The lack of scientifically-based light environment management has constrained the sustainable development of intensive mandarin fish (Siniperca chuatsi). This study systematically evaluated the behavioral preferences and physiological adaptations of mandarin fish to red light (RL), yellow light (YL), green light (GL), blue light (BL), white light (WL) and dark area (DA). Individual behavioral results indicated that S. chuatsi exhibited the strongest phototaxis toward RL, with a preference order of RL > DA > YL > BL > GL > WL. Group distribution dynamics showed that the proportion of fish in the RL remained the highest throughout the 48-h observation period. Fish in the DA exhibited significant aggregation dominance during the initial 26 h, which gradually diminished thereafter. In the YL, the number of individuals progressively increased over time, reaching a proportion of 30.56 % at the 42-h mark. Physiological assays revealed that the YL group showed significantly enhanced total antioxidant capacity (T-AOC) along with markedly reduced malondialdehyde (MDA) levels. Furthermore, cortisol levels were significantly higher in the RL group compared to the YL, GL, and WL groups. The content of 5-hydroxytryptamine (5-HT) was significantly elevated in the RL and DA groups relative to the BL group. Histological examination indicated that cone cell density was significantly greater in the GL and WL groups than in the DA group. The retinal pigment index was highest under RL, significantly exceeding those in the GL and DA groups. Transcriptomic analysis identified 658 up-regulated and 316 down-regulated genes in the YL group compared to the DA group. KEGG enrichment analysis indicated significant activation of the neuroactive ligand-receptor interaction pathway. In summary, S. chuatsi exhibits a distinct behavioral preference for long-wavelength spectra (red and yellow light). While RL may induce chronic stress, YL effectively enhances antioxidant capacity. These findings provide a theoretical basis for the management of light environments in S. chuatsi aquaculture.

This study investigated the interactive effects of salinity and dietary lipid source on growth, flesh quality, and lipid metabolism in juvenile largemouth bass (Micropterus salmoides). The experiment employed a 3 × 2 factorial design with three salinities (0‰, 4‰, 8‰) and two lipid sources (soybean oil and fish oil), resulting in six groups designated as S0, S4, S8 and F0, F4, F8. Fish oil improved growth performance and feed conversion, while 4‰ salinity showed comparable benefits over 8‰; these effects were additive rather than synergistic. Serum acid phosphatase and alkaline phosphatase were highest under the combination of 4‰ salinity and fish oil. Na⁺-K⁺-ATPase activity increased with salinity regardless of lipid source. Antioxidant capacity was highest in the 4‰ fish oil group, whereas oxidative stress markers were highest at 8‰. Muscle proximate composition was largely unaffected by the treatments, except that crude lipid was lower in fish oil groups and ash was higher at 8‰. Total amino acids, essential amino acids, flavor amino acids, and n-3 LC-PUFAs were enriched in the 4‰ fish oil group but depleted at 8‰. Peroxisome proliferator-activated receptor α (PPARα) expression was upregulated by salinity under soybean oil diet, while PPARγ and LPL were suppressed by fish oil. In conclusion, 4‰ salinity combined with fish oil diet improved nutritional quality and lipid metabolism, whereas 8‰ salinity was detrimental regardless of lipid source. These findings inform nutritional strategies for largemouth bass in saline-alkaline aquaculture.

The long-chain polyunsaturated fatty acids (LC-PUFA) synthesis characteristics in fish, including the identification of key genes and their functional activities, are crucial for developing targeted nutritional strategies. Although the endogenous LC-PUFA synthesis capacity of largemouth bass (Micropterus salmoides) has been preliminarily reported, the key genes involved and their functional activities remain uncharacterized. In this study, we systematically validated the LC-PUFA synthesis pathway in largemouth bass by comparing diets supplemented with LC-PUFA (LD) or non-LC-PUFA (NLD). The results demonstrated that largemouth bass can endogenously synthesize LC-PUFA from C18 PUFA, albeit with compromised growth performance and hepatic health under NLD feeding. Furthermore, we characterised the genes potentially involved in LC-PUFA biosynthesis, including two fatty acid desaturases (fads2a and fads2b) and three fatty acid elongases (elovl5, elovl4a and elovl4l). Bioinformatics analysis confirmed the evolutionary conservation of these genes and revealed the unique evolutionary divergence mechanism of the fads2s in largemouth bass. The LC-PUFA biosynthesis-related genes knockdown in primary hepatocyte and yeast heterologous expression confirmed that Fads2a has Delta 4, Delta 5, Delta 8 desaturase activities and Fads2b Delta 5, Delta 6, Delta 8 desaturase activities. And Elovl5 primarily participated in the elongation of C18 and C20 PUFA, whereas Elovl4a and Elovl4l were involved in the elongation of C18, C22 and longer-chain PUFA (> C24). Overall, we constructed a complete LC-PUFA synthesis pathway in the largemouth bass, thereby enhancing the understanding of the characteristics and evolutionary mechanisms of LC-PUFA synthesis in freshwater carnivorous fish.

In China, a newly emerging disease, White Syndrome (WS), has been identified in Macrobrachium rosenbergii. This study investigates the impact of WS, characterized by systemic whitening, abdominal muscle and hepatopancreatic atrophy, and the presence of blisters. Histopathological and transcriptomic analyses were performed on hepatopancreas and abdominal muscle tissues of affected prawns. Histological examinations revealed damaged hepatopancreatic tubules with enlarged intercellular spaces, while muscle tissues exhibited signs of atrophy. A total of 191 differentially expressed genes (DEGs) were identified from the hepatopancreas, along with 233 KEGG pathways. The primary pathways associated with WS include Lysosome, Glycosaminoglycan degradation, Pentose and glucuronate interconversions, Starch and sucrose metabolism, Biosynthesis of unsaturated fatty acids, Sphingolipid metabolism, Steroid biosynthesis, Fatty acid elongation and Retinol metabolism. Similarly, 191 DEGs were identified from the abdominal muscle, with 203 KEGG pathways. WS-related pathways included Proteasome, Glycolysis/Gluconeogenesis, and Starch and sucrose metabolism. These findings suggest that WS in M. rosenbergii may be associated with nutritional deficiencies linked to excessive reproductive activity in female prawns. This study provides critical insights for future research on WS and its management in M. rosenbergii.

This study aims to investigate the effects of dietary supplementation with protease on the growth performance, liver health, immunity, and intestinal microbiota of grass carp. Three levels of protease, 0 U/kg (P0), 6000 U/kg (P6000) and 12,000 U/kg (P12000), were formulated into diets using post-spray technology. After 9 weeks of feeding, the P6000 group had a higher weight gain rate than the P0 group, with both P6000 and P12000 groups exhibiting higher protein retention ratio and lower feed conversion ratio compared to P0. As protease levels increased, crude protein content and intestinal protease activity increased, while alkaline phosphatase (ALP) content decreased. Concurrently, the P6000 group showed higher aspartate transaminase (AST) and triglyceride (TG) levels but lower amylase content compared to P0. In terms of immune indicators, the expression levels of Intelectin and MHC-II β in the P6000 and P12000 groups were significantly lower than in P0, and IgM expression gradually increased with increasing protease levels. After challenge with Aeromonas veronii, the P12000 group showed higher survival rate. The histological results indicated that the intestinal villi length in the P6000 group was notably longer than in other groups. The intestinal microbiota analysis revealed that with increasing protease levels, Fusobacteriota abundance decreased and Actinobacteriota and Cyanobacteria abundance increased at the phylum level, while Aeromonas relative abundance decreased at the genus level. Overall, 6000 U/kg protease boosts grass carp growth and nutrient retention maximally, while 12,000 U/kg protease increases survival but may increase liver metabolic burden. Given these outcomes, the optimal protease inclusion level for grass carp aquaculture is approximately 6000 U/kg.

The cultivation of largemouth bass (Micropterus salmoides), a species of significant economic value in aquaculture, has experienced notable growth recently. However, the deterioration of water quality seriously affects the metabolic responses of M. salmoides. While compound microbial agent (CMA) is widely utilized for ecological rehabilitation and water filtration, its application in M. salmoides has not been reported. Here, based on physio-biochemical tests and 16S rRNA sequencing, we investigated the effects of CMA (yeast, Bacillus subtilis, and lactic acid bacteria) on the water quality within the recirculating aquaculture system, along with physiological indices and gut microbiota of M. salmoides. Compared to the control and single microbial agent (yeast), CMA treatment improved the water quality by improving the dissolved oxygen and delaying the increase of pH, total nitrogen, total phosphorus, ammonia nitrogen, and nitrite. The 16s rRNA gene sequencing revealed that the water treated with CMA exhibited elevated levels of chao1, Shannon, Pd, and a larger population of dominant bacterial. Besides, higher values of ACE, chao1, Shannon, and OTU level, and lower Simpson index were found in CMA treated M. salmoides samples, suggesting that CMA treatment enhanced the species richness and diversity of gut microbiota of M. salmoides. Furthermore, CMA treatment hindered the generation and proliferation of harmful bacteria, such as the Mycoplasma mobile 163K species and the Erysipelotrichaceae family, which was associated with enhanced antioxidant enzymatic activity and decreased MDA level in both the serum and liver. These findings shed light on the essential roles of CMA in M. salmoides culturing and introduce an innovative approach to enhance the aquatic environment.

In this study, we conducted a 16-week feeding trial to investigate the effects of a high-cassava starch diet on growth performance, liver function, and metabolism in largemouth bass (Micropterus salmoides). We formulated five diets containing varying levels of cassava starch: 12%, 9%, 6%, 3%, and 0% (termed M12, M9, M6, M3, and M0, respectively). We distributed these diets among largemouth bass with the initial body weight of 83.33 ± 0.55 g via an in-pond “raceway” aquaculture system. Our findings suggest that high level (12%) of cassava starch dietary inclusion adversely affected growth performance metrics such as weight gain rate and specific growth rate, along with feed utilization efficiency indicators, including protein efficiency, protein deposition rate, and the apparent digestibility of dry matter and protein. This negative impact was accompanied by a decrease in intestinal amylase activity. Through further transcriptomic analysis, we identified several key genes associated with carbohydrate metabolism, which underwent changes influencing liver function. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed the involvement of these differentially expressed genes (DEGs) in the tricarboxylic acid cycle (TCA cycle). Comparative metabolomics analysis further indicated that the M9 group showed significant enrichment in pathways related to amino acid metabolism and alterations in the levels of metabolites involved in carbohydrate metabolism. In conclusion, our study demonstrates that incorporating up to 9% cassava starch in the diet can enhance growth performance in largemouth bass by stimulating digestive enzyme activities and promoting glucose utilization.

加强水产种质资源的保护与利用,既是国家生物和遗传多样性安全的迫切需要,也是人们对优质健康水产品的需求.浙江水生生物多样性丰富,但受人为因素的影响,水产种质资源下降趋势未得到根本性好转,面临的形势依然严峻,如何加强水产种质资源保护与合理开发利用是浙江水产种质持续健康发展的关键.本文通过分析浙江水产种质资源现状、保护利用的成效及存在的问题,提出了相关建议,为推动水产种质资源保护与利用提供参考.

The count, location, and size of shrimp larvae are important observations for their intensive breeding, which could evaluate the culture density, growth, and yield. Recent works on the counting of dense aquatic objects in an image are mainly accomplished by the density map regression based on convolutional neural network (CNN). These regression methods only give the estimated density map and the corresponding count, but cannot locate and size the objects accurately. To realize the noninvasive counting, locating, and sizing during aquatic breeding, we propose a novel detection architecture in computer vision for the larvae of Cherax quadricarinatus . In particular, a new shrimp larvae counting network (SLCNet) using the density map regression is designed to output the estimated density map of the shrimp larvae image and predict the corresponding number of the shrimp larvae. The local peak filtering (LPF) is applied to the estimated density map to locate the coordinates of every shrimp larva. We then use the K-nearest neighbor (KNN) and the bounding box search to find the fitting bounding boxes of the shrimp larvae in sparse regions and calculate the body length of the shrimp larvae in the fitting bounding boxes with the aid of the least squares regression method. Compared with typical CNN-based counting models, the mean absolute error and root mean square error of the proposed SLCNet are 4.13 and 5.75, respectively, and the counting accuracy is up to 98.57%. Then, we perform the detection of the location and size of the shrimp larvae using the density map estimated by the SLCNet. The locating and sizing accuracy can reach 90.6% (i.e., F1 value) and 90.28%, respectively. It proves that this detection architecture could be used as technical support for subsequent studies on larva growth and behavior recognition.

为探讨池塘内循环流水养殖(In-pond Raceway Aquaculture,IPRA)太湖鲂鲌幼鱼的合理放养密度,以初始体重为(5.58±0.45)g的太湖鲂鲌幼鱼为研究对象,设置3个放养密度:0.5(SD1)、1.0(SD2)、1.5 kg/m3(SD3),在养殖第90、第120、第150、第180天采样,对其生长性能、血清和肝脏抗氧化酶活力进行分析,实验结束后分析肠道微生物群落组成.生长结果表明:养殖120d,当放养密度超过1.0 kg/m3时,太湖鲂鲌幼鱼的体重和特定生长率(SGR)显著降低(P<0.05),养殖150—180d,体重和SGR随着放养密度的升高显著降低(P<0.05).血清抗氧化酶结果表明:养殖90d,太湖鲂鲌血清抗氧化酶的活力随着放养密度的升高而增加,SD3组显著高于SD1组(P<0.05).养殖150—180d,血清抗氧化酶的活力随着放养密度的升高而降低,养殖180d,SD3组抗氧化酶的活力显著低于SD1组(P<0.05).肝脏抗氧化酶结果表明:养殖150—180d,肝脏中抗氧化酶活力随着放养密度的增加而升高,GSH-Px的活力随着放养密度的增加显著升高(P<0.05).养殖前120d,丙二醛(MDA)的水平随着放养密度的升高有所降低,养殖180d,SD2和SD3组的MDA水平显著高于SD1组(P<0.05).肠道微生物结果表明,在属水平,各密度组肠道微生物群落组成发生明显改变,气单胞菌属(Aeromonas)、假单胞菌属(Pseudomonas)和不动杆菌属(Acinetobacter)等在SD3组的相对丰度显著增加(P<0.05),而Shannon多样性指数显著降低(P<0.05).综上,在试验条件下,当养殖时间小于120d,放养密度小于1.0 kg/m3时,太湖鲂鲌幼鱼的生长和抗氧化能力未受显著影响,建议放养密度小于1.0 kg/m3;当养殖时间为150—180d,放养密度大于0.5 kg/m3时,放养密度对太湖鲂鲌幼鱼的生长产生了抑制,肠道微生物群落组成中条件致病菌显著增加、多样性指数显著降低,建议放养密度小于0.5 kg/m3.

红螯螯虾(Cherax quadricarinatus)又名澳洲淡水龙虾,属于名贵的淡水经济虾类,对环境条件耐受性强,出肉率明显高于其他品种.分别对4种体重规格红螯螯虾肌肉营养组成和表型性状进行系统性分析,采用国标法测定肌肉粗蛋白、粗脂肪及粗灰分含量,采用氨基酸分析仪测定肌肉氨基酸含量及组成,采用气相色谱法测定肌肉脂肪酸组成.结果表明,红螯螯虾全长和体长显著增加(20～80 g组),雌虾全长和体长显著高于雄虾(60～80 g组);头胸甲长和头胸甲宽以80～100g组雄虾最大,在60～80g组中雌虾显著高于雄虾,头胸甲高在规格60g以上不再有显著变化;腹部肌肉重以80～100g组雄虾最大,但与60～80g组雌虾无显著性差异,各组雌虾出肉率显著高于雄虾(P＜0.05).肌肉粗脂肪含量以80～100 g组雄虾最高,40～60 g组雄虾最低(P＜0.05);肌肉灰分含量小规格20～40 g组较高,40～60 g组雌虾最低.红螯螯虾肌肉氨基酸(AA)、总氨基酸(TAA)、必需氨基酸(EAA)和呈味氨基酸(DAA)均随规格变大而逐渐降低;在氨基酸评分(AAS)模式下,各组第一限制性氨基酸为缬氨酸(Val),第二限制性氨基酸为甲硫氨酸+胱氨酸(Met+Cys);在化学评分(CS)模式下,各组第一限制性氨基酸为Met+Cys,第二限制性氨基酸为Val;随红螯螯虾规格逐渐增大,各组必需氨基酸指数(EAAI)呈现先升高后显著降低的趋势(P＜0.05).肌肉多不饱和脂肪酸(PUFA)含量40～60 g组最高(P＜0.05),EPA含量及EPA+DHA含量在20～40 g组最高,DHA含量在60～80 g组雄虾最高(P＜0.05).综上,相同规格下雌虾腹部指标明显优于雄虾,故雌虾有较高的出肉率,而雄虾第二步足长则明显大于雌虾;40～60g组雄虾肌肉EAAI最高,40～60g组肌肉PUFA含量最高,故红螯螯虾在规格40～60g之间肌肉品质最好.

In order to explore practical water-treating biological fillers for largemouth bass（Micropterus salmoides）in recirculating aquaculture system,with square sponge,Mutag Biochip 30 and fluid sphere as biological fillers,largemouth bass with initial body weight of（20. 46±0. 46）g as experimental objects,the biofilm maturing time and microbial community composition were analyzed,and the growth of largemouth bass was evaluated. The results showed that the maturing time of the three biological fillers was 17—21 d under natural conditions. 16S rDNA high-throughput sequencing results showed that the dominant bacteria of biological fillers at the phylum level were the same as those in the corresponding cultured water samples,namely Proteobacteria and Actinobacteriota. At the genus level,the bacterial microbial community composition of biological fillers was different from that of corresponding cultured water samples. Leifsonia and Incerta-sedis were the dominant bacteria in the water samples. Thermomonas was the dominant genus in the square sponge biological filler,while Mutag Biochip 30 and fluid sphere had the same dominant genus as Nitrospira. The results of breeding experiments indicated that after 44days,the final body weight and weight gain rate of largemouth bass in the square sponge group were significantly higher than those in the other experimental groups,the feed conversion ratio was significantly lower than that of Mutag Biochip 30 group,and there was no significant difference in the survival rate among different biological fillers. In conclusion,in the short term,square sponge is a practical biological filler for recirculating aquaculture water treatment.

In order to explore the changes of nutrients in the fertilized eggs of Australian freshwater lobster during development, the fertilized eggs in the egg-nauplius stage, the embryo with eye pigment forming stage, the prepare-hatchling stage and newly hatched shrimp were systematically analyzed in this study. The results showed that, moisture content in fertilized eggs increased significantly with the development of fertilized eggs to newly hatched shrimp, crude protein and lipid content decreased significantly with the development process, the ash content of newly hatched shrimp was the highest; Total amino acids, essential amino acids, and flavoring amino acids content of fertilized eggs decreased significantly with the development process; Based on the nutritional evaluation by amino acids score（AAS） and chemical score（CS）,（Met+Cys） was the first limiting amino acids of fertilized eggs and newly hatched shrimp; EAAI of fertilized eggs and newly hatched shrimp decreased significantly with the development of fertilized eggs to newly hatched shrimp; 10 main fatty acids were detected in fertilized eggs and newly hatched shrimp of Australian freshwater lobster, and the contents of PUFA and DHA in newly hatched shrimp were significantly lower than those in fertilized eggs, but the content of EPA+DHA was significantly higher than that of fertilized eggs. In conclusion, the content of ash and EPA+DHA of newly hatched shrimp were significantly higher than those of fertilized eggs, so the addition of calcium dihydrogen phosphate and EPA+DHA can be appropriately increased in the preparation of open bait for Australian freshwater lobster larvae.

为探讨配合饲料中分别添加蛹肽粉和蝇蛆粉对拟穴青蟹(Scylla paramamosain)幼蟹生长性能、体成分和消化酶活性的影响,在基础饲料中分别添加10％的蛹肽粉和蝇蛆粉,饲喂拟穴青蟹幼蟹45 d.结果表明:蛹肽料组拟穴青蟹幼蟹增重率、特定生长率显著高于基础料组和蝇蛆料组,蛹肽料组拟穴青蟹幼蟹成活率显著高于基础料组;基础料组拟穴青蟹幼蟹水分含量显著低于蛹肽料组和蝇蛆料组,粗蛋白含量则表现出相反的结果,拟穴青蟹幼蟹粗脂肪含量基础料组＞蝇蛆料组＞蛹肽料组,拟穴青蟹幼蟹蛋白酶活性基础料组＜蝇蛆料组＜蛹肽料组,淀粉酶活性表现出与蛋白酶活性相同的结果,脂肪酶活性则为蛹肽料组与蝇蛆料组显著高于基础料组.拟穴青蟹幼蟹饲料中添加蛹肽粉和蝇蛆粉对促进幼蟹生长、提高其免疫力具有切实可行性.

To solve the problems involved in the mass artificial incubation of redclaw crayfish eggs, we developed a recirculating mechanical pulling device to explore the technology of artificial incubation, including the egg stages, egg densities, attachments and incubator sizes. The eggs were separated and sterilized with 3000 ppm formaldehyde, and the water temperature was 28-29 degrees C. The results were obtained: (1) the hatching rates or survival rates of the groups with 7 pairs of appendages and well-formed eye pigments were significantly higher than those of the egg-nauplius group; (2) the hatching rates of eggs incubated at densities of 300 eggs/incubator box were significantly higher than those of eggs incubated at 700 eggs/incubator box. The survival rates of eggs incubated at densities of 300 or 500 eggs/incubator box were significantly higher than those for eggs incubated at 700 eggs/incubator box; (3) the survival rates of the group whose incubator received a sponge attachment were significantly higher than those of the group without a sponge attachment; (4) the survival rates of the group with 2.5- or 3-cm width of the upper end of boxes were significantly higher than those of the group with 4 cm; and (5) the eggs with 7 pairs of appendages or well-formed eye pigments were selected, with a density of 300-500 eggs/incubator box, and the box was 2.5-cm wide at the upper end. After hatching, sponge attachments were inserted. The hatching rate and survival rate were 85.34% and 61.31%, and a total of 240,031 specific pathogen-free seedlings were cultivated.

红螯螯虾人工繁育中需要对离体虾卵进行准确计数.由于虾卵个体小、密度大、人工计数效率低且可能损伤虾卵,提出了一种基于残差模块的计算机视觉虾卵计数模型.该计数网络模型在前端编码器网络中集成残差模块,对虾卵位置信息进行特征提取和下采样,在后端解码器网络中使用转置卷积,使模型可以自动学习上采样参数.与VGG-16、CSRNet等模型相比,基于残差模块的虾卵计数模型精度达98.88％,具有最低的平均绝对误差、均方误差以及最好的预测密度图质量,可有效解决密集虾卵计数的困难,为红螯螯虾虾卵计数提供了新方法.利用该模型的计算机视觉虾卵自动计数装置,结构简单、计数精准,可以应用于真实场景.

[目的]通过研究水温、流量、受精卵发育时期和孵化密度等因子的变化对澳洲淡水龙虾受精卵离体孵化率影响,以确定澳洲淡水龙虾受精卵离体孵化最适条件因子.[方法]分别设计5个水温梯度、3个流量、3个发育时期及3个孵化密度进行澳洲淡水龙虾受精卵离体孵化试验.[结果]随着水温升高,受精卵孵化时间呈下降趋势;受精卵离体孵化率随着水温的上升呈先上升后下降的趋势,在水温28℃,澳洲淡水龙虾受精卵离体孵化率达最高,显著高于其他试验组(P<0.05),复眼色素形成初期受精卵发育至初孵仔虾的平均有效积温为9375℃·h.不同流量下澳洲淡水龙虾受精卵离体孵化率依次为5 L/min>2 L/min>8 L/min(P<0.05).澳洲淡水龙虾受精卵发育至复眼色素形成初期和孵化准备期的孵化率显著高于前无节幼体期(P<0.05).受精卵孵化密度为500粒/L和1000粒/L时,离体孵化率显著高于1500粒/L(P<0.05),但500粒/L和1000粒/L时离体孵化率差异不显著(P>0.05).[结论]澳洲淡水龙虾受精卵离体孵化的适宜条件为:水温28℃,流量5 L/min,受精卵发育期为复眼色素形成初期,孵化密度为1000粒/L(每个槽的尺寸为长×宽×高为15 cm×9.7 cm×12 cm,水深3 cm±0.5 cm,体积约0.4 L).

传统的虾蟹混养模式一般为中华绒螯蟹套养两茬青虾,但套养的第二茬青虾产量较为不稳定.为探讨效益更好的生态型虾蟹混养模式,笔者开展了中华绒螯蟹—青虾—罗氏沼虾混养试验,在套养青虾起捕后,放养不同密度的罗氏沼虾并进行养殖对比,在8kg/亩密度达到了较好的养殖效果,供大家参考借鉴.

近年来,我国池塘内循环水养鱼模式悄然兴起.这种模式是在池塘内按水面的一定比例建造养鱼跑道(长110米、宽5米),跑道前段通过气提推水装置形成循环流水;跑道末端设置吸污装置可吸出部分粪便,并进行后续处理;池塘的多数面积用于生态养水.因这种养殖方式生产的商品鱼生长在流水的环境中,被认为有较好的体形和营养品质(邓进力,2019).因此,池塘内循环养殖的商品鱼也被称为"跑道鱼"或"跑步鱼".

在当前的淡水石斑鱼人工养殖中,流水养殖模式仍为主流,但随着环保和土地资源管控愈发严格以及养殖病害的逐年增多,淡水石斑鱼养殖业迫切需要转变现有养殖模式和调整养殖结构.工厂化循环水养殖是一种集工程化、设施化、集约化、智能化于一体的新型养殖模式,具有节水、节地、环保、高效和产品质量可控等优点.为优化淡水石斑鱼工厂化循环水苗种培育技术,笔者于2020年在工厂化循环水养殖系统中开展了淡水石斑鱼大规格苗种培育试验,取得了初步成功,现将试验过程和技术要点总结如下,供淡水石斑鱼养殖者参考.