ω_3HUFA对中华绒螯蟹幼体存活率及体脂肪酸组成的影响

分别以经海水小球藻、牟氏角毛藻和５０ＤＥ－Ｇ强化剂强化的轮虫投喂中华绒螯蟹早期幼体,至Ｚａｏ状Ⅲ期后改喂卤虫无节幼体,探讨了饵料ω－３系列高度不饱和脂肪酸对幼体发育和存活的影响。结果表明：小球藻轮虫组的幼体发育至第Ⅰ期幼蟹的存活率最高,为１２．００％,强化剂轮虫组和角毛藻轮虫组次之,分别为１０．６７％和９．６７％,而酵母轮虫组最低,仅为３．６７％;结合分析Ｚａｏ状Ⅴ期幼体脂肪酸组成可知,幼体发育至第Ⅰ期幼蟹的存活率与其总脂含量和ω－３ＨＵＦＡ含量密切相关,而Ｚａｏ状Ⅴ期幼体总脂含量与ω－３ＨＵＦＡ含量随饵料轮虫总脂和ω－３ＨＵＦＡ含量的增加而提高,表明早期幼体所摄取的ω－３ＨＵＦＡ对后期幼体发育和存活有明显的促进作用。     

不同饵料对中华虎头蟹幼体发育和存活率的影响

为探讨中华虎头蟹苗种繁育过程中饵料及投喂的影响,进行了不同饵料对中华虎头蟹溞状幼体和大眼幼体生长发育和存活的影响实验。实验结果,中华虎头蟹各期幼体生长发育效果较好的饵料为动物性饵料,Z1期以卤虫无节幼体为开口饵料,只投喂扁藻后期幼体发育较差;Z2以轮虫和卤虫无节幼体的搭配为好;Z3期则以轮虫为适宜饵料;M期投喂卤虫无节幼体效果相对较好。     

提高河蟹育苗成活率技术研究

采用逐步降低培育用水盐度,合理控制培育密度,严格掌握饵料投喂量,蚤状Ⅰ期投喂烫死的卤虫无节幼体,蚤状Ⅴ期幼体变态时投喂充足的成体卤虫等措施,提高了河蟹育苗成活率和单位水体出苗量。结果：在５００ｍ＾中,５６０只亲蟹一次出苗２０５．６ｋｇ,变态成大眼幼体１４０．６ｋｇ,成活率２３．４％,平均每立方米水体出苗０．４ｋｇ。     

蒜头藻强化轮虫及其对河蟹蚤状幼体生长的影响

驯化的蒜头藻经过培养可以达到一定的密度,其对轮虫种群增长的促进作用优于海水小球藻、酵母,用此轮虫以及海水小球藻、酵母强化的轮虫、蛋黄分别投喂中华绒螯蟹蚤状幼体Z1到Z2期,发现这4种饵料所喂养的蚤状幼体的存活率分别为59.5%、55.0%、50.0%、35.5%;蜕皮时间分别为68.5 h、71.5 h、76.5 h、73.5 h.由此可见,海水蒜头藻强化的轮虫能明显缩短蚤状幼体从Z1到Z2的蜕皮时间,并能提高存活率.     

大黄鱼的几种病害及防治

现将大黄鱼在养殖中常见的几种病害及防治方法综述如下,以供参考。１仔鱼鳔异常膨大病１．１主要症状与病因仔鱼体表发白,常浮于水面,空胃,镜检发现鱼鳔异常膨大,是缺乏高度不饱和脂肪酸（ω３ＨＵＦＡ）所致的一种营养缺乏症。１．２防治方法大黄鱼仔鱼对营养要求很高,特别是高度不饱和脂肪酸,是促其生长发育必需的营养物质,因此,投喂的生物饵料（轮虫、卤虫无节幼体）必须经过营养强化。其方法是：轮虫必须经过高浓度小球藻１２小时以上的二次培养,卤虫无节幼体必须经过乳化鱼肝油１２小时以上的强化。同时,提早投喂桡足类,以…     

红鳍东方鲀开口饵料筛选试验

本文选择水产育苗常用的幼体开口饵料──小球藻、轮虫、卤虫幼体、蛋黄对初孵红鳍东方进行开口饵料筛选试验。结果表明：用小球藻和轮虫混合投喂效果最好,其余依次为轮虫、卤虫幼体、蛋黄。     

轮虫、卤虫无节幼体及蝇蛆三种开口饵料对黄颡鱼仔鱼生长、存活及免疫酶活性的影响

在水温(25±0.5)℃下,将10 000尾4日龄的体长(0.25±0.004)cm的全雄黄颡鱼Pelteobagrus fulvidraco仔鱼放入长2m×宽1.4m×水深30cm的孵化槽中,投喂轮虫、卤虫无节幼体和蝇蛆三种开口饵料,研究不同开口饵料对黄颡鱼仔鱼生长、存活率以及免疫相关酶活性的影响。结果表明,饲养3d时,投喂卤虫无节幼体组仔鱼的体质量显著大于轮虫组(P0.05),而投喂蝇蛆组仔鱼的体质量介于二者之间,且与两组无显著差异(P0.05);7d后,投喂蝇蛆组仔鱼体质量最大,显著大于后两组(P0.05),卤虫无节幼体组次之,轮虫组最小;投喂蝇蛆组仔鱼的存活率最高,投喂蝇蛆组仔鱼酸性磷酸酶(ACP)、碱性磷酸酶(AKP)和溶菌酶(LZM)活力显著高于其他两组(P0.05),而其他两组仔鱼这三种酶活力没有显著影响。认为与轮虫、卤虫无节幼体相比,蝇蛆是一种更适宜黄颡鱼仔鱼培育的开口饵料。     

褶皱臂尾轮虫的土池培养技术

褶皱臂尾轮虫属轮虫纲,简称轮虫,其适应能力强,生长快,繁殖迅速,营养丰富,大小适口,体内含有粗蛋白达60%～70%,是中华绒螯蟹大眼幼体最理想的优质开口饵料,大量培养轮虫是中华绒螯蟹大眼幼体土池生态培育的关键措施之一。近年来,射阳县由于率先掌握了轮虫土池培养技术,推动了射     

营养强化的轮虫、卤虫对牙鲆仔鱼的成活、生长及体脂肪酸组成的影响

用3种营养强化剂强化的轮虫和卤虫无节幼体投喂牙鲆仔鱼,研究牙鲆仔鱼的生长、成活、体脂肪酸的组成。结果表明:用强化的轮虫和卤虫无节幼体投喂牙鲆仔鱼,成活率、增重均显著高于对照组(p<0 01),其中V号强化剂的效果最好,成活率为29 34%,比对照组提高100%;增重倍数为217 90,比对照组提高68 61%;这是由于V号强化剂强化的卤虫无节幼体体内含有较多的AA的缘故,饵料中AA含量的提高,可以提高牙鲆仔鱼的成活率、促进其生长。牙鲆摄食强化过的轮虫、卤虫无节幼体后,其EPA、DHA、n-3HUFA、PUFA的含量随着饵料中含量的升高而升高,这也是牙鲆仔鱼生长速度和成活率提高的重要因素之一。     

4组生物饵料对中华绒螯蟹Z↓（4）到大眼幼体生长发育和脂肪酸组成的影响

采用卤幼(Artemia sp.)、强化卤幼、背刺胸刺水蚤(Centropages dorsispinatus)、背刺胸刺水蚤 日本新糠虾(Neomysis japonica)4组生物饵料投喂4组中华绒螯蟹(Eriocheir sinensis)Z4幼体,以大眼幼体的成活率、Z4→大眼幼体变态时间、头胸甲长度和大眼幼体中脂肪酸组成作为评价指标,探讨了4种生物饵料对大眼幼体生长发育及其脂类含量和脂肪酸组成的影响.结果表明:(1)背刺胸刺水蚤(C组)、背刺胸刺水蚤 日本新糠虾(D组)投喂组的中华绒螯蟹幼体可以获得较高的成活率(70%左右),幼体发育时间缩短1～2 d,大眼幼体头胸甲长度显著大于卤幼组(A组)和强化卤幼组(B组)(P＜0.01),各组大眼幼体头胸甲长度由大到小依次为C组、D组、B组、A组;(2)强化卤幼可以提高其总脂、磷脂及DHA含量,背刺胸刺水蚤和日本新糠虾具有较高的AA、DHA和HUFA含量;(3)各组大眼幼体中脂肪酸组成差异显著(P＜0.05),DHA和HUFA含量随着饵料中含量的上升而上升(n=9,P＜0.01),饵料中的DHA含量和大眼幼体的头胸甲长度呈显著正相关(n=9,P＜0.05).由此可见,背刺胸刺水蚤和日本新糠虾可以作为中华绒螯蟹Z4到大眼幼体阶段的优质活饵料,可以提高其成活率和头胸甲长度.     

Ingestion of Artemia nauplii by Chinese mitten crab Eriocheir sinensis zoea larvae

A series of ingestion trials were conducted to determine the ingestion rate of Artemia nauplii by Eriocheir sinensis zoea larvae with increasing densities of Artemia and with or without rotifers as a co-feed. At each zoeal stage, 10 groups of 10 larvae were reared individually in glass beakers and fed with increasing densities of newly hatched Artemia nauplii (0.5, 2.5, 5, 10 and 20 individual (ind.) mL⁻¹) with or without rotifers (15–25 ind. mL⁻¹) as a co-feed. The average number of ingested Artemia was measured over 24 h. In addition, the average larval development rate (Larval Stage Index, LSI) over a longer period (time needed for the best treatment to reach 100% moult or metamorphosis to the next larval stage) was compared. The results showed that Artemia ingestion rate of E. sinensis larvae increased with increasing prey densities and larval development, and had a significantly negative correlation with rotifer consumption for all zoeal stages. Rotifers as an alternative prey significantly affected the intake of Artemia at early larval stages (Z1 and Z2) and promoted LSI at a lower Artemia density. Further experiments are needed to clarify the effect of prey density on survival and larval development when larvae are reared communally.     

The Influence of Different Rotifer and Artemia Enrichment Diets on Growth, Survival and Pigmentation in Turbot (Scophthalmus maximus L.) Larvae

An experiment was carried out on turbot larvae fed three different rotifer enrichment diets: Dry Selco, Protein Selco and ICES low-HUFA (an enrichment emulsion containing low amounts of highly unsaturated fatty acids—HUFA). Seven tanks were set up for each diet. After the rotifer stage, approximately seven days after hatching, the larvae were fed newly-hatched Artemia salina nauplii (AT-1; Brazil strain). From day 10, enriched Great Salt Lake Artemia nauplii were introduced. Each set of seven tanks was further subdivided and the larvae fed Arternia nauplii enriched with one of four enrichment diets: Dry Selco, Protein Selco, ICES low-HUFA or Super Selco. The rotifer enrichments had no significant effect on larval growth and survival. The nutritional value of the Artemia stage (day 13 to 26) was more important for the overall larval survival.     

Effect of poly-β-hydroxybutyrate on Chinese mitten crab, Eriocheir sinensis, larvae challenged with pathogenic Vibrio anguillarum

This study investigated the protective effect of poly-β-hydroxybutyrate (PHB) on Chinese mitten crab, Eriocheir sinensis, zoea larvae challenged with pathogenic Vibrio anguillarum. PHB was delivered to the crab larvae through rotifer and Artemia bioencapsulation. Zoea 3 larvae were challenged with V. anguillarum at a final concentration of 10(5) CFU mL(-1). PHB-enriched rotifers and Artemia nauplii were added to the culture water 24 h prior to, upon and 24 h after challenge. The results confirmed that PHB could enhance the survival and growth of unexposed E. sinensis larvae. Moreover, PHB protected larvae from the pathogen as the larvae fed PHB-enriched live food showed the highest survival and development rate in all challenged groups (P < 0.05). Furthermore, larval performance was the best when PHB was delivered to the larvae 24 h before challenge (P < 0.05). In conclusion, our results indicate that PHB can be used as part of an effective strategy to protect E. sinensis larvae from V. anguillarum resulting in higher survival and better growth, especially when applied before the challenge.     

Evaluation of Fatty Acid Enrichment of Live Food for Yellowtail Snapper Ocyurus chrysurus Larvae

Abstract— The purpose of this study was to examine the effect of varying dietary levels of highly unsaturated fatty acids (HUFA) in Live prey on the standard length, specific growth rate, survival, and fatty acid composition of yellowtail snapper Ocyurus chrysurus larvae. Two experiments were conducted utilizing rotifers and Artemiu enriched with live algae ( Isochrysis galbana or Nannochloris oculata ) or commercial preparations (Aquagrow Advantage, Aquagrow Advantage plus Aquagrow arachidonic acid, and Algarnac 2000). Larval growth and fatty acid composition were evaluated during the rotifer, B rachionus plicatilis , and Artemia feeding periods and survival rates were calculated at the termination of each trial (18 or 20 d after hatching). In general, prey enriched with the commercial products contained higher levels of docosahexaenoic acid, eicosapentaenoic acid, n-3 HUFA, and × HUFA than those enriched with live algae. The addition of arachidonic acid to the Aquagrow Advantage enrichment medium significantly increased the amount of this fatty acid in rotifers but not in Artemia . At the end of the growth trials, larval standard length was highest when larvae were fed prey enriched with I. galbanu (6.4 mm) or commercial preparations (6.7–7.1 mm) versus N. oculatu (5.2 mm). Furthermore, larvae fed prey enriched with commercial preparations had significantly ( P < 0.05) higher survival rates (2.2-5.9%) than those fed prey enriched with live algae (1.1-1.4%). These results suggest that yellowtail snapper larvae require dietary levels of HUFA beyond those achieved by enriching prey with live N. oculata or I. galbana     

Influence of highly unsaturated fatty acids in live food on larviculture of mud crab Scylla paramamosain (Estampador 1949)

Two experiments were carried out to investigate the effects of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA) levels in rotifers (Brachionus plicatilis) and Artemia on the survival, development and metamorphosis of mud crab Scylla paramamosain larvae. Five different lipid emulsions, varying in the level of total n‐3 and n‐6 highly unsaturated fatty acids (HUFA), DHA, EPA and ARA were used to manipulate the fatty acid profile of the live food. Fatty acid profiles of the live food and crab larvae at zoea one, three and five stages were analysed to study the HUFA uptake by the larvae. The fatty acid content of the live food affected the fatty acid profiles of the crab larvae. In both experiments, the survival rate in the zoeal stages was not statistically different among treatments. However, larval development rate and metamorphosis success were affected by the dietary treatments. In this respect, the DHA/EPA ratio in the live food seems to be a key factor. Enrichment emulsions with a very high (50%) total HUFA content but a low DHA/EPA ratio (0.6), or zero total HUFA content caused developmental retardation and/or metamorphosis failure. An emulsion with a moderate total HUFA (30%) and a high DHA/EPA ratio (4) was the best in terms of larval development during the zoeal stages and resulted in improved metamorphosis. Dietary ARA seemed to improve first metamorphosis, but its exact role needs further clarification. For the larval rearing of S. paramamosain, an enrichment medium containing about 30% total n‐3 HUFA with a minimum DHA/EPA ratio of 1 is recommended. Further investigation is needed on the total HUFA and optimum DHA/EPA ratio requirements for each crab larval stage.     

Effects of n-3 highly unsaturated fatty acid content in Artemia on survival and development of laboratory-reared horsehair crab Erimacrus isenbeckii larvae

The effect of varying levels of dietary n-3 highly unsaturated fatty acid (HUFA) content in Artemia sp. on survival, the number of days required to reach each larval stage, and the growth and morphogenesis of larvae of the horsehair crab Erimacrus isenbeckii were examined. Artemia enriched with materials of six types [condensed Nannochloropsis sp., ethyl oleate, two enrichment levels of eicosapentaenoic acid (EPA), and those of docosahexaenoic acid], and unenriched Artemia were fed to larvae. Newly hatched larvae were reared in groups of 50 individuals in two 2-l beakers until they reached the first crab stage. No significant difference was found in survival rate, growth, or morphogenesis of larvae, but fewer days tended to be required to reach the first crab stage in the group enriched with high EPA compared to the other groups. Results show that, although the amount of n-3 HUFA in unenriched Artemia might meet the demands of horsehair crab larvae for their survival, growth, and morphogenesis, Artemia should be enriched with high EPA to improve the rate of larval development.     

Effects of Food and Temperature on Survival and Development in the Peppermint Shrimp Lysmata wurdemanni

Abstract— The effects of four kinds of foods ( Artemia nauplii, rotifer, and microalgae Chaetoceros gracilis and Isochrysis galbana ) and four temperature regimes on survival and development of larval Lysmata wurdemanni , a marine ornamental shrimp, were determined. The larvae fed with Chaetoceros or Isochrysis only survived for a maximum of 17 d, before developing to zoea IV. The survivorship of the larvae fed with Artemia nauplii or rotifer from zoea II to post-larvae was 66.7% and 68.9%. respectively, without significant difference ( P > 0.05). But larvae fed with Artemia nauplii grew significantly ( P < 0.05) faster than those fed with rotifer. Larvae fed with Artemia nauplii reached postlarvae in 29–32 d, compared with 32–36 d in the rotifer treatment. Artemia nauplii are also suitable food for the postlarvae and juveniles of L. wurdemanni . The 30 postlarvae fed on Artemia nauplii all survived to reach sexual maturity in 50 to 70 d, growing from about 7 to 28 mm in total length. The effects of four temperature regimes on larval development of L. wurdemanni was also investigated. The duration (mean ± SD d) to the postlarvae at temperatures of 26 C (37.4 ± 5.4) and of 26–30 C daily (40.2 ± 5.8) was significantly ( P < 0.05) longer than that at 28.5 C (29.3 ± 4.8) and at 27–29 C daily (28.7 ± 3.5).     

Evaluation of Live Feeds for Larval and Postlarval Mahimahi Coryphaena hippurus

Live hatchery feeds were assayed for fatty acids (FA), amino acids (AA), and their ability to support growth and survival of larval and postlarval mahimahi Coryphaena hippurus at two different hatchery stages. Euterpina acuritrons copepods (C), mahimahi yolk-sac larvae (YSL), Artemia parthenogenica brine shrimp nauplii (BSn), A. parthenogenica juveniles (BSj), and Brachionus plicatilis rotifers (R) were assayed, using several enrichment media. There was little difference in AAs among feeds.
Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were about 10 times higher in YSL than in their feeds. This explains previous findings where first stage larval survival (0–9 days) was not affected by feed HUFA levels. Second stage survival was significantly higher when larvae were fed copepods. Enrichment with 100 ppm SuperSelco greatly improved the survival of larvae that were fed brine shrimp. The even higher omega-3 fatty acids found in copepods appear to be important for survival of larvae under more stressful conditions.
Brine shrimp juveniles enriched with SuperSelco are a good food for postlarval mahimahi. Yolksac larvae of mahimahi are an even better food, promoting faster growth at less cost, for large scale mahimahi aquaculturists. Different batches of yolksac mahimahi larvae varied by a factor of 10 in their concentration of DHA, but always had the highest level of DHA as much as 40% of total fatty acids (FAs). These "high HUFA" batches of YSL also had the highest levels of EPA and total fatty acids. The data suggest that climate and broodstock age may have considerable influence on larval nutrition.