大口黑鲈仔、稚鱼生长和食性的观察

大口黑鲈仔、稚鱼生长和食性的观察陆伟民（上海水产大学，２０００９０）关键词大口黑鲈，仔、稚鱼，生长，食性ＯＢＳＥＲＶＡＴＩＯＮＯＮＧＲＯＷＴＨＡＮＤＦＥＥＤＩＮＧＨＡＢＩＴＳＯＦＬＡＲＧＥＭＯＵＴＨＢＡＳＳ，ＭＩＣＲＯＲＴＥＲＵＳＳＡＬＭＯＩＤＥＳ，...     

海水仔稚鱼早期阶段氨基酸的营养生理研究进展

深海海鱼鱼卵中的游离氨基酸占鱼卵总氨基酸含量的近50％（干重），游离氨基酸库中的游离氨基酸似乎是卵黄蛋白的水解产物。仔鱼吸收卵黄内源营养的过程中，游离氨基酸库中的游离氨基酸逐渐减少，到仔鱼开始摄食时，库中的游离氨基酸已近枯竭，游离氨基酸不仅是代谢能源，而且是体蛋白合成的基本原料，仔鱼开始摄食后，氨基酸作为分解代谢的重要物质，可能有高达60％的能量由氨基酸提供，由于仔稚鱼的生长主要是通过合成蛋白质增加鱼体的重量，加之仔稚鱼的生长速度很高，因此，仔稚鱼需要其饲料中有较高的氨基酸含量。仔鱼开始摄食后，其消化系统对蛋白质的水解和吸收能力较弱，海水仔稚鱼的早期阶段，仔鱼的肠道对游离氨基酸的吸收要高于对多肽和蛋白质中氨基酸的吸收，仔鱼开始摄食后，由浮游生物获得大量的游离氨基酸，用微粒饲料培育仔稚鱼，微脂粒技术可能是向饲料中添加游离氨基酸的实用技术。     

海水仔稚鱼的营养需求与微颗粒饲料研究进展

综述了近年来海水仔稚鱼对蛋白质、脂肪和维生素营养需求的研究状况,同时对其微颗粒饲料的特性和制作工艺进行探讨,以期为研制海水仔稚鱼的微颗粒饲料提供参考。     

日本研究轮虫的摄饵量与小球藻大小的关系

轮虫,是海产鱼类仔、稚鱼的初期饵料。而培养轮虫的方法主要有二种。一是饲用海水小球藻,二是投喂酵母类以进行高密度培养。但实践表明,用酵母类培养的轮虫投喂鱼类仔、稚鱼易造成仔、稚鱼的大量死亡。竟其     

真鲷仔稚鱼对实验微粒饲料中卵磷脂适宜需要量的研究

制备了4种n-3HUFA含量基本相等、卵磷脂含量分别为0、2．5％、5．0％、7．5％的实验微粒饲料，探讨了卵磷脂的含量对真鲷仔稚鱼生长、存活、体内相关成分以及对外部压力的耐受性的影响。25d的养殖试验结果表明，当真鲷仔稚鱼的实验微粒饲料中卵磷脂含量不超过5．0％时，随着实验微粒饲料中卵磷脂含量的增加，真鲷仔稚鱼的生长速度和成活率也相应增加。养殖试验结束后，对仔稚鱼体内相关成分的分析结果表明，仔稚鱼体内n-3HUFA和DHA的含量随着实验微粒饲料中卵磷脂含量的增加而增加。但当卵磷脂含量从5．0%增加到7．5％时，真鲷仔稚鱼的生长速度、成活率以及体内n-3HUFA和DHA的含量却没有相应增加，因此，真鲷仔稚鱼对实验微粒饲料中卵磷腊的适宜需要量应为5．0％左右。活力测试结果表明，当真鲷仔稚鱼的实验微粒饲料中卵磷脂的含量不超过5．0％时，随着实验微粒饲料中卵磷脂含量的增加，真鲷仔稚鱼对外部压力的耐受性增强，但是当实验微粒饲料中卵磷脂的含量从5．0％增加到7．5％时，真鲷仔稚鱼对外部压力的耐受性并没有继续增强，从而进一步说明真鲷仔稚鱼对实验微粒饲料中卵磷脂的适宜需要量应为5．0％左右。     

海水鱼类仔稚鱼消化生理学研究进展

综述了海水鱼类仔稚鱼消化系统的发育过程，讨论了消化系统中各种酶的分布以及各发育时期参与消化的酶的种类及其活性，分析了饵料与消化系统中酶的互动关系，以及外源性消化酶和神经肽在仔稚鱼消化过程中所起的作用。     

池养条件下黄河鲤仔稚鱼的生长及形态发育初步观察

本文结合生产试验过程，对黄河鲤仔稚鱼生长过程中的形态特征进行了初步描述，研究了仔稚鱼的生长以及全长、体长、体重的相互关系。从初孵仔鱼发育至稚鱼约需12天左右，全长达到13.4-21.7mm。仔鱼期体长的增长大于体重的增长；而进入稚鱼期后，体重的增长明显加快。     

不同开口饵料对黄颡鱼仔稚鱼生长和成活率的影响试验

以人工催产、孵化的黄颡鱼仔稚鱼为材料,用红虫、人工微粒子粉料、鸡蛋黄和红虫+人工微粒子粉料+鸡蛋黄混合等4种饵料投喂25d,研究其对黄颡鱼仔稚鱼生长和成活率的影响。试验结果表明,黄颡鱼仔稚鱼的生长速度大小为:红虫组混合饵料组人工微粒子粉料组鸡蛋黄组,黄颡鱼仔稚鱼成活率大小为:混合饵料组红虫组人工微粒子粉料组鸡蛋黄组。采用混合饵料投喂的方法能满足黄颡鱼仔稚鱼开口期以后的摄食能力和营养需求,是黄颡鱼仔稚鱼适宜的开口饵料。     

丁(鱼岁)仔稚幼鱼期的摄食与生长

丁Gui仔、稚、幼鱼期具有明显的昼夜摄食节律，其中，仔、稚鱼最大饱食率出现在16：00到20：00，00：00到04：00时有停食现象。幼鱼最大饱食率出现在14：00到22：00，昼夜无明显的停食现象。仔鱼食谱中主要是轮虫，稚鱼食谱渐丰富，幼鱼期食谱更为扩大，且出现了一定量的底栖动物。仔、稚鱼体重、全长瞬时增长率要高于幼鱼期，而且，体重快速增长期要先于全长快速生长期。仔、稚和幼鱼阶段是匀速生长。     

海水鱼苗种二次培育技术

苗种二次培育的概念最早在1985年的文献中提出,是室内外结合培育苗种的方式。单纯的室内水泥池育苗方式不受天气影响,可进行高密度育苗,前期仔鱼存活率较高;单纯的室外海水池塘育苗方式能提供仔稚鱼各发育阶段的适口饵料生物,鱼苗活动的空间大,生长快,体质健壮,育苗成本低。苗种二次培育技术就是有机地结合了前期仔鱼的室内水泥池高密度培育与后期仔稚鱼的室外海水池塘培育的优点,既解决了单纯室外海水池塘育苗成活率偏低的问题,又解决了单纯室内育     

黑鲷幼鱼饲料蛋白源氨基酸平衡的研究

以黑鲷幼鱼肌肉的氨基酸组成作为幼鱼饲料中必需氨基酸需要量的标准模式,通过必须氨基酸指数（ＥＡＡＩ）和生物饲养试验结果相结合,对黑钱财幼鱼的９种不同蛋白源酸比的饲料进行了比较研究,对黑钱财幼鱼配合饲料中氨基酸平衡和蛋白质营养价值进行了评估,筛选出个高效饲料蛋白源配方;表明ＥＡＡＩ是鱼用饲料蛋白质营养价值评估和氨基酸平衡研究的一种简便有效的评价指标。     

Effects of partial substitution of dietary fish meal by fermented soybean meal on growth performance,amino acid and biochemical parameters of juvenile black sea bream Acanthopagrus schlegeli

A feeding trial was conducted to evaluate the effect of replacing fish meal protein with fermented soybean meal (FSM) on the growth performance, feed utilization, amino acid profile, body composition, morphological parameters, activity of antioxidant and digestive enzymes of black sea bream (Acanthopagrus schlegeli) juvenile. Five isonitrogenic and isolipidic diets were prepared with levels of 0 (control), 80, 160, 240 and 320 g kg^?1 FSM. Triplicate groups (40 fish per tank) of juvenile black sea bream with initial weight of 1.17 ± 0.04 g were hand‐fed to visual satiation at three meals per day for 8 weeks. The fish fed diets containing different levels of FSM had no significant differences regarding survival and specific growth rate compared with control group. Feed and protein efficiency ratios of fish fed diet containing 320 g kg^?1 FSM were significantly lower than those of control group. Daily feed intake and daily protein intake of fish fed diet containing 240–320 g kg^?1 were significantly higher than those of control group. Hepatosomatic index and condition factor of fish were not affected by different dietary FSM level. Fish fed diets containing 240–320 g kg^?1 FSM had significantly higher visceral somatic index than control group. Whole body proximate and amino acid compositions of fish were not affected by dietary FSM level. The activity of digestive enzymes in the intestine was not affected by dietary FSM level. The activity of glutathione peroxidase in liver was significantly higher for fish fed the diet containing 160 g kg^?1 FSM compared with control group. This study showed that up to 40% fish meal in the diets of juvenile black sea bream could be replaced by fermented soybean meal with supplementation of methionine, lysine and taurine.     

Gut pH as a limiting factor for digestive proteolysis in cultured juveniles of the gilthead sea bream (Sparus aurata)

After the development of the gastric function in juvenile fish, dietary proteins enter a two-phase digestive process comprising an acidic gastric phase followed by an alkaline intestinal phase. However, the main gastric protease, pepsin, is strictly dependent on the existence of a low-enough environmental pH. In 20-g gilthead sea bream, Sparus aurata, the mean minimal gastric pH is close to 4.5, while the mean pH in the duodenal portion of the intestine was nearly fixed at 6.5. The mean maximal gastric content of HCl was approximately 20 microEq for a low-buffering diet. Gastric proteases were more severely affected than intestinal proteases when assayed at actual sub-optimal pH values, 4.5 and 6.5, respectively. When the gastric proteases of juvenile fish were pre-incubated with a citric acid buffer at pH 6.0, the activity at pH 4.5 was very low, whereas when they were pre-incubated with the same buffer at pH 3.0, the activity at pH 4.5 was significantly increased; this fact suggests a deficient activation of zymogens during the gastric digestion and points to a potential approach to improve protein digestion in juvenile gilthead sea bream.     

Effect of dietary taurine and cystine on growth performance of juvenile red sea bream Pagrus major

Two experiments were conducted to investigate the effect of dietary taurine and cystine on growth and body composition of juvenile red sea bream Pagrus major. In Experiment I, a casein-based semi-purified diet included a small amount of fish meal were supplemented with taurine at the levels of 0 (control) and 1.0%. The experimental diets in Experiment II were without fishmeal and supplemented with taurine at 0 (control), 0.5, 1.0 and 2.0% or cystine at 1.0 and 2.0%. These diets were fed three times a day for 6 weeks to fish (average body weight: 2.3 g in Experiment I and 2.5 g in Experiment II). In Experiment I, fish fed the taurine-supplemented diet showed significantly (P < 0.05) improved growth, feed efficiency and feed consumption relative to fish fed the unsupplemental diet. The whole body taurine content increased, whereas the non-essential amino acid contents decreased, in fish fed the taurine-supplemental diet compared to fish fed the unsupplemented diet. In Experiment II, the growth, feed efficiency and feed consumption of fish fed the taurine-supplemented diets, irrespective of the dietary taurine levels, were significantly higher than those of fish fed the control diet and the cystine-supplemented diets. Taurine content in the whole body increased with the dietary taurine level, while the taurine contents did not increase by the supplemental cystine. Other free amino acid contents in the taurine-supplemented diet groups followed similar trends to those in Experiment I. These results indicate that supplemental taurine to a casein-based semi-purified diet at more than 0.5% improved the growth and feed performance of juvenile red sea bream. It is also suggested that juvenile red sea bream cannot metabolize cystine into taurine.     

Requirement of n-3 long chain polyunsaturated fatty acids for European sea bass (Dicentrarchus labrax) juveniles: growth and fatty acid composition

European sea bass juveniles (14.4±0.1 g mean weight) were fed diets containing different levels of fish oil then of n-3 highly unsaturated fatty acids (n-3 HUFA) for 12 weeks. The fish performance as well as fatty acid (FA) composition of neutral and polar lipids from whole body after 7 and 12 weeks feeding were studied. The requirements of juvenile sea bass for n-3 highly unsaturated fatty acids (n-3 HUFA) were studied by feeding fish diets containing six different levels of n-3 HUFA ranging from 0.2% to 1.9% of the diet, with approximately the same DHA/EPA ratio (1.5:1).

The growth rate at the end of the trial showed significant differences. Fish fed low dietary n-3 HUFA (0.2% DM of the diet) showed significantly lower growth than the diet 3 (0.7%), then no further improvement (P>0.05) of growth performance was seen by elevating the n-3 HUFA level in the diet up to 1.9% (diet 6). No difference in feed efficiency, protein efficiency ratio or protein retention was observed among treatments, nor in protein and total lipid content. However, the n-3 HUFA levels in diets highly influenced fish fatty acid composition in neutral lipid, while polar lipid composition was less affected. Comparison of polar lipid content after 7 or 12 weeks indicated that DHA remained stable at the requirement level, while arachidonic acid decreased with time. Results of this experiment suggest that the requirement for growth of n-3 HUFA of juvenile sea bass of 14 g weight is at least 0.7% of the dry diet.     

Assessment of reference dietary amino acid pattern for juvenile red sea bream, <Emphasis Type="Italic">Pagrus major</Emphasis>

Four semi-purified diets, containing crystalline amino acids (CAAs), were fed to juvenile red sea bream, Pagrus major in order to ascertain the ideal dietary amino acid pattern for this species. A control diet containing 50% casein–gelatin as protein sources, but no CAAs were fed to the fish. The other diets contained 30% casein–gelatin and 20% CAAs. CAAs were added to diets to simulate with amino acid pattern of the red sea bream eggs protein (REP), red sea bream larvae whole body protein (RLP), red sea bream juvenile whole body protein (RJP), and brown fishmeal protein (BFP). The juveniles (average initial body weight, 1.58 ± 0.01 g) were maintained in triplicate tanks and fed twice daily for 30 days. The highest weight gain was observed in juveniles fed the RJP diet. No significant difference was observed in juveniles fed the RLP and BFP diet. Feed efficiency ratio, protein efficiency ratio and amino acid retention in the whole body were significantly (p < 0.05) affected by the simulated dietary amino acid patterns. The essential amino acid profile and A/E ratios of the whole body after the growth trial showed little difference among the dietary treatments. The results suggest that red sea bream juveniles are able to utilize high amounts of CAA in coated form. The amino acid pattern of RJP could be used as an appropriate of reference dietary amino acid for this species.     

Influence of different dietary amino acid patterns on growth and body composition of juvenile Japanese flounder, Paralichthys olivaceus

A feeding trial using five semi-purified diets (50% crude protein) was conducted to investigate the effects of different dietary amino acid patterns on growth and body composition of juvenile Japanese flounder. The control diet contained casein and gelatin as intact protein sources and four other diets contained 30% casein–gelatin (2:1, w/w) and 20% crystalline amino acids (CAA). CAA were added to the diets to simulate the amino acid pattern found in red sea bream egg protein (REP), Japanese flounder larvae whole body protein (FLP), Japanese flounder juvenile whole body protein (FJP), and brown fish meal protein (BFP), respectively. The test diets were fed to triplicate groups of juveniles (2.75±0.05 g) twice a day for 40 days to evaluate weight gain, survival, feed conversion efficiency (FCE), protein efficiency ratio (PER), and apparent protein utilization (APU). The apparent retention of total dietary amino acids in the whole body and A/E ratios of the whole body were also evaluated. The highest weight gain was observed in fish fed the diet containing the dietary amino acid pattern of BFP followed by fish fed the control, FJP, FLP and the REP diets. Percent survival, FCE, PER and APU were also significantly (P<0.05) affected by the amino acid pattern in the diets, indicating the highest value in fish fed the BFP diet. Except for a few amino acids, the amino acid composition of the whole body did not show marked differences with different dietary amino acid pattern. Results suggest that BFP could be more suitable as a reference amino acid pattern in the diet of juvenile Japanese flounder compared to the amino acid pattern of FLP, FJP or REP.     

Supplementations of dl‐Methionine and Methionine Dipeptide in Diets are Effective for the Development and Growth of Larvae and Juvenile Red Sea Bream,Pagrus major

Growth trials for larvae and juvenile red sea bream, Pagrus major, were conducted to elucidate the efficacy of two molecular forms of methionine; dl ‐methionine (dl ‐Met) and methionine dipeptide (Met‐Met). For the larvae experiment, five experimental diets were formulated and fed to fish (42 mg) for 30 days. A diet which has 15% soy protein isolate served as the control diet. Similarly, test diets supplemented with dl ‐Met and Met‐Met at 0.5%, which were either precoated by zein or intact, were also formulated. For the juvenile experiment, five experimental diets were formulated wherein the control diet contained 25% soy protein isolate. Test diets were supplemented with dl ‐Met and Met‐Met at 0.75%, which were either coated by carboxymethycellulose or intact and fed to juveniles (0.75 g) for 56 days. The results of two feeding trials showed both dl ‐Met and Met‐Met can be equally utilized by red sea bream larvae and juveniles. Coating the amino acid significantly improved both fish larval and juvenile growth performance. The development of digestive protease activity of larvae was significantly influenced by coating the amino acid, but the type of methionine was not a factor in changing the protease activity of larvae.     

Effect of dietary oxidized fish oil and vitamin C supplementation on growth performance and reduction of oxidative stress in Red Sea Bream Pagrus major

A 50‐day feeding trial was conducted to determine the effects of dietary oxidized fish oil (OFO) and vitamin C (VC) on growth and oxidative stress in juvenile red sea bream. Test diets were formulated with 2 degrees of peroxide value (23 and 29 meq kg^?1) combined with 3 levels of VC (0, 400 and 800 ppm). No significant difference was found on growth performance between fish fed OFO with 400 or 800 mg VC and the control group that fed a diet with fresh fish oil after 50 days. However, fish fed OFO without VC supplement indicated significantly poor growth than the control group. Liver and muscle thiobarbituric acid reactive substances were reduced by increased VC intake of fish. Fish fed diets containing low OFO with 400 and 800 mg VC, high OFO with 800 mg VC, and fresh fish oil are allocated in the zone of high resistance against oxidative stress together with low oxidative stress condition. On the other hand, no VC supplemented group was under the highest oxidative stress condition. In conclusion, dietary oxidized lipid increased the oxidative stress condition of fish, but more than 400 mg VC kg^?1 of dietary supplement improved growth and health of juvenile red sea bream.     

Otolith microstructure of chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis>: formation of sea entry check and daily deposition of otolith increments in seawater conditions

To apply otolith microstructure to examination of age and growth of juvenile chum salmon Oncorhynchus keta inhabiting coastal waters, formation of otolith increments was investigated for juveniles reared in a seawater aquarium and in net pens. In all otoliths examined, a distinctive check was formed at the time of sea entry of the fish. The deposition of otolith increments after the check was daily for rearing both in the aquarium (57 days) and in the net pens (26 days). Check formation associated with sea entry was also observed in otoliths of juvenile salmon collected 1 km off the coast of Shari, Hokkaido, Japan. Transmitted light observation of otoliths of those fish revealed a transition in otolith increment appearance from dark to light. Otolith Sr: Ca ratio remarkably changed from a low to a high level, coinciding with the transition in otolith appearance. It is suggested that the transition was associated with individual sea entry. This study demonstrated that the check and/or transition associated with sea entry are applicable to a benchmark for otolith increment counts of juvenile chum salmon inhabiting coastal waters.