饲料中不同脂肪源对七彩神仙鱼幼鱼生长和成活的影响

在水温为29.0±1.0℃条件下,将体质量为6～7g的七彩神仙鱼(Symphysodon aequifasciata)放入54cm×40cm×28cm的水箱中,投喂以鱼粉和豆粕为蛋白源(粗蛋白45.0%)、以花生油(PO)、芝麻油(ZO)、豆油(SO)、深海鱼油(FO)为脂肪源(添加5.0%,粗脂肪16.0%),相互搭配使亚油酸和亚麻酸含量为0.55%(1.0%SO 4.0%FO)、1.61%(5.0%PO)、1.98%(1.31%PO 3.69%ZO)、2.36%(3.04%ZO 1.96%SO)和2.74%(5.0%SO)的5种饲料,每种饲料3个重复.60d的饲养期间,七彩神仙鱼幼鱼的成活率变化在83.33%～100%之间,各组间差异不显著(P>0.05).但摄食添加豆油饲料鱼的特殊生长率(SGK)最高,显著高于其它组(P<0.05).摄食添加鱼油饲料的鱼最低.摄食含豆油和芝麻油与豆油混合饲料的鱼饲料效率(FER)最高,显著高于其它组(P<0.05),摄食鱼油为主、单一花生油和花生油与芝麻油混合饲料的鱼最低.摄食3种植物油混合饲料的鱼的蛋白效率最高,显著高于其它组(P<0.05),摄食单一花生油饲料的鱼最低.鱼体蛋白含量(y)与亚油酸和亚麻酸含量(x)的二次曲线方程为:Y==40.161x2=187.55x=133.76,即亚油酸 亚麻酸含量占饲料干物质的2.36%～2.74%时,生长较快,饲料转化效率较高.     

叶黄素对七彩神仙鱼生长和体色的影响

为研究叶黄素对七彩神仙鱼体色和生长的影响,在"牛心汉堡"饲料中分别添加0、50、100、200、300和400 mg/kg叶黄素,饲喂初始平均体质量(10.3±0.3)g的七彩神仙鱼8周。结果显示,添加叶黄素50~200 mg/kg,对鱼体增重率无显著影响,但添加量达200 mg/kg后,饲料系数显著增大,添加量达300 mg/kg后,增重率显著降低。在养殖4周、8周时,鱼体皮肤亮度(L*)无显著变化,皮肤黄度(b*)和叶黄素含量随叶黄素添加量增加而显著升高;8周时,各叶黄素添加组的皮肤b*值和叶黄素含量显著高于4周时,当叶黄素添加量达300 mg/kg后,皮肤b*值(4周、8周)和全鱼叶黄素含量(8周)趋于稳定;4周时,各处理组间的皮肤红度(a*)无显著差异;8周时,当叶黄素添加量达100 mg/kg后,皮肤a*值显著降低;饲料中添加300 mg/kg叶黄素显著提高了七彩神仙鱼肝脏总抗氧化能力。研究表明,在饲料中添加叶黄素可有效改善七彩神仙鱼体表黄色,提高肝脏总抗氧化能力,但高添加量的叶黄素会降低鱼体生长性能,七彩神仙鱼饲料中的叶黄素添加量建议为200~300 mg/kg。     

水硬度对七彩神仙鱼幼鱼发育的影响

采用不同硬度的水对七彩神仙鱼幼鱼进行饲养。6周龄幼鱼在硬度为7.94°dH±0.30°dH时饲养84d后,比在硬度为14.71°dH±0.23°dH水中的幼鱼个体大,生长速度快。表明较高硬度的水有利于七彩神仙鱼幼鱼的生长发育。     

七彩神仙鱼生产技术(中)

3．蓄水池 蓄水池的主要作用是水的预处理。七彩神仙不同生长阶段对水质有不同要求,因此在将新水加入到鱼缸之前需经过处理。水处理一般考虑这几个方面：①水温,如果新水温度与鱼缸内水温相差较大．则必须调整到相近的水温、因此建议蓄水池不要设在室外,②酸碱度,七彩神仙喜欢弱酸性的水质,而且酸碱度必须稳定．如果一天之内pH值变化超过0．2就会令其不适而染病。如果水源水pH值大于7．0,就必须在储备水中加入增酸剂,     

繁殖优秀七彩神仙鱼的技巧

七彩神仙鱼的人工繁殖现在已不是什么新鲜话题了，但要想繁殖出艳丽优秀的七彩神仙鱼，还须掌握好以下几点技巧：     

饲料中维生素C对七彩神仙鱼仔幼鱼非特异性免疫的影响

通过投喂维生素C含量为0～2000.0mg/kg的饲料,对七彩神仙鱼仔幼鱼非特异性免疫进行了研究。结果表明,当饲料中维生素C的添加量达到500.0mg/kg(Ⅴ组)以上时,七彩神仙鱼仔幼鱼血清替代补体活力、溶菌酶活力和白细胞吞噬活性均开始显著高于对照组(P<0.05),且同一水平随时间的增加而升高。添加量达1500.0mg/kg(Ⅷ组)之后,随着饲料中维生素C添加量的进一步增加,各组数据反而呈下降趋势。可见饲料中适量添加维生素C能够提高七彩神仙鱼仔幼鱼的非特异性免疫力,维生素C缺乏和过量都会对其带来不利影响。     

七彩神仙鱼的选购与放养

笔者从事七彩神仙鱼的养殖销售几年，借此就有关七彩神仙鱼的选购与放养中所遇到的问题与大家共同探讨。只有健康的七彩神仙鱼才能留住鲜艳色彩和美丽迷人的图案。如何挑选一款健康的七彩神仙鱼呢？首先看鱼的摄食与排泄是否正常。索饵敏捷的鱼，不但身体强壮，而且适应力强，容易饲养。好的七彩神仙鱼排出的粪便结实而分段，颜色深褐色或暗红色。如果有粪便拖拉，或拉白便现象则切不可购买。其次看七彩神仙鱼的眼睛、鳍及体形表现情况。眼睛是七彩神仙鱼的健康与否的窗口，好的七彩神仙鱼眼睛红而明亮，眼珠越亮表示鱼越健康，眼球与身体的…     

卡拉胶对七彩神仙鱼生长、酶活性和肠道微生物组成的影响

为探究黏合剂卡拉胶对七彩神仙鱼生长、消化酶活性、抗氧化酶活性和肠道微生物组成的影响,在水温(28.0±0.5)℃下,将初始体质量(10.81±2.41) g的七彩神仙鱼饲养在80 L养殖缸中,每缸15尾,投喂添加3%、6%、9%、12%和15%卡拉胶的饲料,以投喂不添加卡拉胶的颗粒饲料和牛心汉堡为对照,养殖56 d。结果表明：3%卡拉胶组七彩神仙鱼质量增加率和特定生长率最高,胃蛋白酶活性和前肠淀粉酶活性显著高于其他组,肝脏丙二醛含量和谷胱甘肽过氧化物酶活性显著低于其他试验组;12%卡拉胶组肝脏超氧化物歧化酶活性显著高于其他试验组。在肠道微生物组成的门水平方面,3%卡拉胶组变形菌门相对丰度显著高于其他组,梭杆菌门的相对丰度减少;在属水平方面,牛心汉堡组不含有乳球菌属,3%卡拉胶组罗姆布茨菌属相对丰度显著高于其他卡拉胶组,牛心汉堡组的鲸杆菌属相对丰度显著高于其他组。添加3%的卡拉胶能够提高七彩神仙鱼的质量增加率和特定生长率,显著提高胃蛋白酶和前肠淀粉酶活性,且不会造成氧化应激,肠道变形菌、罗姆布茨菌和乳球菌的相对丰度增加。在本试验条件下,七彩神仙鱼饲料中卡拉胶的适宜添加量为3%。     

七彩神仙鱼的繁育试验

随着人民生活水平的提高,居住条件的不断改善,观赏鱼作为一种活的艺术品成为广大群众,尤其是都市人工作后的消遣佳品,使得观赏鱼市场急剧升温,中高档名贵观赏鱼的养殖具有广阔的发展空间。据介绍,广州市芳村区观赏鱼批发市场去年从国外引进的名贵观赏鱼交易就超过10亿元人民币。七彩神仙鱼又名七彩燕,原产南美亚马逊河流域,属热带鱼。因其仔鱼靠吸吮亲鱼体表分泌的粘液而生长,所以又称“奶子鱼”。七彩燕因其丰富华丽的体色,侧扁的圆盘体型而广受观赏鱼爱好者的喜爱,是世界上名贵的观赏鱼之一。七彩燕的繁殖具有一定的难度,笔者曾进行过…     

七彩神仙鱼工厂化养殖技术初探

为探究七彩神仙鱼工厂化养殖技术,在水温28～30℃的室内水泥池中开展了七彩神仙鱼养殖试验,放养的幼鱼全长1.5～2.0 cm,放养密度为200尾/m³。经过约120 d养殖,试验鱼全长达9.0～10.0 cm,达到商品规格。结果表明,七彩神仙鱼每年可养殖3茬,平均成活率达87.8%,平均单位水体产出达175.6尾/m³。工厂化养殖系统可全年生产运转,水质相对稳定,单位水体养殖密度较高。     

Assessment of soybean meal in diets for discus (Symphysodon aequifasciata HECKEL) farming through a fishmeal replacement study

A 12‐week feeding trial was carried out with discus (Symphysodon aequifasciata HECKEL), a valuable ornamental species produced in South East Asia, to determine the suitability of using soybean meal as a partial fishmeal substitution in the diet. Juvenile discus (4.3–4.8 g) was fed eight experimental diets with graded levels of soybean meal replacing fish meal (0%, 10%, 20%, 25%, 30%, 35%, 40%, 50%). Growth performance (relative growth rate, specific growth rate) decreased and feed utilization (feed conversion ratio, protein efficiency ratio) was worsened at 30% replacement and higher. Amino‐acid analysis indicated methionine and lysine deficiencies at dietary high soybean replacement levels, although the essential amino‐acid requirements for this species are unknown. The level of soybean in diets negatively affected both dry matter and protein digestibility. This present trial showed the need for further studies involving amino‐acid supplementation, different soy products and palatability enhancement to improve utilization of diets containing soybean meal to allow higher than the maximum 30% replacement level suggested here.     

Characterization of protease activity in developing discus Symphysodon aequifasciata larva

The activity of different protease classes was monitored in developing discus (Symphysodon spp.) larvae using a combination of biochemical assays and substrate SDS–PAGE techniques. Results showed the presence of alkaline proteases of serine proteases such as trypsin with a significant increase in activity levels detected beginning 3 days after hatching. Other alkaline proteases such as metallo‐proteases and chymotrypsin, a type of serine protease, were only detected in older larval stages, at around 20–30 days after hatching. Acidic protease activity was very low during the first 20–25 days of development before showing a significant (P < 0.01) rise. This is despite the formation of a stomach observed 10 days after hatching. Based on the development of the protein digestive system observed, the use of microdiets to replace Artemia should be considered 25 days after hatching.     

比较3种饲料对牙鲆生长和消化率的影响

选取平均体重为(359±16)g/尾的健康牙鲆48尾,随机分成3组,每组2个重复。采用3种不同饲料进行投喂,比较牙鲆专用配合饲料对牙鲆生长速度、饲料效率及消化率的影响。经过42d的饲养,结果表明:自配饲料(A组)增重速度最快、饲料系数最低,尾相对增重率达到230.1%、饲料系数达到1.59。牙鲆每增重1.0kg所需饲料成本最低,与B组、C组相比分别节省了13.7%和18.9%。A组的干物质消化率为81.56%,比B组、C组分别高5.33%和9.39%。A组的蛋白质消化率为91.17%,比B组、C组分别高3.26%和7.51%。     

Amino Acid Profile of Various Body Tissues and Eggs of Discus Fish,Symphysodon aequifasciata

Abstract

Amino acid profiles of various body tissues from juvenile and adult discus fish, Symphysodon aequifasciata, were compared. Results from whole-body tissue revealed significant difference (P < 0.05) between the levels of lysine, phenylalanine, alanine, aspartic acid, and serine among the two different fish sizes. Levels of arginine, histidine, leucine, methionine, phenylalanine, and threonine were also higher in muscle tissue of adult fishes. Analysis of gill tissues showed significant difference in levels of histidine, isoleucine, lysine, methionine, threonine, tryptophan, aspartic acid, glutamic acid, proline, and serine were significantly different among the different fish stages. This study also showed that among all ten essential amino acids, muscle had the highest levels of histidine, isoleucine, lysine, and tryptophan; gills had the highest level of arginine; while levels of methionine and threonine were higher in the intestinal tissue. Regression analysis between the calculated whole-body A/E ratio of discus juveniles and with quantitative dietary amino acid requirements of several fish species also showed significant correlation, with highest r values (> 0.90) obtained with tilapia, common carp, channel catfish, and Japanese eel. This profile may be useful as a preliminary reference index to evaluate suitability of various ingredients in terms of amino acid profile for development of economical diet for discus farming.     

Effect of varying levels of dietary protein on the growth performance and feed conversion efficiency of snakehead Channa striata fry

Six isocaloric test diets, based on fishmeal-groundnut oil cake and containing 350–600 g kg^?1 protein at 50 g kg^?1 incremental levels were fed to snakehead, Channa Striata (Bloch), fry at a rate of 10% of body weight per day under laboratory conditions to determine the effect of varying level of dietary protein on the growth response. On the basis of percentage weight gain, daily weight gain, specific growth rate and daily tissue protein deposition, the dietary protein requirement of fry was found to be 550 g kg^?1 when fish meal was used as the major source of protein. There was a significant increase in carcass protein and a significant decrease in ash content with progressive dietary protein substitution. Fry fed with high protein diets tended to have lower carcass lipid contents and higher moisture contents.     

Effects of dietary vitamin C and vitamin E on the growth,antioxidant defence and digestive enzyme activities of juvenile discus fish (Symphysodon haraldi)

A 56‐day experiment was carried out to investigate the effects of dietary vitamin C and vitamin E on the growth, antioxidant status and digestive enzyme activities of discus fish (Symphysodon haraldi; initial body weight: 7.96 ± 0.61 g and body length: 5.45 ± 0.65 cm). Animals were fed with 13 different diets including one control diet and 12 treatment diets containing four levels of vitamin C (magnesium‐L‐ascorbyl‐2‐phosphate; 40, 80, 120 and 160 mg/kg) crossed with three levels of vitamin E (DL‐α‐tocopheryl acetate; 40, 80 and 120 mg/kg). The results showed that the fish fed diets containing additional vitamin C (40 mg/kg) and vitamin E (80 mg/kg) showed higher specific growth rate, length growth rate, total antioxidant capacity and protease activity but had lower feed conversion ratio and total superoxide dismutase activity than those fed the control diet. Collectively, these findings suggest that the inclusion of additional 40 mg/kg of vitamin C and 80 mg/kg of vitamin E in the basal diet could have beneficial effect on the growth, antioxidant defence and digestion of S. haraldi.     

糖和蛋白质水平对饲养于咸淡水中的凡纳滨对虾生长、体营养成分组成和消化率的影响

试验制作了蛋白梯度为35%,40%,45%的6种饲料,在每种蛋白水平下设计两种糖水平（15%和20%）,饲养初始体重为(1.10±0.02) g的凡纳滨对虾,经过56 d的生长试验,观察不同糖和蛋白质水平对于凡纳滨对虾的生长、成活率、机体营养组成和消化率的影响。实验结果表明,凡纳滨对虾对不同水平的糖和蛋白质的利用表现出差异性。各组的成活率没有表现出显著差异,糖水平为20%且蛋白水平为35%组的成活率要高于其它各组,糖水平为20%且蛋白水平为45%组最低,它们分别为93.3%和61.1%。糖水平为20%且蛋白水平为35%组的凡纳滨对虾体增重在各组间最高(269.4%),而且明显高于糖水平为20%且蛋白水平为45%组(117%)（P<0.05)。糖和蛋白质水平对全虾脂肪含量影响较大,在同一糖水平下,体脂肪含量随饲料蛋白含量的升高而升高;同样,在同一蛋白水平下,20%糖组的体脂肪含量要高于15%糖组。糖和蛋白质的水平对凡纳滨对虾对干物质和蛋白质的消化率影响不显著;糖的消化率在蛋白水平为35%且糖水平为20%组最高（P<0.05)。表4参21     

Interactive effect of photoperiod and temperature on the growth rates,muscle growth and feed intake in juvenile Atlantic halibut

To investigate the interactive effects of temperature and photoperiod on the growth performance, feeding parameters and muscle growth dynamics in juvenile Atlantic halibut (Hippoglossus hippoglossus L.), a total of 1212 juvenile halibut, including 383 tagged fish (mean initial weight of tagged individuals: 17.6 ± 0.3 g SE), were reared under a simulated natural light regime for Bergen (60°25′N) or continuous light at 9, 12 and 15 °C from 3 December 2007 until 11 March 2008. The mean weight and growth rate were significantly higher at 12 and 15 °C than at 9 °C. In addition, significantly higher mean weight and growth rate were observed in halibut reared under continuous light at a low temperature, indicating an interactive effect of temperature and photoperiod on growth performance. No effect of temperature or photoperiod was found with respect to feed conversion efficiency, whereas a higher feed consumption at increasing temperature and a higher overall daily feeding rate at continuous light at a low temperature were observed. Indications of continuous light having a stronger effect at low temperatures on muscle growth dynamics were found. A difference in the size class distribution of fibre diameter was found between photoperiod treatments at 9 °C, suggesting that continuous light resulted in elevated hypertrophic growth at low temperature. This may suggest that the increased growth rate found at continuous light at 9 °C may be a result of hypertrophic growth in juvenile halibut.