白斑综合征病毒(WSSV)对不同规格克氏原螯虾(Procambarus clarkii)致病力及ATPase活性的影响

以投喂患白斑综合征病毒病(WSSV)的南美白对虾组织的方法人工感染健康的克氏原螯虾,利用PCR检测实验克氏原螯虾的感染情况;同时比较健康的克氏原螯虾和感染病毒的克氏原螯虾体内ATPase活性.结果显示:白斑综合征病毒可以感染克氏原螯虾,受感染的克氏原螯虾体内病毒含量与其死亡呈正相关;健康的克氏原螯虾和感染病毒的克氏原螯虾体内的ATPase活性分别为7.337 U/mgprot和4.212 U/mgprot,有极其显著的差异.     

蛋白质水平及能量蛋白比对克氏原螯虾生长与蛋白酶活力的影响

用3种不同蛋白质水平及能量蛋白比(E/P)水平饲料投喂克氏原螯虾,分析比较不同饲料对克氏原螯虾生长及蛋白酶活力的影响.试验结果表明,当饲料蛋白质水平为31.86%、E/P为35.85 kJ/g时,克氏原螯虾生长最快.随着饲料蛋白质含的上升, 克氏原螯虾肠蛋白酶活力无显著变化(P＞0.05),肝胰脏、胃蛋白酶活力显著增强(P＜0.05);饲料E/P水平未引起胃、肠、肝胰脏蛋白酶活力的显著变化(P＞0.05),当饲料蛋白质水平为31.47%、E/P为40.42 kJ/g时,克氏原螯虾蛋白酶活力最高.     

利用生物絮团技术对克氏原螯虾的养殖效果初探

为探究将生物絮团技术应用到克氏原螯虾养殖的可能性，本实验利用生物絮团技术和普通饲料投喂2种方式短期养殖体质量为(9.70±0.32) g的克氏原螯虾30 d。比较养殖期间2实验组的水化学指标以及实验结束时2实验组幼虾的生长情况，肌肉及肝胰腺营养成分组成，胃、肠和肝胰腺组织的消化酶活性，肝胰腺和肌肉组织的抗氧化能力。结果显示，①在养殖期间，絮团组水体总氮(TN)、亚硝态氮(NO₂^--N)、硝态氮(NO₃^--N)的质量浓度均维持在较低的水平。②本实验条件下2实验组虾的终末体质量、增重率(WG)、特定生长率(SGR)、存活率(SR)均无显著差异。③絮团的粗蛋白含量可以达到36.8%，能够满足克氏原螯虾对于蛋白的需求。但絮团的粗脂肪含量较低，这也影响了絮团组幼虾肌肉组织的粗脂肪沉积量。④絮团组幼虾肝胰腺中α-淀粉酶(α-AL)、脂肪酶(LPS)、纤维素酶(CL)活性均显著高于饲料组幼虾，而饲料组幼虾在胃、肠组织中的α-AL活性较高，2实验组幼虾的胃蛋白酶活性无明显差异。⑤絮团组幼虾的抗氧化能力与饲料组幼虾相比，肝胰腺中超氧化物歧化酶(SOD)活性较高，丙二醛(MDA)含量较低，但总抗氧化能力(T-AOC)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)以及溶菌酶(LZM)无明显差异。研究表明，生物絮团技术在克氏原螯虾的养殖中具有积极作用，可以达到与饲料投喂相同甚至更好的养殖效果。     

功能性饲料添加剂对克氏原螯虾非特异性免疫力及抗氧化能力的影响

为探索功能性饲料添加剂对克氏原螯虾非特异性免疫力及抗氧化能力的影响,选取大小一致、附肢完好的克氏原螯虾幼虾[初始平均体质量(9.84±1.17)g],随机分为2组,其中一组为对照组(D1,投喂普通商品料),另一组为试验组(D2,投喂功能性饲料).连续投喂40 d,分别于试验前(0d)、试验后第10、20、30、40天采...     

采用不同粒径膨化饲料养殖克氏原螯虾投饲策略研究

<正>饲料粒径会直接影响水产动物对营养成分的消化吸收，从而影响生长性能。克氏原螯虾在早期生长阶段生长速度快、个体变化大，只投喂一种粒径的饲料并不能满足克氏原螯虾幼虾快速生长阶段所需的营养。因此，有必要针对克氏原螯虾幼虾生长阶段制定不同粒径饲料的投饲策略。在实际养殖生产和试验研究中，多采用2毫米或3毫米粒径的饲料饲喂克氏原螯虾幼虾。     

不同含量螺旋藻饲料对克氏原螯虾两种消化酶的影响

在克氏原螯虾饲料中设置了0～8%共6个梯度的螺旋藻添加量,投喂成年及幼年虾35 d后,测定螯虾肠胃道蛋白酶和纤维素酶.结果表明:各梯度螺旋藻添加量下,幼虾胃蛋白酶活力和纤维素酶活力均显著高于成虾,但螯虾虾龄对消化酶的变化趋势并无明显影响.螯虾胃蛋白酶活力和纤维素酶活力升高的螺旋藻最低有效添加量分别为0.5%和2%,并分别在1%和2%螺旋藻添加量下达到一较高水平,此后随螺旋藻含量增加,两种酶活力仍随之升高,效果虽然不显著,但也一直维持在这一较高水平上.     

饥饿对克氏原螯虾仔虾消化酶和生化成分的影响

对照组连续饱食投喂6 d,处理组分别饥饿1、2、3、4、5、6 d,每组3个重复,研究了短期饥饿对克氏原螯虾仔虾消化酶活力和主要生化成分的影响.试验结果表明,在饥饿过程中,处理组胃蛋白酶、类胰蛋白酶、淀粉酶及纤维素酶变化趋势相同,先减小后增大,饥饿2 d后,4种消化酶均最小;淀粉酶与类胰蛋白酶活力比值(A/T值)不断增大.随着饥饿时间的延长,克氏原螯虾仔虾体内水分含量逐渐增多,总蛋白含量和碳水化合物含量不断减少,总脂含量变化不显著(P>0.05).     

养殖密度对克氏原螯虾幼虾生长、消化酶活力和生理生化指标的影响

以体质量(0.015±0.004)g克氏原螯虾幼虾为研究对象,研究了50、100、300、600、900尾/m25种养殖密度对克氏原螯虾幼虾生长、消化酶活力和生理生化指标的影响,实验周期为30 d。结果显示,克氏原螯虾幼虾的终末体质量随着养殖密度的增大而减小。胃蛋白酶、类胰蛋白酶和淀粉酶活力随着养殖密度的增大表现出减小趋势,纤维素酶和脂肪酶活力在5种养殖密度下变化规律不显著(P>0.05)。克氏原螯虾幼虾体内水分含量在5种养殖密度下差异较小(P>0.05);粗蛋白含量随养殖密度的升高呈增高趋势,由54.02%增高至60.75%(P<0.05);粗脂肪含量不断减少(P<0.05),由26.19%减少至19.19%(P<0.05)。随着养殖密度的增大,克氏原螯虾幼虾肌肉葡萄糖的含量呈下降趋势(P<0.05),甘油三酯、总蛋白、尿素氮和胆固醇含量呈不断增多趋势(P<0.05)。克氏原螯虾幼虾肝胰腺葡萄糖、甘油三酯、总蛋白和尿素氮含量随着养殖密度的增大呈不断增多趋势。结果表明,高密度养殖对克氏原螯虾幼虾生长和消化酶活力具有一定负面影响,体内蛋白、脂肪、葡萄糖和尿素氮等物质的含量也随着养殖密度的增大而发生变化。     

克氏原螯虾幼体发育时期消化酶活力及氨基酸含量研究

采用生物化学方法对克氏原螯虾各期幼体消化酶活力与氨基酸组成进行了分析。实验结果显示,在克氏原螯虾幼体发育过程中,五种消化酶活力(胃蛋白酶、类胰蛋白酶、淀粉酶、纤维素酶和脂肪酶)表现出两种变化模式:胃蛋白酶和类胰蛋白酶在幼体发育Ⅱ龄幼体期和Ⅳ龄幼体期活力较高,其中Ⅳ龄幼体期该两种酶活力最高;淀粉酶、纤维素酶和脂肪酶活力为先增高后降低,在Ⅲ龄幼体期,三种酶的活力达到最高,但与Ⅳ龄幼体期的酶活力比较无显著差异。总氨基酸含量在幼体发育早期逐渐降低,幼体发育至Ⅲ龄幼体期,其氨基酸含量最低,Ⅳ龄幼体期又有所增加。在测定的所有氨基酸中谷氨酸含量最高,必需氨基酸中赖氨酸含量最高,单个必需氨基酸含量与必需氨基酸总量的比值(A/E)在整个胚胎发育过程中的变化趋于一致。     

水草和螺蛳对克氏原螯虾性腺发育的影响

本文对水草、螺蛳、水草+螺蛳三种投喂方式对克氏原螯虾性腺发育的影响进行了研究。结果显示,水草+螺蛳组的克氏原螯虾(雌虾体长9.5cm)的抱卵量826粒/尾,显著高于水草组、螺蛳组(P<0.05),成熟度5.95%、抱卵指数19.20粒/g、亲虾成活率89.66%、抱卵率79.31%,结果均高于投喂水草组或螺蛳组。显然,植物性和动物性饵料混合喂养更有利于促进克氏原螯虾雌虾性腺发育及提高亲虾的成活率。     

Evaluation of a spray-dried artificial diet for larval culture of freshwater prawn, Macrobrachium rosenbergii, and striped bass, Morone saxatilis

Larvae of the freshwater prawn, Macrobrachium rosenbergii (De Man), and the striped bass, Morone saxatilis (Walbaum), were fed artificial diets manufactured by a spray-drying process or live Artemia nauplii , separately or in various combinations. Spray-dried diets were neutrally buoyant, water stable (low protein leaching rate), and were satisfactorily consumed as verified by the observation of full guts after feeding. Survival and growth of larvae fed live Artemia nauplii was significantly greater than those of larvae fed spray-dried diets. Lowest survival and growth rates were observed when larvae were fed artificial diets exclusively from the onset of exogenous feeding. Survival rates were positively related to the duration of feeding live Artemia nauplii before weaning to artificial diets. The poor performance associated with spray-dried artificial diets may be the result of the digestive capabilities of the larvae of caridean shrimp and striped bass being insufficient to process compact, dense particles.     

Factors influencing the survival and growth of turbot larvae, Scophthalmus maximus L., during the change from live to compound feeds

In a series of 14 trials the survival of turbot larvae during transfer from a live to an inert food ranged from 45% to 95%. The time taken for up to 50% of each batch to establish feeding was also highly variable, ranging from 1 to 11 days. The potential to accept inert food was probably established during the initial stages of weaning or even earlier. Final survival could reliably be predicted from survival and feeding response during the first few days of weaning. Evidence was presented which suggests that the quality of the live food (Artemia salina L.) influenced the subsequent acceptance of an inert diet. For example, larvae reared on San Francisco Bay nauplii accepted an artificial diet less readily than those reared on Artemia which had first been fed on the unicellular alga Isochrysis for 2 days. Dietary water content was not an important factor governing weaning success.     

Effects of weaning age and diets on ontogeny of digestive activities and structures of pikeperch (<Emphasis Type="Italic">Sander lucioperca</Emphasis>) larvae

Growth and ontogeny of digestive function were studied in pikeperch (Sander lucioperca) larvae weaned on artificial food at different ages. Three weaning treatments initiated respectively on day 9 (W9), day 15 (W15) or day 21 (W21) post-hatching (p.h.) were compared with a control group, fed Artemia nauplii from first feeding until the end of the rearing trial on day 36 p.h. The digestive enzyme activities and the ontogeny of digestive structures were investigated using enzymatic assays and histological methods. Growth of pikeperch larvae was significantly affected by precocious weaning. Pancreatic (trypsin and amylase) and intestinal (leucine-alanine peptidase, leucine aminopeptidase N and alkaline phosphatase) enzyme activities were detected from hatching onwards, increased at the moment of first feeding and then decreased. Pepsin secretion occurred at day 29 p. h. only, concurrently with the stomach development and differentiation of gastric glands. In the early weaning group (W9) the maturation process of intestinal enterocytes seems to be impaired and/or delayed and several signs of malnutrition were recorded. Except for alkaline phosphatase activity, no differences in enzyme activities and development of digestive structures were observed among the control, W21, and W15 groups. Moreover, at the end of the experiment, no differences in proteolytic activities were observed among larvae from the different treatments, indicating that, in surviving individuals, the digestive structures were properly developed and the larvae had acquired an adult mode of digestion. Based on the artificial diet used, our results suggested that pikeperch larvae can be weaned from day 15 p.h. without significant adverse effect on digestive capacities (except for alkaline phosphatase) or development of digestive tract, while earlier weaning impaired the onset of the maturation processes of the digestive system, both in terms of morphological structures and enzymatic activities.     

不同饵料对海蜇幼体生长、消化酶、抗氧化和免疫酶活力的影响

本研究旨在探讨不同饵料对海蜇(Rhopilema esculentum)幼体生长、消化酶、抗氧化酶和非特异性免疫酶活力的影响。实验设置4个饵料组:小球藻组、虾片(对虾开口饵料)组、卤虫无节幼体组和混合组(卤虫无节幼体和虾片等比例混合),养殖实验持续进行30 d。结果显示:混合组和卤虫无节幼体组海蜇的增重率(WGR)和特定生长率(SGR)都显著高于其他各组(P<0.05);混合组海蜇胃丝的蛋白酶活力显著高于小球藻组和虾片组(P<0.05);虾片组海蜇口腕的淀粉酶活力显著高于其他各组(P<0.05);各饵料实验组的脂肪酶活力均显著高于初始组(P<0.05);在海蜇的体腔液中,混合组和卤虫无节幼体组的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、总抗氧化能力(T-AOC)和溶菌酶(LZM)活力均显著高于其他各组(P<0.05)。研究表明,混合组和卤虫无节幼体组可以显著促进海蜇的生长,增强海蜇的抗氧化能力和免疫酶活力。     

Larval Rearing of Common Carp Cyprinus carpio: A Comparision Between Natural and Artificial Diets Under Three Stocking Densities

Common carp Cyprinus carpio larvae were cultured under two feeding conditions: live food or an artificial diet for 40 d in recirculating systems. Three stocking densities of 25 (low), 50 (medium), and 100 (high) larvae/15-L aquarium were maintained for each feeding treatment. Significantly higher survival (91%) and growth (401.08 ± 2.61 mg) were observed in the low density, live food system. Average weight of larvae in the live food system was 3- to 5-fold higher than larvae at the same stocking density for the artificial diet. Proteolytic activity showed a direct relationship with the length of the digestive tract (r = 0.95). The highest enzyme activity was observed in the low density, live food system. Survival and growth of common carp larvae are influenced by both the stocking density and the type of food.     

The Use of Decapsulated Cysts of the Brine Shrimp Artemia as Direct Food for Carp Cyprinus carpio L. Larvae

Decapsulated Arremia cysts have been evaluated as a direct food source for larvae of the carp Cyprinus carpio L. All decapsulated cyst diets gave excellent survival of carp larvae during the first two weeks of culturing. Unlike traditionally brine-stored decapsulated cysts, dried Artemia embryos provided growth results comparable to those obtained with freshly hatched Artemia nauplii. Furthermore, except for Artemia embryos that lost their hatchability after long-term storage in air, several other inactivation treatments, simulating improper harvesting and processing of cysts, did not produce a significant decrease in the nutritional quality of the decapsulated cysts.
Using decapsulated cysts 89 a direct food source for carp larvae, instead of nauplii, the quantity of cysts needed can be reduced by about 25% to 35% after one and two weeks of culturing, respectively. Moreover, the use of decapsulated cysts advances the possible commercialition of poor-hatching and less expensive cyst products for culture of carp larvae.     

饲料蛋白质和能量水平对草鱼幼鱼生长和消化酶活性的影响

在水温24～29℃下,将675尾规格整齐、健康、体质量为（35.59士0.44）g的草鱼（Ctenopharyngodon idel-lus）随机分为9个处理,每处理3个重复,放养于水泥池中的网箱（100cm×50cm×100cm）内,投喂以鱼粉和豆粕为蛋白源,豆油作为脂肪源配制的3个蛋白水平（24%、28%、32%）,每一蛋白水平设3个脂肪水平（4%、6%、8%）,共计9种饲料。饲料蛋能比（P/E）在15.81-22.46 mg·kJ-1之间。92d的饲养表明：D4组（蛋白质含量为28.02%,脂肪为4.30%）草鱼的特定生长率最高,显著高于其他各组（P〈0.05）。随着饲料中蛋白含量的增加,草鱼全肠中蛋白酶的活力逐渐升高,之后又降低,以D4组饲料的蛋白酶活性最高,显著高于D1、D8和D9（P〈0.05）。本实验表明,该生长阶段的草鱼所需最适蛋白水平为28.02%,能量为14307kJ.kg-1,P/E约为19.58mg·kJ-1。     

Heat treatment affects protein quality and protease activity in decapsulated cysts of Artemia when used as starter food for larvae of African catfish Clarias gariepinus (Burchell)

Decapsulated cysts of Artemia subjected to different heat treatments (40, 60, 80 and 96 °C) were fed to African catfish Clarias gariepinus larvae. Heated cysts, untreated cysts and live Artemia nauplii as control constituted the experimental diets. Protein denaturation and solubility, total alkaline protease and specific trypsin activities in the cyst diets were evaluated. The growth of catfish larvae and the proteolytic activity of larval samples during development were also determined. Heat treatment of cysts increased protein denaturation and decreased protein solubility. The protease activity in the cyst diets decreased with higher heating temperatures. The growth of catfish larvae differed according to the diet; higher fish growth was achieved with nauplii and cysts heated at 40 °C. The digestive enzyme activity in larval samples remained similar in all dietary treatments during larval development. The quality of food protein and the way this protein is processed might be more important for successful larval growth than exogenous enzyme supply.     

Larval Rearing and Weaning Techniques for White Bass Morone chrysops

The effects of culture parameters of tank color and feeding regimes were examined on larval white bass Morone chrysops during 1994–1995. Under high surface illumination (998 lux), dark tank walls were essential for effective prey capture. Larvae reared in clear glass aquaria did not grow and had died by day 6 of the study. In contrast, 48.7% of the larvae reared in black-walled tanks were alive on day 24 and had grown to 17.2 mm total length (TL). In another study, larvae were fed rotifers Brachionus plicatilis and Artemia nauplii in different feeding protocols. In one treatment only rotifers (10/mL) were fed day 1 (4 d post-hatch), rotifers and Artemia (3/mL) were fed days 2–4, and Artemia fed days 5–15. This protocol produced similar growth (mean size 11.7 mm TL) and survival (mean 30.3%) as slower weaning times from rotifers to Artemia . Juveniles (27-day-old, 17.2 mm TL) were converted to a dry crumble diet over a 14-d period by slow transfer from a combination diet consisting of live Artemia nauplii, frozen adult Artemia , plankton flakes and dry crumbles. Survival offish weaned to the dry diet was 64.5%. Most of the mortalities during the weaning period were fish with uninflated swim bladders which were cannibalized by larger fish. Using the above tank culture techniques, white bass were reared to a mean size of 73.2 mm TL (mean weight 5.8 g) over a 73-d period. This essentially closes the life cycle of white bass.     

史氏鲟南移驯养及生物学的研究:Ⅲ.仔鱼的开口摄食

用单一的水蚯蚓、卤虫无节幼体、池塘浮游动物、人工配合饲料投喂及先卤虫无节幼体后人工配合饲料混合投喂等五种方式培育史氏鲟仔鱼。结果为：卤虫无节幼体是史氏鲟最好的开口饵料,可获得高的成活率和生长率;开口摄食后３－５天,即可开始投喂人工饵料进行食性驯化,２０日龄的鱼苗可获得满意的饵料驯化效果。