The search for sustainable alternatives to fish oil (FO) in aquafeeds is imperative for the long-term sustainability of aquaculture. This study evaluated the effects of partially replacing FO with oils derived from Hermetia illucens (RH) and Musca domestica (RY) larvae at 10%, 30%, and 50% levels on growth, lipid metabolism, hepatic antioxidant capacity, and gut microbiota in juvenile Cyprinus carpio. Results showed distinct source- and dose-dependent responses. RY produced a consistent dose-dependent trend in growth parameters, whereas RH exhibited a biphasic pattern, with growth impairment at 30% replacement and recovery at 50%. Both oils significantly suppressed hepatic fatty acid synthase (FAS) activity, yet this suppression was accompanied by dose-dependent up-regulation of fas expression, particularly at high RH and RY levels, indicating complex post-transcriptional regulation. RH at higher replacement levels reduced digestive enzyme activities and antioxidant capacity, while higher RY caused minimal disruption. Both oils reshaped gut microbiota toward oil-specific community structures. Two-way ANOVA revealed significant synergistic interactions between oil source and replacement level for most serum biochemical and hepatic antioxidant parameters (ηp2 > 0.90). These findings demonstrate that RY is a tolerable alternative across a wide replacement range, though all RY groups exhibited lower growth than the control, 30% is identified as the maximum tolerable level; whereas RH requires precise dosing at 10% to avoid the 30% impairment threshold.

Marine microplastic (MP) pollution and its ecotoxicological effects represent a core focus in global marine environmental research. To assess the toxic effects and mechanisms of different-sized PS-MPs, pearl gentian grouper were exposed to suspensions of two particle sizes (5 μm and 180-220 μm) at a concentration of 500 μg/L for 3, 7, or 14 days. The results revealed a significant size-dependent pattern of the toxic effects: both particle sizes reduced the hepatosomatic index (HSI) but did not affect survival rates. Small (5 μm) MPs penetrated the intestines, entered the circulatory system, accumulated in the liver, and induced progressive liver damage (hepatocyte vacuolation, lipid deposition, and inflammatory infiltration), leading to the collapse of the antioxidant system; moreover, early exposure upregulates the proinflammatory factors IL-1β, IL-8, and TNF-α, quickly triggering an acute inflammatory response and promoting fatty acid oxidation while inhibiting fat synthesis, resulting in energy metabolism imbalance. In contrast, large MPs (180-220 μm) remained mainly in the intestinal tract and caused local inflammation. Liver blood cell infiltration was caused by the obstruction of microvessels by MPs, resulting in circulatory disorders, which are associated mainly with acute oxidative stress. This blockage demonstrated a distinct delayed regulatory mechanism for immune interference, directly and persistently impeding lipid metabolism and inhibiting the expression of PPAR-α and PPAR-γ. In conclusion, compared with large MPs, small MPs pose more severe comprehensive health risks to pearl gentian grouper because of their ability to cross barriers, their accumulation capacity, and the various toxic effects that cause harm over time.

Shrimp aquaculture ponds are dynamic ecosystems in which water quality and microbial interactions play a central role in animal health. This study aimed to investigate the relationship between the intestinal microbiota of Penaeus monodon and the microbial community of polyculture pond water. Shrimp and water samples were collected from polyculture ponds at four time points during the rearing period. Water-quality parameters were measured, and microbial community structures were analyzed by high-throughput 16S rRNA sequencing. Statistical analyses, including one-way ANOVA, revealed significant variations in water-quality parameters and microbial diversity among sampling stages (p < 0.05). Water quality indicators showed progressive changes from July to September, with pH decreasing from 8.1 to 7.5 but remaining within a suitable range. Nitrogen compounds, including ammonia, nitrite, and nitrate, increased steadily, with total nitrogen rising from 0.71 to 1.86 mg·L−1, while phosphate and total phosphorus reached 0.31 and 0.36 mg·L−1, respectively, exceeding thresholds commonly associated with algal bloom risk. Microbial community profiling using Illumina MiSeq sequencing revealed 166 OTUs shared between shrimp intestine and pond water, while both habitats contained more than 350 OTUs overall. Alpha diversity analysis showed higher microbial richness in water than in shrimp intestines, dominated by unclassified taxa, whereas shrimp guts were enriched in specific genera such as Vibrio. Cluster analysis indicated partial overlap but distinct grouping of gut and water microbiota, with the PMB intestinal community diverging most strongly. These findings highlight a close link between water quality and microbial composition, emphasizing the importance of pond management for maintaining ecological stability and shrimp health.

Shrimp aquaculture ponds are dynamic ecosystems in which water quality and microbial interactions play a central role in animal health. This study aimed to investigate the relationship between the intestinal microbiota of Penaeus monodon and the microbial community of mixed-culture pond water. Water quality indicators showed progressive changes from July to September, with pH decreasing from 8.1 to 7.5 but remaining within a suitable range. Nitrogen compounds, including ammonia, nitrite, and nitrate, increased steadily, with total nitrogen rising from 0.71 to 1.86 mg·L⁻¹, while phosphate and total phosphorus reached 0.31 and 0.36 mg·L⁻¹, respectively, exceeding thresholds commonly associated with algal bloom risk. Microbial community profiling using Illumina MiSeq sequencing revealed 166 OTUs shared between shrimp intestine and pond water, while both habitats contained more than 350 OTUs overall. Alpha diversity analysis showed higher microbial richness in water than in shrimp intestines, dominated by unclassified taxa, whereas shrimp guts were enriched in specific genera such as Vibrio. Cluster analysis indicated partial overlap but distinct grouping of gut and water microbiota, with the PMB intestinal community diverging most strongly. These findings highlight a close link between water quality and microbial composition, emphasizing the importance of pond management for maintaining ecological stability and shrimp health.

For decades, the photosynthetic bacteria (PSB)-based nitrogen treatment and valorization from wastewater have been explored. However, balancing nitrogen removal performance and resource recovery potential in PSB has remained a key unresolved issue for a long time. This study employed generative deep learning algorithms to achieve high-quality data generation, supporting multi-objective optimization in nitrogen removal, protein concentration, and nitrogen-to-protein conversion. In this study, the Variational Auto-Encoders model generated 5000 samples related to PSB nitrogen recovery, significantly enhancing the original dataset. The Elastic Neural Network (ENN) model showed better fitting results with the generated data. In single-objective evaluations, SHapley Additive exPlanations analysis identified the most important factors: carbon source, nitrogen source, and light type for total nitrogen (TN) removal; nitrogen source, nitrogen loading rate (NLR), and light type for protein concentration; nitrogen source, light type, and chemical oxygen demand (COD) for nitrogen conversion. Multi-objective optimization identified eight pareto front points, with the following input variable ranges: COD 3.42-7.48 g L-1, TN 0.22-0.37 g L-1, COD:TN ratio 9.28-33.22, hydraulic retention time 4.02-7.67 days, illuminance 967.71-1405.56 lx, and NLR 0.28-0.77 g L-1 d-1. The pareto solutions were mostly achieved under Near Infrared (NIR) light. Validation experiments further supported these findings, showing that NIR light achieved nitrogen-to-protein conversion reaching 44 % of the removed nitrogen. Additionally, NIR light significantly enhanced gene expression related to ammonia assimilation and protein translation processes compared to white light. The proposed generative framework provided an innovative solution for multi-objective optimization of wastewater nitrogen valorization under limited data conditions.

The experiment aimed to study the effect of Bupleuri radix and its extract on the growth, physiology and biochemistry, liver antioxidant, and antibacterial ability of juvenile koi carp. A total of 360 juvenile koi carp with an initial body weight of (21.0±0.5) g were randomly divided into three groups with three replicates in each group and 40 juvenile koi carp in each replicate. The juvenile koi carp in the group K, group C, and group T were fed a basal diet, a basal diet + 5‰ Bupleuri radix meal, a basal diet + 5‰ Bupleuri radix extract. The experiment lasted for 14 days. The results showed that in the serum of juvenile koi carp, the activity of lysozyme (LZM) in the group C and alkaline phosphatase (AKP) in the group C and group T at 14 days were significantly higher than those at 0 day, and significantly higher than those in the group K (P<0.05). In the liver of juvenile koi carp, the activity of LZM, acid phosphatase (ACP) in the group C and AKP in the group T at 14 days were significantly higher than those at 0 day (P<0.05). The activity of superoxide dismutase (SOD) and the total antioxidant capacity (T-AOC) in the group C at 14 days were significantly higher than those at 0 day (P<0.05), and the content of malondialdehyde (MDA) in the group C was lower than that at 0 day and 7 days. In the challenge test, the mortality rate of juvenile koi carp in the group K within 24 hours was 41.7%. The mortality rate in the group C was 18.3% and the protection rate was 56%. The mortality rate in the group T was 21.7% and the protection rate was 48%. In the serum, the interleukin-13 (IL-13) content in the group C at 48 hours was significantly higher than that at 24 hours and 96 hours (P<0.05), and the immunoglobulin M (IgM) content in the group C and group T at 48 hours was significantly higher than that at 24 hours (P<0.05). In the liver, the content of interleukin-4 (IL-4), IL-13, and IgM in the group C at 48 hours were significantly higher than those at 24 hours, and the content of IL-13 in the group C was significantly higher than that of the group K (P<0.05). The experiment indicates that adding Bupleuri radix and its extract to the diet for 14 days can effectively improve the physiological and biochemical indexes and anti-Aeromonas vickeri ability of juvenile koi carp, but the action time and effect of the two are different, and the effect of Bupleuri radix is more prominent.

To explore the changes in nitrite nitrogen, ammoniacal nitrogen, nitrate nitrogen, phosphates, pH, dissolved oxygen, salinity, and water temperature over time and the correlations and mutual influences between these indexes in the traditional farming of largemouth bass, this study selected three ponds in Lizigu Farm in Baodi District of Tianjin, China as research objects. From May to October 2021, nutrient salts and other water quality indexes in the ponds were measured, and water samples were collected at different depths for repetition, Water is collected from the ponds using Plexiglas samplers and sent back to the lab for determination of water quality indexes using our national laboratory standards. According to the analysis of the measurement results, in traditional farming, nitrite nitrogen, ammoniacal nitrogen, nitrate nitrogen, phosphates, pH, dissolved oxygen, salinity, and water temperature in the ponds for largemouth bass all change significantly over time, with different changing trends and certain correlations with each other. In particular, nutrient salts indexes in ponds are influenced by other water quality indexes, human activities, and phytoplankton. During the breeding process, strengthening the dynamic monitoring of nutrient salts and other water quality indexes in the ponds and adjusting the nitrogen, phosphorus, and ammonia levels in the ponds artificially play an important role in preventing eutrophication in the water and promoting the green and sustainable production of pond ecosystems, in particular, allowing better quality growth of the largemouth bass, as well as ensuring the production and economic efficiency. This study provides a theoretical basis and data support for further optimization of traditional pond aquaculture in similar regions, in order to provide aquatic products with better quality and achieve higher economic benefits.

This study investigated whether adding Herba Houttuyniae to feed can improve intestinal function and prevent diseases for koi carp (Cyprinus carpio) infected with Aeromonas veronii. There was a total of 168 koi carp with an average body length of (9.43 ± 0.99) cm and an average body weight of (26.00 ± 11.40) g. The K group was the control group fed with basal feed, while the C group was fed with feed with a H. houttuyniae content of six per thousand. After 14 days of feeding, the fish were fasted for a day and then intraperitoneally injected with A. veronii for artificial infection, injection dose is 0.2 mL, and the concentration is 1 × 107 CFU/mL. Samples were collected from the two groups on days 0, 1, 2, and 4. The fold height, intestinal villus width, and muscle layer thickness in the gut of the koi carp were measured. In addition, on day 4, the activities of trypsin, α-amylase, and lipase in the gut were determined, and the intestinal flora of the carp in both groups was tested. The results showed that on the second and fourth days of sampling, the fold height and muscle layer thickness in the C group were significantly higher than those in the K group (P < 0.05). The villus width in the C group was slightly higher than that in the K group, but the difference was not significant (P > 0.05). Microscopic observation revealed that the intestinal structure of the carp in the C4 (day 4 in C group) group was more intact than that in the K4 (day 4 in K group) group. Moreover, the activities of trypsin, α-amylase, and lipase in the foregut and midgut in the C4 group were higher than those in the K4 group (P < 0.05). The activities of trypsin and α-amylase in the hindgut in the C4 group were higher than those in the K4 group (P < 0.05). Furthermore, beneficial bacteria, especially those in the genus Cetobacterium, were more abundant in the intestinal tract of the carp in the C4 group compared to the K group. In addition, comparisons and tests of IL-4 and IL-10 in the intestines of the fish in both groups demonstrated that the H. houttuyniae added to feed enhanced the immune function of the fish intestines after bacterial attack. In conclusion, for koi carp infected with A.veronii, adding H. houttuyniae to their feed not only improves the activity of digestive enzymes and the morphological structure of the intestine but also optimizes the beneficial intestinal microbiota, thereby protecting the intestinal tract.

Abstract Purpose This paper studies the effects of bupleurum and its extract on intestinal function of juvenile Cyprinus carpio, lipid metabolism, foregut digestive enzymes, intestinal flora, intestinal structure and non-specific immune-related genes of juvenile Cyprinus carpio were analyzed before and after infection by artificial infection with aeromonas vickerii. [Methods]Three groups (K group, feeding basic feed;Piglets in group C were fed basic diet +5‰ bupleurum meal, and piglets in group T were fed basic diet +5‰ bupleurum extract). There were 3 replicates in each group and 40 fish in each replicate. Juvenile Cyprinus carpio with initial body weight of (21±0.5) g were fed for 14 days. Main results Before infection: the contents of TC and LDL in C and T groups were significantly decreased (P<0.05),HDL was significantly increased (P<0.05), and TBL content in C group was significantly decreased (P<0.05) at 14 days. At 14 days, the activities of LPS and PRO in group C were significantly increased (P<0.05). Compared with group K, sobs, shannon, ace and chao index increased in group C and T, and simpson index decreased. At the phylum level, the dominant bacterial groups in each group were Proteobacteria, Firmicutes, Fusobacteria and Actinobacteria. On the genus level, the relative abundance of cetobacterium in group C and T is significantly lower than that in group K. The villus length and muscle thickness in group C were significantly higher than those in group K (P<0.05). After infection: LPS and AMS were decreased in K group (P<0.05), but there was no significant difference in other groups (P>0.05). Compared with group K, sobs, shannon, ace and chao index increased in group C and T, and simpson index decreased. At the phylum level, the relative abundance of Proteobacteria increased in groups C and T and decreased in groups firmicutes compared with group K.The relative abundance of groups C and K decreased. The relative abundance of actinomycetes increased in group C and decreased in group T and K. At the genus level, the relative abundance of cetobacterium in group C and group T decreased less than that in group K. The relative abundance of aeromonas and acinetobacter in groups C and T was less than that in group K. After group C was infected with Aeromonas vickerii, flavobacteria decreased significantly, and pilomonas increased significantly. The villus length and muscle thickness in group C were significantly higher than those in group K (P<0.05). At 96h, the relative expressions of Hsp70 and Hamp in group C were significantly higher than those in groups K and T (P<0.05). [Conclusions] Dietary supplementation of bupleurum and its extract can improve lipid metabolism, intestinal enzyme activity, intestinal flora diversity, intestinal structure, non-specific immune gene expression and resistance to aeromonas vickerii infection of juvenile cyprinus carpio.However, the action time and effect of the two groups are different, and the effect is more prominent than that of bupleurum group.

本试验构建了滴流式循环水养殖系统,以锦鲤为养殖对象,测定了120d内锦鲤的生长情况和系统水质的变化情况.统计表明:锦鲤体质量的生长方程为m=48.733e0.0086 t(R2=0.9999);体长生长方程为L=0.0668t+11.734(R2=0.9950);体质量(m)随体长(L)呈指数增长趋势,二者的关系为m=10.953e0.1278L(R2=0.9954).循环水系统中pH在7.1～8.0,呈不断下降趋势;溶解氧在6.48～6.83mg·L-1,在整个养殖过程中波动不大.氨态氮0.77～1.28mg·L-1,在养殖前期氨氮质量浓度呈不断上升趋势,养殖中期和后期呈逐渐下降趋势;亚硝态氮0.13～0.35mg·L-1,在养殖前期和中期亚硝态氮浓度呈逐渐上升趋势,养殖后期亚硝态氮质量浓度呈不断下降趋势.系统运行稳定,锦鲤生长状态良好.

为探究在饲料中添加凹凸棒石对锦鲤(Cyprinus carpio haematopterus)抗氧化能力及非特异性免疫指标的影响,选用规格一致、健康活泼的锦鲤 240 尾,随机分成 4 个试验组(其中 3 组为试验组,1 组为对照组),每组 3 个重复,每个重复 20 尾鱼.将凹凸棒石添加量设为 0%(A1 组)、3%(A2 组)、5%(A3 组)、8%(A4 组)四个梯度,饲喂 28d后,取血液和组织等样本,检测相应指标.结果表明,血清中,A3 组 SOD活性显著高于其他组(P<0.05);A2 组CAT及T-AOC活性显著高于其他组(P<0.05);A3 组 MDA含量显著低于其他组(P<0.05).肝脏中,SOD 活性在 A2 组达到最高,但与 A1、A2 组差异不显著(P>0.05);A3 组CAT及T-AOC活性显著高于 A1、A4 组(P<0.05);各试验组 MDA 含量均显著低于对照组(P<0.05).血清中,A2 组 ACP活性显著高于其他组(P<0.05),GOT和 GPT活性均显著低于对照组(P<0.05).肝脏中,A3 组ACP活性显著高于A1、A4 组(P<0.05);A2、A3 组AKP活性显著高于A1、A4 组(P<0.05);各试验组GOT活性均显著低于对照组(P<0.05).综上所述,在基础饲料中添加 3%～5%的凹凸棒石,能够提高锦鲤的非特异性免疫和抗氧化能力,促进锦鲤健康生长.

Purpose This paper studies the effects of bupleurum and its extract on intestinal function of juvenile Cyprinus carpio, lipid metabolism, foregut digestive enzymes, intestinal flora, intestinal structure and non-specific immune-related genes of juvenile Cyprinus carpio were analyzed before and after infection by artificial infection with aeromonas vickerii. [Methods]Three groups (K group, feeding basic feed;Piglets in group C were fed basic diet +5‰ bupleurum meal, and piglets in group T were fed basic diet +5‰ bupleurum extract). There were 3 replicates in each group and 40 fish in each replicate. Juvenile Cyprinus carpio with initial body weight of (21±0.5) g were fed for 14 days. Main results Before infection: the contents of TC and LDL in C and T groups were significantly decreased (P<0.05),HDL was significantly increased (P<0.05), and TBL content in C group was significantly decreased (P<0.05) at 14 days. At 14 days, the activities of LPS and PRO in group C were significantly increased (P<0.05). Compared with group K, sobs, shannon, ace and chao index increased in group C and T, and simpson index decreased. At the phylum level, the dominant bacterial groups in each group were Proteobacteria, Firmicutes, Fusobacteria and Actinobacteria. On the genus level, the relative abundance of cetobacterium in group C and T is significantly lower than that in group K. The villus length and muscle thickness in group C were significantly higher than those in group K (P<0.05). After infection: LPS and AMS were decreased in K group (P<0.05), but there was no significant difference in other groups (P>0.05). Compared with group K, sobs, shannon, ace and chao index increased in group C and T, and simpson index decreased. At the phylum level, the relative abundance of Proteobacteria increased in groups C and T and decreased in groups firmicutes compared with group K.The relative abundance of groups C and K decreased. The relative abundance of actinomycetes increased in group C and decreased in group T and K. At the genus level, the relative abundance of cetobacterium in group C and group T decreased less than that in group K. The relative abundance of aeromonas and acinetobacter in groups C and T was less than that in group K. After group C was infected with Aeromonas vickerii, flavobacteria decreased significantly, and pilomonas increased significantly. The villus length and muscle thickness in group C were significantly higher than those in group K (P<0.05). At 96h, the relative expressions of Hsp70 and Hamp in group C were significantly higher than those in groups K and T (P<0.05). [Conclusions] Dietary supplementation of bupleurum and its extract can improve lipid metabolism, intestinal enzyme activity, intestinal flora diversity, intestinal structure, non-specific immune gene expression and resistance to aeromonas vickerii infection of juvenile cyprinus carpio.However, the action time and effect of the two groups are different, and the effect is more prominent than that of bupleurum group.

以平菇多糖为饲料添加剂,以鹦鹉鱼为研究对象,探究不同水平的平菇多糖对鹦鹉鱼(Amphilophus)免疫能力的影响.选用规格一致、健康活泼的鹦鹉鱼 375 尾,随机分为 5 个试验组(其中 2、3、4、5 组为试验组,1 组为对照组),每组 3 个重复,每个重复 25 尾鱼;平菇多糖添加量 5 个梯度为 0‰、5‰、10‰、15‰、20‰,分别在 0、7、14、21、28 d取血液和组织等样本,检测相应指标.结果表明:14、21 d时 15‰、20‰添加量AKP活力显著高于其他添加量(P<0.05);14 d时 5‰、10‰、15‰浓度组ACP活力显著高于对照组(P<0.05);20‰浓度组ACP活力显著高于其他组(P<0.05);14 d时 15‰浓度组溶菌酶活力显著高于对照组(P<0.05);14 d采样中 10‰浓度组NO含量显著提高(P<0.05);21 d时,5‰浓度组CAT、GSH-PX、T-AOC的活性显著高于对照组,MDA含量显著低于对照组.综上所述,在鹦鹉鱼所摄入的食物中添加适量的平菇多糖可以起到提高免疫力的作用.

[背景]屎肠球菌(Enterococcus faecium)作为乳酸菌属的潜在益生菌,因其具有良好的生物学特性在动物养殖中应用广泛,但是屎肠球菌对肠道代谢组学的研究很少.[目的]以斑节对虾为试验动物,初步探究屎肠球菌R8对肠道代谢组学及炎性因子的影响,为屎肠球菌作为益生菌在对虾养殖中的应用提供理论基础.[方法]将400条斑节对虾随机分配,设计饲料中屎肠球菌添加量分别为107、108、109CFU/g的3个试验组,不添加屎肠球菌为对照组进行试验,养殖周期为28 d.养殖周期结束后测定斑节对虾免疫球蛋白M(immunoglobulin M,IgM)、对虾酚氧化酶(phenoloxidase,PO)、白介素 6(interleukin 6,IL-6)、补体片段 3a(complement fragment 3a,C3a)的活性含量并运用LC-MS代谢组学研究肠道内源代谢物的变化,分析差异代谢物和相关的代谢通路.[结果]添加屎肠球菌对斑节对虾炎性因子有积极的影响,增加了斑节对虾体内免疫球蛋白IgM、对虾酚氧化酶、补体片段3a的含量,降低了其体内IL-6的含量,对肠道差异代谢物的分析发现,对照组与试验组共同差异代谢物165个,化合物成分主要是脂质和类脂分子、有机酸和衍生物、有机氧化合物、有机杂环化合物、核苷、核苷酸和类似物等.差异代谢物对37条代谢通路有影响,其中,花生四烯酸代谢通路、a-亚麻酸代谢通路、胆碱代谢通路和嘧啶代谢通路是显著富集的代谢通路(P＜0.05),而且花生四烯酸代谢、α-亚麻酸代谢、胆碱代谢、嘧啶代谢和甘油磷脂代谢的富集代谢物数目最多.[结论]屎肠球菌对斑节对虾肠道中的脂代谢、氨基酸代谢、核苷酸代谢及炎性因子有积极的影响,为屎肠球菌在对虾养殖中的应用奠定理论基础,具有重要的意义和应用前景.

Koi（Cyprinus carpio）with an initial average body mass of（45.00±3.00）g were placed in a breeding box of 780 mm×575 mm×467 mm（actually added water 110 L）and bathed the water with a non-woven bag of Chinese herbal medicine Areca catechu and Artemisia carvifolia at ratio of 1:1 preparations at water temperature of （28.5±1.0）°C at concentrations of 0 mg·L -1 （control group）and 6.25 mg·L -1 （group A）,12.5 mg·L -1 （group B）,125 mg·L -1 （group C）and 250 mg·L -1 （group D）.The contents of C3a,C5aR,PGE2,PGF-2a,LZM and IL-6 were measured in serum of 3 fish samples collected randomly and the appearance of gills and lesions of gill filaments were observed on the 0th,3rd,6th,9th,12th and 15th day of the experiment to effects of Chinese herbal medicine bath on the activity of non-specific immune factors and lesions of gill and gill filament tissues in koi carp.The contents of C3a,PGE2,PGF-2a and LZM were shown to be increased significantly in the soaking group on the same day （P＜0.05）,while the contents of C5aR and IL-6 did not change significantly （P＞0.05）.The contents of C3a,C5aR,PGE2,PGF-2a,LZM and IL-6 in the same concentration were found to be increased first and then decreased with the extension of soaking time,with the maximal content in group D.The histological sections showed that the gill filaments of the fish were normal without lesions on day 0.On the 9th day of the experiment,there was no swelling at the end of gill filament in each immersion group due to the increase in blood cells,and there was no increase in inflammatory cells.In the control group,the gill filaments were red,swollen and festered.It can be seen that this traditional Chinese medicine formula can regulate the inflammatory factors and enhance non-specific immunity in koi carp.In general,the better effect was observed at immersion concentration of 250 mg·L -1 .

The experiment was to investigate the effect of different protein levels diets on growth performance, intestinal digestive enzymes and antioxidant function of Cyprynus carpio. A total of 270 Cyprynus carpio with an initial average weight of (92.36±3.32) g and an initial body length of (14.84±0.32) cm were randomly divided into three groups, with three replicates in each group and 30 Cyprynus carpio in each replicate. F1 group (43.12%), F2 group (41.96%) and F3 group (38.21) were fed diets with different protein levels, respectively. The experiment lasted for 60 d. The results showed that the weight gain rate and specific growth rate of Cyprynus carpio in F1 group and F2 group were significantly higher than those in F3 group (P<0.05). Intestinal amylase and lipase activity decreased from foregut to hindgut in all groups. The activity of trypsin increased from foregut to hindgut. The activity of serum superoxide dismutase, catalase and glutathione peroxidase in F1 group were significantly higher than those in F2 group and F3 groups (P<0.05). The study indicates that the feed with protein level of 43.12% has better effect on breeding of Cyprynus carpio.

为了探究饲料中添加喹乙醇和肉碱对鹦鹉鱼的生长和抗氧化指标的影响,本研究分别在基础饲料中添加0.5％肉碱和0.5％喹乙醇,以基础饲料为对照,鹦鹉鱼养殖30 d后,测定各组增重率、饵料系数、成活率、肝脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛含量(MDA).结果表明:与对照相比较,饲料中添加0.5％肉碱显著降低了鹦鹉鱼的增重率(P<0.05),显著提高了成活率和饲料系数及CAT和SOD活性(P<0.05),但MDA含量无显著变化;饲料中添加0.5％喹乙醇显著提高了鹦鹉鱼的增重率和CAT、SOD活性及MDA含量(P<0.05),显著降低了饲料系数(P<0.05).综上,饲料中添加0.5％肉碱有助于提高机体的成活率、饲料系数和抗氧化能力,添加0.5％喹乙醇有助于提高增重率和抗氧化能力.

为了探究速大肥和高稳胺对血鹦鹉鱼生长和抗氧化指标的影响,本研究以血鹦鹉鱼作为试验对象,在基础饲料中分别添加0.5％速大肥和高稳胺.养殖30 d后,测定鱼体内丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)等相关抗氧化指标,探究这两种饲料添加剂对于血鹦鹉的生长和相关抗氧化指标的影响.试验结果表明:添加量为0.5％的高稳胺组,鹦鹉鱼的成活率和增重率显著提高(P<0.05),显著提高了血鹦鹉鱼机体的过氧化氢酶和超氧化物歧化酶的活性(P<0.05),同时也降低了丙二醛的含量.0.5％高剂量的速大肥并没有显著提高其丙二醛含量(P>0.05),且其超氧化物歧化酶,过氧化氢酶的差异变化也不明显(P>0.05),添加量为0.5％的速大肥对于血鹦鹉增重方面效果不显著(P>0.05),但成活率提升显著(P<0.05).综上所述,将高稳胺和速大肥作为血鹦鹉观赏鱼饲料添加剂能有效地促进血鹦鹉鱼生长,并提高其自身抗氧化能力.

Salinity is an important environmental factor that affects fish growth, development, and reproduction. As euryhaline fish, half-smooth tongue sole (Cynoglossus semilaevis) are a suitable species for deciphering the salinity adaptation mechanism of fish; however, the molecular mechanisms underlying low- and high-salinity responses remain unclear. In this study, RNA-seq was applied to characterize the genes and regulatory pathways involved in C. semilaevis gill responses to high- (32 ppt), low- (8 ppt), and control-salinity (24 ppt) water. Gills were rich in mitochondria-rich cells (MRCs) in high salinity. Compared with control, 2137 and 218 differentially expressed genes (DEGs) were identified in low and high salinity, respectively. The enriched functions of most DEGs were metabolism, ion transport, regulation of cell cycle, and immune response. The DEGs involved in oxidative phosphorylation, citrate cycle, and fatty acid metabolism were down-regulated in low salinity. For ion transport, high and low salinity significantly altered the expressions of prlr, ca12, and cftr. In cell cycle arrest and cellular repair, gadd45b, igfbp5, and igfbp2 were significantly upregulated in high and low salinity. For immune response, il10, il34, il12b, and crp increased in high and low salinity. Our findings suggested that alterations in material and energy metabolism, ions transport, cell cycle arrest, cellular repair, and immune response, are required to maintain C. semilaevis gill homeostasis under high and low salinity. This study provides insight into the divergence of C. semilaevis osmoregulation mechanisms acclimating to high and low salinity, which will serve as reference for the healthy culture of C. semilaevis.

为研究添加茯苓多糖对鹦鹉鱼肝功能、抗氧化、非特异性免疫以及肠道消化酶的影响,分别投喂FL0(添加0％茯苓多糖),FL05(添加0.5％茯苓多糖),FL1(添加1％茯苓多糖),FL15(添加1.5％茯苓多糖),FL2(添加2％茯苓多糖)的饲料,每组3个平行,每个平行30尾鱼,试验28 d.结果表明:添加1％茯苓多糖14 d,该试验组鹦鹉鱼肝脏抗氧化指标SOD、T-AOC活力显著高于0 d(P<0.05);肝功能指标A/G值与GPT活力与0 d相比显著降低(P<0.05);肝脏非特异性免疫指标溶菌酶、AKP活力高于0 d,差异不显著(P>0.05),ACP活力显著高于0 d(P<0.05).添加1％茯苓多糖14 d,该试验组鹦鹉鱼前肠蛋白酶、脂肪酶显著高于0 d(P<0.05).综上,茯苓多糖可以增强鹦鹉鱼肝功能、抗氧化、非特异性免疫以及肠道消化酶活力,在饲料中添加1％的茯苓多糖投喂14 d效果最佳.