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1.
Solutions of chitosan (2%, w/v), garlic essential oil (5%, v/v), and their combination (2%, w/v chitosan +5%, v/v garlic essential oil) were applied to the surface of grass carp fillets. Subsequently, sensory, microbiological analyses (total viable count (TVC), Pseudomonas spp., Aeromonas spp., and H2S-producing bacteria), and physicochemical changes (total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and centrifugation loss) of grass carp fillets were evaluated over a 16-day storage at 4 ± 1°C. The treated samples resulted in significantly (p < 0.05) higher overall acceptance scores than the control from day 8. The TVC of grass carp fillets was reduced from the initial level (4.0 log CFU/g) to 2–3 log CFU/g when the fillets were treated with either garlic essential oil or chitosan solution. After 4 days of storage, the Pseudomonas spp. counts in the chitosan-treated samples were significantly lower (p < 0.05) than the counts in control and samples treated with garlic essential oil. A lag phase of 6 days for the counts of H2S-producing bacteria of fish fillets that were treated with chitosan or the combination solution was observed. The combination of chitosan with garlic essential oil did not show synergistic effects, although it displayed a higher degree of antimicrobial efficacy with respect to the spoiled bacteria. However, the combination of chitosan with garlic essential oil was the most effective at inhibiting the formation of TVB-N. Samples that were treated with garlic essential oil displayed the highest TBARS levels on days 4 and 6 (p < 0.05).  相似文献   

2.
To investigate the effects of chitosan composite coatings for maintaining the quality of grass carp portions, indictors of microbiology (total bacteria count, TBC), chemistry (pH; total volatile basic nitrogen, TVB-N; 2-thiobarbituric acid, TBA; K-value), and sensory characteristics were analyzed periodically. The results showed that chitosan (1.5%, w/v) + acetic acid (1.0%, v/v) + tea polyphenol (TP, 0.5%, w/v) coating significantly (p ≤ 0.05) reduced growth of microorganisms as reflected in TBC, lipid oxidation as displayed in TBA, chemical spoilage as reflected in pH, TVB-N, K-value, and sensory characteristic scores compared to the control samples. The effect of chitosan (1.5%, w/v) + acetic acid (1.0%, v/v) + vitamin C (VC, 0.5%, w/v) coating was better than chitosan (1.5%, w/v) + acetic acid (1.0%, v/v) coating. Chitosan together with acetic acid and TP can be used as a type of preservative coating for grass carp portions under chilled storage.  相似文献   

3.
Farmed grass carp (Ctenopharyngodon idella) at commercial size were transported to a natural lake for long‐term depuration while being food deprived. The effect of depuration time on the quality of fish fillets was investigated based on proximate compositions, textural parameters and flavour characteristics. The results showed that protein and lipids, but not carbohydrates, were the major source of energy for grass carp during depuration and starvation. Textural parameters that included hardness, springiness, gumminess and cohesiveness increased significantly after depuration, as well as water‐holding capacity of fish muscle. Taste and odour characteristics of grass carp muscle were obviously changed by depuration based on tests by an electronic tongue and nose. Off‐flavour volatile compounds, such as nonanal and hexanal, were reduced after depuration. In conclusion, the quality of grass carp fillets was improved effectively by long‐term depuration and food deprivation. More than 20 days of depuration was appropriate for the enhancement of grass carp quality before marketing.  相似文献   

4.
ABSTRACT

In order to evaluate the effect of chilled (T1), frozen (T2), and freeze-chilled (T3) treatment on the flavor of grass carp fillets and soups, adenosine triphosphate (ATP)-related compounds, umami-taste amino acids (UTAA), thiobarbituric acid (TBA), peroxide value (PV), and soup sensory score were analyzed. Results showed that the sum of ATP, ADP, and AMP contents in T2 fillets were significantly higher (p < 0.05) than others, but the sum of hypoxanthine riboside (HxR) and hypoxanthine (Hx) contents for T2 fillets and soups were significantly lower (p < 0.05) than others during storage. The T3 fillets and soups had lower inosine 5-monophosphate (IMP) contents than T1 after Day 2, but higher UTAA contents than T1 during storage. The T3 fillets had the highest TBA and PV values among the three groups during storage. According to the total aerobic counts, K value, and sensory score, all the fillets and soups kept good quality during storage. Therefore, freeze-chilled treatment not only can extend fish shelf life but also retain excellent fish flavor.  相似文献   

5.
陈红  杨方  夏文水 《水产学报》2021,45(7):1121-1131
现有淡水鱼片评价方法存在评价体系单一、不稳定的问题,为提供一种冷藏草鱼片新鲜度分级方法,实验以生鲜鱼片的色泽、气味、组织形态、肌肉弹性和熟鱼片的气味、滋味、汤汁形态各细分感官描述为指标,依据主成分分析(PCA)和系统聚类分析(HCA)划分鲜度区间;将K值等理化指标和肌间线蛋白、肌钙蛋白T等生化指标与细分感官描述指标比较;最后依据感官、理化、生化指标的PCA和HCA结果,评价以上冷藏草鱼片新鲜度。结果显示,根据感官描述分析PCA和HCA,冷藏草鱼片可分为3个鲜度等级:0～1 d (一级鲜度),2～7 d (二级鲜度),8～10 d (三级鲜度)。一级鲜度终点肌间线蛋白和肌钙蛋白T相对灰度值下降至95.68%和96.75%;二级鲜度终点肌间线蛋白和肌钙蛋白T分别下降至56.4%和69.6%;三级鲜度终点肌间线蛋白和肌钙蛋白T相对灰度值分别下降至56.36%和52.85%。研究表明,HCA鲜度划分区间与细分感官描述分析鲜度划分区间一致,细分感官描述分析可较全面反映冷藏草鱼新鲜度变化情况;肌钙蛋白T与细分感官描述变化规律一致,可以根据其变化判定冷藏草鱼片的新鲜度。本研究依据细分感官评价指标划分了鲜度区间并评价了该方法;在此基础上,研究了肌间线蛋白和肌钙蛋白T变化规律与感官评价HCA的关系,得出肌钙蛋白T反映冷藏草鱼片鲜度效果好,为后续根据新鲜度指示蛋白的变化规律开发鱼肉新鲜度检测试纸奠定基础。  相似文献   

6.
The effect of Ultraviolet radiation type C (UV-C) radiation (0.100 ± 0.010 J/cm2) on shelf life of Arapaima gigas fillets stored at 4 ± 1°C for 18 days was investigated. The samples were analyzed for total aerobic mesophilic bacteria (TAMB) counts; total aerobic psychrotrophic bacteria (TAPB) counts; Enterobacteriaceae; purge loss; pH; lipid oxidation; total volatile bases (TVB-N); ammonia; biogenic amines (BAs); and L*, a*, and b* values. UV-C radiation increased (P < 0.05) the generation time of all bacterial groups evaluated, increasing the shelf life by 2 days. UV-C-treated fillets showed lower (P < 0.05) L* values, purge loss, pH, TVB-N, ammonia, and BAs levels than their control counterparts throughout the storage period. Moreover, UV-C treatment did not result (P > 0.05) in detrimental effects on lipid oxidation or a* and b* values. UV-C at 0.100 J/cm2 demonstrated a good potential for use in A. gigas fillets and, therefore, it could be applied at industrial scale.  相似文献   

7.
ABSTRACT

This study assessed effects of high pressure processing on physicochemical quality and endogenous enzyme activities of grass carp fillets stored at 4 ºC for 21-day storage. Fresh fillets were vacuum-packed and subjected to high pressure processing (0.1, 200, 300, 400, 500, and 600 MPa at room temperature for 15 min). Results showed that high pressure processing significantly delayed microbial growth, and reduced total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) levels of grass carp fillets, especially for the 600 MPa group. On the 21st day, the corresponding increases of 6%, 35%, 45%, 43%, and 53% in hardness were observed for 200 MPa, 300 MPa, 400 MPa, 500 MPa, and 600 MPa samples compared with control samples, respectively. In addition, enzyme activities in different groups decreased during storage. Among them, calpain, and myofibril-bound serine proteinases (MBSP) activities were immediately reduced after high pressure treatments, while the activities of collagenase, cathepsin B, and cathepsin D were significantly (P < 0.05) inhibited when the pressure exceeded 400 MPa. However, the pressure treatments activated cathepsin L initially, and then the activity gradually decreased in treated samples. Generally, high pressure processing reduced activities of most of the endogenous enzymes and improved the quality and extended the shelf life by at least 4 ~ 6 days of refrigerated grass carp fillets.  相似文献   

8.
The biogenic amine contents in fillets of three freshwater fish of kutum (Rutilus frisii), common carp (Cyprinus carpio), and Caspian salmon (Salmon caspius) were monitored during storage at 4°C for 20 days. The amounts of biogenic amines were determined at regular intervals using high performance liquid chromatography after derivatization with benzoyl chloride. Significant differences in the levels of selected biogenic amines among the fish samples were found (p < 0.05) during storage times. While the amount of putrescine, cadaverine, histamine, and tyramine in the fish fillets increased during the storage time, the changes in spermine and spermidine contents of the fish species were minor and both showed low and inverse correlations with storage time. For each of the three fish species, the sensory acceptability limit was found to be 4–8 days. The quality and biogenic amine indices of fish samples showed high correlation with storage time (r > 0.9). The principal component analysis of the results indicated that the formation of biogenic amines displays a certain behavioral pattern in all fish samples.  相似文献   

9.
草鱼、银鲫和青鱼捕捞后的应激反应   总被引：2，自引：0，他引：2  
姜丹莉  林雅云  吴玉波  王岩 《水产学报》2016,40(9):1479-1485
分别评价了捕捞对草食性(草鱼)、杂食性(银鲫)和肉食性(青鱼)鲤科鱼类血液指标(血浆史质醇、葡萄糖和乳酸浓度)、肝糖原含量和两种肝脏糖酵解酶(己糖激酶和丙酮酸激酶)活性的影响。结果显示:草鱼、银鲫和青鱼捕捞后血浆史质醇、葡萄糖和乳酸浓度均显著升高;草鱼和青鱼捕捞后2 h时肝糖原含量呈下降趋势,但银鲫捕捞前、后肝糖原含量未出现显著变化;捕捞前、后青鱼血糖浓度显著高于草鱼和银鲫。银鲫肝糖原含量显著高于草鱼和青鱼,其捕捞后血浆葡萄糖和乳酸浓度增加幅度较小,这意味着捕捞后银鲫应激反应强度相对较低。草鱼和银鲫捕捞后肝脏己糖激酶和丙酮酸激酶活性未发生显著变化,青鱼捕捞后2 h己糖激酶活性显著下降,这意味着捕捞应激后血糖升高未导致草鱼、银鲫和青鱼的肝脏糖酵解酶活性增强。  相似文献   

10.
The effect of chitosan coating enriched with 6-gingerol on the quality and shelf life of red drum fillets during refrigerated storage was investigated in this study. Samples were applied with chitosan coating (CH), 6-gingerol (GI), and chitosan coating with 6-gingerol (CH+GI) before storing at 4°C for 20 days. The data in this study showed that treatment with CH+GI could significantly decrease pH value, K-value, thiobarbituric acid value, and total volatile basic nitrogen in red drum fillets during refrigerated storage. The counts of microorganisms, such as Enterobacteriaceae, psychrotrophic, mesophilic bacteria, and lactic acid bacteria, were also significantly lower in the CH+GI group compared with those in the CH and GI groups. Moreover, the combination of chitosan coating and 6-gingerol was more effective in relieving the deterioration of tissue texture and sensory characteristics in the red drum fillets. In addition, the results suggested that chitosan coating and 6-gingerol had a synergistic effect on the quality improvement of red drum fillets. This work demonstrates that chitosan coating enriched with 6-gingerol may be a promising natural preservative for red drum during refrigerated storage.  相似文献   

11.
A new strain of Paenibacillus polymyxa S3 with antagonistic effects on 11 major fish pathogens (especially Aeromonas hydrophila), but had no toxicity to grass carp, was screened from the sediment of fishponds. In vivo colonization studies showed that strain S3 could be colonized and distributed in the gill and abdomen of the grass carp. Bioassay results showed that the weight growth rate of grass carp in the strain S3 oral group (16.01%) and strain S3 immersion group (16.44%) was significantly higher than those of the control group (8.61%). At the same time, the activities of ACP, AKP, CAT and GSH-Px in the serum of grass carp in oral and immersion groups were significantly higher than those of the control group. In addition, the treatment with strain S3 could significantly upregulate the expression of the antioxidant-related genes and immune-related genes Keap1, Nrf2, C3, LZM, IgM, TLR-4 and MyD-88 in grass carp tissues. The challenge test showed that strain S3 treatment significantly increased the survival rate of grass carp infected with Aeromonas hydrophila. Whole genome sequencing analysis showed that strain S3 had 16 active metabolite gene clusters, indicating that it had abundant gene resources, which provided important support for its development for fish microecological preparations. In summary, a new strain of Paenibacillus polymyxa S3 with antibacterial activity against a variety of fish pathogens was screened in this study and its probiotic function was evaluated, proving its potential value in fisheries.  相似文献   

12.
Microbiological quality, sensory attributes and consumer preferences of common carp (Cyprinus carpio L.) fillets descaled by four different methods under two storage conditions (air packed and vacuum packaged) and refrigerated storage conditions were studied. Farmed common carps (scaly and mirror), of marketable size (2.2 kg, 3 years old), were randomly divided into four experimental groups (n = 10), and filleted and fillets were processed by four descaling methods: without skin, without scales, undercut scales and mirror carp (without any other treatment). Microbiological analyses were determined by total viable counts (TVCs) in logarithm of colony-forming units per gram (log CFU/g), and sensory quality of fillets was classified by odour, flavour, after taste and consistency on storage days 0, 3, 6 and 9. Vacuum packaging conditions affected the growth of microbiota and extended the shelf life of fillets in all experimental groups. Microbial communities grew to between 3.19–3.90, 4.03–6.00 and 6.35–8.28 log CFU/g after 3, 6 and 9 days of storage, respectively, and fillets without skin showed the lowest TVC among all analysed groups throughout storage. Also sensory analyses showed that consistency and odour of carp fillets were influenced by packaging conditions as well as descaling methods. The survey on consumer preferences of carp found out that 58.9 % of customers preferred scaly carp with undercut scales and processed to fillets instead of mirror carp. The results of present study show that different types of descaling methods combined with air/vacuum packaging can significantly prolong the shelf life of carp fillets.  相似文献   

13.
ABSTRACT

The objective of the current study was to determine the effects of chitosan (CH) coatings containing Mentha spicata essential oil (MSO; 0.2 and 0.4%) and zinc oxide nanoparticle (ZnO; 0.2 and 0.4%) on chemical (total volatile basic nitrogen (TVB-N), 2-thiobarbituric acid reactive substances (TBARS) and peroxide value (PV)), microbial (total viable count, psychrotrophic count, Pseudomonas spp., and Enterobacteriaceae) and sensory (odor, color, and overall acceptability) properties of raw rainbow trout fillets during 14 days of refrigerated storage. Final microbial population of CH + MSO 0.4% + ZnO 0.4% and CH + MSO 0.4% + ZnO 0.2% retarded approximately 3–5 log CFU/g as compared to control groups (P < 0.05). At the end of storage time in control samples, TVB-N, TBARS, and PV reached 49.3 mg N/100 g, 3.31 mg malonaldehyde/kg, and 2.04 meq peroxide/kg lipid, while the values for the treated samples with MSO (0.2 and 0.4%) in combination with ZnO (0.2 and 0.4%) remained lower than 25 mg N/100 g, 2 mg malonaldehyde/kg, and 1.1 meq peroxide/kg lipid, respectively. The results indicate a potential use of CH coating containing MSO and ZnO as an effective type of antimicrobial packaging to maintain quality of rainbow trout fillets.  相似文献   

14.
为研究草鱼MSTN-1基因多态性及与早期生长性状和肌肉成分的相关性,本研究扩增出全长为3824 bp的草鱼MSTN-1基因,用长江选育草鱼群体对MSTN-1基因多态性进行筛选和验证。结果共发现3个多态性位点(Locus 1:C1799T,野生型EE/突变型EF;Locus2:C1842T,野生型HH/突变型HI;Locus 3:TGAAGCGCTGGTTCT/2585-,野生型BB/缺失型BD)。利用一般线性模型分析3个位点及其组合型(剔除个体数少于3的组合)与生长性状和肌肉成分的相关性,发现2个位点对幼鱼生长性状表型差异有显著影响,但3个位点对肌肉成分差异均无显著影响。多重比较发现,单倍型HI突变组的体长和体质量显著高于HH野生组,BD突变组的体长和体质量显著性低于BB野生组;多倍型中存在HI突变组合的体长、体质量均显著高于其他组,存在BD突变的组合在体长性状方面显著低于其他组。表明草鱼MSTN-1基因3个SNPs中,HI突变是对草鱼生长性状的有利突变,BD突变是不利突变,而EF突变无显著影响,可将MSTN-1基因作为分子标记辅助草鱼选育的候选基因。  相似文献   

15.
草鱼体组成的数学描述   总被引：1，自引：1，他引：0  
陈拥军  邹滔  林仕梅  罗莉  李云 《水产学报》2016,40(4):566-576
为了对草鱼体组成进行定量描述,本研究从中外文数据库收集并采纳了51个草鱼营养生理相关研究的数据,数据点约3700个,草鱼体质量为1.52~694.80 g。通过数据整理、相关性分析和线性回归分析,结果显示,草鱼蛋白质含量和内脏重(y,g)与体质量(x,g)间的线性关系分别为y=0.1604x–0.3645,R2=0.994;y=0.1059x–0.3097,R2=0.9875。随着草鱼体质量增加,草鱼脂肪和灰分含量(尤其是脂肪含量)受饲料组成的影响逐渐增加。草鱼全鱼每沉积1 g蛋白质伴随着4.57 g水分保留,而每沉积1 g脂肪会导致水分含量减少0.95 g。草鱼肝脏每沉积1 g脂肪会导致其水分含量减少0.66 g,说明草鱼不同组织沉积脂肪导致的水分损失率不尽相同。本研究亦表明,肠系膜是草鱼脂肪沉积的重要部位,肠系膜、肝脏和肌肉脂肪的积累是全鱼脂肪含量上升的重要原因,全鱼脂肪累积伴随着内脏重的增加。本研究的执行有利于定量描述草鱼体组成规律,为草鱼的生产和销售提供指导作用。  相似文献   

16.
利用筛选的13对草鱼多态性微卫星标记,开展了2011至2015年长江中游草鱼亲本增殖放流对野生群体遗传多样性的影响评估。通过对各位点的遗传多样性分析,13个微卫星位点的多态信息含量为0.8622(0.657~0.950),基因多样度为0.8555(0.675~0.936)。15个群体的有效等位基因数为7.4503~10.1536,等位基因丰度为11.483~15.204,说明15个草鱼群体的遗传多样性水平总体较高。遗传分化指数分析表明,群体间不存在显著遗传分化(FST5%)。通过贝叶斯聚类分析和主成分分析可将草鱼群体分为4个组群,根据分组结果以及来源划分分别对草鱼群体进行AMOVA分析,发现遗传变异大部分来自于群体内个体间,组间及组内群体间的分化水平较低(FCT5%,FSC5%),与FST分析结果一致。研究表明,当前草鱼亲本增殖放流模式对野生群体遗传结构影响不明显。  相似文献   

17.
A 60‐day trial was conducted in a recirculation system to determine the responses of herbivorous grass carp (Ctenopharyngodon idellus) (0.43 g), omnivorous gibel carp (Carassius auratus gibelio CAS III) (0.46 g) and carnivorous black carp (Mylopharyngodon piceus) (0.46 g) when fed with fishmeal (FM)‐ or soybean meal (SBM)‐based diets. Two isonitrogenous (380 g kg?1 DM), isolipid (80 g kg?1 DM), isocaloric (17.75 kJ g?1) diets were formulated using FM and SBM as main protein sources. The results showed that weight gain (WG), feed efficiency (FE) and protein retention efficiency (PRE) in FM group were significantly higher than those in SBM group. Grass carp showed better utilization on SBM than other two species and presented higher WG, FE and PRE. When fed with SBM diet, intestinal chymotrypsin (CHY), lipase and trypsin (TRY) activities of gibel carp and black carp decreased while higher α‐amylase (α‐AMY) activity of grass carp increased. An enteritis‐like effect was observed in black carp and grass carp fed SBM diet. Intestine bacteria mainly belonged to Firmicutes in gibel carp and Proteobacteria in black carp. The dominant genera identified in three species were Cellulomonas, belonging to Actinobacteria. In conclusion, SBM decreased the growth of three carps. Grass carp was more adapted to plant protein.  相似文献   

18.
Two, 8‐week feeding trials were conducted to compare protein‐sparing capability of dietary lipid in herbivorous grass carp (Ctenopharyngodon idella) and omnivorous tilapia (Oreochomis niloticus × O. aureus). Utilizing a 2 × 3 factorial design, experimental diets containing two levels of crude protein (380 and 250 g kg−1) and three levels of lipid (0, 40 and 100 g kg−1) were formulated for use in both feeding trials. Growth performances showed better response of both fish fed 380 g kg−1 protein diet than those fed 250 g kg−1 protein diet. Despite the dietary protein level, weight gain (WG), specific growth ratio (SGR), feed conversion ratio (FCR) and protein efficiency ratio were much higher (P < 0.05) for grass carp fed 40 g kg−1 lipid diet than those fed 100 g kg−1 lipid diet; however, there were no significant differences in tilapia fed the two diets. The feed intake of grass carp fed lipid‐free diet was the lowest, but it tended to decrease with increase in dietary lipids in tilapia. Lipid retention (LR) was negatively correlated with dietary lipid concentration of both fish. Viscerosomatic index (VSI), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF) and whole‐body and liver lipid content positively correlated with dietary lipid concentration of both fish. Plasma parameters and liver enzymes activities were also positively correlated with dietary lipid concentration of both fish. Liver lipid contents were higher and enzymes activities were lower in grass carp when compared with tilapia. These data suggested that there was no evidence of a protein‐sparing effect of dietary lipids in grass carp. Tilapia has relatively higher capacity to endure high dietary lipid level compared to grass carp.  相似文献   

19.
To investigate the effects of supplemental nutrient additives in broad bean-based diets on growth, flesh quality, and collagen gene expression of grass carp, five diets were prepared, including complete formula diet (control), soaked broad bean (SBB), and three broad bean-based diets containing 80% broad bean without (BBD1) or with the supplementation of methionine (BBD2), and methionine+vitamins+minerals (BBD3), and were fed to grass carp (171.9 ± 1.1 g), Ctenopharyngodon idellus, for 84 days. The results showed that broad bean-based diets significantly increased weight gain (WG) and reduced the feed conversion ratio (FCR) of grass carp when compared to the SBB (p < .05). The BBD3 group reached levels similar to the WG and FCR of the control group (p > .05). Grass carp fed the BBD3 diet had lower steaming loss of flesh, higher muscle fiber density, and higher collagen content in muscle and skin than the control (p < .05). The relative expressions of COL1A1 and COL1A2 mRNA in muscle and skin were significantly higher in the BBD3 and SBB groups than in other groups (p < .05). In conclusion, the combination of methionine, vitamins, and minerals in broad bean-based diets promoted the growth of “crisped” grass carp and improved flesh quality and collagen gene expression when compared to the control formula diet.  相似文献   

20.
The aims of this experiment were (1) toquantify the ability of grass carp to processduckweed and (2) to assess indirect changes inwater chemistry and phytoplankton community,caused by grass carp feeding. Yearling grass carp sized 126 ± 7.7 mm (TL) and19.6 g in weight were kept in 9 laminate tanksof 1 m3 for 14 days. Two stockingdensities (2 and 6 fish per m3) anda control without fish were used. Standard growthrate (SGR) of grass carp fed exclusively onduckweed was 0.70% body weight (BW) d–1and food conversion ratio (FCR) reached 2.0(average water temperature =21.1 ± 3.8 °C). Daily food intakewas 0.2 g of duckweed dry weight (DW), i.e.,1% of average BW of grass carp. SGR ofduckweed growing in 20 × 20 cm floatingenclosures, differed significantly[F(6,2) = 417.9; p = 0.002] between the twostocking densities of grass carp and thecontrol tanks (without fish). Mean SGR ofduckweed was 0.02 g g–1 day–1 and thehighest SGR was recorded in the control tanks.Both decrease in NH4-N and increase inNO2-N concentrations differedsignificantly between the treatments[F(2,2) = 45.3; p = 0.02 and F(2,2) = 19.2; p = 0.04 respectively]. Changes in other nitrogenand phosphorus components (NO3-N, TN, TPand PO4-P) caused by stocking of grasscarp were not significant. Biomass ofphytoplankton, dominated by filamentous algaeand blue-greens, increased proportionately tostocking density of grass carp. Althoughduckweed has a large potential for nutrientremoval, the most common pathway for thenutrients released through grass carp grazingif duckweed cover is loose is theirincorporation into phytoplankton biomass.  相似文献   

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