云斑尖塘鳢转饵期仔鱼生长和存活率的研究

在水温(30±1)℃条件下对人工孵化的云斑尖塘鳢(Oxyeleotris marmorata)仔鱼进行转饵期不同投喂策略实验,对仔鱼生长和成活情况进行了研究,设计5个投喂组:轮虫投喂组(A组);70%轮虫+30%卤虫投喂组(B组);50%轮虫+50%卤虫投喂组(C组);30%轮虫+70%卤虫投喂组(D组);卤虫(幼虫)投喂组(E组)。结果显示:云斑尖塘鳢仔鱼对卤虫的摄食强度随卤虫在饵料中比例的升高而增大,其对混合饵料中轮虫和卤虫的摄食强度的比值(Ir/Ia)随食物组成的变化发生相应的变化。以轮虫-卤虫不同比例的混合饵料投喂时,D组仔鱼的增长率、增重率最高,可存活率不足50%,高于E组,显著低于其它各组;C组仔鱼生长指标略低于D组,但存活率为(74.00±2.29)%,综合指标显著好于其它各组。当混合饵料中轮虫和卤虫各占50%时,10日龄开始投喂组仔鱼的全长(13.07±0.13)mm,特定生长率(10.25±0.37)%/d,存活率(82.14±0.72)%,综合生长指标最好。结果表明,云斑尖塘鳢仔鱼转饵期进行联合投喂的最佳饵料比例为50%轮虫+50%卤虫,最佳转饵时间为10日龄。     

扁吻鱼仔鱼集约化培育技术研究

正2014年～2016年,在新疆水生野生动物救护中心工厂化鱼类繁育车间,使用循环水矩形槽进行扁吻鱼子二代仔鱼的集约化培育,对仔鱼发育的主要形态特征及生活习性进行了观察,对仔鱼开口饵料的选择及培育水环境进行了分析。结果表明,水温11℃～24℃时,初孵仔鱼发育至第6天～7天开口摄食,以卤虫无节幼体作为开口饵料,第10天～11天开始投喂卤虫无节幼体+鳗仔鱼饲料,经过5天～10天的投喂培育,仔鱼全长长至10mm～15mm,存活率为67.2%～84.3%,静水环境下存活率明显高于循环水环境。     

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。     

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。     

日本鳗鲡人工育苗及仔鱼饲料研究

日本通过40年对鳗鲡成熟控制技术的研究,特别是近几年来采用17,20β-dihydroxy-4-pregnen-3-one(DHP)的鳗鲡雌鱼成熟诱导技术,使高质量鳗鲡受精卵的取得具有相当高的把握性。日本水产厅养殖研究所采用以鲨鱼卵冷冻干燥粉末为主要成份并含有磷虾或其它鲜鱼虾抽提液的糊状饲料,喂食人工孵化的日本鳗鲡仔鱼取得举世嘱目的突破性进展,但柳叶状仔鱼全长达到30mm以后几乎不再摄食,出现生长停滞,并已变得十分衰弱。全面攻克日本鳗鲡人工育苗难题尚待时日,特别是研制能有效促进后期柳叶状仔鱼生长并变态的全价育苗饲料已成为目前关注的焦点。     

卤虫在不同饵料培养介质中的生长规律

以啤酒酵母和单胞藻为投喂饵料，新疆艾比湖卤虫（Artemia parthenogenetica)为投喂对象，建立三个实验组分别进行研究，观察在不同饵料条件下艾比湖卤虫的生长，探讨不同饵料对卤虫的生长、成活的影响。通过对卤虫体长和存活率的测量，建立了卤虫在不同饵料情况下的生长方程、生长曲线和存活率曲线，并通过对方程和曲线的分析获得以下结论：投喂单胞藻组卤虫的生长最慢，存活率最低25表面以后全部死亡；投喂酵母组卤虫生长最快，在0≤t≤42.6时体长值最高，存活率较低，投喂单胞藻和酵母的混合饲料组卤虫的前期生长次于酵母组，后期生长超过之，存活率较高且成熟个体产虫量和产卵量也多于酵母组。     

河鲀苗种培育中饵料应用研究

对刚孵出2d的暗纹东方鲀仔鱼进行2个阶段培育，结果发现：第1阶段使用轮虫投喂仔鱼组其生长速度、成活率明显大于蛋黄投喂组；第2阶段使用相同量卤虫和发头裸腹蚤作为饵料投喂以上两组鱼苗，结果仍是第1阶段轮虫投喂组在生长速度和成活率方面大于蛋黄投喂组，这表明仔鱼培育阶段其饵料的选择对以后河鲀的生长和存活率仍起着关键作用。     

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。     

不同饵料对美洲西鲱仔鱼生长、相关酶活力及体脂肪酸的影响

以美洲西鲱(Alosa sapidissima)仔鱼(孵化后10 d)为实验对象,在室内进行为期30 d的摄食生长试验,分别投喂不同的饵料[单独投喂卤虫(Artemia)、单独投喂微颗粒饲料、卤虫与微颗粒饲料混合投喂],分析不同饵料的投喂对存活、生长、消化酶活性、非特异性免疫相关酶活性以及体脂肪酸组成的影响。结果表明:(1)混合投喂组的存活与生长表现都要显著优于卤虫组和微颗粒饲料组(P0.05),微颗粒饲料组与卤虫组相比差异不大,而试验后期(20~30 d)微颗粒饲料组的存活与生长表现要优于卤虫组;(2)消化酶的结果显示,胃蛋白酶和淀粉酶活力在各组中无显著性差异(P0.05),胰蛋白酶、糜蛋白酶和脂肪酶在卤虫组中活力最低,显著低于其他两组(P0.05),其中糜蛋白酶和脂肪酶活性在微颗粒饲料组中要显著高于混合投喂组(P0.05);(3)碱性磷酸酶和超氧化物岐化酶活力在各组中无显著性差异(P0.05),过氧化氢酶和溶菌酶活力在微颗粒饲料组中最高,卤虫组中最低,两者之间差异显著(P0.05);(4)鱼体脂肪酸受饵料脂肪酸组成影响较大,微颗粒饲料中n-3HUFA和DHA含量较高,其投喂后在鱼体中的含量也高。综上所述,不同饵料投喂对美洲西鲱仔稚鱼存活、生长、消化酶活性、非特异性免疫相关酶活性以及体脂肪酸影响显著,在试验20 d之前使用卤虫与微颗粒饲料混合投喂,20 d后完全转食微颗粒饲料,可以降低成本,同时提高生产效率。     

牙鲆仔、幼鱼期饵料的选择与投喂

通过饵料的对比试验表明，在牙鲆育苗中，选择轮虫作为仔鱼开口饵料，投喂密度为５一７个／毫升；选择大卤虫或大卤虫和卤虫无节幼体混合投喂体为幼鱼初期食性转换的饵料，提高了鱼苗的成活率，并使鱼苗正常生长。     

Decreasing dietary lipids improves larval survival and growth of Japanese eel Anguilla japonica

Shark eggs-based diet is the only diet by which eel larvae can grow to glass eels in captivity. However, the high level of lipids in the diet is suggested to negatively affect eel larvae. This paper examines the effect of defatted shark eggs (DSE) and hen egg yolk (HY) on growth and survival of larvae of Japanese eel Anguilla japonica. Lyophilized shark egg and commercial HY were defatted with n-hexane, and four experimental diets were prepared using both defatted and untreated shark eggs and HY. Larvae were reared for 3 weeks by feeding the experimental diets. The highest survival rate was observed in the larvae fed DSE, and larvae fed HY showed the lowest survival rate. The best growth was found in larvae fed DSE, followed by shark eggs and defatted HY, and the worst growth was in HY-fed larvae. These results show that decreasing dietary lipids improves the nutritional value of both shark eggs and HY for eel larvae. Regulation of the dietary lipid level may positively affect the larval performance of eels by combination of ingredients with a low lipid content.     

A step forward in development of fish protein hydrolysate-based diets for larvae of Japanese eel Anguilla japonica

Eggs of spiny dogfish Squalus acanthias are an indispensable and effective component of the compound diets currently used for larvae of the Japanese eel Anguilla japonica. However, this fish species, a natural resource, is becoming more scarce, suggesting that suitable diets should be developed using more sustainable components. In the search for appropriate diets without shark eggs, we have designed test diets in which shark eggs were replaced with general feed materials, such as fish protein hydrolysate (FPH), with the notable improvement that the FPH had been pre-digested with integral enzymes from frozen krill. Feeding trials were conducted to assess the effects of the test diets on survival and growth of Japanese eel larvae at early developmental stages. Larvae fed on the test diets were found to be able to survive up to 65 days after hatching, the maximum total length and body depth were 14.1 and 1.5 mm, respectively. Although larvae fed on the test diets still exhibited a low survival rate and poor growth, the FPH-based diets had a nutritional value that promoted substantial larval growth based on the significant difference between the initial and final body sizes. Our results suggest that the development of FPH-based diets not based on shark eggs but rather on general feed ingredients is promising but that there is much room for improvement.     

Hen egg yolk and skinned krill as possible foods for rearing leptocephalus larvae of Anguilla japonica Temminck & Schlegel

Usual diets for rearing leptocephalus larvae of Japanese eel Anguilla japonica include eggs of the endangered spiny dogfish Squalus acanthias (SE). We investigated the effects of alternative food materials, hen egg yolk (HEY) and exoskeleton‐free (skinned) Antarctic krill (SAK), on the growth and survival of eel larvae. We found that feed comprising whole krill including exoskeleton (WAK) containing higher levels of fluoride (37.89 mg kg^?1) was acutely toxic to eel larvae exposed to this alone. In contrast, extract from SAK containing lower concentrations of fluoride (4.25 mg kg^?1) showed no apparent adverse effects. Growth of larvae fed a mixture of SE and SAK in a feed trial of 58 days [mean body weight (BW), 6.0 mg] was about twofold higher than that of larvae fed a mixture of SE and WAK (3.2 mg) (P < 0.01). A mixture of HEY and SAK also had some dietary benefits for eel larvae, enabling them to survive for up to 58 days and to grow significantly (mean BW, 2.4 mg), compared with their initial weight (mean BW, 0.2 mg) (P < 0.001). Although additional nutritional improvements are needed, the present results suggest that combination diet HEY and SAK may be a good alternative to SE as an effective diet for eel larvae.     

不同饵料对奥尼罗非鱼仔稚鱼生长发育及消化酶活力的影响

将初始体质量为(0.006±0.0005)g的仔鱼,随机分为4组,每组3个平行,分别投喂4种饵料:人工配合饵料、轮虫、蛋黄和轮虫+人工配合饵料.试验周期为28 d.结果表明,(1)轮虫+人工配合饵料和人工配合饵料组生长较快,特定生长率分别为0.014 %/d和0.013 %/d, 绝对生长率达到0.150、0.142 g/d,二组差异不显著(P>0.05);蛋黄组生长最慢,与其他各组差异显著(P<0.05).(2)轮虫+人工配合饵料与轮虫组仔稚鱼的成活率达到90.3%和 89.7%,大部分个体发育进入幼鱼阶段,二组差异不显著(P>0.05);蛋黄组存活率较低,只有40.7%,与其他各组差异显著(P<0.05).(3)投喂不同饵料对奥尼罗非鱼仔稚鱼的消化酶具有显著影响,蛋黄组的淀粉酶和脂肪酶活力显著高于其他各组(P<0.05);轮虫+人工配合饵料组的胃蛋白酶活力较高,天然饵料(轮虫)组较低.     

Reproductive conditioning of Chilean scallop (Argopecten purpuratus) and the Pacific oyster (Crassostrea gigas): effects of enriched diets

The quality of diet fed to bivalve broodstock during reproductive conditioning directly affects growth and survival of their larval and postlarval progeny. The objective of the present study was to improve the quality of larval production in the Chilean scallop (Argopecten purpuratus) and the Pacific oyster (Crassostrea gigas) by testing of the effects of different experimentally enriched diets on the conditioning and early development of progeny under laboratory conditions. The diets used included protein-rich microalgae and mixtures of microalgae and lipid emulsions. Quality of D-larvae, pediveligers, and 1-mm postlarvae from the variously fed broodstock was measured to evaluate each diet as indicators of growth and survival of the early life stages. Biochemical analyses were carried out on eggs and larvae to determine the effects of the different diets on these parameters. The main results for the scallops and oysters were that a conditioning diet containing algae rich in protein improved larval growth and survival. This effect did not, however, extend past metamorphosis. Also, the best conditioning diet increased the lipid content of the eggs, as well as the protein content of the D-larvae, although the mechanism for this remains unclear.     

Dietary effects of n-3 highly unsaturated fatty acid levels on egg and larval quality, and the fatty acid composition of the eggs of Chilean flounder Paralichthys adspersus broodstock

The effects of dietary n-3 highly unsaturated fatty acid (n-3 HUFA) on eggs and larval quality were investigated in the Chilean flounder Paralichthys adspersus . Broodstock were fed with three formulated diets with similar proximate compositions but different n-3 HUFA (2.1%, 3.1% or 4.1%) estimated levels from 5 months before and during the spawning period. The diet with an intermediate n-3 HUFA level resulted in a significantly higher ( P <0.05) percentage of buoyant eggs (68.2 ± 2.9%), fertilization (92.8 ± 3.9%), normal cell cleavages (93.5 ± 1.9%), hatching rate (87.7 ± 4.1%) and normal larvae (76.3 ± 3.7%) compared with the other two diets. In contrast, high levels of n-3 HUFA produced larvae with a higher survival capacity when subjected to fasting. The diet with the lowest content of n-3 HUFA produces lower quality eggs and larvae. The n-3 HUFA level in eggs increased with an increase in the dietary level, and the n-3/n-6 ratios were 1:1, 2:1 and 3:1. The DHA/EPA and EPA/ARA ratios of 2 and 4 in eggs, respectively, were associated with improved egg and larval quality and were similar to the ratios found in eggs from wild broodstock. Attainment of optimal fatty acid contents in broodstock diets is one of the key factors for producing the high-quality spawning required for managed culture of this flounder.     

Antarctic krill (Euphausia superba) meal in the diets improved the reproductive performance of tongue sole (Cynoglossus semilaevis) broodstock

A three‐month feeding trial was conducted to investigate the effects of dietary krill meal on the reproductive performance of tongue sole broodstock. Three diets were formulated to contain different levels of krill meal, 0 (Diet K‐0), 10 (K‐100) and 200 (K‐200) g kg^–1 dry matter, replacing the corresponding contents of protein and lipid from fishmeal and fish oil. Each diet was assigned to triplicate tanks. Compared with K‐0, both K‐100 and K‐200 increased the egg properties such as buoyant eggs rate, egg diameter, oil droplet diameter and SOD activity of the fertilized egg. However, the maturation rate, serum estradiol content, the relative fecundity and hatching rate were improved only by K‐100. The krill meal supplementation increased the concentrations of astaxanthin and n‐3 fatty acids in eggs, but decreased the n‐6 fatty acid concentrations. Both K‐100 and K‐200 increased the survival activity index, but the larval deformity rate was decreased only by K‐100. At 15 DPH, the larval length and the digestive enzyme activities were significantly higher in group K‐200 compared with groups K‐0 and K‐100. In conclusion, dietary supplementation of krill meal, at the level of 100 or 200 g kg^–1 dry matter in exchange of fishmeal and fish oil had the considerable positive effects on C. semilaevis reproduction.     

Fatty acid nutritional quality of sea urchin Paracentrotus lividus (Lamarck 1816) eggs and endotrophic larvae: relevance for feeding of marine larval fish

Sea urchin eggs and larvae have been suggested as potential live prey for marine fish larval feeding. This study evaluated the fatty acid composition of Paracentrotus lividus eggs, prisms and four-armed plutei, obtained from wild and captive broodstocks fed on raw diets: maize, seaweed and a combination of maize and seaweed. Amounts of essential fatty acids (EFA) for marine fish larvae [arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA)] were determined in eggs and endotrophic larvae. ARA ranged from 3.93% in eggs from combination to 18.7% in plutei from maize diets. In any developmental stage, EPA amounts were always lower than 5% for the raw diets, and DHA showed null or trace amounts including the wild diet. Thus, broodstock-prepared diets had to be formulated based on different lipid sources (Algamac, linseed oil, cod liver oil and olive oil) in order to test eggs and larvae EFA enhancement. EFA improvement was possible for all tested prepared diets. Algamac diet lead to superior EFA enhancement mainly in DHA (7.24%, 4.92% and 6.09% for eggs, prisms and plutei, respectively) followed by cod liver oil diet. Only these two lipid sources should be considered for prepared broodstock diets in order to obtain suitable live prey for fish larval feeding.     

4种饵料对玉足海参幼体生长和发育的影响

为了解单一饵料或混合投喂对玉足海参(Holothuria leucospilota)幼体生长的影响,采用2种单胞藻(牟氏角毛藻、球等鞭金藻)和2种酵母(酿酒酵母、海洋红酵母)单一或组合搭配投喂玉足海参耳状幼体,测定并比较海参幼体的体长、胃宽、水体腔长、变态成活率等指标。试验结果显示：单一饵料组中,牟氏角毛藻对玉足海参幼体体长的生长及变态存活最有利,而球等鞭金藻对其脏器(胃、水体腔)的发育最有利;综合所有处理组的投喂效果看,混合投喂组比单一饵料组更有利于玉足海参幼体的生长和存活,其中酿酒酵母+海洋红酵母的混合投喂组合得到了最高的体长、胃宽和水体腔长特定生长率,牟氏角毛藻+海洋红酵母投喂组的变态成活率最高,变态发育速度最快。结果表明,在玉足海参幼体培养早期适合以混合酵母为主投喂,后期则可较多投喂牟氏角毛藻和海洋红酵母。     

Effects of dietary levels and ratio of phosphatidylcholine and phosphatidylinositol on the growth,survival and deformity levels of Atlantic cod larvae and early juveniles

Effects of two weaning diets that differed in phospholipid (PL) classes on growth, survival and deformities of cod larvae and early juveniles were evaluated. Cod larvae were fed rotifers until 21 days post hatch (dph) and then weaning onto dry diet started. One group of larvae were fed a control diet with low levels of phosphatidylcholine (PC), PE and phosphatidylinositol (PI) and the other group of larvae were fed with an experimental diet containing higher levels of PC, PE and PI. Larvae fed with the control diet were significantly smaller than larvae fed with the experimental diet at the end of the experiment. Swim bladder abnormalities were significantly higher in larvae fed with control diet at 35 dph than the larvae fed with experimental diet; however, no significant difference was evident at 42 dph. Vertebral deformities were significantly higher in larvae fed with control diet and scoliosis was significantly different between the treatments. Survival was also significantly higher in the experimental group. Our results indicate that dietary levels of PL, PC and PI may affect the cod larval growth, survival and deformities. More detail studies are needed to find out the optimal levels of these important PL classes in larval cod diets.