Dietary lipid requirement of whiteleg shrimp Litopenaeus vannamei juveniles cultured in biofloc system

An eight‐week feeding trial was conducted to evaluate the contribution of biofloc on dietary lipid requirement in whiteleg shrimp Litopenaeus vannamei. Five diets with graded levels of dietary lipid (45, 60, 90, 120 and 150 g/kg) were fed to juvenile shrimp. Final weight, weight gain and specific growth rate of shrimp fed diets with 60, 90 and 120 g/kg lipid levels were significantly higher than those of shrimp fed diets with lipid levels 45 and 150 g/kg (p < .05). Feed efficiency and protein efficiency ratio of shrimp fed 60, 90 and 120 g/kg were higher than those fed 150 g/kg diet. Plasma total cholesterol and triglyceride levels were lower in shrimp fed 45 g/kg compared with those fed the 90 g/kg (p < .05). Also, lysozyme activity for 90 g/kg group was higher than the 15 g/kg group. Hepatopancreas lipase and amylase activities of shrimp fed 90 and 120 g/kg diets were significantly higher than those of shrimp fed 45 and 150 g/kg diets. Broken‐line regression analysis for weight gain indicated that the dietary lipid requirement of whiteleg shrimp juveniles reared in a biofloc system was estimated to be higher than 56 g/kg but <60 g/kg.     

Growth performance,haematology, antioxidant status,immune response and histology of common carp (Cyprinus carpio L.) fed biofloc grown on different carbon sources

A 10 weeks trial was performed to investigate how different carbon sources (sugar beet molasses: SBM+BFT, sugar: S+BFT, corn starch: CS+BFT) along with control affect welfare status of common carp (Cyprinus carpio L.) fingerlings in biofloc‐based tanks. Three hundred healthy fingerlings (22.5 ± 0.2 g) were randomly distributed in 12 tanks (70 L) at a density of 8.02 kg/m³ (25 fish/tank). The fish in BFT treatments fed only 75% feeding rate of control. At the end of the experiment no differences were seen between the groups in case of growth performance, but the fish reared in CS+BFT had a significant lower food conversion ratio compared with the others (p < .05). Different carbon sources did not affect on haematological parameters (p > .05). Total serum protein and antibody concentration differed in treatments, and the highest values were found in S+BFT and CS+BFT treatments (p < .05). No significant differences were observed in case of lysozyme, superoxide dismutase and complement activity in treatments (p > .05), whereas the fish in BFT treatments showed a significant higher total antioxidant capacity and lower glutathione peroxidase than the control (p < .05). Different carbon sources resulted in no change in goblet and kupffer cells in intestine and liver respectively. The highest relative percentage survival was obtained in the CS+BFT and S+BFT (50%) in comparison with SBM+BFT (20%) treatment. The results obtained in this experiment, suggest that corn starch improves immune response, diseases resistance and histology of digestive and respiratory systems in carp fingerlings when used as a carbon source in zero water exchange system.     

黄河鲤肾脏的显微和亚显微结构观察

应用常规解剖学和组织学方法在光镜和电镜下观察成体黄河鲤肾脏的显微和亚显微结构.试验结果显示,黄河鲤的肾脏包括头肾和中肾两部分.头肾实质中没有肾单位,主要由造血组织和淋巴组织构成,可观察到黑色素巨噬细胞中心和甲状腺滤泡;中肾实质中包含有肾小体、肾小管和拟淋巴组织,肾小体由鲍曼氏囊和与其相接触的血管球组成.肾小管由颈段、第...     

饲料脂肪水平对锦鲤幼鱼生长和血液生化指标的影响

本实验以初始体重为(5.85±0.19)g红白锦鲤(Cyprinus carpioL)幼鱼为实验对象,研究在螺旋藻添加量为12％时,饲料脂肪水平对锦鲤生长、饲料表观消化率、肠道消化酶和血液生化指标的影响.实验设5.36％、7.74％、10.52％、12.85％、15.45％5个脂肪梯度,每组设3个重复,每个重复10尾鱼,表观饱食投喂60 do结果显示:脂肪水平为5.36％ ～ 10.52％,锦鲤增重率(BWG)、特定生长率(SGR)随脂肪水平的升高而升高,均在脂肪水平为10.52％时,达到最大值.实验鱼血清谷丙转氨酶(ALT)随脂肪添加比例呈现先下降再升高的趋势,脂肪水平为12.85％后,血清ALT显著升高(P＜0.05),脂肪水平为15.45％时,血清GLU浓度显著升高(P＜0.05),而甘油三酯(TG)、总胆固醇(CHOL)随脂肪水平的升高各实验组间无显著性差异(P＞0.05).结果表明,螺旋藻添加量一定时,锦鲤适宜脂肪添加水平为10.52％.     

Magnesium status in freshwater fish,common carp (Cyprinus carpio,L.) and the dietary protein-magnesium interaction

Common carp juveniles were fed for 9 weeks one of the eight semipurified diets containing graded levels of magnesium, 0.08, 0.6, 1.1, 3, 2 g Mg kg^–1 and 25 or 44% protein.Fish growth and feed utilization were significantly affected by both Mg and protein levels in the diets. Significant interaction between these two studied variables existed in relation to the fish performance as well as to mean deposition rate of several minerals in common carp body. The fish fed diets containing 0.08 g Mg kg^–1 had reduced growth and developed deficiency signs such as muscle flaccidity and skin hemorrhages.Results indicated that a minimum Mg level of 0.6 g Mg kg^–1 was required to elevate plasma and bone magnesium content and to reduce the whole body Ca concentration (hypercalcinosis symptom). Further increase of dietary Mg up to 3.2 g Mg kg^–1 improved growth rate of fish insignificantly, but the deposition rate of dietary Mg fell to as low as 7.4 and 10.7 percent in low- and high-protein diet fed fish, respectively. In Mg-deficient fish, considerable amount of magnesium was absorbed via extra-oral routes, however, this way of the covering magnesium need becomes insufficient in fast growing fish.     

Replacement of fishmeal by vegetable meal mix in the diets of Litopenaeus vannamei reared in low‐salinity biofloc system: effect on digestive enzymatic activity

Biofloc (consortium of diverse microorganisms associated to suspending substrates) was developed from waste of shrimp Litopenaeus vannamei postlarvae culture under low salinity (5 g L^?1) to provide an additional nutritious biomass and reduce fishmeal inclusion in feeds in a 28‐day indoor shrimp nursery trial conducted in 15 experimental containers (250 L stocked at 600 org m^?3). Four experimental diets (isoproteic and isocaloric) containing different percentage of fishmeal: 0%, 10%, 20% and 30% substituted by vegetable meal mix (corn, sorghum and wheat) were formulated and elaborated. A control treatment consisted of a commercial feed. The main water quality parameters were monitored, and no significant differences were found among treatments. The growth and survival were similar among treatments. In general, digestive enzymatic activities showed differences being greater in the biofloc system compared with clear water. It was concluded that low‐salinity shrimp nursery could be successfully developed with minimum inclusion of fishmeal in feeds, without significant effect on production response. The adjustment of C : N ratio allowed the increase of microbial biomass in the bioflocs, which contributed to maintain good water quality, provide live food and enhance digestive enzymatic activity of cultured organisms.     

Effects of pimozide and LHRH-Aa on carp (Cyprinus carpio L.) oocyte maturation and ovulationin vivo

Effects of pimozide (Pim) and [(D-Ala⁶, Pro⁹-NEt) LHRH] (LRH-Aa) on common carp oocytes maturation and ovulationin vivo under laboratory and commercial fisheries farm conditions were investigated.Although injections of Pim and LRH-Aa at the doses of 10 mg and 50 µg/kg body weight respectively, did not increase mGtH levels (66.7–155.8 mg/ml) as much as injections of carp pituitary extract (chh) (382.1 ng/ml), induced GtH levels were high enough to induce ovulation. Changes in the ovary caused by Pim and LRH-Aa were similar to those induced by chh, and Pim injected together with LRH-Aa in a single injection gave the same results concerning ovulation induction as when they were applied separately at 6h interval.     

Optimum dietary protein‐to‐energy ratio for juvenile whiteleg shrimp,Litopenaeus vannamei,reared in a biofloc system

An 8‐week feeding trial was conducted to evaluate the optimum dietary protein‐to‐energy (P/E) ratio in juvenile whiteleg shrimp, Litopenaeus vannamei. Six diets were formulated with two protein levels (30% and 35%) and three digestible energy levels (16, 17.5 and 19 kJ/g diet) at each protein level (₃₀P₁₆, ₃₀P_17.5, ₃₀P₁₉, ₃₅P₁₆, ₃₅P_17.5 and ₃₅P₁₉). Fifty shrimp averaging 0.97 ± 0.03g (Mean ± SD) were randomly distributed in biofloc tanks and fed one of the experimental diets. Weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of shrimp fed the ₃₅P_17.5 diet were significantly higher than those of shrimp fed ₃₀P₁₆, ₃₀P_17.5 and ₃₀P₁₉ diets (p < .05). Results for non‐specific immune responses showed that diet ₃₅P_17.5 caused higher lysozyme activity in shrimp comparing to lower protein diets. Thiobarbituric acid reactive substances (TBARS) of plasma were lower for shrimp fed on diets consisting of higher protein and energy levels than shrimp fed on the ₃₀P₁₉ diet. Analyses of digestive enzyme activities showed higher trypsin activities for shrimp fed on ₃₅P_17.5 and ₃₅P₁₉ diets comparing to ₃₀P₁₆ and ₃₀P_17.5 diets. Also, hepatopancreatic lipase activity of shrimp fed ₃₅P₁₆, ₃₅P_17.5 and ₃₅P₁₉ diets were significantly higher than those of shrimp fed the other diets. In conclusion, based on the results for growth performance, biochemical parameters, immune responses, oxidative stress and enzyme activities, 35% protein and 17.5 kJ/g digestible energy (₃₅P_17.5) could be considered as the optimum protein‐to‐energy ratio in the diet of juvenile whiteleg shrimp reared in a biofloc system.     

不同脂肪源对施氏鲟幼鱼血清生化指标的影响

在饲料蛋白质水平和能量水平均能满足生长需要的基础上,以不同的油脂(添加水平均为6%)配制成6种试验饲料,投喂施氏鲟幼鱼7周,分析脂肪源对幼鱼血清胆固醇(TC)、甘油三酯(TG)和高密度脂蛋白(HDL-C)的含量和谷丙转氨酶活性(GPT)等生化指标的影响。结果显示:猪油组、葵花籽油组和氧化鱼油组幼鱼的TG和TC都高于鱼油组、混合油组,而其HDL-C、TC含量显著低于鱼油组、混合油组。表明猪油、葵花籽油和氧化鱼油都不利于鲟鱼的脂肪代谢;而鱼油能够调节和平衡鱼体内的脂肪代谢,降低体脂和肝脂的含量,有利于施氏鲟的健康生长。这与不同油脂具有不同的脂肪酸种类和比例有关。     

Detoxified Jatropha curcas kernel meal as a dietary protein source: growth performance,nutrient utilization and digestive enzymes in common carp (Cyprinus carpio L.) fingerlings

Jatropha curcas kernel meal is rich in protein; however, it is toxic. Two durations of detoxification process were investigated: 30 and 60 min; designated as J_a and J_b, respectively. Common carp fingerlings (252 fish; 3.2 ± 0.07 g) were fed diets: control containing fishmeal (FM); S₅₀, J_a50 and J_b50: 50% of FM protein replaced by soybean meal (SBM), detoxified Jatropha kernel meal (DJ_aKM and DJ_bKM); S₇₅, J_a75 and J_b75: 75% of FM protein replaced by SBM, DJ_aKM and DJ_bKM. Highest body mass gain, specific growth rate, metabolic growth rate (MGR) and energy production value were observed for the J_b50 group which were statistically similar to that for control group and significantly (P < 0.05) higher than for all other groups. Lowest feed gain ratio was observed in control group, which was statistically similar to than in J_b50 group. Lowest MGR, protein efficiency ratio, protein productive value and lipid production value were observed in J_a75 group. The dry matter and lipid digestibilities were statistically (P < 0.05) highest in control group and lowest in J_a50 group. Protein and energy digestibilities were statistically similar (P > 0.05) for control and J_b50 groups, and these values were highest among the groups. Highest crude protein efficiency was observed in J_b50 group, whereas lowest in J_b75 group. Relative intestinal length and hepatosomatic index were higher in plant protein–fed groups. Intestinal amylase, protease and lipase activities for control group were statistically higher (P < 0.05) than for plant protein–fed groups. Conclusively, performance of J_b50 group was similar to control group and better than other groups and, thus, is recommended as the most optimal diet for common carp fingerlings.     

镉对鲤血清促性腺激素和生长激素的影响

采用ＣｄＣｌ２浸没法处理鲤，研究镉对鲤血清促性腺激素（ＧｔＨ）和生长激素（ＧＨ）水平的影响，结果表明，较镐浓度镉（ＣｄＣｌ２９ｍｇ／Ｌ）处理引起血清ＧｔＨ水平降低，ＧＨ水平升高，提高水中钙浓度，能使由镉引起的ＧｔＨ水平的降低恢得取正常水平，并对镉引起的ＧＨ水平升高起延迟作用，镉处理使鲤对ＬＨＲＨ－Ａ刺激ＧｔＨ分泌的反应性下降，提高水中钙浓度也不能恢复正常，实验结果提示，镉引起的ＧｔＨ和ＧＨ的变化可     

饲料蛋白水平对鲤幼鱼肝功能和抗氧化能力的影响

研究了不同蛋白水平饲料对鲤(Cyprinus carpio)幼鱼肝功能和抗氧化能力的影响。选用体质量为(10±1.2)g的健康鲤幼鱼,随机分为5组,每组设3个重复,每个重复35尾鱼。放养在15个规格相同的白色水箱中,分别投喂蛋白水平为30%、30.5%、31%、31.5%和32%的饲料(分别记作Diet 1、Diet 2、Diet 3、Diet 4和Diet5),饲养实验时间为8周,每隔4周对相关生理生化指标进行测定。结果表明,养殖第4和第8周时,31%蛋白水平组血清和肝胰脏的谷丙转氨酶(ALT)和谷草转氨酶(AST)活性均显著降低(P0.05);血清、肝胰脏和肾脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和溶菌酶(LZM)活性升高(P0.05),丙二醛(MDA)浓度显著降低(P0.05)。根据实验结果,从饲料配制的成本考虑,31%蛋白水平饲料能够达到维持鲤幼鱼机体正常的抗氧化能力以及保护肝功能的营养需求。     

Lipid metabolism responses of common carp (Cyprinus carpio L.) to mulberry leaf meal in diet

This study investigated the lipid metabolism responses of common carp (Cyprinus carpio L.) to mulberry leaf meal (MLM) replacing of some fish meal in diet. Six iso‐nitrogenous and iso‐energetic diets containing different levels of MLM (0%, 6.3%, 12.6%, 18.9%, 25.2% and 31.5%) were prepared and fed to common carps in tanks for 56 days. Analysis showed that serum total protein, albumin contents and glutamic‐pyruvic transaminase, glutamic oxalacetic transaminase activities were not significantly different among treatments, blood glucose, cholesterol, high‐density lipoprotein and low‐density lipoprotein but triglyceride concentration depicted a declining trend in MLM supplementation groups compared with control. Liver and muscle lipid content decreased with increased supplementation of MLM in the diet. Hepatic lpl showed an up‐regulated trend in the MLM groups, apo‐a1 was up‐regulated in common carp fed 31.5% MLM diet, pparα was up‐regulated in 18.9% and 25.2% MLM groups, while apo‐a4, pparβ and pparγ were down‐regulated in all the MLM‐treated groups compared with control, fabp1 was down‐regulated in fish fed high‐MLM diets (≥25.2%). The results revealed that half of fish meal in common carp diet could be replaced by MLM with no hepatotoxicity; MLM promoted the reversal of cholesterol transport thereby reducing the cholesterol in blood; MLM elevated the ability of fatty acid oxidation of the common carp, but did not activated the activity of lipoprotein lipase fully, and the suppressed transportation of fatty acid affected the degradation of triglyceride in blood together; MLM reduced liver lipid contents might through suppressing the isolation and proliferation of adipocytes.     

Toxic effects of indoxacarb on gill and kidney histopathology and biochemical indicators in common carp (Cyprinus carpio)

The aim of this study was to determine the biochemical and histopathological effects of indoxacarb on an economic fish species Cyprinus carpio. The fish were divided into four triplicated groups exposed to either of 0% (control), 5% (0.75 mg/L), 10% (1.5 mg/L) or 20% (3 mg/L) of the pesticide LC₅₀. Blood sampling was performed after 7, 14 and 21 days exposure. There were no changes in blood calcium levels at any times. In the indoxacarb‐treated fish, chloride levels decreased at the first and increased at the second sampling compared to the control. In 3 mg/L treatment, phosphorus increased significantly after 7 days compared to the control. Plasma glucose levels decreased significantly at the 7th and 14th days sampling; however, it increased at the 21st day. After 7 days, creatinine level in 3 mg/L treatment was significantly lower than the control; however, the creatinine levels of indoxacarb treatments were higher than the control at the 21st day. The indoxacarb‐treated fish had higher plasma urea levels compared to the control at the 7th day. At the 21st day, plasma urea level at 3 mg/L was significantly lower than the control treatment. Edema, Lamellar curling, hyperplasia, lamellar fusion and hyperaemia were observed in the indoxacarb‐treated fish gill. Tubular necrosis, hematopoietic necrosis, melanomacrophage aggregates, Bowman's capsule edema, glomerulus degeneration and hyperaemia were observed in the indoxacarb‐treated fish kidney. Generally, sublethal concentrations of indoxacarb cause stress, hydromineral imbalance, metabolism alteration and gill and kidney damages in common carp.     

Movement, social cohesion and site fidelity in adult koi carp, Cyprinus carpio

Abstract  Koi carp is an ornamental variant of the common carp, Cyprinus carpio L., that was introduced to New Zealand in the 1960s and has since become a major aquatic pest. A total of 1265 wild adult koi carp were caught by boat electric fishing, dart tagged and released at multiple sites in the lower Waikato River and associated lakes and wetlands between September 2002 and February 2005. Subsequent recaptures by boat electric fishing and recreational fishing returned 76 koi carp (6% of all tagged fish). Of these, 85% were recaptured less than 5 km from their release site; only one fish moved more than 50 km. On seven occasions, pairs or small groups of koi carp (20% of all tag returns) that had previously been tagged and released at the same locations and times were subsequently recaptured together after considerable periods of time at liberty (mean 551 days ± 419 SD). Adult koi carp in the Waikato River showed a high degree of site fidelity, exhibited prolonged social groupings and females moved downstream more often than males.     

Use of biofloc technology during the pre‐maturation period of Litopenaeus vannamei males: effect of feeds with different protein levels on the spermatophore and sperm quality

The objectives of this study were: (1) Compare two systems for pre‐maturation of Litopenaeus vannamei in terms of spermatophore and sperm quality, (2) Compare the effect of feeds with different protein levels on reproductive quality of males reared in a biofloc‐dominated system. Animals (36.40 ± 3.13 g) reared under biofloc technology (BFT) were used in the 30‐day experiment, which involved four treatments: one in a clear water system (CW) and other three in a BFT system. The BFT treatments were differentiated by feed: mix of fish, squid and crab (BFT+FF) composed of 68.48% dietary protein (DP); broodstock feed (BFT+BF) composed of 52.51% DP; and juvenile feed (BFT+JF) composed of 39.91% DP. Feed in the CW was also the mix of fresh food. Spermatophore and sperm quality were analyzed at the beginning and end of the experiment. Higher normal sperm rate was recorded in the CW compared with the BFT+FF. Among the BFT treatments, the BFT+FF had the lowest normal sperm rate. Thus, the use of BFT for pre‐maturation of L. vannamei allowed the reduction in dietary protein levels from 68.48% (BFT+FF) to 39.91% (BFT+JF) and the maintenance of spermatophore and sperm quality compared to the system based on high daily exchange rate.     

饲料中添加丁酸钠对草鱼生长、消化酶活性、血清生化指标和肠道组织学的影响

为了探究饲料中补充不同水平丁酸钠对草鱼生长性能、肠道消化酶活性、血清生化指标和肠道组织形态的影响,分别添加0 mg/kg (SB0)、1 000 mg/kg (SB1)、2 000 mg/kg(SB2)和3 000 mg/kg (SB3)的微囊丁酸钠(含50%丁酸钠)至基础饲料中,设计4组等氮等脂的实验饲料。选取300尾体质健康的草鱼(10.0±0.1) g,分成4组,每组3个重复,每个重复25尾鱼,放置在水泥池中养殖8周。结果显示,各组草鱼增重率为273.7%～279.9%,饲料系数为1.55～1.60,饲料中补充丁酸钠对草鱼生长性能和体成分无显著影响。与对照组相比,添加不同水平的丁酸钠均显著提高了肠道蛋白酶活性和血清超氧化物歧化酶(SOD)活性,降低了血清谷草转氨酶(AST)活性,SB1组血清碱性磷酸酶(AKP)活性显著升高,而SB2和SB3组血清谷丙转氨酶(ALT)活性显著降低。各组肠道淀粉酶活性、血清酸性磷酸酶(ACP)、甘油三酯(TG)、葡萄糖(GLU)、总蛋白(TP)和D-乳酸(D-LA)无显著差异。在肠道组织学方面,各丁酸钠补充组肠道绒毛高度和SB1、SB2组肌层厚度显著...     

红鲤四品系的形态差异和种系关系

综合传统形态学数据和框架测定数据，通过多元变量分析，研究了我国红鲤四个品系（兴国红鲤、玻璃红鲤、荷包红鲤及瓯江彩鲤）的形态差异和种系关系。主要结果：（1）可数性状方面，4品系红鲤无显著差异（P〉0．05）。（2）传统可量性状和框架测定数据合在一起，4品系红鲤间有显著差异（P〈0．05）；聚类分析表明，瓯江彩鲤、兴国红鲤及玻璃红鲤三者形态相近，而荷包红鲤与这三种红鲤的形态差异明显。在28项比例变量基础上所作判别分析表明，红鲤4品系问形态差异极显著（P〈0．01），用优选的8项比例变量判别，综合判别准确率达92％；主成分分析表明，4品系红鲤间形态差异主要系躯体前半部差异所致。（3）把传统可量性状数据和框架测定数据结合在一起，使用多种多元变量分析技术，可大大增强鱼类种内不同群体间差异和亲缘关系的研究能力。