黑鲷的生长和生态转换效率及其主要影响因素

黑鲷的特定生长率随温度或摄食水平升高而减速增长,其关系分别可用公式SGR＝1.0７lnT－2.4４ 或SGR＝0.46ln( FL )－0.071定量描述;而生态转换效率则随温度或摄食水平增大而增至一峰值,然后随其进一步增加而降低,其关系则分别可用二次曲线Eg＝－0.1２T2 ４．６４T－２９．７４或Eg＝-5.92FL2 35.57FL 26.69定量描述,且依据上述公式可分别求得实验条件下的最佳生长温度为19.4℃,维持摄食量和最佳摄食量分别为黑鲷体重的1.17％和2. 62％。黑鲷的群居性和摄食小型鱼类饵料,虽有利于加速其生长速度,却不能影响相同条件下测得的生态转换效率。     

日粮水平和饵料种类对黑鲷能量收支的影响

采用室内流水实验法研究了摄食水平和饵料种类对黑鲷能量收支各组分和模式的影响。结果表明，黑鲷的生长量，总呼吸代谢量，排泄量及生态转换效率均随日粮水平升高呈增长趋势，二者之间的定量关系可分别用对数曲线或直线加以定量描述；不同生物饵料能造成黑鲷摄食，生长，排泄和总呼吸代水平的显著差异，但却不能改变以比能值为单位的生态转换效率。黑鲷的呼能量收支分配率随摄食水平不同有较显著差异；代谢能分配率和排泄能分配率随摄食水平增大呈U型变化趋势，而生长能分配率却恰恰相反。除摄食高蛋白饵料时引起排泄能分配率增加外，摄食不同饵料对黑铜的能量分配模式影响不十分显著。     

摄食水平和饵料种类对黑癇能量收支的影响

以玉筋鱼和鹰抓糙对虾为生物饵料，采用室内流水模拟实验法研究了摄食水平和饵料种类对黑Jun能量收支各组分和能量收支模式的影响。结果表明，黑Jun的生长量、总代谢量、排泄量及生态转换效率均随摄食水平升高呈增长趋势，二者之间的定量关系可分别用对数曲线或直线加以定量描述；不同生物饵料能造成黑Jun摄食、生长，排泄和总代谢水平的显著差异，但却不能改变以比能值为单位的生态转换效率。黑Jun的能量收支模型摄食水平不同有较明显差异，代谢能分配率和排泄能分配率随摄食水平增大呈U型变化趋势，而生长能分配率却恰恰相反。另外，摄食不同饵料对黑Jun的能量收支模型的影响也十分显著。     

密度和投饵频率对凡纳滨对虾存活和生长的影响

研究了密度(361、722和1 084尾/m2)和投饵频率(1、2和4次/d)对凡纳滨对虾存活和生长的影响,实验时间6周。结果表明:在3个密度水平,随投饵频率的升高,对虾摄食量、存活率、特定生长率、饲料系数和吸收效率均呈上升趋势;在3个投饵频率水平,随密度的升高,对虾摄食量、存活率、特定生长率和饲料系数均呈下降趋势,而吸收效率呈上升趋势。     

摄食水平对中华鳖幼鳖生长的影响

在 30℃水温下进行摄食生长实验 (实验周期为 5 6d) ,设饥饿、 1%、 2 %和饱食 4个摄食水平 ,研究了摄食水平对中华鳖幼鳖 (2 96 6 0～ 396 0 9)g生长的影响。结果表明 ,摄食水平对中华鳖幼鳖的特定生长率有显著影响 (P <0 0 1) ,其特定生长率随摄食水平的增加而增加 ,除湿重特定生长率外 ,干物质、蛋白质和能量的特定生长率摄食率之间的关系以二次方程表述可靠性最高 ,而湿重的特定生长率摄食率关系以对数方程表述时可靠性最高。方差分析表明 ,摄食水平对中华鳖幼鳖湿重和能量的转化效率有显著影响 (P0 0 5 ) ,除湿重的转化效率外 ,干物质、蛋白质和能量的转化效率在 2 %组均达到最大。     

摄食水平对几种重要海水养殖鱼类生长和氮收支的影响

本文研究了不同摄食水平（从饥饿至饱食）军曹鱼幼鱼（平均初始体重10.0g）、青石斑鱼幼鱼（平均初始体重5.5g）和卵形鲳鲹幼鱼（平均初始体重7.7g）的生长和氮收支，建立了生长和氮排泄与摄食水平的回归方程。结果表明，军曹鱼幼鱼特定生长率随摄食水平的增加呈显著增长趋势，在9%和饱食两个摄食水平之间无显著性差异，而青石斑鱼和卵形鲳鲹幼鱼的特定生长率随摄食水平增加呈线性增长趋势；饱食时，青石斑鱼和卵形鲳鲹幼鱼的生长速率接近而明显低于军曹鱼幼鱼的。军曹鱼幼鱼食物转化效率随摄食水平的增加呈先增长后下降的趋势，在9%/d摄食水平组有最大值，而青石斑鱼和卵形鲳鲹幼鱼食物转化效率随摄食水平的增加而持续增长，在饱食摄食水平时有最大值；饱食时，军曹鱼和青石斑鱼幼鱼的食物转化效率接近而明显高于卵形鲳鲹幼鱼的。3种海水鱼摄食氮、排粪氮、生长氮和氮排泄均随摄食水平的增加呈显著增长趋势；比较可知，军曹鱼幼鱼的摄食氮和氮排泄均最大，而青石斑鱼幼鱼的最小。军曹鱼、青石斑鱼和卵形鲳鲹幼鱼饱食和次饱食摄食水平时的氮收支方程分别为100CN = 7.7(6.0)FN + 22.6(31.31)GN + 69.7(62.68)UN、100CN = 2.7(2.8)FN + 20.9(8.4)GN + 76.4(88.8)UN和100CN = 1.8(1.4)FN + 12.8(9.3)GN + 85.4(89.3)UN（氮收支方程括号中的为次饱食数据）；3种海水鱼饱时和次饱食时摄食氮中用于排粪的比例较小且变化不大，军曹鱼次饱食时摄食氮中用于生长的比例较饱食时的大而用于排泄的比例较饱食时的小，青石斑鱼和卵形鲳鲹幼鱼的则相反。因此，鱼类的氮排泄率和氮收支方程存在种间差异，而当食物中氮含量较为接近时，摄食量增大是导致鱼类氮排泄增加的主要原因之一。综合考虑生长、食物转化效率、氮排泄和氮收支方程各因素，可得出在实验的生长阶段，3种海水养殖鱼中，军曹鱼幼鱼的最佳摄食水平为次饱食摄食水平（9%/d或约为饱食摄食水平的70%），而青石斑鱼和卵形鲳鲹幼鱼的最佳摄食水平为饱食摄食水平。     

盐度和草药野马追对中国明对虾生长的影响

经5周饲养,研究了盐度(10、30)和草药野马追(0、0.1%、0.2%、0.4%、0.8%、1.6%、3.2%)对中国明对虾生长的影响。试验结果表明,野马追及盐度和野马追交互作用显著地影响明对虾的终末质量、特定生长率、摄食量和饲料系数。在2个盐度水平,随饲料中野马追添加量的升高,中国明对虾特定生长率、摄食量和吸收效率均呈上升趋势,当到达最大值后,中国明对虾特定生长率、摄食量和吸收效率随着野马追添加量的升高而下降;而饲料系数呈下降趋势,达到最小值后,然后上升。     

黑鲷的生长和生态转换效率及基主要影响因素

黑鲷的特定生长率随温度或摄 食水平升高而减速增长，其关系分别可用公式ＳＧＲ＝１．０７１nＴ－２．４４或ＳＧＲ＝０．４６１n（ＦＬ）－０．０７１定量描述；而生态转换效率则随温度或摄食水平增大而增至一峰值，然后随其进一步增加而降低，其关系则分别可用二次曲线Ｅg＝－０．１２Ｔ＾２＋４．６４Ｔ－２９．７４或Ｅg＝－５．９２ＦＬ＾２＋３５．５７ＦＬ＋２６．６９定量描述，且依据上述公式可分别求得实验条件下的最佳生     

温度对中华鳖稚鳖最大摄食率、转化效率和生长的影响

温度对稚鳖消化率无显著影响(P>0.05);而对其最大摄食率、特定生长率和转化效率均有显著影响(P<0.01),3指标均有随温度升高而增加的趋势。31℃时湿重、干物质和蛋白质的特定生长率和湿重及蛋白质的转化效率均为最大值。温度对中华鳖稚鳖特定生长率的影响机制有2个:温度-最大摄食率-生长和温度-转化效率-生长。     

低盐和低温对脊尾白虾生长和能量收支的影响

研究了低盐和低温对脊尾白虾(Exopalaemon carinicauda Holthuis)生长和能量收支的影响,实验周期60d。结果表明,随盐度的升高,脊尾白虾存活率、特定生长率、摄食量和饲料转换效率呈上升趋势;随温度的升高,白虾特定生长率、摄食量和吸收效率呈上升趋势,而饲料转换效率呈下降趋势。能量分配中,呼吸能的支出最大,占摄食能的68.78%~74.91%;其次是排粪能和生长能部分,分别占摄食能的10.23%~13.24%和6.97%~13.24%;排泄能和蜕壳能是能量支出中较小的部分,分别占摄食能的4.61%~5.56%和0.63%~0.73%。随盐度的升高,脊尾白虾生长能占摄食能的比例呈上升趋势,而排泄能和排粪能占摄食能的比例呈下降趋势。随温度的升高,白虾生长能和排粪能占摄食能的比例呈下降趋势,而呼吸能和排泄能占摄食能的比例呈上升趋势。     

鲈鲤苗种培育及苗种生长特性的研究

为研究鲈鲤(Percocypris pingi)苗种的生长特性,开发鲈鲤育苗技术,采用水泥池流水单养模式,在自然水温条件下,开展了10日龄至110日龄鲈鲤苗种培育试验。经过100 d的培育,鲈鲤鱼苗体质量从(46.45±4.03)mg增加到(2600.09±105.18)mg,平均体长从(16.22±0.46)mm增长到(50.78±2.97)mm,平均成活率为82.00%;体质量变异系数在4.05%~24.80%,体长变异系数在2.49%~7.32%,体质量变异系数大于体长变异系数;体质量变异系数整体呈现先升高后降低的变化趋势,体长变异系数整体变化较为平缓,在整个培育阶段,鲈鲤种群生长离散呈现从加剧到减弱的变化规律;体质量特定生长率在(0.91±0.49)%/d~(7.75±2.18)%/d,体长特定生长率在(0.47±0.29)%/d~(1.94±1.46)%/d,体质量特定生长率大于体长特定生长率;在水温16.8~23.0℃条件下,鲈鲤生长状况良好,特定生长率相对较高,当水温高于23.0℃之后,特定生长率呈降低趋势,表明16.8~23.0℃是鲈鲤鱼苗适宜的生长水温范围;肥满度变化范围在(1.09±0.10)~(2.85±0.18)g/cm^3,肥满度变化呈现先升高后降低的变化趋势;体长(x)和体质量(y)的拟合方程为y=0.0015x^3.7566(R^2=0.9806),b值为3.7566;全长(y)和体长(x)的拟合方程为y=1.223x-0.5055(R^2=0.9908)。试验结果表明,鲈鲤苗种在水泥池流水单养模式及自然水温条件下生长状况良好,16.8~23.0℃是鲈鲤苗种的适宜生长水温。     

细鳞鱼摄食和生长最适水温的研究

在室内控温水族箱中设6℃、11℃、16℃和21℃四个水温组,饲养7周,研究了初始体重为1.72±0.24g的细鳞鱼（Brachymystax lenok）幼鱼摄食和生长的最适水温。结果表明,16℃时细鳞鱼的特定生长率（SGR）、日增重（DWG）、食物转化率（FCE）和摄食率（FI）显著高于其他处理组。这些参数与水温（T）之间的相关关系可用二次回归曲线来描述,特定生长率与水温的回归方程为SGR=（-2.601）＋（0.887）T＋（-0.027）T2;摄食率与水温的回归方程为FI=（0.111）＋（0.292）T＋（-0.009）T2（P〈0.01,R=0.990）;食物转化率水温的回归方程为FCE=（52.828）＋（11.951）T＋（-0.393）T2。细鳞鱼在11～21℃都可以摄食生长,最适水温为15.20℃～16.43℃。     

Ration level for salmonids II. Growth, feed intake, protein digestibility, body composition, and feed conversion in rainbow trout weighing 0.5–1.0 kg

Six groups of rainbow trout (Salmo gairdneri Richardson), raised in fibre-glass tanks, were fed at six different ration levels for two periods of 21 days each. Each tank contained 20 individually tagged fish with a mean initial weight of 415 g. The water temperature averaged 8.4°C and 10.2°C in the two periods. The basic ration level was calculated from an expected maximum growth rate, depending on fish size and water temperature. This level was defined as “level 1.000”. The other experimental levels were 0.125, 0.250, 0.500, 2.000, and 4.000 relative to this, respectively.

No fish died during the experiment. The growth of the fish increased significantly with increasing rations up to the level 2.000. The fish lost weight at the ration level 0.125. The growth rate was near zero at the ration level 0.250. The growth of the fish receiving the highest ration level was 1.72% of their weight per day. The variation in growth of the fish within various weight classes was influenced by the ration level so that the growth distribution of the scantiest fed groups was skewed to the left. There was no skewness in the distribution of the most plentifully fed groups. The ration level had no significant effect on the apparent protein digestibility. Measurements of the feed intake using a radioactive isotope in a 6-h meal showed that the fish ingested all the feed at the ration levels from 0.125 to 1.000. The feed intake recorded was equivalent to the requirements for fish growth at the ration level 2.000, while it was lower at the ration level 4.000. The liver weight percentage increased with increasing ration while the dressed-out carcass percentage decreased. The chemical compostion of the carcass was influenced to a greater extent by the feeding than that of the intestines. The feed conversion efficiency (FCE) and the productive protein value (PPV) of the feed were highest at the ration level 1.000. The values obtained were an FCE of 1.0 kg growth per kg dry feed ingredients and a PPV of 41%.     

A novel konjac glucomannan–xanthan gum binder for aquaculture feeds: the effect of binder configuration on formulated feed stability,feed palatability and growth performance of the Japanese abalone,Haliotis discus hannai

As part of a programme to develop sustainable diets for macroalgivores, a 3‐month experiment was conducted to determine the effects of konjac glucomannan–xanthan gum (KX) binder configuration on formulated feed stability, feed palatability and growth performance of juvenile, hatchery‐reared, Haliotis discus hannai. This study was conducted in a recirculation facility in which four KX binder configurations were evaluated in a series of isonitrogenous experimental feeds and freshly harvested Laminaria digitata was included as a natural feed type. Dry matter leaching of the experimental feed treatments was assessed with no significant difference in the dry matter leaching between treatments observed. No differences (P > 0.05) were found in percentage survival, daily food consumption (DFC) and linear growth rate (LGR) between treatments. Food conversion efficiency (FCE), specific growth rate (SGR) and body weight/shell length (BW/SL) ratio were significantly higher when offered L. digitata. Trends showed that the best performing KX feed in terms of FCE, LGR, SGR and BW/SL ratio was produced with the 2% KX; 1 : 1 binder.     

Growth effects in Arctic charr reared in cold water: Feed frequency, access to bottom feeding and stocking density

The effects of time restricted feeding, possibility of bottomfeeding and stocking density on the growth of Arctic charr(Salvelinus alpinus L.) were examined in fish held at lowtemperature (<2 °C). Fish fed for a restricted time (1 h) hadsignificantly (p < 0.05) lower specific growth rate (0.15 vs0.32% per day) than those fed the same ration over an extendedtime period (12 h). Increasing stocking densities had a positive andsignificant effect (p < 0.05) on growth with SGR increasing from 0.27to 0.52% per day at 2–30 kg m^-3. Fish withaccess to feed on the tank floor had a significantly higher (p <0.05) growth rate (0.3 vs 0.13% per day) than those without thepossibility to feed from the bottom. When fish were held underconditions without access to the bottom a doubling of the feed rationdid not result in a significant (p > 0.05) increase in growth rate(0.13 vs 0.12%percnt; per day).     

Effect of meal size modulation on growth performance and feeding rhythms in European sea bass (Dicentrarchus labrax, L.)

The combined effect of feeding time and meal size on the growth performance and feeding rhythms were studied in European sea bass maintained under natural summer–autumn conditions. Three feeding strategies were compared: a modulated automatic-feeding (MF), a fixed automatic-feeding (FF) and a free access to self-feeders (SF). Under MF, feed was supplied in meals of different size, three times a day (morning, afternoon and evening, 33.33:16.67:50% of daily feed ration, respectively) during the first (31 days) and second (35 days) period of the experiment, and twice a day (morning and evening, 33.33:66.67% of daily feed ration, respectively) during the third period (27 days). In FF feed was supplied in equally-sized meals, three times a day (morning, afternoon and evening, 33.33:33.33:33.33% of daily feed ration) in all three periods of the experiment. Under SF, fish showed a diurnal self-feeding pattern, with the greatest percentage of self-feeding activity concentrated in the evening. In MF and FF, although feed was delivered automatically, the trigger was left in the tank to register activations as an indicator of feeding activity. The trigger activation of both treatments MF and FF was associated with the time of feed delivery. Feeding strategies affected biomass increase, specific growth rate (SGR) and feed conversion ratio (FCR), the greatest biomass increase and highest SGR being obtained with MF and the poorest FCR with FF. The results demonstrate that automatic-feeding systems, in which the quantity of feed supplied is modulated in accordance with the natural feeding rhythms of sea bass, may improve growth and feed efficiency.     

pH与氨氮对黄颡鱼幼鱼生长与肝脏超氧化物歧化酶的影响

为了解不同水体pH和氨氮组合对瓦氏黄颡鱼(Pelteobagrus vachelli)特定生长率(SGR),饲料效率(FE)和肝脏超氧化物歧化酶(SOD)活力的影响。实验采用中心复合设计与响应曲面法分析方法,利用瓦氏黄颡鱼幼鱼开展试验,养殖周期为7周。结果表明,水体氨氮对SGR,FE和肝脏SOD活力有显著影响;pH对SGR有显著影响。pH对SGR,FE和SOD活力存在显著的二次效应。氨氮浓度小于1.7 mg/L时对黄颡鱼生长无抑制作用;高氨氮与高pH环境对幼鱼的生长、饲料利用与肝脏SOD活力有明显的抑制作用。水体pH和氨氮水平分别为7.5和1 mg/L时,SGR、FE和SOD同时最优,分别为1.47%/d、1.71和97.9 U/(mg.prot),优化的可信度为0.836。建议在黄颡鱼养殖中,将pH与水体氨氮维持在7.0~8.0与0.1~1.7 mg/L内,从而保证黄颡鱼的正常生长与较强的抗氧化活性。     

Effects of restricted feeding regimes on growth and feed conversion on juvenile green sea urchin,Strongylocentrotus droebachiensis

Groups of juvenile green sea urchin, Strongylocentrotus droebachiensis (average wet weight = 3.3 g), were fed five different dry feed rations (0.2%, 0.4%, 0.8%, 1.2% and 2.4% of their body weight per week) under constant light and temperature conditions for 160 days (Experiment I) in groups to examine growth effects, and for 40 days as individual treatments (Experiment II) to examine feeding efficiency. There was 100% survival of the sea urchins during both experiments. In Experiment I, the lowest ration group (0.2%) had significantly lower growth than the rest of the groups. There was no significant differences in growth between the sea urchin fed ration over 0.4% dry feed of the body wet weight per week. In Experiment II, the lowest feed ration groups (0.2%) had significant lowest growth but had the best feed conversion ratio (FCR), using 0.5 g of feed of dry feed per gram of sea urchin wet weight body growth. The FCR increased with increasing feed ration and the 2.4% group had the poorest FCR, using 1.3 g of feed per gram weight gain. Results from Experiments I and II illustrate that juvenile green sea urchin can grow at a restricted feed ration that is under maximum feed intake, without reduction in growth.     

Growth of cultured seahorses (<Emphasis Type="Italic">Hippocampus abdominalis</Emphasis>) in relation to feed ration

This investigation examined the effect of varying feed ratios on cultured seahorse (Hippocampus abdominalis) growth and survival using frozen mysids (Amblyops kempii) at daily feed rations of 5, 10, 15 or 20% wet body weight. Feeding these different feed rations did not result in any significant difference in seahorse standard length after 3 months. However, seahorses fed the 10–20% rations were heavier and with higher condition factor (CF). Based on the total amount of frozen mysids offered to the seahorses, the food conversion ratio (FCR) became less efficient with increasing feed ration. However, when the actual mysid consumption was factored in there were no significant differences in FCR. There was a significant difference in daily specific growth rate (SGR), with the 5% ration having the lowest SGR. On a cost/benefit basis, based on the total amount of mysids offered the most cost effective ration for daily length and weight increase was the 5% ration. With actual mysid consumption taken into account, cost/benefit value favoured the 5 and 10% feed rations. Survival was 100% across all treatments. Based on this, a feed ration of 5–10% wet body weight per day of frozen mysids is recommended for cultured H. abdominalis