虫草菌粉对日本沼虾免疫功能的影响

在饵料中添加0.5%的虫草菌粉,以口服形式对日本沼虾进行免疫。日本沼虾血淋巴吞噬活性,血清抗菌、溶菌活力及酚氧化酶活力均显著提高。经嗜水气单胞菌攻毒后,试验组的免疫保护率也明显提高。因此,投喂虫草菌粉,能够明显地增强日本沼虾的免疫抵抗能力。     

虫草菌粉对罗氏沼虾免疫功能的影响

罗氏沼虾饵料中添加0．5％虫草菌丝，罗氏沼虾血细胞吞噬百分比和吞噬指数、血清溶菌酶活力及酚氧化酶活力均显著提高。经嗜水气单胞菌攻毒后，试验组的免疫保护率也明显提高。试验证明，口服虫草菌粉可显著地提高罗氏沼虾的免疫功能，有效地预防嗜水气单胞菌的感染。     

急性硫化物胁迫对日本沼虾免疫和抗氧化系统的影响

日本沼虾（Macrobrachium nipponense）在硫化物浓度为0.4、1.2和4.0mg/L的水体中暴露48h,研究硫化物胁迫对其血液免疫指标和机体抗氧化能力的影响。结果表明,硫化物对日本沼虾的24、48、72、96hLC50分别为22.5、15.2、12.5、11.35mg/L。血细胞密度（THC）和吞噬活力（吞噬百分比和吞噬指数）随硫化物质量浓度升高而降低,至48h,0.4、1.2和4.0mg/L组的THC显著降低,分别为对照组的85.71%、70.75%和57.48%。各试验组沼虾的凝血时间与对照组相比延长,1.2mg/L和4.0mg/L组分别从12h和6h开始显著长于对照组（P〈0.05）。沼虾肌肉中的总抗氧化能力（T-AOC）随硫化物浓度的升高而降低,至48h,1.2mg/L和4.0mg/L组显著低于对照组（P〈0.05）。超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活力随硫化物浓度的升高而增强,至48h,1.2mg/L和4.0mg/L组的SOD活力显著高于对照组（P〈0.05）,表明日本沼虾免疫系统对低浓度硫化物有一定的耐受力;当硫化物浓度过高时,沼虾的免疫能力降低,对机体抗氧化系统产生显著影响。     

虾青素对微囊藻毒素MC-LR胁迫下克氏原螯虾的生长、繁殖及免疫力的影响

本文目的旨在研究虾青素对微囊藻毒素MC-LR胁迫下(25μg/L)克氏原螯虾的免疫力及生长繁殖的影响。实验设计四个梯度的饲料中虾青素添加比例分别为(0、5、10、20 mg/g)养殖周期持续8星期。结果表明虾青素显著提高了克氏原螯虾肝脏中超氧化物歧化酶(SOD)和碱性磷酸(AKP)的活力(P0.05)。5g/kg虾青素的添加量即可对SOD酶活具有明显提升(P0.05);10 g/kg的虾青素添加量对AKP的提升最为明显(P0.05);研究还发现虾青素可显著提高微囊藻毒素MC-LR胁迫下克氏原螯虾的存活率和特定生长率(SGR)(P0.05),提高克氏原螯虾雌虾的抱卵量。研究表明虾青素作为一种抗氧化剂适宜于在克氏原螯虾饲料中添加,并且具有提高虾体免疫活力,缓解微囊藻毒素MC-LR对虾体氧化胁迫的作用。     

急性硫化物胁迫对日本沼虾免疫和抗氧化系统的影响

日本沼虾(Macrobrachium nipponense)在硫化物浓度为0.4、1.2和4.0 mg/L的水体中暴露48 h,研究硫化物胁迫对其血液免疫指标和机体抗氧化能力的影响.结果表明,硫化物对日本沼虾的24、48、72、96 h LC50分别为22.5、15.2、12.5、11.35 mg/L.血细胞密度(THC)和吞噬活力(吞噬百分比和吞噬指数)随硫化物质量浓度升高而降低,至48 h,0.4、1.2和4.0 mg/L组的THC显著降低,分别为对照组的85.71％、70.75％和57.48％.各试验组沼虾的凝血时间与对照组相比延长,1.2 mg/L和4.0 mg/L组分别从12 h和6h开始显著长于对照组(P＜0.05).沼虾肌肉中的总抗氧化能力( T-AOC)随硫化物浓度的升高而降低,至48 h,1.2 mg/L和4.0 mg/L组显著低于对照组(P＜0.05).超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活力随硫化物浓度的升高而增强,至48 h,1.2 mg/L和4.0 mg/L组的SOD活力显著高于对照组(P＜0.05),表明日本沼虾免疫系统对低浓度硫化物有一定的耐受力；当硫化物浓度过高时,沼虾的免疫能力降低,对机体抗氧化系统产生显著影响.     

复方中草药制剂对罗氏沼虾生长和非特异性免疫功能的影响

在基础饲料中添加0.5%、1.0%和2.0%的复方中草药制剂,连续投喂56 d后,通过测定供试罗氏沼虾(Macrobrachium rosenbergii)的生长性能、血细胞的吞噬活性、血清酶活性、酚氧化酶活性,比较了复合中草药制剂对罗氏沼虾促生长及非特异性免疫功能的影响。结果显示:饲料中添加0.5%的复方中草药制剂对罗氏沼虾的生长影响显著(P<0.05),添加1%和2%的中草药制剂对罗氏沼虾的血细胞的吞噬活性、溶菌酶活力、酚氧化酶活力影响极显著(P<0.01)。用嗜水气单胞菌攻毒7 d显示试验组免疫保护率高达44.7%~59.8%。因此,从促生长、提高免疫力和经济角度3方面考虑,建议添加剂量为1.0%为宜。     

牛磺酸对日本沼虾生长及酚氧化酶活性的影响

通过在饵料中分别添加不同含量的牛磺酸, 初步研究牛磺酸对日本沼虾生长及体内酚氧化酶活性的影响。结果表明, 在饵料中添加 0 .4% ~0. 8%的牛磺酸, 日本沼虾的增重率显著增加 (P<0 .05); 饵料中添加 0. 4%的牛磺酸, 日本沼虾肌肉中的酚氧化酶活性也显著升高 (P<0 .05)。说明饵料中牛磺酸的含量对日本沼虾的生长和免疫力存在显著影响, 以饵料中添加 0. 4 %的牛磺酸比较适宜。     

北方地区罗氏沼虾育苗高产试验

罗氏沼虾（Macrobrachiumrosenbergii）又称马来西亚大虾、淡水长臂大虾，原产于印度洋沿岸的热带、亚热带地区。该虾食性广泛、生长迅速、养殖周期短，并且个体大、营养丰富、肉质鲜嫩，自1960年以来，美国、泰国、日本等国率先引进养殖，现已成为许多国家淡水养殖的名贵虾种之一。我国1976年由日本引进罗氏沼虾，已在十多个省、市、自治区养殖推广。北方地区养殖罗氏沼虾现已形成规模，但其虾苗主要靠南方（如广东、广西、上海等）供应，造成诸多不便。为此，河北省科委1995年立项，经两年的试验研究，育苗高产试验取得显著成效，为东北…     

罗氏沼虾饲料中添加青霉素药渣的效果

采用梯度法分别在配合饲料中添加５％、１０％、１５％和２０％的青霉素药渣，制成直径２ｍｍ的颗粒饲料饲养罗氏沼虾。试验结果表明，饲料中添加５％的青霉素药渣，罗氏沼虾的增重率比对照组高２５．２％；添加５－２０％的青霉素药渣，试验虾的存活率大于（或等于）对照虾，其中添加１５％青霉素药渣的试验组，沼虾的存活率最高。     

4种沼虾的SRFA指纹研究↑（*）

本文用沼虾属（Ｍａｃｒｏｂｒａｃｈｉｕｍ）的４个主要种：罗氏沼虾（Ｍ．ｒｏｓｅｎｂｅｒｇｉ）、海南沼虾（Ｍ．ｈａｉｎａｎｅｎｓｅ）、日本沼虾（Ｍ．ｎｉｐｐｏｎｅｎｓｅ）、粗糙沼虾（Ｍ．ａｓｐｅｒｕｌｕｍ）作材料,构建了它们的ＳＲＦＡ－ＤＮＡ指纹,经比较得到这４个种的ＳＲＦＡ分子标记,并构建了它们之间的谱系关系图,发现日本沼虾和海南沼虾在遗传上比较接近,属于同一“支序”,粗糙沼虾与另外３者在遗传上都相距较远。     

虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响

分别在基础饲料(对照组)中添加100 mg/kg的虾青素、角黄素，混合色素(50 mg/kg虾青素+50 mg/kg角黄素)饲喂初始体重为(56.60±0.63) g的虹鳟60 d，考察虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响。结果显示，饲料中添加了虾青素、角黄素和混合色素后对虹鳟增重率、饲料系数及肌肉常规成分、肌肉失水率、含肉率均无显著影响(P> 0.05)。虾青素组、角黄素组和混合色素组虹鳟肌肉的比色卡得分、红度、虾青素含量和血清总类胡萝卜素含量均比对照组有显著提高(P< 0.05)；虾青素组虹鳟肌肉比色卡得分(26.25)和红度值(18.40)显著高于角黄素组(22.38, 14.13)和混合色素组(24.00, 15.70)(P< 0.05)；虾青素组虹鳟肌肉虾青素含量为4.75 mg/kg (30 d)和6.45 mg/kg (60 d)，均显著高于混合色素组的3.87 mg/kg (30 d)和5.48 mg/kg (60 d)(P< 0.05)；在虹鳟血清总类胡萝卜素含量方面，虾青素组 > 混合色素组 > 角黄素组；虾青素组、角黄素组、混合色素组虹鳟肝脏的总抗氧化能力之间无显著差异(P> 0.05)，分别为2.39 U/mg，2.25 U/mg，2.39 U/mg，均较对照组(2.03 U/mg)显著提高(P< 0.05)。上述结果表明：饲料中添加100 mg/kg虾青素、角黄素及虾青素+角黄素混合(1∶1)均能有效改善虹鳟肌肉颜色，提高肝脏总抗氧化能力，虾青素、虾青素+角黄素混合(1∶1)对虹鳟肌肉的着色效果优于角黄素。     

The feasibility of using primary shrimp hemocyte culture to screen herbal immunostimulants

An analysis of the immune activity of herbal extract in vivo and in vitro assays was performed to explore the feasibility of using primary shrimp hemocyte culture to screen herbal immunostimulants. In vitro experiment was conducted by adding herbal extract into the medium of primary cultured hemocytes and incubating for 24h. In vivo experiment was carried out by feeding shrimp with diets incorporated with herbal extract for 21 days. Challenge test can be used to directly reflect comprehensive immune capacity of organisms. Four immune indexes, total hemocyte counts (THC and lysozyme, phenoloxidase (PO), and phagocytic activity were examined both in vitro and in vivo. The results showed that effects of herbal extract on THC or lysozyme activity were different between in vitro and in vivo. On the contrary, effects of herbal extract on PO activity and phagocytic activity in vitro and in vivo showed a strong correlation. Herbal extract, which enhanced PO activity and phagocytic activity in vitro, had ultimate immune-promoting function in vivo. Therefore, it was feasible to use primary hemocyte culture to screen herbal immunostimulants by determining the effects of herbal immunostimulants on PO and phagocytic activities.     

Effect of Astaxanthin from Xanthophyllomyces dendrorhous on the Pigmentation of Goldfish, Carassius auratus

Two experiments were conducted to evaluate the addition of astaxanthin from red yeast, Xanthophyllomyces dendrorhous, in the diets of goldfish, Carassius auratus. The first was designed to investigate the distribution of pigments in different tissues of goldfish and the effect of astaxanthin in the diet. The carotenoid concentration of tissues was not homogenous. The content of pigments in fish caudal fin was the highest followed by those of scales and head. Flesh had the least carotenoid deposition. Fish fed the diet containing 60 mg/kg astaxanthin had increased concentration of pigment in its head (22.6%), scales (45.5%), flesh (31.0%), and fin (21.2%), compared to fish fed basal diet (P < 0.05). Sixty parts per million astaxanthin had no effect on the weight gain and survival rate. High‐performance liquid chromatography analysis showed astaxanthin in its esterified form in goldfish. The second experiment was aimed at determining the dietary level of astaxanthin that improved color of goldfish. Goldfish were fed the same diet supplemented with 0, 10, 20, 40, 60, and 80 mg yeast astaxanthin/kg for 60 d. The deposition of carotenoids in goldfish fed diets supplemented with astaxanthin increased significantly (P < 0.05) after 15 d of feeding compared to that of the fish fed the diet without astaxanthin, but the effect of dosage of astaxanthin in the diets on the color of goldfish was not completely evident until Day 60 (P < 0.05). During the period of 15–45 d, the deposition of pigments in fish did not increase significantly (P > 0.05) in any treatment with the exception of the diet with 40 mg yeast astaxanthin/kg.     

左旋咪唑对罗氏沼虾免疫功能及抗病力的影响

以0(对照)、50、100和150 mg/kg饲料的剂量将左旋咪唑(LMS)添加于基础饲料中制成颗粒饲料投喂罗氏沼虾(Macrobrachium rosenbergii)14 d,采样测定了罗氏沼虾血细胞吞噬活性、血清酚氧化酶(PO)、溶菌酶(LSZ)及超氧化物岐化酶(SOD)活性,并以6×105cells/mL浓度的致病性嗜水气单胞菌(Aerom onas hydrophila)对罗氏沼虾进行肌肉注射(20μL/尾),记录接种7 d后罗氏沼虾的累积死亡率。结果表明,3个LMS处理组的罗氏沼虾血细胞吞噬百分比和吞噬指数、血清PO、LSZ及SOD活性均显著地高于对照组(P<0.05);LMS处理组的罗氏沼虾对嗜水气单胞菌的抵抗力明显增强。因此,饲喂适量的LMS能促进罗氏沼虾的免疫力和抗病力;在本试验条件下,100 mg/kg饲料的剂量为最适添加剂量。     

Effect of Dietary Astaxanthin on Growth,Survival, and Stress Tolerance of Postlarval Shrimp,Litopenaeus vannamei

The effect of dietary astaxanthin on growth, survival, and stress tolerance was determined in postlarval Litopenaeus vannamei. An experiment was performed with postlarval shrimp (mean initial wet weight 1.2 mg) fed four isoenergic and isonitrogenous diets containing four supplemented levels of astaxanthin (0, 100, 200, and 400 mg/kg diet, respectively). Shrimp fed diets containing 100, 200, and 400 mg astaxanthin/kg diet for 30 d showed higher weight gain (WG, %) and survival compared to the control (without supplementation of astaxanthin). Specific growth rate (SGR, %/day) and final body wet weight (FBW, mg) showed the same pattern as WG. There were no significant differences in growth performance (FBW, WG, and SGR) among the groups fed the diets with astaxanthin supplementation at the termination of feeding trial. Survival of shrimp in the control and 100 mg/kg diet treatments was significantly lower than that of shrimp in the treatments with 200 and 400 mg/kg diet. After 9 d of a stress tolerance test, survival of shrimp in the 200 and 400 mg astaxanthin/kg treatments was significantly higher than that of shrimp in the 0 and 100 mg astaxanthin/kg treatments (P < 0.05). We concluded from this experiment that astaxanthin was a necessary ingredient for the development of larval L. vannamei. Considering the effect of astaxanthin on both, growth performance and survival of postlarval L. vannamei, the level of astaxanthin supplemented in the diet should be between 100 mg and 200 mg/kg of diet.     

Oral Administration of Hot‐water Extract of Tropical Brown Seaweed,Sargassum cristaefolium,to Enhance Immune Response,Stress Tolerance,and Resistance of White Shrimp,Litopenaeus vannamei,to Vibrio parahaemolyticus

The efficacy of hot‐water extract of tropical brown seaweed, Sargassum cristaefolium (SCE), supplemented in diets on immune response, stress tolerance, and disease resistance of Litopenaeus vannamei to Vibrio parahaemolyticus was evaluated. Shrimp were fed diets containing graded levels of SCE (0, 250, 500, 750, and 1000 mg/kg). The results showed that shrimp fed all diets containing SCE had significantly higher (P < 0.05) immune response in total hemocyte count (THC), differential hemocyte count (granular and hyaline cells), and phagocytic activity than those of shrimp fed the control diet. Similarly, in low dissolved oxygen stress tolerance test and the challenge test with V. parahaemolyticus, survival rates of shrimp fed all diets containing SCE were significantly higher (P < 0.05) (83–93% in stress test and 27–47% in challenge test) than those of shrimp fed the control diet (77 and 3.3%, respectively). These results suggest that oral administration of SCE at 500 and 750 mg/kg can be effectively used to enhance immune response, stress tolerance, and resistance of white shrimp, L. vannamei, against V. parahaemolyticus infection. These findings also confirm that using dietary SCE as immunostimulant is effective at increasing the nonspecific immune system in penaeid shrimp, L. vannamei.     

Effects of dietary vitamin E and astaxanthin on growth,skin colour and antioxidative capacity of large yellow croaker Larimichthys crocea

A 10‐week feeding trial was conducted to evaluate the effect of dietary vitamin E and astaxanthin on growth performance, skin colour and antioxidative capacity of large yellow croaker Larimichthys crocea. Six practical diets were formulated in a 2 × 3 factorial design to supplement with two levels of astaxanthin (25 and 50 mg/kg) and three levels of vitamin E (0, 120 and 800 mg/kg). The results showed that both the highest final body weight and specific growth rate were found in fish fed diets with 120 mg/kg vitamin E supplementation. No significant differences were found in survival rate, feed conversion ratio and protein efficiency ratio among all the treatments (p > .05). Skin lightness (L*) was not significantly affected by dietary treatments (p > .05). Ventral skin redness (a*) of fish fed diet with 25 mg/kg astaxanthin and 0 mg/kg vitamin E supplementation was significantly lower than that of fish fed with other diets. Yellowness (b*) and carotenoid contents both in the dorsal and in the ventral skin were found to be significantly increased with increasing dietary astaxanthin or vitamin E (p < .05), but no significant interactions were found (p > .05). The vitamin E content in liver reflected the dietary vitamin E content. Level of vitamin E content in fish fed diets with 800 mg/kg vitamin E supplementation was significantly higher than that in fish fed with the other diets (p < .05). Liver superoxide dismutase activity and thiobarbituric acid reactive substance levels were found to be decreased with increasing dietary astaxanthin and vitamin E levels, respectively. Levels of reduced glutathione in the liver were found to be increased with increasing dietary vitamin E contents. The total antioxidative capacity in the liver was found to be decreased with increasing dietary vitamin E or astaxanthin contents. In conclusion, adequate dietary vitamin E can improve the growth of large yellow croaker, and the supplementation of astaxanthin and vitamin E benefited the skin coloration and antioxidative capacity of large yellow croaker.     

Effects of dietary astaxanthin on the growth,innate immunity and antioxidant defence system of Paramisgurnus dabryanus

The effects of astaxanthin supplementationon the growth, innate immunity and antioxidant defence system of loach (Paramisgurnus dabryanus) were investigated in this study. A total of 450 fish (initial average weights of 3.00 ± 0.10 g) were fed five diets with graded levels of astaxanthin (0.00, 50.00, 100.00, 150.00 and 200.00 mg/kg) for 56 days. The results showed that astaxanthin supplementation significantly stimulated the growth (FBW, WG, FER, HSI), innate immunity (AKP activity in the hepatopancreas, intestinal tract, muscle and skin and LZM activity in the hepatopancreas, intestinal tract and skin), antioxidant ability (T‐SOD, GSH‐PX and CAT activities and T‐AOC, GSH and MDA contents in the hepatopancreas, intestinal tract, muscle and skin) of loach. Moreover, dietary astaxanthin supplementation significantly up‐regulated the relative mRNA levels of Nrf2 and Maf, and down‐regulated the relative mRNA level of Keap1 in the hepatopancreas when the supplementation levels of astaxanthin were 50–200 mg/kg. In conclusion, the diets with 100–151.06 mg/kg astaxanthin supplementation were optimal for loach, which based on the growth, immunity and antioxidant‐related indicators, and the astaxanthin supplementation regulated the antioxidant ability partially referring to Keap1‐Nrf2 signallings.     

Effect of Astaxanthin on the Pigmentation of Goldfish Carassius auratus

The optimal dosage of astaxanthin for goldfish Carassius auratus was determined by feeding a series of diets containing 0, 25, 50, 75, and 100 mg of astaxanthin/kg of diet for 4 wk. The pigmentation on fish skin was measured by visual assessment against a color chart and by counting chromatophores produced in the dermis layer of fish skin. Both criteria showed that 36–37 mg/kg astaxanthin was the optimal dosage to stimulate fish color. A 4-wk observation after this experiment demonstrated that fish color stimulated by dietary astaxanthin was stable in its intensity. Therefore feeding astaxanthin could be a suitable way for goldfish producers to stimulate color among fish grown in an algae-free environment. The survival rate of fish fed diets with astaxanthin was significantly higher than fish fed diets without astaxanthin. However, there was no significant effect of astaxanthin on fish weight gain.     

Astaxanthin deposition in the flesh of Atlantic Salmon, Salmo salar L., in relation to dietary astaxanthin concentration and feeding period

Atlantic salmon, Salmo salar L., were fed nine experimental diets containing from 0 to 200 mg astaxanthin per kg^?1 for six time periods, ranging from 3 to 21 months, in sea cages at Matre Aquaculture Research Station, Matredal, Norway. The sampled fish had an initial mean weight of 115 g and reached a weight of 3.2 kg at the termination of the experiment. Every third month, 10 fish from each dose and time group were sampled and the astaxanthin concentration in the flesh determined. The amount of astaxanthin in the flesh ranged from 0.7 to 8.9 mg kg^?1 at the termination of the experiment. This paper discusses deposition of astaxanthin in the flesh of Atlantic salmon in relation to dietary carotenoid levels in the 0–200 mg kg^?1 range and feeding times of 3–21 months. Under the conditions of this experiment, no significant effect on astaxanthin deposition rate could be achieved by increasing the astaxanthin level above 60 mg kg dry feed^?1. Atlantic salmon should be fed astaxanthin-supplemented diets during the whole seawater stage in order to obtain maximal astaxanthin level in the flesh.