Feeding responses of juvenile shrimp Litopenaeus vannamei (Boone) fed at different frequencies under laboratory conditions     

Cibele Soares Pontes  Patricia Pereira De Lima  Maria de Fátima Arruda 《Aquaculture Research》2008,39(13):1416-1422

In shrimp farms, food partitioning during the course of the day is contradictory, ethology studies may help in determining the proper frequency. Litopenaeus vannamei juveniles were placed in 30 L aquariums (41 m⁻²), exposed to a 12:12 h light–dark cycle. Feeding was provided at 10% of biomass three, four and seven times per day, with observations made in 15 min h⁻¹ windows, initiated after the ration was offered. Latency to access the feeding tray and to start eating was recorded using instantaneous focal sampling and digestive tract filling (DTF) by the continuous focal method. Weight gain was recorded at the end of the experiment. We performed seven repetitions, with 28 individuals observed for 33 days for each treatment (490 h of observation). The three-times offering induced less latency for accessing the tray and for ingesting the feed as well as a higher DTF when compared with the other frequencies. Animals fed three and four times had similar weight gains, and were greater than those fed seven times. Our results indicate that a more spaced food offering stimulates the search for and ingestion of feed. As compared with other frequencies, the three-times-per-day option assumes lower labour costs and a more efficient use of the feed.  相似文献   

Effects of formalin on total haemocytes count and histopathological changes in the shrimp Litopenaeus schmitti (Pérez‐Farfante & Kensley 1997)     

Raico E Laria Lamela  Yanis Cruz Quintana  Raquel Silveira Coffigny  Mercedes Martínez  Norma González Herrate 《Aquaculture Research》2008,39(12):1316-1321

Formalin is used in shrimp industry to eliminate ectoparasites and as a disinfectant. However, the effect of formalin on shrimp's defense mechanism is unknown. Several biomarkers were used to assess the immune response of juveniles of the shrimp Litopenaeus schmitti exposed to different concentrations of formalin (10, 25 and 50 mg L^?1) during 24 and 48 h. Formalin concentrations of 25 and 50 mg L^?1 produced a significant reduction in the total haemocyte count at both 24 and 48 h. Peroxidase and phenoloxidase activity did not show variations. The total protein concentration in haemolymph of shrimps was not significantly different between experimental groups. Histological analysis showed hyperplasia in the gills of animals exposed at 10 mg L^?1 for 24 h; however, the exposure at 25 and 50 mg L^?1 caused necrosis in gills, hepathopancreas and the antennal gland.  相似文献   

Effect of casein substitution with fishmeal, soybean meal and crustacean meal in the diet of the abalone Haliotis discus hannai Ino     

S.H. CHO  J. PARK  C. KIM  & J.-H. YOO 《Aquaculture Nutrition》2008,14(1):61-66

The effect of dietary substitution of casein with fishmeal, soybean meal and crustacean meal on the growth of the abalone Haliotis discus hannai Ino was determined. A 350 g casein per kilogram diet was included into the CS diet. The whole casein was then substituted by: (1) 300 g fishmeal and 200 g soybean meal per kilogram diet (FS), (2) 200 g fishmeal, 200 g soybean meal and 130 g krill meal per kilogram diet (FSK), (3) 200 g fishmeal, 200 g soybean meal and 280 g red crab meal per kilogram diet (FSC) or (4) 200 g fishmeal, 200 g soybean meal and 130 g shrimp head meal per kilogram diet (FSS). In addition, a 50‐g by‐product of green tea per kilogram diet was included in the FS diet to form the FSG diet. Sea tangle (ST)diet was supplied to abalone as a control feed. Weight gain, final shell length and final shell width of abalone fed with the various substitution feeds (FS, FSK, FSC, FSS and FSG) were not different from those obtained with the CS diet. All the formulated feeds, however, produced higher weight gain and final shell width values than the ST diet. The results of this study show that casein can be replaced with a combination of fishmeal, soybean meal, krill meal, crab meal and/or shrimp head meal in the diet without a retardation of growth of abalone.  相似文献   

饲料中添加天蚕素抗菌肽对南美白对虾免疫功能、抗病力的影响     

房媛  董林娟  王孟  张龙龙 《中国饲料》2022,1(4):73-76

本研究以南美白对虾为研究对象,探究饲料中天蚕素抗菌肽的合适添加量。在饲料中依次添加不同浓度水平（0%、1%、2%、3%、4%和5%）的天蚕素抗菌肽,配制为6种配合饲料,用以投喂南美白对虾,饲养周期8周。结果显示：与对照组相比,饲料中添加天蚕抗菌肽对南美白对虾增重率、蛋白质沉积率和特定生长率有显著影响（P＜0.05）,高水平天蚕素抗菌肽会抑制南美白对虾的增重率和特定生长率,南美白对虾的饵料系数显著下降,但对南美白对虾存活率和摄食率无显著影响（P＞0.05）|随着饲料中天蚕素抗菌肽的添加水平不断增加,3%组南美白对虾的ACP、POD和SOD含量达到最大水平,与对照组有明显差异（P＜0.05）|随着饲料中天蚕素抗菌肽的添加水平的不断上升,3%组南美白对虾的淀粉酶、脂肪酶和胃蛋白酶含量最高,与对照组存在明显差异（P＜0.05）。结果表明,饲料中添加天蚕素抗菌肽显著提高南美白对虾的增重率和特定生长率,提高南美白对虾的生长发育速度,从而增强机体免疫力,提高南美白对虾的抗病能力。 [关键词]天蚕抗菌肽|南美白对虾|抗病力|免疫功能  相似文献   

笼养东北虎(Panthera tigiris altacia)的行为观察(英文)   总被引：3，自引：0，他引：3  

滕丽微  李枫  刘振生 《林业研究》2002,(3)

从1998年3月至2001年3月,采用全事件取样法和焦点动物取样法对哈尔滨动物园的4只笼养东北虎(1雄3雌)进行了系统的行为观察。笼养东北虎的行为可以分成5种主要的方式:运动、卧息、睡眠、取食和其他行为(饮水、排尿、修饰、嬉戏和站立)。在所有的行为类型中,睡眠和运动所占的比值很高(占整个时间分配的75.18%);而卧息、取食和其他行为仅占24.82%。除了取食,一只雄性和其中两种雌性东北虎的其他4种主要行为具有相似的活动规律,在白昼和夜晚各有一个活动高峰;而另外一只雌性东北虎在夜晚则具有两个活动高峰期。表2参16。  相似文献   

卷丹保健饮料的研制     

钟海雁  李忠海  王纯荣  农全畅 《中南林业科技大学学报(自然科学版)》2003,23(1):28-31

根据卷丹富含淀粉、蛋白质的特点 ,以干片及制淀粉所得的清汁为原料 ,进行了保健饮料的加工工艺研究 .结果表明 :采用 0 .0 2 %的黄原胶、0 .1%的 CMC—Na和 0 .1%的海藻酸钠作为稳定剂 ,使卷丹奶有较好的稳定性 ;卷丹奶饮料最佳配方为 :1∶ 9的卷丹与水混合 ,6%的白砂糖 ,4%的脱脂乳 ,0 .1%的柠檬酸 .清汁饮料的最佳配方为 :6%的白砂糖 ,0 .1%的柠檬酸  相似文献   

虾塘养殖对红树林沉积物和间隙水理化性质的影响     

覃盈盈  罗万次  梁铭忠  魏明月  高长颢  郑海雷 《农业现代化研究》2021,42(2):357-366

红树林湿地在近海水体营养控制和营养盐循环过程中扮演着重要的角色。沉积物、水体和植被相互作用共同维持其生态功能的运转,了解虾塘养殖对林下沉积物和间隙水养分特征影响对评价红树林生态功能具有重要指导意义。本研究以受虾塘养殖废水排放不同影响程度的红树林（无排放区、直排区、修复区）为研究样地,通过不同生境下沉积物与间隙水养分特征的分析,探讨虾塘养殖对他们的影响。结果如下：1）受虾塘养殖废水排放影响区中（直排区、修复区）红树林下沉积物TN与OM、TP呈正相关关系,虾塘养殖废水直排对林下沉积物具有明显酸化作用;2)NH4+-N是红树林下间隙水可溶性无机氮（DIN）的主要组成形式,无排放区沉积物还原性较强,更利于NH4+-N累积在间隙水中;NO3--N与DIN呈极显著相关,虾塘养殖废水排放增强了NO3--N、NO2--N和DIN的累积效应。研究结果表明沉积物和间隙水的理化性质可作为评价虾塘养殖区边邻红树林生境变化规律的定量指标之一。  相似文献   

致对虾肝胰腺坏死病副溶血弧菌荧光定量PCR检测方法的建立     

陈平亚  张亮亮  吴少荣  黄纪徽  王绥家  吴山楠 《广东农业科学》2021,48(11):119-125

【目的】建立一种对虾急性肝胰腺坏死病（Acute Hepatopancreatic Necrosis Disease）病原菌副溶血弧菌（Vibrio parahaemolyticus, VpAHPND）荧光定量 PCR 检测方法,对该病进行快速检测。【方法】根据副溶血弧菌基因保守序列设计特异性引物和探针,经优化反应体系及条件,建立检测 VpAHPND 的荧光定量 PCR 方法;以重组质粒为标准品制作标准曲线,并进行特异性、敏感性、重复性及临床应用试验。【结果】该方法定量范围宽,起始模板浓度范围为 2.3×101 ~2.3×107 拷贝 /μL 时,标准曲线具有良好的线性关系;最低检测限为 2.3 拷贝/μL,与对虾其他病原菌及病毒无交叉反应,重复试验变异系数为 0.45%~0.69%,可在 1 h 内完成样品检测;对临床对虾样品的检测结果表明,该方法与世界动物卫生组织（OIE）推荐的套式 PCR 法检测结果一致。【结论】应用 TaqMan 探针建立的检测 VpAHPND 的荧光定量 PCR 方法具有灵敏度高、特异性强、重复性好的特点,可有效用于临床对虾样品的 VpAHPND 检测。  相似文献   

卤虫卵化学成分的分离与分析   总被引：1，自引：0，他引：1       下载免费PDF全文

陶海荣  阮栋梁  戴宇容  李和 《水产科技情报》2004,31(2):59-61

本试验对卤虫卵的化学成分进行分离和分析。卤虫卵的含油量为7．1％，油中不皂化物的含量为4．9％，主要为胆甾醇。脂肪酸中含有较大量的油酸、棕榈酸、棕榈油酸、花生四烯酸和二十碳五烯酸。卤虫卵含蛋白质为20．9％，还含有多种氨基酸。  相似文献   

The effects of variation in feed protein level on the culture of white shrimp, Litopenaeus vannamei (Boone) in low-water exchange experimental ponds     

L R Martinez-Cordova  A Campaña-Torres  & M A Porchas-Cornejo 《Aquaculture Research》2002,33(12):995-998

The present study was conducted to evaluate the effect of varying dietary protein level on pond water quality and production parameters of white shrimp Litopenaeus vannamei (Boone). Experimental units consisted of nine 400‐m² earthen ponds with a low water exchange. Two treatments were tested: treatment HP consisted of shrimp fed a high‐protein diet (40%) during the whole grow‐out, and treatment LP consisted of the use of a low‐protein diet for the complete farming period. No differences on any of the water quality parameters were observed among treatments. Excellent survival (over 85%) and feed conversion ratios (around 1.6), and acceptable growth (over 12 g) and biomass (from 1721 to 1793 kg ha^?1) were recorded in all experimental ponds. No significant differences in any of the production parameters were found among treatment groups.  相似文献