Aquaculture International最新文献

{"title":"Grow-out culture of the abalone Haliotis asinina in Guimaras, Philippines: comparison of tubes and drums as culture containers and the effects of serpulid infestation","authors":"Ma. Junemie Hazel L. Lebata-Ramos,&nbsp;Ellen Flor D. Solis","doi":"10.1007/s10499-025-01855-7","DOIUrl":"10.1007/s10499-025-01855-7","url":null,"abstract":"<div><p>This study compared tubes and drums as containers for the grow-out culture of abalone <i>Haliotis asinina</i> using mixed seaweeds and formulated diet as feed. The recycled drums were newly tested containers for abalone culture as the cheaper and larger alternative. However, on the 10th month of culture, serpulids (<i>Pomatoceros</i> sp. and <i>Spirorbis</i> sp.) were observed on the abalone shells; hence, the 12-month culture was extended to 16 months to observe further the effects of these ectoparasites on the growth and survival of abalone. Throughout the culture period, abalone reared in tubes had significantly higher mean shell length and body weight than those reared in drums, measuring 45.42 ± 0.36 mm, 23.40 ± 0.99 g, and 41.45 ± 0.23 mm, 18.26 ± 0.40 g at harvest, respectively. Mean growth rates of those in tubes were significantly higher than those in drums before serpulid infestation but did not differ during months of infestation. Survival was consistently higher in tubes than drums, except during May–September 2023. At harvest, survival in tubes was 46.7 ± 11.0%, 37.8 ± 5.9% in drums. Daily water temperature ranged 28.00–32.33 °C, salinity 16.00–34.37 ppt. Monthly readings (ppm) of dissolved oxygen ranged 3.1–7.4, sulfide 0.00–0.73, phosphate 0.01–0.87, nitrate 0.00–0.99, nitrite 0.00–0.22, and total suspended solids 0.22–4.83. In April–October 2023, serpulids became prevalent (tubes = 31.5 ± 3.4%; drums = 38.3 ± 3.4%) when mean DO was significantly lower and sulfide higher than in June 2022-March 2023. These fluctuations in water parameters may have triggered the infestation, resulting in lower growth rates and abalone survival. But, despite these fluctuations and infestations, tubes remained a better culture container for the abalone.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landscapes of alternative splicing genes/events in the gills of Mozambique tilapia (Oreochromis mossambicus) and their roles in high-salinity adaptation","authors":"Ming Huang,&nbsp;Han Yu,&nbsp;Boyuan Wang,&nbsp;Wenxin Jiang,&nbsp;Na Xue,&nbsp;Hancheng Bao,&nbsp;Yining Yu,&nbsp;Qingkai Tang,&nbsp;Qinfeng Gao,&nbsp;Yuan Tian","doi":"10.1007/s10499-025-01846-8","DOIUrl":"10.1007/s10499-025-01846-8","url":null,"abstract":"<div><p>Salinity could directly influence the survival and physiological conditions of fishes. Because of its importance, the salinity adaptation and osmoregulation mechanism have been extensively studied in the last decade. However, the adaptation to high-salinity environments has yet to be explored, particularly at the post-transcriptional level. In the present study, 18 RNA-seq datasets were utilized to investigate the alternative splicing (AS) events of functional genes in the gills of Mozambique tilapia (<i>Oreochromis mossambicus</i>) exposed to different salinity environments ranging from 0‰ (T0) to 110‰ (T110). A total of 1266 ~ 3194 differential alternative splicing (DAS) events were identified in 5 pairwise comparisons (T30 vs. T0, T50 vs. T0, T70 vs. T0, T90 vs. T0, and T110 vs. T0). It was derived from 971 to 2080 functional genes that were defined as DAS genes. Enrichment analysis indicated that these DAS genes in 5 comparison groups were commonly enriched in the spliceosome pathway. In detail, 31 spliceosome-associated genes were tightly related to spliceosome assembly, RNA binding, and RNA splicing. DAS events of these spliceosome-associated genes would alter the splicing decisions of downstream target genes. Differential expression analysis, together with protein interaction networks, was performed to determine their target genes. Functional categorization revealed that these target genes were mainly involved in energy metabolism in the mitochondrion, protein synthesis in the ribosome, and signal transduction in the cytoplasm, which may be responsible for the high-salinity adaptation in the gills of Mozambique tilapia. This study provides novel insights into the post-transcriptional regulation mechanisms underlying high-salinity adaptation in fishes.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reference genes for gene expression studies in pacu (Piaractus mesopotamicus) raised in different culture systems","authors":"Gabriella Hippy da Rocha,&nbsp;Jayme Aparecido Povh,&nbsp;Lucas de Oliveira Brasileiro,&nbsp;Louise Nex Spica,&nbsp;Rebeca Maria Sousa,&nbsp;Herbert Patric Kellermann Cleveland,&nbsp;Letícia da Silva Ferreira Ribeiro Mathias,&nbsp;Frederico Nakasone Ferreira,&nbsp;Leila Sabrina Ullmann,&nbsp;Ruy Alberto Caetano Corrêa Filho,&nbsp;Susana Amaral Teixeira","doi":"10.1007/s10499-025-01858-4","DOIUrl":"10.1007/s10499-025-01858-4","url":null,"abstract":"<div><p>Reference genes (RGs) are crucial for reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis as they allow accounting for uncontrolled environmental variations in gene expression results. Thus, prior reliability assessment of RGs is essential. In this study, candidate RGs were evaluated to investigate the gene expression responses of <i>Piaractus mesopotamicus</i> (pacu) reared in biofloc technology (BFT) and recirculating aquaculture systems (RAS). Samples from skeletal muscle (<i>n</i> = 9 BFT and 9 RAS) and kidney (<i>n</i> = 9 BFT and 9 RAS) were collected from juvenile pacu weighing 68 ± 4.43 g. The stability of three candidate RGs (<i>GAPDH</i>, <i>ACTB</i>, and <i>18S</i>) was evaluated using GeNorm, BestKeeper, and NormFinder software. <i>GAPDH</i> was the least stable gene in pacu, due to high variability within and between BFT and RAS. In kidney tissue, <i>ACTB</i> was identified as the most stable gene by all three software. In skeletal muscle, NormFinder and BestKeeper classified <i>18S</i> as the most stable gene, while GeNorm suggested a combination of <i>18S</i> and <i>ACTB</i>. This is the first investigation on reference genes for qPCR in juvenile pacu tissues, and the findings will provide valuable support for gene expression studies in this species. Among the three candidate RGs tested in this study, <i>ACTB</i> and <i>18S</i> genes are recommended for qPCR in kidney and muscle tissues of pacu, respectively, while <i>GAPDH</i> was deemed the least suitable. The observed differences in the expression of candidate genes among BFT and RAS and tissues emphasize the importance of appropriate RG selection prior to conducting RT-qPCR experiments.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of multiple stressors and their interactions on seaweed aquaculture households in island regions of Southeast China","authors":"Ye Liu,&nbsp;Haihong Yuan,&nbsp;Langzi Shen,&nbsp;Panpan Yang","doi":"10.1007/s10499-025-01853-9","DOIUrl":"10.1007/s10499-025-01853-9","url":null,"abstract":"<div><p>Aquaculture households in island regions of Southeast China face significant threats to their economic stability and livelihoods from various stressors. However, there is a notable research gap regarding the combined effects of these stressors on island aquaculture households. This study adopts a participatory approach, integrating qualitative analysis of semi-structured interviews and quantitative analysis of questionnaire data, to explore how the interactions among multiple stressors affect the economic and livelihood conditions of seaweed aquaculture households in the island regions of Southeast China. The research revealed that these households were impacted by both climate and non-climate stressors, with rising temperatures, marine pollution, and market price fluctuations being identified as significant stressors. Qualitative interviews revealed the synergistic and cumulative effects of stressor interactions, such as between rising temperatures and marine pollution, as well as between market competition and technological constraints. These combined effects reduce aquaculture productivity, increase economic losses, shrink farming areas, and destabilize livelihoods. The study further conducted a quantitative analysis of the severity of the stressors, the exposure of aquaculture systems, and the sensitivity and adaptive capacity of households, providing insights into the economic risks faced by aquaculture households. Additionally, this study highlighted how the unique geographical characteristics of the islands intensify the impacts of these stressors. This study provides concrete evidence for developing policies and management measures to enhance the economic adaptability of island seaweed aquaculture households.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on production strategies for marine aquaculture in China at different scales: a case study of large yellow croaker (Larimichthys crocea)","authors":"Zhengyong Yang,&nbsp;Nannan Lu,&nbsp;Lu Zhai","doi":"10.1007/s10499-025-01854-8","DOIUrl":"10.1007/s10499-025-01854-8","url":null,"abstract":"<div><p>China is the largest marine fish farming country of the world, contributing greatly to world food security and nutrition. Though yields have been increasing yearly, it is still an open question whether farming strategies on farms of different sizes can achieve optimal economic efficiency. In this study, a dynamic bio-economic model based on the production data from 71 farms in China from 2020 to 2023 was developed to simulate the optimal farming cycle and the initial number of fry to be released for different farm scales, using cage culture of the large yellow croaker (<i>Larimichthys crocea</i>) as an example. This work suggests that producing larger fish is more profitable for farms across three different scales. Under the assumption of a stable and suitable farming environment, and without accounting for other potential risks associated with farming, all three scales of farms tend to achieve higher profits at a 27-month farming cycle. Prolonging the farming cycle could result in losses. Specifically, large and medium-sized farms begin to incur losses by the 32nd month, while small farms start to suffer losses by the 31st month. In the future, it is anticipated that more production risks will be factored in to further validate this perspective. The corresponding recommended initial number of fry is 450,000, 2,240,000, and 39,810,000 for small-, medium-, and large-scale farms, respectively. An excessive initial number of fry is common on farms, resulting in cost losses, especially on small-scale farms. Medium- and large-scale farms are more profitable and risk-resistant than small-scale farms. The study identified the key factors affecting the farm profitability. The price at the farm gate and feed expenditure were the main factors affecting the net profits. The government should assist in improving feeding management practices to reduce feed costs, offer guidance on farming techniques to small-scale farmers, and steer the market to broaden consumption. This theoretical model maximally reveals the profit process of different scales and stages of marine fish farming in China and providing a foundation for further research.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating larviculture protocols for the melanurus wrasse (Halichoeres melanurus)","authors":"Grace E. Sowaske,&nbsp;Casey A. Murray,&nbsp;Sarah W. Hutchins,&nbsp;Taylor N. Lipscomb,&nbsp;Matthew A. DiMaggio","doi":"10.1007/s10499-025-01851-x","DOIUrl":"10.1007/s10499-025-01851-x","url":null,"abstract":"<div><p>Marine ornamental aquaculture provides sustainable alternatives to wild-caught fish for the aquarium trade, yet only a small fraction of the 1800 traded species are aquacultured. Wrasses (family Labridae) are the second most imported family of marine ornamental fishes imported into the USA, but none are currently produced through aquaculture. This study investigated several key larviculture parameters for the melanurus wrasse, <i>Halicheores melanurus,</i> such as microalgae species and density, feeding stimulants, live prey preferences, and lighting conditions. Larval survival and feeding incidence were highest when <i>Tisochrysis lutea</i> at a density of 300,000 cells mL⁻¹ was used as greenwater. There were no differences in larval prey preference between <i>Parvocalanus crassirostris</i> and <i>Oithona colcarva</i> copepod nauplii. Also, copeped nauplii could be offered at densities as low as 2.5 nauplii mL⁻¹ without affecting survival or feeding incidence. Feeding stimulants added to culture water did not increase larval feeding incidence and decreased larval survival. A photoperiod of 16 h light:8 h dark maximized larval performance, and microalgae-based light reduction outperformed dimmed lighting alone. These findings address early larviculture bottlenecks and further refine aquaculture protocols for <i>H. melanurus,</i> moving this species closer to commercial production.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing growth, survival, and predator management in juvenile black-lip pearl oyster (Pinctada margaritifera) farming: insights from Savusavu Bay, Fiji","authors":"Jasha Dehm,&nbsp;Teari Kaure,&nbsp;Epineri Tunaka,&nbsp;Sandra Vanukon,&nbsp;Robert Hunter,&nbsp;Justin Hunter,&nbsp;Timothy Pickering,&nbsp;Chinthaka Hewavitharane","doi":"10.1007/s10499-025-01852-w","DOIUrl":"10.1007/s10499-025-01852-w","url":null,"abstract":"<div><p>The growth, survival, and predation interactions of juvenile <i>Pinctada margaritifera</i> in Savusavu Bay, Fiji, with a focus on assessing the effectiveness of fish exclusion devices as a predator management tool were investigated. Results showed favorable environmental conditions for oyster growth, with an average monthly growth rate of 4.87 mm; however, maintaining high survival rates proved challenging with survival rates as low as ~ 22%, with significant variation between farm sites—Matuku farm achieved 85.4% survival over 4 months, while Vatulele farm experienced lower survival rates at 45.6%. Multiple species were found to interact with oyster lines, with species such as puffer fish (<i>Arothron</i> spp.), titan triggerfish (<i>Balistoides viridescens</i>), and golden trevally (<i>Caranx sexfasciatus</i>), emerging as key predators. Fish exclusion devices had limited impact on improving overall oyster survival, suggesting that other factors, including site selection, regular maintenance, and targeted predator management, should be considered. The economic feasibility of exclusion devices is promising, but a more comprehensive approach combining these devices with predator removal could enhance both sustainability and profitability. This study provides valuable insights into improving pearl oyster farming practices in Fiji, highlighting the need for future research on predator–prey dynamics and integrated management strategies to optimize survival and growth.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuous use of settling chamber in saltwort Batis maritima and marine shrimp Penaeus vannamei biofloc-based aquaponics","authors":"Ramires Eloise Queiroz Rafael,&nbsp;Isabela de Almeida Gomes,&nbsp;Esdras Salgado da Silva,&nbsp;Mateus Aranha Martins,&nbsp;Matheus Moreira Rocha,&nbsp;Ramon Felipe Siqueira Carneiro,&nbsp;Isabela Claudiana Pinheiro,&nbsp;Luciano Valdemiro Gonzaga,&nbsp;Ana Carolina de Oliveira Costa,&nbsp;André Batista de Souza,&nbsp;Felipe Boéchat Vieira,&nbsp;Walter Quadros Seiffert","doi":"10.1007/s10499-025-01849-5","DOIUrl":"10.1007/s10499-025-01849-5","url":null,"abstract":"<div><p>This study evaluated the continuous use of settling chamber in saltwort <i>Batis maritima</i> and marine shrimp <i>Penaeus vannamei</i> biofloc-based aquaponics, as regards shrimp and plant growth performance, water quality, biofloc size, and phytochemical analysis. Two treatments were assessed in triplicate for 55 days: continuous use of settling chamber before the shrimp tank water was sent to the plant channels compared to no settling chamber. The shrimp (250 animals m⁻³) were cultivated in 800-L tanks equipped with heating and aeration systems, whereas the plants were cultivated in hydroponic channels that received the shrimp tank water through pumping. The continuous use of the settling chamber resulted in significantly higher values of ammonia and nitrite, in addition to lower concentrations of nitrate and total suspended solids in the aquaponics system (<i>p</i> &lt; 0.05). Lower biofloc size (<i>p</i> &lt; 0.05) in the treatment with settling chamber suggests the shear effect of the pump could have contributed to the instability in the concentrations of ammonia and nitrite due to destabilizing the bacterial community in the bioflocs. No significant differences in shrimp and plant performance were observed (<i>p</i> &gt; 0.05), whereas the plants cultivated in the treatment with settling chamber exhibited higher values of antioxidant capacity and total phenolics compounds (<i>p</i> &lt; 0.05), suggesting a higher stress environment.</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The potential of hydrolyzed chicken feather meal as a partial replacement for fish meal and its effects on the growth and health status of African catfish (Clarias gariepinus) fingerlings","authors":"Nik Nur Akmal ‘Aliah Abdul Rashid,&nbsp;Zulhisyam Abdul Kari,&nbsp;Parashuram Kallem,&nbsp;Suniza Anis Mohamad Sukri,&nbsp;Syed Muhammad Al-Amsyar,&nbsp;Noor Khalidah Abdul Hamid,&nbsp;Muhammad Anamul Kabir,&nbsp;El-Sayed Hemdan Eissa,&nbsp;Martina Irwan Khoo,&nbsp;Krishnakumar Velayudhannair,&nbsp;Ajay Guru","doi":"10.1007/s10499-025-01847-7","DOIUrl":"10.1007/s10499-025-01847-7","url":null,"abstract":"<div><p>The application of agricultural by-products as alternative feed has received tremendous interest from the aquaculture industry. The current study explored the potential of hydrolyzed chicken feather meal (CFM) at different percentages as fish meal (FM) replacement and the impacts on growth, feed stability, apparent protein digestibility, digestive enzyme, body amino acid profiling, body proximate analysis, hematology, and morphology of African catfish (<i>Clarias gariepinus</i>) fingerlings. Five isonitrogenous (32% crude protein) CFM diets were prepared [0% CFM (T1), 5% CFM (T2), 15% CFM (T3), and 30% CFM (T4)] and applied in a 70-day feeding trial. At the end of the experiment, fingerlings fed with the T2 diet exhibited the best final length, final weight, net weight gain, weight gain, specific growth rate, intraperitoneal fat, and condition factor than other treatment groups. Furthermore, the highest digestive enzyme activity and apparent protein digestibility (APD) were highest in the T2 diet. There were significant differences between the groups in the liver, muscle, and intestine amino acid profiles and proximate analysis. Moreover, the T2 group recorded the best villus length, width, and crypt depth in the anterior and posterior regions. The highest white blood cells, lymphocytosis, monocytes, red blood cells, hemoglobin, and hematocrit were also found in the T2 diet group. Meanwhile, albumin, globulin, and creatine levels were the lowest in the T4 diet group. Notably, fingerlings supplemented with the highest CFM percentage demonstrated the highest morphological deterioration in the liver and intestine. In conclusion, 5% CFM is a promising FM replacement to improve the growth, apparent protein digestibility, digestive enzyme, liver and intestine histology, and blood indices of African catfish fingerlings.\u0000</p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the nutritional and effluent properties of potential fish-meal-free diets for rainbow trout (Oncorhynchus mykiss W.) in Iran","authors":"Hamed Salehi,&nbsp;Stefan Reiser,&nbsp;Ulfert Focken","doi":"10.1007/s10499-025-01841-z","DOIUrl":"10.1007/s10499-025-01841-z","url":null,"abstract":"<div><p>Research is needed on alternative ingredients for aquafeeds due to rising demand and limited fish meal availability. This study evaluated fish-meal–free diets for rainbow trout in two phases. The first phase focused on assessing the growth performance and nutrient digestibility of six cold-pelleted diets. Aside from the control diet, the test diets contained poultry protein concentrate, blood meal, low-ash poultry by-product meal, 20–40% canola meal, and feather meal (Goldmehl^®). Juvenile fish, averaging 5.3 g, were fed the diets for 56 days in a random-block design with four replicates per feed. Feces were collected using the settling method to evaluate nutritional digestibility and phosphorus availability. The feed from the primary phase, which resulted in the least-cost feed conversion ratio, was extruded and fed to fingerlings (14.6 g) in the second phase. This trial added to the first run in measuring digestibility parameters over a 28-day period. In parallel, extruded feed was given to grow-out fish, averaging 172.5 g, for 55 days in triplicate completely randomized tanks to evaluate growth performance and nutrient effluents. Throughout all the experimental runs, a casein-based laboratory pelleted feed was used for the respective controls. Feeding rainbow trout with 35% canola meal in both pelleted and extruded forms showed comparable results (<i>P</i> &gt; 0.05) to the control in terms of growth performance and apparent digestibility for lipid (&gt; 91%), crude protein (&gt; 87%), and organic matter (&gt; 78%). The extruded feed in this study represents an eco-friendly option for the growing aquafeed sector. </p></div>","PeriodicalId":8122,"journal":{"name":"Aquaculture International","volume":"33 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10499-025-01841-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143110213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}