate dehydrogenase activities peaked at 25 % substitution, and malate and pyruvate dehydrogenase reached maximum levels at 50 %. Acid and alkaline phosphatase activities increased at 25 % and 50 % substitution levels, whereas superoxide dismutase activity decreased, accompanied by elevated malondialdehyde content. Additionally, catalase and lysozyme activities, along with their corresponding mRNA expression, decreased at higher substitution levels. Notably, NF-κB (p105) mRNA expression declined at 75 % and 100 % substitution, while Toll-like receptor mRNA showed slight upregulation. The integrated biomarker response model revealed that 25 % substitution level yielded the highest physiological adaptability, and substitution levels exceeding 50 % induced significant stress responses. Cubic regression analysis identified an optimal substitution level of 17.28 % for maximizing growth performance. These findings provide a valuable reference for incorporating mixed seaweed meal into sea cucumber diets effectively.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102789"},"PeriodicalIF":3.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of alkalinity treatments on biofloc dynamics and growth performance in Penaeus vannamei shrimp culture","authors":"Khalid Amjad ,&nbsp;Hans-Uwe Dahms ,&nbsp;Agus Triawan ,&nbsp;Feng-You Lin ,&nbsp;Yu-Chen Wu ,&nbsp;Hong-Thih Lai","doi":"10.1016/j.aqrep.2025.102797","DOIUrl":"10.1016/j.aqrep.2025.102797","url":null,"abstract":"<div><div>Biofloc technology is eco-friendly due to its minimal water exchange in aquaculture. However, it may lower alkalinity in pond water due to organic acids produced during biofloc incubation. This study assessed the effects of three alkalinity treatments—CaCO₃ (C), MgCO₃ (M), and their combination (MC)—on water quality, biofloc incubation, and <em>Penaeus vannamei</em> shrimp growth. Treatments C and M were dosed at 20 mg L⁻¹, while MC combined 10 mg L⁻¹ of each compound. Shrimp larvae with an initial weight of 0.044 ± 0.01 g were cultured for 52 days. Treatment MC significantly increased floc densities compared to the control, although differences among treatments were not significant. Ammonium levels in M and MC were lower than the control on days 10, 25, and 30, while nitrate levels in M and MC were higher. Total hardness was higher in all treatments compared to the control but did not differ significantly among treatments. Shrimp in treatment C showed significantly higher weight gains (0.21 ± 0.03 g) compared to treatments M and MC (0.19 ± 0.003 and 0.20 ± 0.02 g, respectively) and better food conversion ratios (1.27 ± 0.2) compared to treatment M (1.42 ± 0.02). Meanwhile, survival rates did not vary significantly between treatments. It indicates that the addition of C is better for shrimp growth than with M and MC. Overall, M and MC treatments enhanced water quality and biofloc levels, while C was most effective for shrimp growth.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102797"},"PeriodicalIF":3.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of dietary curcumin on growth, antioxidant, transcriptome, and metabolomics in Macrobrachium rosenbergii fed a high plant-protein diet","authors":"Li Wang ,&nbsp;Qincheng Huang ,&nbsp;Zhimin Gu ,&nbsp;Cui Liu ,&nbsp;Xing Ren ,&nbsp;Yangxin Dai ,&nbsp;Tiantian Ye ,&nbsp;Junjun Yan ,&nbsp;Jilun Meng ,&nbsp;Yutong Zheng ,&nbsp;Bo Liu","doi":"10.1016/j.aqrep.2025.102782","DOIUrl":"10.1016/j.aqrep.2025.102782","url":null,"abstract":"<div><div>Insufficient attention has been directed towards the effects of incorporating curcumin (CU) into high plant-protein feeds and the underlying mechanisms at play. This study aims to evaluate the physiological responses of <em>Macrobrachium rosenbergii</em> to varying levels of CU in diets with high soy protein concentrate (SPC), examining factors such as growth characteristics, proximate composition, antioxidant capacity, immunity, histopathology, transcriptome, and metabolomics. Dietary formulations included a fishmeal-based diet (R), a high plant-protein diet (C, with 60 % fishmeal replaced by SPC), and C diets supplemented with CU at different concentrations: CU1 (1 g/kg), CU5 (5 g/kg), and CU10 (10 g/kg). Compared to R diet, the C diet did not significantly alter growth, proximate composition, antioxidant defense, or immune parameters of <em>M. rosenbergii</em>. However, the CU10 diet significantly improved final body weight (FBW), weight gain, and specific growth rate (SGR). Prawns in the CU10 group demonstrated the highest crude lipid content, succeeded by those in the C and CU5 groups, while the CU1 group had the lowest lipid content. Additionally, the CU10 diet reduced hemolymph malondialdehyde (MDA) levels and increased intestinal mucosal thickness significantly. Transcriptome analysis of the hepatopancreas revealed nine significantly expression genes across treatments. Metabolomics of the hepatopancreas identified three significantly expression metabolites across treatments: gemigliptin, artonol A, and lucuminoside. Moreover, the substitution of SPC and the addition of CU regulated ‘glycerophospholipid metabolism’ through their effects on the gene-metabolite regulatory network. In summary, a 10 g/kg CU supplementation in a high plant-protein diet notably augmented growth characteristics, enhanced antioxidant capacity, and improved hepatopancreas and intestinal health, while also refining transcriptome and metabolomics profiles.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102782"},"PeriodicalIF":3.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of dietary protein on the antioxidant capability and inflammatory response in juvenile Chinese soft-shelled turtles (Pelodiscus sinensis) injected with exogenous hydrogen peroxide","authors":"Hongyan Kou ,&nbsp;Yiwen Zhao ,&nbsp;Junru Hu ,&nbsp;Dehui Pan ,&nbsp;Xueting Liu ,&nbsp;Guangren Ye","doi":"10.1016/j.aqrep.2025.102790","DOIUrl":"10.1016/j.aqrep.2025.102790","url":null,"abstract":"<div><div>This study estimated the influence of dietary protein on the anti-oxidative enzyme activity, mRNA expression of antioxidant-related enzymes, and inflammatory responses in the Chinese soft-shelled turtle (<em>Pelodiscus sinensis</em>) when injected with exogenous hydrogen peroxide (H₂O₂). Six diets containing 14.38 %, 20.41 %, 26.19 %, 32.23 %, 37.63 %, and 45.23 % protein were fed to turtles over an 8-week breeding trial, after which the turtles were injected intraperitoneally with H₂O₂. High protein diets (≥ 26.19 %) produced the following effects: 1) decreased aspartate aminotransferase and alanine transaminase activities in the serum; 2) decreased lipid peroxidation (ROS and MDA) levels; 3) improved the GSH-PX, SOD, T-AOC, and CAT levels in the liver; 4) activated the nuclear factor erythroid 2-related factor/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) signaling pathway; 5) enhanced the gene expression of <em>CAT</em>, <em>CuZnSOD</em>, <em>MnSOD</em>, <em>Nrf2</em>, <em>Keap1</em>, <em>GPX1</em>, <em>GPX2</em>, <em>GPX3</em>, and <em>GPX4</em>; 6) repressed the gene expression level of interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor alpha; and 7) improved the level of interleukin-10 mRNA. Overall, the results showed that feeding the optimal dietary protein level played a protective role against H₂O₂-mediated oxidative damage by regulating the Nrf2 signaling pathway and inflammation. Using broken-line analysis with ALT and AST activities as the evaluation indicators, the optimal dietary protein requirement for the Chinese soft-shelled turtle was estimated to be 25.78 % for ALT and 26.25 % for AST.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102790"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dietary alfalfa improved growth performance, survival, body and fatty acid composition, flesh quality and immune-antioxidant system in Pacific white shrimp (Litopenaeus vannamei)","authors":"Kobra Babanejad-Abkenar,&nbsp;Arash Akbarzadeh,&nbsp;Ahmad Noori,&nbsp;Mohammad Niroomand","doi":"10.1016/j.aqrep.2025.102792","DOIUrl":"10.1016/j.aqrep.2025.102792","url":null,"abstract":"<div><div>Alfalfa is a suitable food item in the diet of aquaculture species, offering valuable nutritional components, cost-effectiveness, widespread availability, and sustainable production practices. This study investigated the effects of dietary alfalfa leaf powder (ALP) on growth performance, survival, body and fatty acid composition, astaxanthin content, flesh quality, and the immune-antioxidant system of Pacific white shrimp (<em>Litopenaeus vannamei</em>). A total of 1050 healthy shrimp with an initial mean weight of 7.58 ± 0.10 g were fed diets containing 0 (control), 60 (ALP60), 120 (ALP120), and 180 (ALP180) g/kg of ALP for eight weeks. Results showed significantly improved growth indices in the ALP60 treatment compared to the control group (<em>p</em> &lt; 0.05). Additionally, all ALP-fed shrimp showed significantly higher survival rates compared to the control group (<em>p</em> &lt; 0.05). The highest carcass protein and lowest lipid levels were observed in the ALP180 treatment. The fatty acid composition showed that C14:0 levels were lower in all ALP treatments compared to the control, while ALP120 and ALP180 treatments had higher ALA, total (n-6) fatty acids, and EPA levels compared to the control group (<em>p</em> &lt; 0.05). It also increased astaxanthin levels, meat quality (redness index), and the activity of immune antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and lysozyme), especially in ALP120 and ALP180 treatments. Furthermore, ALP supplementation reduced hemolymph cholesterol and glucose levels. Overall, this study demonstrates that dietary ALP positively influences growth, survival, body composition, astaxanthin content, flesh quality, and immune function in shrimp, highlighting its potential to improve shrimp health and quality.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102792"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of reliable transgenic systems for inducing in vitro-cultured hematopoietic cell proliferation in Cherax quadricarinatus","authors":"Yaqi Zhao ,&nbsp;Jinwu Wang ,&nbsp;Liu Song ,&nbsp;Ting Xue ,&nbsp;Yifu Xu ,&nbsp;Zhenxin Zhao ,&nbsp;Zhenmin Bao ,&nbsp;Huarong Guo","doi":"10.1016/j.aqrep.2025.102780","DOIUrl":"10.1016/j.aqrep.2025.102780","url":null,"abstract":"<div><div>The absence of a stable and efficient transgenic system for crustacean cells has significantly impeded advancements in gene function studies and the establishment of continuous cell lines. In this study, we successfully developed a functional transgenic system for both two-dimensional (2D)- and three-dimensional (3D)-cultured hematopoietic tissue (HPT) cells of <em>Cherax quadricarinatus</em>, through the modification of crustacean viral promoters and the optimization of transfection methods. To evaluate the effectiveness of this system, the coding sequence of crayfish hematopoietic factor, astakine, was cloned and inserted into an expression vector as a transgene. Subsequent optimization of truncated crustacean viral promoters, along with their strategic combinations, led to the design of a highly efficient expression vector for crayfish cells, driven by the hybrid promoter OpIE2-P2-WSV249_(-300/-1). Following the optimization of transfection parameters, stable expression of the exogenous gene <em>astakine</em> was successfully achieved in both 2D and 3D cultures of crayfish HPT cells using electroporation and chemical transfection techniques. Notably, chemical transfection resulted in <em>astakine</em> overexpression with an efficiency of approximately 18 %, which was associated with a 7 % enhancement in the proliferation rate of the transgenic cells. Furthermore, these cells exhibited sustained, healthy growth for months. In summary, this study presented a reliable transgenic system for gene functional analysis in shrimp and crayfish, laying the foundation for the development of immortalized cell lines in crustaceans.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102780"},"PeriodicalIF":3.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth, serum biochemical, digestive enzyme activities, antioxidant, lipid metabolism and inflammation responses of juvenile hybrid snakehead (Channa maculata♀× Channa argus♂) fed diets with different dietary lipid levels","authors":"Yuwan Li ,&nbsp;Wenqing Huang ,&nbsp;Kai Peng ,&nbsp;Junru Hu ,&nbsp;Huijie Lu ,&nbsp;Guoxia Wang","doi":"10.1016/j.aqrep.2025.102779","DOIUrl":"10.1016/j.aqrep.2025.102779","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The study investigated the effects of different dietary lipid levels on the growth, serum biochemical, digestive enzyme activities, antioxidant, lipid metabolism and inflammation responses of juvenile hybrid snakehead (&lt;em&gt;Channa maculata♀&lt;/em&gt;×&lt;em&gt;Channa argus♂&lt;/em&gt;). Six different dietary lipid levels (4.70 %, 6.25 %, 8.10 %, 10.35 %, 12.28 %, 14.39 %, labeled as L4, L6, L8, L10, L12, and L14) were prepared as equal protein feed for the experiment. 540 juvenile hybrid snakehead was selected for 63-day culture experiment with an initial weight of (5.31 ± 0.01) g and randomly divided into 6 groups. The results indicated that when the dietary lipid levels ranged from 4.70 % to 10.35 %, the weight gain rate (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) of juvenile hybrid snakehead were significantly increased, while the feed conversion ratio (FCR) was significantly decreased (&lt;em&gt;P &lt; 0.05&lt;/em&gt;). The condition factor (CF), and visceral somatic index (VSI) of the fish showed an upward trend. The crude lipid of juvenile hybrid snakehead was significantly increased, while crude protein and moisture was showed the opposite change(&lt;em&gt;P &lt; 0.05&lt;/em&gt;). The serum levels of plasma cholesterol (CHOL) and high-density lipoprotein cholesterol (HDL-C) were significantly higher than the L14 group compared to the other groups(&lt;em&gt;P &lt; 0.05&lt;/em&gt;). There was no significant effect on alanine aminotransferase(ALT), aspartate aminotransferase (AST), total protein (TP), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and LDL-C/HDL-C (&lt;em&gt;p &gt; 0.05&lt;/em&gt;). The ALT in the L14 and L12 groups were significantly higher than the L4, L6, and L8 groups, and the glutathione peroxidase (GSH-Px) of the L12 group was significantly higher than the other groups (&lt;em&gt;P &lt; 0.05&lt;/em&gt;). There was no significant effect on liver glycogen, AST, superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), and total antioxidant capacity (T-AOC) (&lt;em&gt;P &gt; 0.05&lt;/em&gt;). Furthermore, the expression levels of the mammalian target of rapamycin (mTOR) and acetyl-CoA carboxylase (ACC) in the liver first decreased and then increased, while the peroxisome proliferator-activated receptor α (&lt;em&gt;PPARα&lt;/em&gt;) showed the opposite phenomenon(&lt;em&gt;P &lt; 0.05&lt;/em&gt;). There was no significant difference in the fatty acid synthase (FAS) (&lt;em&gt;P &gt; 0.05&lt;/em&gt;). The expression of the inhibitory subunit of nuclear factor-kappa B alpha (&lt;em&gt;IκBα&lt;/em&gt;) in the L4 and L10 groups were higher than those in the L14 group, while the tumor necrosis factor-α (&lt;em&gt;TNF-α&lt;/em&gt;) and interleukin-8 (&lt;em&gt;IL-8&lt;/em&gt;) in the L6 group were significantly lower than those in the L4 group, and the interleukin-10 (&lt;em&gt;IL-10&lt;/em&gt;) showed the opposite change(&lt;em&gt;P &lt; 0.05&lt;/em&gt;). The expression of interleukin-1β (&lt;em&gt;IL-1β&lt;/em&gt;) in the L6 group was significantly higher than that in the L12 group (&lt;em&gt;P &lt; 0.05&lt;/em&gt;). In summary, considering the overall situation, the optim","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102779"},"PeriodicalIF":3.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selection and evaluation of new reference genes for qRT-PCR analysis in humpback grouper Cromileptes altivelis based on transcriptome data","authors":"Xiaona Xu ,&nbsp;Dailiang Kou ,&nbsp;Huibang Sun ,&nbsp;Chenxi Wang ,&nbsp;Dongxue Xia ,&nbsp;Zhennian Chen ,&nbsp;Jinxiang Liu","doi":"10.1016/j.aqrep.2025.102781","DOIUrl":"10.1016/j.aqrep.2025.102781","url":null,"abstract":"<div><div>Quantitative Real-Time PCR (qRT-PCR) is widely used in molecular biology research. A stable reference gene is essential for accurate quantification of target gene expression. Traditionally, these reference genes were selected from housekeeping genes. RNA-seq has enabled high-throughput selection. The humpback grouper (<em>Cromileptes altivelis</em>) is a species of significant economic value in aquaculture, patchily distributed across reef habitats in the Western Pacific. The available internal reference genes were insufficient for accurate normalization in qRT-PCR experiments. No previous report has explored the use of transcriptome data for screening reference genes in <em>C. altivelis</em>. This study assessed the stability of candidate reference genes and their suitability for normalization in <em>C. altivelis</em> tissues and different embryonic developmental stages. Additionally, the stability of candidate reference gene was evaluated under conditions of low salinity stress and <em>Vibrio harveyi</em> infection. Different analytical methods, including the Comparative ΔCt method, geNorm, NormFinder, and BestKeeper, were employed. Finally, RefFinder was employed to integrate the reusults. The results indicated that <em>RPL35</em> and <em>EEF1G</em> are reliable internal control genes in normal tissues in <em>C. altivelis</em>. Additionally, <em>RPLP1</em>, <em>FH</em>, and <em>METAP2</em> exhibited the highest stability under salinity stress. During the embryonic developmental stages, <em>EIF5A</em>, <em>EIF3F</em>, and <em>CCNG1</em> were identified as the most suitable reference genes. <em>RPSA</em>, <em>RPL25A</em>, and <em>GNB211</em> were found to be the most stable reference genes following <em>V. harveyi</em> injection. Importantly, the finding revealed that the optimal reference genes varied depending on experimental conditions. These candidate genes could serve as valuable tools for future studies on exploring molecular mechanisms. This study represents the transcriptome-wide identification and validation of reference genes for qRT-PCR in <em>C. altivelis</em>. Furthermore, this research will significantly contribute to the study of functional genes in <em>C. altivelis</em>.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102781"},"PeriodicalIF":3.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crowding causes detachment and loss of mobile sea lice: Fine-meshed crowding nets may mitigate spread","authors":"Lena Geitung ,&nbsp;Luke T. Barrett ,&nbsp;Velimir Nola ,&nbsp;Sussie Dalvin ,&nbsp;Line Vatne Martinsen ,&nbsp;Adele Dahlgren ,&nbsp;Frode Oppedal","doi":"10.1016/j.aqrep.2025.102784","DOIUrl":"10.1016/j.aqrep.2025.102784","url":null,"abstract":"<div><div>Detachment of mobile lice from salmon during crowding and handling procedures in sea-cage fish farms may lead to loss and unwanted spread of ectoparasitic sea lice to other cages, farms or wild fish. However, rates of detachment and loss of lice during crowding are not well understood. We conducted a series of replicate crowding events in 125–2000 m³ sea-cages, using either a standard coarse-meshed crowding net, or a more fine-meshed crowding net intended to retain detached mobile lice. Lice that were detached during crowding and passed through the crowding net were collected using a 350-µm plankton net positioned around the crowding net (in some cases pumps and filters were also used), allowing lice ‘lost’ from the crowding net to be directly quantified. Detachment of lice during crowding varied from 2 % to 38 %, with higher detachment rates for smaller life stages (highest for pre-adult 1 salmon lice) and in trials involving larger fish and/or longer crowding durations (up to 2 h). In most cases, the type of crowding net did not affect detachment rates, but the fine-meshed crowding net did retain some detached lice, including 75 % of adult female salmon lice. The fine-meshed crowding net also improved welfare outcomes for crowded fish, including significantly reduced scale loss, fin damage and bleeding. Provided dissolved oxygen levels can be maintained, fine-meshed crowding nets may be the most promising means of limiting the spread of mobile lice into the surrounding environment, while also reducing injuries to fish. Supplementary benefits may be achieved by minimising crowding time but also ensuring filter collection on the water used to bring fish into wellboats and delousing systems.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102784"},"PeriodicalIF":3.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilization of ursolic acid methyl ester in the treatment of Streptococcus pyogenes in Nile tilapia, concerning physiological, genetic, immune-oxidative, stress, and neuro-ethological parameters","authors":"Rewan Abdelaziz ,&nbsp;Mona Abd El khalek Salem ,&nbsp;Walaa El-Houseiny ,&nbsp;Abdelwahab A. Abdelwarith ,&nbsp;Elsayed M. Younis ,&nbsp;Heba H. Mahboub ,&nbsp;Shimaa Zayed ,&nbsp;Reham A. Abd El-Wahab ,&nbsp;Basma A. Elshafey ,&nbsp;Simon J. Davies ,&nbsp;Amany Omar Selim","doi":"10.1016/j.aqrep.2025.102776","DOIUrl":"10.1016/j.aqrep.2025.102776","url":null,"abstract":"<div><div>The present work is an innovative approach for application the <em>Streptomyces misakiensis S. misakiensis</em> metabolite called ursolic acid methyl ester (UAME) in treating <em>Streptococcus pyogenes</em> of Nile tilapia. A total of 110 fish was used for assessment of the therapeutic dose of UAME. In addition, the therapeutic efficacy of UAME was tested <em>in vivo</em> against <em>S. pyogenes</em> infection (after determination of LC₅₀) using 200 Nile tilapia. Fish (30.00 ± 1.5 g) were divided into four groups: CON (control), UAME (1.0 mg/L), <em>S. pyogenes</em>, and UAME (1.0 mg/L) + <em>S. pyogenes</em> groups. The inoculations of 0.2 mL of <em>S. pyogenes</em> (1 ×10⁷ CFU/mL) were administered to the fish in the <em>S. pyogenes</em> and UAME + <em>S. pyogenes</em> groups and continued for ten days. The minimal inhibitory concentration of UAME was 0.5 µg/mL. Moreover, irregularity and bacterial cell shape distortion were evident after treatment with UAME under a scanning Electron Microscope. Challenged groups in <em>S. pyogenes</em> exhibited significant increases in surfacing frequency, swimming, laterality and aggression behavior (<em>P</em> &lt; 0.05). Along with this, the hepatorenal metrics (ALT, ALP, AST, creatinine, total bilirubin, and urea.), MDA (an oxidant biomarker), (8-OHdG), glucose and cortisol (stress indicators) were all significantly elevated in the diseased fish (<em>P</em> &lt; 0.05). Contrariwise, the infected fish showed a significant drop (<em>P</em> &lt; 0.05) in survival %, red blood cells, hemoglobin, total proteins, total globulin, albumin, AchE activity, and the immune-antioxidant indices (IgM, complement factor 3, lysozyme activity, nitric oxide, hepatic CAT, SOD, GSH, and GPx). Analysis of genes in response to <em>S. pyogenes</em> infection demonstrated an up-regulation of the pro/anti-inflammatory genes (<em>il1b, tnfa, il8</em>, <em>tgfb, il10</em>). Surprisingly, enriched groups in UAME modulated all the measured parameters. Overall, UAME is a promising antibacterial candidate that can efficiently retrieve stress and enhance behavioral, biochemical, immune-antioxidant, and genetic changes endowed by <em>S. pyogenes</em> infection.</div></div>","PeriodicalId":8103,"journal":{"name":"Aquaculture Reports","volume":"42 ","pages":"Article 102776"},"PeriodicalIF":3.2,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}