Microbial levan in the diet of Labeo rohita Hamilton juveniles: effect on non-specific immunity and histopathological changes after challenge with Aeromonas hydrophila

A 60-day feeding trial was conducted to study the immuno-protective effect of microbial levan on Labeo rohita juveniles challenged with Aeromonas hydrophila. Six purified diets were prepared with different levels of microbial levan: control (no levan), T1 (Basal + 0.25%), T2 (Basal + 0.50%), T3 (Basal + 0.75%), T4 (Basal + 1%) and T5 (Basal + 1.25%), fed to six groups of fish in triplicate. Among the treatment groups the haemoglobin content and total leucocyte count were increased with a dietary supplementation of levan at 1% or more. An increasing trend for total erythrocyte count was observed with increasing level of dietary levan. Lower levan-supplemented groups showed a higher albumin/globulin ratio. As the levan supplementation was increased, there was a gradual increase in serum lysozyme activity and respiratory burst activity [nitroblue tetrazolium (NBT) assay] reduction values. The highest lysozyme activity and NBT were observed in the T5 group although this was similar to the T4 group ( P  > 0.05). No significant histo-architectural changes were associated with dietary levan levels. After challenge with A. hydrophila , moderately degenerated hepatocytes, oedema and leucocytic infiltration in parenchymatous tissues, and extensive haemorrhage and haemosiderosis in the kidney were observed in the control group. However, the T5 group supplemented with 1.25% levan showed infiltrating leucocytes in the liver while the kidney showed only moderate degeneration of renal tubules. The relative survival per cent of juveniles after challenge with A. hydrophila was the highest in the T5 group followed by T4. This suggests that microbial levan at 1.25% can be used as dietary immunostimulant for L. rohita juveniles.     

The impact of Aeromonas salmonicida infection on behaviour and physiology of Atlantic salmon (Salmo salar L.)

This study examined the effect of Aeromonas salmonicida infection on the swimming behaviour and physiology of Atlantic salmon (Salmo salar L.). Fish were injected in the dorsal muscle with either 100 μL bacterium solution (3.05 × 10⁷CFU mL^?1) Aeromonas salmonicida, or 100 μL 0.9% NaCl (as control group). Compared with the control group, the pathogen injected group significantly impaired the critical swimming speed (U_crit) and exhausting time (P < 0.05), which were reduced by 37% and 39% at severe time (day 6, when most of the fish challenged by Aeromonas salmonicida died) respectively. Furthermore, the blood parameters related to their swimming behaviour were also influenced significantly by pathogen injection (P < 0.05). The results showed that the high density lipoprotein (HDL), haemoglobin and total protein decreased by about 63%, 49% and 74% at the end, respectively, while lactate increased by about 29% on day 6. The results suggested that the swimming performance of Atlantic salmon might be a useful indicator of disease, and it was feasible to warn the outbreaks of acute disease by fish behaviour.     

多种接种途径对翘嘴鳜细菌性烂鳃和败血症的免疫预防效果

多种接种途径对翘嘴鳜细菌性烂鳃和败血症的免疫预防效果陈昌福，周文豪（华中农业大学水产学院，武汉４３００７０）陈昌福等（１９９５）先后用从患细菌性烂鳃病的翘嘴鳜（ＳｉｎｉｐｅｒｃａｃｈｕａｔｓｉＢ．）上分离的柱状嗜纤维菌（Ｃｙｔｏｐｈａｇａｃｏｌｕｍｎ...     

Plasma ladderlectin concentration following sterile inflammation and Aeromonas salmonicida subsp. salmonicida infection

Plasma samples obtained from rainbow trout either experimentally infected with Aeromonas salmonicida or injected with either A. salmonicida lipopolysaccharide (LPS) or a commercial A. salmonicida vaccine (Lipogen) were analysed by enzyme immunoassay to evaluate changes in rainbow trout ladderlectin (RTLL) concentrations during the acute phase response (APR). Plasma RTLL concentrations in fish injected with A. salmonicida LPS, vaccine or live A. salmonicida varied over a 10 day period, but did not significantly increase. In contrast, fish experimentally infected with A. salmonicida exhibited a modest, but statistically significant ( P  <   0.05), decrease in RTLL concentration. These studies demonstrate that RTLL is not detectably induced during the trout APR to sterile inflammation or A. salmonicida infection, but plasma concentration of this protein may be reduced during bacterial infection.     

Physiological responses and HSP70 mRNA expression in GIFT tilapia juveniles,Oreochromis niloticus under short‐term crowding

Physiological responses and HSP70 mRNA expression to short‐term crowding were tested in juveniles genetically improved farmed tilapia (Oreochromis niloticus) (70.43 ± 4.43 g). Fish were kept at control group (5 g L^?1) and stress groups (low density 10 g L^?1, medium density 40 g L^?1 and high density 70 and 100 g L^?1) for 48 h. Each density was tested in triplicates. The effects of a short‐term exposure on the physiological responses of fish were determined before stress (0 h) and at 6, 12, 24 or 48 h post‐crowding. There was a significant increase in serum cortisol, total protein, lysozyme and aspartate aminotransferase (AST) activities in all stressed groups at 24 h post‐crowding (P < 0.05). Serum glucose and alanine aminotransferase (ALT) of 100 g L^?1 stressed group were lower than that of the control after 48 h of crowding stress (P < 0.05). The levels of serum triglyceride and cholesterol in crowding stress with high density were significantly decreased compared with the control group at 48 h. The mRNA expression data showed that hepatic HSP70 mRNA levels were markedly elevated at all stressed groups. HSP70 mRNA levels of 70 and 100 g L^?1 stressed groups decreased at 48 h compared with the 24 h post‐crowding. The protective ability of HSP70 was limited.     

Effect of Manganese and Iron on Growth and Feeding of Juvenile Giant River Prawn, Macrobrachium rosenbergii (De-Man)

Abstract.— The effect of either manganese or iron on survival, growth, and feeding of giant river prawn, Macrobrachium rosenbergii (De-Man), juveniles was studied in two separate experiments. Survival rates of M. rosenbergii juveniles (4.58 ± 0.48 g) following 60-d exposure to 0.01 (control), 0.3, 0.6, and 1.2 mg/L of total manganese (Mn) were 100, 93.3 ± 3.4, 83.3 ± 4.3, and 83.3 ± 4.3%, respectively, while the same were 100, 83.3 ± 3.6, 73.3 ± 3.3, and 63.3 ± 4.7%, respectively, at the total iron levels of 0.02 (control), 0.32, 0.65, and 1.2 mg/L. Average daily growth of the prawn was significantly ( P  < 0.05) lower at 0.3 mg/L and higher levels of total manganese compared to control (0.01 mg/L). Average growth of the prawn exposed to 0.65 and 1.2 mg/L total iron was significantly lower ( P  < 0.05) than in control (0.02 mg/L iron) and 0.32 mg/L treatments after 60 d of exposure. Feed utilization was significantly ( P  < 0.05) reduced in M. rosenbergii juveniles exposed to 0.3 mg/L and higher levels of manganese. Feed utilization was significantly ( P  < 0.05) reduced in the prawns at all the iron treatments compared to control (0.02 mg/L iron). The accumulation of Fe and Mn was minimum in the muscle and maximum in the hepatopancreas of the prawns.     

Control of Aeromonas hydrophila Infection in Spotted Snakehead, Channa punctatus, by Solanum nigrum L., a Medicinal Plant

The present study describes the potential of black nightshade, Solanum nigrum , to control Aeromonas hydrophila infection in spotted snakehead, Channa punctatus . Similar sizes of Ch.   punctatus were grouped into three categories as follows: control (injected with sterilized water), Ae.   hydrophila infected   +   untreated, and Ae.   hydrophila infected   +   treated with S.   nigrum leaf extract. Hematological parameters (white blood cell [WBC], red blood cell [RBC], hemoglobin [Hb], and packed cell volume [PCV]) were analyzed in these fishes once every 5   d from Days 5 to 30 postexposure. Preliminary antibacterial assay reported that leaf extracted with ethyl acetate had the maximum inhibition compared to other parts of the plant (i.e., berries and whole plant) or when extracted with other solvent extracts (chloroform and ethanol). Except for WBC count, all other parameters showed a declining trend from Day 5 onward and reaching to a minimum on Day 30 in Ae.   hydrophila -infected fish, whereas the WBC count increased. The infected fish treated with S.   nigrum leaf extract reported a significant reversion to normal RBC, WBC, Hb, and PCV levels and the skin ulceration recovered within a short period. The antiulcer potential of the medicinal plant as described in humans may be extended to the fish population.     

Dietary administration of natural immunostimulants on growth performance,haematological, biochemical parameters and disease resistance of Asian Sea bass Lates calcarifer (Bloch, 1790)

This study was aimed to address the promising evaluation of Cissus quadrangularis plant (stem) and lipopolysaccharide (LPS from bacteria) supplemented diets on innate immune response in Lates calcarifer fingerlings against Aeromonas hydrophila infection. Fingerlings were fed supplemented diets containing four different concentrations of C. quadrangularis (0.5, 1.0, 1.5 and 2.0 g kg^?1 feed), LPS (25, 50, 75 and 100 mg kg^?1 feed) and control (normal formulated diet) for 60 days. The fish fingerlings fed supplemented diet displayed significant differences (P < 0.05) in specific growth rate (SGR) and relative percentage survival compared to the control group fed without C. quadrangularis and LPS‐supplemented diet. Fingerlings were injected intraperitoneally with 100 μL lethal dose of A. hydrophila containing 1 × 10⁶ CFU g^?1. Supplementation of C. quadrangularis and LPS diet significantly increased biochemical profile such as protein, lipid and carbohydrate content, haematological parameters of L. calcarifer fingerlings in different experimental periods when compared with the control group. Dietary doses of C. quadrangularis and LPS‐supplemented diet significantly influenced growth performance and increased survival rate in L. calcarifer fingerlings against A. hydrophila infection.     

Immune protection in carp, Cyprinus carpio L., after immunization with Aeromonas hydrophila crude lipopolysaccharide

Abstract. Vaccination with crude lipopolysaccharide (LPS) induced better protection against infection with Aeromonas hydrophila in carp than vaccination with formalin killed vaccine. Dipping fish in vaccine for 2 h at 25°C was more effective than intraperitoneal injection of the vaccine in procedural simplicity, lower stress loading and the degree of protection acquired. In carp immunized with crude LPS by the dip method, antibodies were not detected by bacteriai agglutination, passive haemagglutination and the agar diffusion tests. The results indicate that the protection against A. hydrophila infection in carp is not dependent on humoral immunity.     

Effects of supplemental Azomite in diets on growth,immune function and disease resistance of white shrimp (Litopenaeus vannamei)

This study was conducted to evaluate effects of dietary Azomite, a natural mineral of volcanic ash, on growth performance, digestive enzyme activities, serum non‐specific immunity and disease resistance of white shrimp (Litopenaeus vannamei). Graded levels of 0.0 g kg^?1 (control group), 2.0, 4.0, 6.0 and 8.0 g kg^?1 Azomite were supplemented in basal diet to feed shrimps. After 6 weeks feeding, weight gains of the 2.0 and 4.0 g kg^?1 Azomite groups were significantly higher than that of the control group (P < 0.05). Compared with control group, the activities of stomach protease, hepatopancreas lipase, and serum alkaline phosphatase, lysozyme and phenoloxidase were significantly increased by the 4.0 g kg^?1 Azomite addition (P < 0.05). When subjected to hypoxia stress, the lethal times of the first shrimp and all shrimps were both delayed by the addition of 2.0–6.0 g kg^?1 Azomite to diets, compared with the lethal time of control group. At the 96th hour after the injection of bacterium (Vibrio alginolyticus), the accumulated mortality of 4.0 g kg^?1 Azomite addition group was 34.6% lower than that of control group (P < 0.05). The results showed that dietary levels of 2.0 and 4.0 g kg^?1 Azomite can improve the growth performance, digestive enzyme activities, serum non‐specific immune function and disease resistance of white shrimp.     

Effects of dietary organic selenium on immune responses,total selenium accumulation and digestive system health of marron,Cherax cainii (Austin, 2002)

A 90‐day feeding trial was conducted to determine the effects of dietary organic selenium (OS) supplementation on immune responses, total selenium accumulation in various tissues and the digestive system health of marron Cherax cainii. A group of marron (initial weight 3.65 ± 0.05 g) were fed 0.2 g kg^?1 of Sel‐Plex^® as a source of OS and were compared to a control group of marron that were not fed OS. After 90 days of feeding OS, total haemocyte counts (THC) and the percentages of granular and semigranular cells in marron were significantly higher than in marron fed a control diet. However, dietary OS did not affect the proportion of hyaline cells. The marron fed OS had significantly lower bacteraemia and longer neutral red retention times than the control group. Total selenium levels in the haemolymph, hepatopancreas and muscle tissues of the OS‐fed marron group were significantly higher (P < 0.05) than in control diet group. The highest total soluble selenium levels were found in the muscle tissues of OS‐fed marron on the final day of the feeding trial. Amylase and protease activity, soluble protein, and numbers of microvilli were significantly higher (P < 0.05) in marron fed OS. These findings demonstrate the benefits of including 0.2 g kg^?1 OS in marron diet to enhance immune parameters, increase total selenium accumulation in muscle and improve marron digestive system health.     

Use of dietary ginger, Zingiber officinale Roscoe, as an immunostimulant to control Aeromonas hydrophila infections in rainbow trout, Oncorhynchus mykiss (Walbaum)

Ginger, Zingiber officinale, which was fed at 0, 0.05, 0.1, 0.5 and 1.0 g per 100 g of feed for 14 days to rainbow trout, Oncorhynchus mykiss (Walbaum), led to control of experimental infection with Aeromonas hydrophila . At 0.5 g ginger per 100 g of feed, there was a reduction in mortalities to 0% compared with the controls (64%). Moreover, there was a significant increase in growth, feed conversion and protein efficiency. There was proliferation in the number of neutrophils, macrophages and lymphocytes, and enhanced phagocytic, respiratory burst, lysozyme, bactericidal and anti-protease activities compared with the controls.     

The effect of lysine‐supplemented wheat gluten‐based diet on yellow perch Perca flavescens (Mitchill) performance

Formulation of nutritionally complete and cost efficient diets for yellow perch (Perca flavescens) is a prerequisite for successful intensive culture of this species. One of the objectives of this study was to determine the optimum diet for the grow‐out phase of juvenile yellow perch. Fish at the size of 12.9 ± 4 g were individually marked with passive integrated transponders (PIT)‐tags and randomly distributed into six 400 L tanks, 45 fish per tank. This experiment included lysine‐deficient [(?) Lys] and lysine‐supplemented [(+) Lys] wheat‐gluten‐based diets in triplicate groups. Our experiment showed that the mean weight of fish fed (+) Lys diet (83.9 ± 1.5 g) was significantly larger than fish fed (?) Lys diet (68.6 ± 5.2 g) (P < 0.05). This experiment also showed that the blood plasma concentration of free lysine in (+) Lys group was significantly higher than in (?) Lys group (P < 0.05) and the same trend appeared also in methionine concentrations. The concentration of Lys in deficient group of fish, 3 h after a meal was lower compared with levels of Lys 24 h post‐feeding (P < 0.05). Lysine deficiency in diet resulted in significantly higher level of serine, and a similar trend occurred in small and large fish.     

载铜蒙脱石对嗜水气单胞菌粘附尼罗罗非鱼上皮细胞的影响

采用尼罗罗非鱼上皮细胞培养模型,观察嗜水气单胞菌对鳃上皮、皮肤上皮、肠上皮细胞的粘附率,研究载铜蒙脱石对细菌粘附的阻断作用及其对细菌粘附引起鱼上皮细胞膜生物特性变化的影响。结果显示：嗜水气单胞菌与鱼上皮细胞均有不同程度的粘附作用,粘附率大小顺序为鳃上皮〉皮肤上皮〉肠上皮细胞。载铜蒙脱石均显著降低了嗜水气单胞菌对鳃、皮肤和肠上皮细胞的粘附率（P〈0．05）,而且对不同上皮细胞的粘附阻断率无显著差异。嗜水气单胞菌粘附肠上皮细胞后细胞膜生物特性发生了显著变化,与正常对照组相比,嗜水气单胞菌粘附鱼上皮细胞后,胞浆游离钙和细胞膜磷脂酶A2活性显著上升。载铜蒙脱石可显著降低由于嗜水气单胞菌粘附鱼上皮细胞引起的胞浆游离钙和细胞膜磷脂酶A2活性的升高。结果表明,载铜蒙脱石可有效阻断病原菌粘附,从而防治细菌感染和细菌移位。     

Synchronization of ovulation in cultured northern whitefish (Coregonus peled,Gmelin 1788) using [D‐Arg6Pro9Net]‐sGnRH analogue and its effect on egg quality

Female northern whitefish were treated with salmon [D‐Arg⁶Pro⁹Net]‐sGnRHa emulsified in Freund′s incomplete adjuvant as a sustained release treatment (sGnRHa‐FIA) or with [D‐Arg⁶Pro⁹Net]‐sGnRHa dissolved in physiological saline as acute release treatment (sGnRHa‐PS). Females in four experimental groups (A, B, C, D) and one control group (E) were injected intraperitoneally as follows: A and B – sGnRHa‐FIA at doses of 50 and 25 μg kg^?1, respectively; C – double injection (DI) of sGnRHa‐PS at 25 μg kg^?1 administered 3 days apart; D – single injection (SI) of sGnRHa‐PS at 25 μg kg^?1; and E – control group receiving a 1:1 mixture of FIA and physiological saline. All treatments induced and synchronized ovulation. Mean time to ovulation was significantly reduced (P < 0.05) in GnRHa‐treated groups compared with control. Hormone treatments did not affect the relative fecundity. Slight differences were found in ovarian fluid pH between group A and D (P < 0.05). Except for group C, egg size was significantly reduced (P < 0.01) in hormonally synchronized groups compared with the control. Survival to the eyed stage of eggs from females in groups A, B and C was significantly lower (P < 0.01) than in groups D and E. Per cent hatched alevins was lower (P < 0.01) in groups A, B and C than in groups D and E. We conclude that synchronization of ovulation in northern whitefish can be induced by a single acute injection of [D‐Arg⁶Pro⁹NEt]‐sGnRHa at 25 μg kg^?1 BW if given near the natural spawning time determined by water temperature below 2°C.     

Impact of sublethal di‐n‐butyl phthalate on the aquaculture fish species Nile tilapia (Oreochromis niloticus): histopathology and oxidative stress assessment

Phthalates such as di‐n‐butyl phthalate (DBP) and their esters are widely used plasticizers, their ubiquitous presence in daily life, inevitably leads to their restricted use due to important environmental pollution and health impacts and endocrine disruption potential. The aim of this study was to examine the effects of a sublethal concentration of 10 mg L^?1 DBP on haematocrit (HCT) values, gills and liver histology, malondialdehyde (MDA, 2‐thiobarbituric acid‐TBA reactivity) and reduced glutathione (GSH) levels in gills and liver tissue as oxidative stress biomarkers in the aquaculture fish species Nile tilapia (Oreochromis niloticus) after 24 (DBP‐24) and 96 (DBP‐96) h exposure. No differences were found between per cent HCT values in the 24 h exposure groups (P > 0.05). Response of antioxidant defence systems in liver and gill tissues of the fish were dependent on exposure duration and changed to a higher extent during 96 h. MDA levels in liver tissue increased in DBP treated fish in comparison to the control fish. However, the differences between the exposure and control groups were not significant (P > 0.05). A statistically significant decrease (P > 0.05) was recorded in gill MDA levels in the DBP‐96 group when compared to the control and DBP‐24 groups. The liver GSH levels were unchanged in the DBP treated fish. However, GSH levels were significantly lower in the gill tissue of the DBP‐96 group. Exposure to DBP caused several degenerative changes in the histology of gill and liver tissue. Gills displayed hyperaemia, epithelial lifting, oedema, talengiectasia, epithelial hyperplasia and fusion of secondary lamellae, whereas in liver several circulatory anomalies (hyperaemia, blood congestion and sinosoid dilatation) and vacuolization of hepatocytes were observed. Histopathological results demonstrated that the gills were more affected than the liver perhaps due to their direct contact with DBP.     

Effects of dietary phosphorus on growth,body composition and immunity of young taimen Hucho taimen (Pallas, 1773)

The effects of dietary phosphorus (P) on growth, body composition and immunity of young taimen (Hucho taimen) were studied. Six purified diets contained graded levels (2.3‐control, 4.0, 5.6, 7.5, 9.1 and 10.8 g kg^?1 diet) of available P. Each diet was fed to triplicate groups of 30 fish with an initial average weight (55.31 ± 0.38) g for 84 days. The weight gain, specific growth rate and feed conversion ratio were improved by dietary available P up to 4.35 g kg^?1 (P < 0.05) and then levelled off. Hepatosomatic index and body crude lipid content decreased significantly with increasing P levels, while ash contents and P concentrations in the whole body and vertebrae increased by dietary available P up to 4.36 and 4.44 g kg^?1 and then levelled off respectively (P < 0.05). Liver superoxide dismutase and glutathione peroxidase and plasma alkaline phosphatase activities in the treatment groups were significantly higher compared with the control group (P < 0.05). Plasma IgM contents increased linearly with increasing dietary P from 4.0 to 9.1 g kg^?1 group and then decreased. Dietary P supplementation reduced plasma triglyceride, malondialdehyde and liver malondialdehyde contents. There were no significant effects on plasma total protein, albumin, globulin, glucose, aspartate aminotransferase and alanine aminotransferase, catalase, lysozyme and liver catalase compared with the control group (P > 0.05). Broken line regression analysis indicated that dietary available P requirement was 4.34 and 4.35 g kg^?1, based on weight gain and P concentration in the whole body respectively.     

Use of garlic, Allium sativum, to control Aeromonas hydrophila infection in rainbow trout, Oncorhynchus mykiss (Walbaum)

Garlic, Allium sativum , which was fed at 0, 0.05, 0.1, 0.5 and 1.0 g per 100 g of feed for 14 days to rainbow trout, Oncorhynchus mykiss (Walbaum), led to control of experimental infection with Aeromonas hydrophila. At doses of 0.5 and 1.0 g garlic per 100 g of feed, there was a reduction in mortalities to 4% compared with the controls (88%). Moreover, there was a significant increase in growth, feed conversion and protein efficiency. There was stimulation of the number of erythrocytes and leucocytes, a significantly higher haematocrit, enhancement of phagocytic activity, respiratory burst, lysozyme, anti-protease and bactericidal activities following feeding with garlic.     

Effect of dietary supplementation of probiotic on performance and intestinal microflora of Chinese soft‐shelled turtle (Trionyx sinensis)

This experiment was conducted to study the effect of dietary supplementation of probiotic on performance and intestinal microflora of Chinese soft‐shelled turtle. Healthy Chinese soft‐shelled turtles (6000 pieces with average weight of 5 g) were selected and randomly divided into two groups: control and treatment with three replicates each. The control was fed on normal basal diet, whereas treatment was fed on basal diet supplemented with 1 × 10⁸ cfu.g^?1 Bacillus subtilis preparation. The results showed that the final mean weight of treatment (265.84 ± 3.48 g) was significantly higher (P < 0.05) than that of control (240.45 ± 4.32 g). There was significant difference (P < 0.05) in FCR, and DGs were obtained in probiotics fed group as compared to control. The level of sucrase, maltase, amylase, lipase and ATPase of treatment was significantly higher (P < 0.05) than that of control. Pyrosequencing showed that the dietary supplementation of probiotic Bacillus strain decreased microbial diversity. Phylum Firmicutes was dominant in both groups. Compared with the control, Firmicutes was increased, while others were decreased in treatment group. The results indicated that dietary supplementation of probiotic can improve growth performance, digestibility and intestinal microflora in Chinese soft‐shelled turtle.     

Effect of soybean meal replacement by cottonseed meal on growth,feed utilization and some blood physiological/biochemical indices of juvenile black carp,Mylopharyngodon piceus

A feeding trial was conducted to evaluate the effect of replacing soybean meal (SBM) with cottonseed meal (CSM) for juvenile black carp. The inclusion levels of CSM were 0 (control), 96.6, 193.3, 289.8 and 386.5 g kg^?1, in which 0, 25, 50, 75 and 100% of protein from SBM were replaced with that from CSM respectively. The results showed that up to 75% of SBM could be replaced by CSM without significant reduction in growth. The apparent digestibility coefficients of dry matter and protein, red blood cell and white blood cell count were significantly decreased with the increase in dietary CSM levels (P < 0.05). The activities of serum catalase (CAT), lysozyme (LSZ) and complement C3 were significantly lower than that of control group when dietary CSM level were increased to 386.5 g kg^?1, 96.6 g kg^?1 and 289.8 g kg^?1 or higher respectively. The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were significantly higher than that of control group when dietary CSM levels were increased to 289.8 g kg^?1 or higher (P < 0.05). These results suggested that growth of black carp was not affected when CSM levels up to 289.8 g kg^?1; however, negative influence on immune and liver function was found when CSM levels up to 96.6 g kg^?1 and 289.8 g kg^?1 respectively.