延迟投饵对瓦氏黄颡鱼仔鱼存活、摄食和生长的影响

以瓦氏黄颡鱼仔鱼为研究对象,将其分为15个处理组,每组200尾（各设3个平行组）,分别在孵化后3、4、5、6、7．8、9、10、11、12、13、14、15和16d开始投喂大型涵,第15组为饥饿组,从不投饵。水温24．5～25．5℃,实验周期为30d。结果表明：（1）孵化后3d的瓦氏黄颡鱼仔鱼初次摄食,15日龄不能建立外源性营养的仔鱼进入PNR期,卵黄囊已耗尽。混合营养期持续4．12h。（2）瓦氏黄颡鱼仔鱼在不同饥饿阶段初次摄食率的变化为：开始较低,此后迅速上升,在4～10日龄达到高峰,最高初次摄食率为100％,此后逐步下降。（3）延迟5天投饵对瓦氏黄颡鱼仔鱼的存活率影响不显著,延迟6d投饵瓦氏黄颡鱼仔鱼的存活率随延迟投饵天数的增加而降低。延迟6d投饵,瓦氏黄颡鱼仔鱼的体长增长率随延迟投饵天数的增加而降低。     

温度和盐度对鞍带石斑鱼受精卵发育及仔鱼成活率的影响

研究了在8个盐度梯度(18.3‰、19.7‰、21.2‰、23.5‰、25.6‰、27.1‰、29.5‰和31.7‰)下鞍带石斑鱼Epinephelus lanceol受精卵和仔鱼在水中的分布状态、出膜率和仔鱼存活率;在9个温度梯度(18℃、20℃、22℃、24℃、26℃、28℃、30℃、33℃和35℃)下,其受精卵孵化率、畸形率和仔鱼成活率。结果表明:(1)在水温为25~26℃,当盐度≤25.6‰时,受精卵表现为沉性;当盐度≥27.1‰时,受精卵表现为浮性。仔鱼的分布与受精卵有相似的特点,当盐度≤21.2‰时仔鱼分布在底层水体;当盐度≥27.1‰时,仔鱼集中分布在上层水体。(2)以孵化率和成活率为指标,鞍带石斑鱼孵化的适宜盐度范围为21.2‰~31.7‰,最适盐度范围为25.6‰~31.7‰。在盐度为31.7‰时仔鱼成活率最高达到75.9%。(3)鞍带石斑鱼胚胎发育的适温范围是26~30℃。28℃时受精卵孵化率、仔鱼成活率均最高,畸形率最低。     

盐度对赤点石斑鱼受精卵发育的影响及仔鱼活力的判断

观察比较了10个盐度梯度（44.0,41.0,38.0,35.0，自然海水盐度30.5-32.5,27.0,24.0,21.0,18.0,15.0)下赤点石斑鱼受精卵的孵化率和畸形率，对12批初孵仔鱼进行耐饥饿试验。并测定其不投饵存活系数SAI值。结果表明，赤点石斑鱼受精卵孵化的适宜盐度为38.0-24.0，最适盐度为35.0-27.0。盐度高于35.0，孵化率随盐度的升高而降低，仔鱼畸形率则随之升高。盐度低于24.0，孵化率随盐度的降低而降低，仔鱼畸形率则随之升高，从盐度38.0到41.0以及24.0到21.0是2个对受精卵孵化率和仔鱼畸形率影响很大的盐度梯度，高于或低于这2个盐度梯度，孵化率即明显大幅度降低，畸形率则大幅度升高，赤点石斑鱼仔鱼的SAI值为3.19-12.42，低于长吻Sheng和黄条Shi的SAI值，仔鱼的SAI值与卵的受精率，孵化率呈正相关关系。只有SAI值大于5的仔鱼才有可能被进一步培育成苗，低于5的将在数天内死亡。     

Effect of dietary iron supplement on growth, haematology and microelements of juvenile grouper, Epinephelus coioides

An experiment was conducted to investigate the effect of dietary iron supplement on growth, haematology and microelements of juvenile grouper, Epinephelus coioides. Casein–gelatine‐based diets supplemented with 0, 50, 100, 150, 200 and 250 mg kg⁻¹ iron from ferrous sulphate were fed to grouper (mean initial weight: 21.0 ± 0.2 g) for 8 weeks. Weight gain was highest in fish fed the diet supplemented with 100 mg kg⁻¹ iron, intermediate in fish fed diets with 50, 150, 200 and 250 mg kg⁻¹ iron and lowest in fish fed the basal diet. Feed efficiency followed a similar trend except that the lowest value was in fish fed the basal diet and the diet supplemented with 250 mg kg⁻¹ iron. Hepatic iron was highest in fish fed diets supplemented with iron ≥100 mg kg⁻¹, followed by fish fed diet with 50 mg kg⁻¹ iron and lowest in fish fed the basal diet. The whole‐body iron was lowest in fish fed the basal diet but not significantly different from other groups, as judged by anova . Iron supplement to the basal diet had no significant effect on haematological parameters (red blood cell count, haematocrit and haemoglobin), hepatic copper concentration or manganese, zinc concentration in liver and whole body. Broken‐line analysis of hepatic iron indicated that iron supplementation of 100 mg kg⁻¹ satisfied the hepatic iron storage and that further supplementation did not expand the iron status.     

饥饿对斜带石斑鱼肝脏和肌肉脂肪酸组成的影响

在室外水泥池(4m×1.5m×1m)进行石斑鱼(62.3±0.6g)的饥饿实验,每池放养35尾,设3个重复,实验时间分别为0、1、2、3和4周。随着饥饿时间的延长,体重减轻,肥满度和肝体比显著降低;肌肉水分显著增加而蛋白质含量显著下降(P<0.05),脂肪含量在第1周下降后基本保持稳定。肝脏饱和脂肪酸在饥饿前3周基本保持不变,第4周显著下降。单不饱和脂肪酸在饥饿第1周保持不变,然后呈下降趋势。多不饱和脂肪酸和高不饱和脂肪酸的总和随着饥饿时间的延长,含量显著增加。与肝脏相比,肌肉中脂肪酸变化程度较小。随着饥饿时间的延长,肌肉中140减少而205增加。饥饿使肌肉中DHA/EPA比率呈下降趋势,但肝脏DHA/EPA比率显著上升;肌肉和肝脏中DHA EPA的百分比都随饥饿时间的延长而显著上升。     

不同开口饵料对四川裂腹鱼仔鱼生长和成活率的影响

采用丰年虫、冰冻轮虫、水蚯蚓、人工配合饲料4种开口饵料投喂四川裂腹鱼（ Schizothorax kozlovi Nikol-sky）仔鱼30 d,研究其对四川裂腹鱼仔鱼生长和成活率的影响。结果显示：投喂水蚯蚓和丰年虫能保证四川裂腹鱼仔鱼具有较快的生长速度和较高的成活率。而人工配合饲料组生长速度明显低于其他组,且成活率最低。结果表明,4种开口饵料中,丰年虫是四川裂腹鱼仔鱼最适宜的开口饵料。     

Effects of dietary blend of fish oil with corn oil on growth and non-specific immune responses of grouper, Epinephelus malabaricus

A growth trial was conducted to investigate the effects of fish oil and corn oil on the growth and non‐specific immune responses of juvenile grouper, Epinephelus malabaricus. Five semi‐purified diets were supplemented with 40 g kg⁻¹ of either fish oil (F4), corn oil (C4) or blend of fish oil with corn oil at ratio of 3 : 1 (F3C1); 1 : 1 (F2C2) and 1 : 3 (F1C3). Each diet was fed to triplicate groups of grouper (mean initial weight: 10.26 ± 0.14 g) in a recirculating rearing system for 8 weeks. Weight gain and feed efficiency of fish fed the F4, F3C1 and F2C2 diets were the highest (P < 0.05), followed by fish fed the F1C3 diet, and the lowest in fish fed the C4 diet. Fish fed the C4 diet had a lower survival rate than fish on other dietary treatments. Fatty acid composition of liver and muscle in fish generally reflected the composition of the diet. Leukocyte superoxide anion (O⁻₂) production ratio was the highest in fish fed the F3C1 and F2C2 diets, followed by fish fed the F4 and F1C3 diets, and the lowest in fish fed the C4 diet. Fish fed the F3C1 and F2C2 diets had higher plasma lysozyme activities than fish fed the F4 and C4 diets. Plasma alternative complement activity was higher in fish fed the F3C1, F2C2 and F1C3 diets than fish fed the F4 and C4 diets. These results suggest that grouper fed diets with 3 : 1 or 1 : 1 of fish oil to corn oil ratio had similar growth to the fish fed diet with fish oil. Blend of fish oil with corn oil in diet significantly enhanced non‐specific immune responses of grouper when the fed diet contained fish oil as the only lipid source.     

Influence of feeding regime on fatty acid composition in young red-spotted grouper Epinephelus akaara

ABSTRACT:   Young red-spotted grouper Epinephelus akaara with an average total length of 3.4 cm were divided into five groups in floating net-cages, and reared under satiated conditions with different feeding frequencies (0.5, 1, 2, 4 and 8 times per day) for 40 days. Total food intake increased with feeding frequency. Feeding four times per day resulted in the highest growth and food conversion efficiency. Total lipid accumulation in the muscle, liver and intraperitoneal fat body (IPF) increased with feeding frequency. Red-spotted grouper were found to contain a high proportion of docosahexaenoic acid (DHA) in the muscle. Fish fed 0.5 times per day were characterized as having a high proportion of DHA in triglycerides (TG) in muscle (80%), liver (69%) and IPF (18%). Increasing saturated fatty acids and a relative reduction of DHA were observed in the muscle TG as the feeding frequency increased. Frequent feeding accelerated the accumulation of eicosapentaenoic acid and saturated acids in the liver and IPF. Low saturated acids and a subsidiary proportional increase in DHA were the result of the low lipid reserves. A possible role for DHA and saturated acids are discussed with regard to lipid reserves.     

养殖密度对豹纹鳃棘鲈生长和血液生化指标的影响

采用实验生态学方法研究了饥饿对豹纹鳃棘鲈(Plectropomus leopardus)仔鱼形态发育、生长和成活的影响,并测定了饥饿仔鱼的初次摄食率和不可逆点(PNR)。结果显示,水温23~24 ℃下豹纹鳃棘鲈仔鱼2.5 DPH(孵化后天数)开口摄食,3.0 DPH卵黄囊和油球消失,混合营养期仅0.5 d,容易遭受饥饿胁迫。饥饿仔鱼最高初次摄食率为65%,出现在3.5 DPH; PNR发生在4.5~5.0 DPH,仔鱼具有初次摄食能力的时间仅2.0~2.5 d。对照组和饥饿组仔鱼在3.5 DPH前全长无明显差异(P>0.05),之后饥饿组仔鱼出现生理性萎缩,全长开始与对照组差异显著(P < 0.05)。饥饿组仔鱼在内源性营养消耗完毕后出现了一系列因饥饿所导致的形态发育特征,并于6.5 DPH全部死亡,因此豹纹鳃棘鲈仔鱼最佳投喂时间为2.5~3.5 DPH。

     

Effects of dietary choline on growth performance,lipid deposition and hepatic lipid transport of grouper (Epinephelus coioides)

The number of 360 individuals with an average initial weight of 87.8 ± 0.04 g was fed six diets containing graded levels of choline at 8.1 (control group), 602.5, 1119.0, 1511.5, 1970.0 and 4029.0 mg choline kg^?1 diet, respectively, to investigate the effects of dietary choline on growth performance, lipid deposition and hepatic lipid transport for grouper, Epinephelus coioides. Dietary methionine was estimated to be 10.02 g kg^?1, less than the requirement (13.10 g kg^?1). The results of 10‐week study period indicated that the best values of specific growth rate (SGR), feed conversion rate (FCR) and protein efficiency rate (PER) all occurred in 1119.0 mg choline kg^?1 diet (P < 0.05). The survival range increased from 8.1 to 1511.5 mg choline kg^?1 diet and then plateaued. Dietary choline supplementation significantly decreased the liver lipid content of grouper (P < 0.05), but the lipid content of the muscle tended to be increased firstly and then decreased (P < 0.05). Liver choline concentration reached a plateau in 1511.5 mg choline kg^?1 diet and then levelled off (P < 0.05). Serum high density lipoprotein‐cholesterol (HDL‐C) and total cholesterol (TCHO) levels were firstly decreased and then increased with dietary choline supplementation. A reversed tendency, however, was found in triglyceride. Broken‐line regression analysis of SGR and liver choline content indicated that choline requirement of grouper was 1093.7 and 1579.7 mg kg^?1 diet, respectively.     

Influence of light intensity on feeding, growth, and early survival of leopard coral grouper (Plectropomus leopardus) larvae under mass-scale rearing conditions

This study investigated the effect of different light intensities on feeding, growth and survival of early stage leopard coral grouper Plectropomus leopardus larvae. Four different light intensities (0, 500, 1000 and 3000 lx) were used and larvae were kept under constant light conditions from 0 day after hatching (DAH) to 5 DAH. The larvae were fed a small S-type of Thai strain rotifers at a density of 20 individuals/mL from 2 DAH. The number of rotifers in larval digestive organ and total length of larvae were examined at 3 h intervals between 04:00 and 22:00 h on 3 DAH, and thereafter at 6 h intervals until the end of the experiment (5 DAH). Four experimental trials of the larval rearing were repeated using by 60 kL mass-scale rearing tanks. The results indicate that coral grouper larvae are visual feeders and their food intake increases with increasing light intensity. Food intake of larvae reared at 3000 lx was significantly higher than those reared at 0–1000 lx on 3 DAH despite being the first-feeding day (P < 0.01). On 4 DAH, total length of larvae reared at 3000 lx was significantly larger than those reared at the lower light intensities (0, 500 and 1000 lx), and thereafter light intensity significantly influenced larval feeding and growth until the end of the experiment. Survival on 5 DAH did not show a significant difference between light intensities, but survival rate at 3000 lx and 1000 lx had a tendency to be higher than those reared at the lower light intensities (0 and 500 lx). In contrast, larvae reared at 0 lx exhibited stagnant and/or negative growth. These results indicate that light intensity is significantly the factor affecting larval feeding, growth, and survival in coral grouper larvae under the rearing conditions.     

Effects of fish oil with difference oxidation degree on growth performance and expression abundance of antioxidant and fat metabolism genes in orange spotted grouper,Epinephelus coioides

The present study was designed to assess the effects of fish oil with different oxidation degree on growth performance, serum biochemistry parameters and expressive abundance of oxidative stress and fat metabolism genes of orange spotted grouper Epinephelus coioides. The oxidized fish oil was conducted as follows: storage temperature: 4°C, ambient temperature (AT, [31.5 ± 3.5]°C); storage time: 45, 90, 135 days; antioxidant contents: 30 mg/kg (ethoxyquin [EQ]), 300 mg/kg Higher EQ (HEQ). According to the different treated conditions, 14 kinds of fish oil with different oxidation degree were obtained: T_F+EQ [positive control (fresh oil + EQ)], T_F (negative control [fresh oil]), T_4°C+45d+EQ, T_4°C+45d+HEQ, T_4°C+90d+EQ, T_4°C+90d+HEQ, T_4°C+135d+EQ, T_{4°C+135d+HEQ}, T_AT+45d+EQ, T_AT+45d+HEQ, T_AT+90d+EQ, T_AT+90d+HEQ, T_AT+135d+EQ, T_AT+135d+HEQ. Groupers were fed isonitrogenous and isolipidic diets containing 14 kinds of fish oil for 8 weeks, respectively. The results showed that survival, weight gain rate and thermal growth coefficient decreased as oxidation degree of dietary fish oil increased (p < 0.05). Higher serum total protein, triglyceride and glucose were observed with ascending oxidation degree of fish oil (p < 0.05). The genes expression levels of catalase, superoxide dismutase and glutathione peroxidase were up‐regulated with dietary oxidized level increasing (p < 0.05). In addition, the similar status also appeared in expression of peroxisome proliferator‐activated receptor gamma (PPARγ), hormone‐sensitive lipase (HSL) and fatty acid synthase (FAS) genes. In conclusion, the fish oil would show negative influence on the fish health until peroxide value and p‐anisidine value in oil exceed 12.96 meq/kg and 20.89. The best storage condition for fish oil is 4°C, 45 days and 30 mg/kg EQ which could keep fish oil available property to grouper.     

Effects of delayed first feeding on the survival and growth of tiger grouper,Epinephelus fuscoguttatus (Forsskål, 1775), larvae

The effects of delayed first feeding on the survival and growth of tiger grouper, Epinephelus fuscoguttatus (Forsskål 1775), larvae were examined under controlled conditions. The total length, yolk sac volume, oil globule volume, yolk sac absorption time and nutritional transition period (NTP) of the larvae fed at different first times (0, 6, 12, 18 and 24 h after the mouth opening stage; h AMO) were compared. Larval first feed intake was observed at 54 h after hatching (h AH) at 27.5 ± 0.5 °C. The yolk sac was consumed more rapidly with an increase in delayed first feeding and was significantly different among treatments (P<0.05). Larvae first fed at 0 h AMO had the longest yolk sac absorption (72 h AH) and NTP (20 h) times and had the highest survival and growth rates at the end of the experimental period (360 h AH), being significantly higher (P<0.05) than the other treatments. First mortality was observed at 69 h AH, approximately 2 h after point of no return (PNR) occurred. This study suggests that first feeding of tiger grouper larvae should commence at 0 h AMO for enhancement of larval survival and growth.     

Effect of light intensity and feed density on feeding behaviour,growth and survival of larval sablefish Anoplopoma fimbria

We studied the effects of light intensity on larval activity, feeding behaviour, growth and survival of a candidate species for aquaculture – sablefish (Anoplopoma fimbria). Of six light intensities ranging from 2 to 750 lux at the water surface, the greatest surviving biomass in small tanks was observed at 12–42 lux. In another experiment in larger tanks, behavioural observations showed that larvae fed poorly under light brighter than 800 lux but fed better at lower light intensities, depending on tank type. In a separate experiment, where live feed densities were varied between 2.5 and 17.5 rotifers per mL of tank water, surviving biomass and dry weight increased with higher feed densities. These experiments help refine methods for rearing larval sablefish by demonstrating effects of light intensity and feed density on larval performance.     

光照强度、温度和盐度对鹿角沙菜生长及生化组分的影响

以鹿角沙菜（Hypneacervicornis）为材料,分别研究了其在不同光照强度（2000lx、4000lx、7500lx、10000lx和15000lx）、不同温度（15℃、20℃、25℃、30℃和35℃）、不同盐度（5、10、15、20、25、30和35）下生长及生化组分的变化。结果显示,适合鹿角沙菜生长的光照强度为2000—4000lx,温度为20～30℃,盐度为20—35;最适合生长的光照强度为4000lx,温度为25℃,盐度为30,在此条件下藻体具有最高的相对生长速率（RGR）,SOD活性最低。在光照强度4000～5000lx范围内随着光照强度的升高,可溶性蛋白（SP）、叶绿素a（Chl—a）和类胡萝卜素（Car）的质量分数降低,而藻红蛋白（PE）和藻蓝蛋白（Pc）的质量分数上升;在温度25～35℃、盐度30～35范围内随着温度、盐度的升高,可溶性蛋白、叶绿素a、类胡萝卜素、藻红蛋白和藻蓝蛋白的质量分数降低,说明适宜的温度和盐度有利于其生化组分积累。     

Effects of dietary docosahexaenoic acid sources,microalgae meal and oil,on growth,fatty acid composition and docosahexaenoic acid retention of orange‐spotted grouper,Epinephelus coioides

This study evaluated the effects of Aurantiochytrium spp. microalgae meal and oil as dietary docosahexaenoic acid (DHA) sources on the growth, fatty acid composition and DHA retention of orange‐spotted grouper, Epinephelus coioides. Dietary fish oil was replaced with microalgae meal or oil to provide an equal amount of DHA as a fish oil‐containing basal diet. In total, three experimental diets were fed to triplicate groups of fish (initial wt: 8.48 ± 0.06 g) in a recirculating system for 8 weeks. The weight gain and feed efficiency of the fish did not differ significantly among the experimental diets. The fatty acid composition of the whole body of the fish generally reflected the composition of their diet. The concentration of eicosapentaenoic acid in the whole body was higher in the fish fed the fish meal control diet than in those fed the two experimental diets The fish fed the control diet and those fed the diet containing microalgae oil exhibited higher DHA concentrations than did the fish fed the diet containing microalgae meal. The whole‐body DHA retention was the highest in the fish fed the diet with microalgae oil, followed by the fish fed the control diet. The lowest whole‐body DHA retention was observed in the fish fed the diet containing microalgae meal. The results suggested that the oil from Aurantiochytrium spp. microalgae can be used as DHA source for the grouper. DHA utilization by the fish was higher when the diet was supplemented with microalgae oil than with dry microalgae meal.     

光照强度、温度和盐度条件对鹿角沙菜生长及生化组分的影响

以鹿角沙菜（Hypnea cervicornis）为材料,分别研究了其在不同光照强度（2 000 lx和4 000 lx和7 500 lx、10 000 lx和15 000 lx）、不同温度（15 ℃、20 ℃、25 ℃、30 ℃和35℃）、不同盐度（5、10、15、20、25、30和35）下生长及生化组分的变化。结果显示,适合鹿角沙菜生长的光照强度为2 000~4 000 lx,温度为20~30 ℃,盐度为20~35;最适合生长的光照强度为4 000 lx,温度为25 ℃,盐度为30,在此条件下藻体具有最高的相对生长速率（RGR）,SOD活性最低。在光照强度4 000~5 000 lx范围内随着光照强度的升高,可溶性蛋白（SP）、叶绿素a（Chl-a）和类胡萝卜素（Car）的质量分数降低,而藻红蛋白（PE）和藻蓝蛋白（PC）的质量分数上升;在温度25~35 ℃、盐度30~35范围内随着温度、盐度的升高,可溶性蛋白、叶绿素a、类胡萝卜素、藻红蛋白和藻蓝蛋白的质量分数降低,说明适宜的温度和盐度有利于其生化组分积累。

     

延迟投饵对杂交鲟仔鱼生长、存活和体成分的影响

以杂交鲟(Huso huso ×Acipenser baeri )仔鱼为研究对象,将其分为 8个处理组,每组100尾(各设2个平行组),分别在孵化后6 d(对照组)、8 d、10 d、12 d、14 d、16 d和18 d开始投喂冰冻卤虫和碎水蚯蚓(以质量比1:1混合),5 d后只投喂碎水蚯蚓。第8组为饥饿组,从不投饵。水温17 ℃,实验周期30 d。结果显示,仔鱼于孵出后8日龄进入混合营养期;10日龄左右是仔鱼开始加速生长的关键时期;12日龄仔鱼进入外源性营养期。随起始投饵时间的延迟,仔鱼的全长、湿重、干重和粗蛋白含量下降,鱼体水分含量则随之升高。但对照组、8日龄及10日龄起始投喂组之间的鱼体水分、粗蛋白、粗脂肪含量并没有显著差异(P>0.05),14日龄及其以后各起始投喂组仔鱼的生长和鱼体生化成分则与上述各组存在显著差异(P相似文献