菊黄东方鲀仔鱼摄食节律及消化时间的研究

为研究菊黄东方鲀仔鱼的摄食节律和对丰年虫的消化时间,在盐度28,水温18～20 ℃条件下,对12日龄的菊黄东方鲀仔鱼进行了饲养试验。试验结果:菊黄东方鲀仔鱼对丰年虫的消化时间为2.5 h。持续光照组中,仔鱼的摄食强度和饱食量在5:00~17:00都较高,随后开始降低,而在21:00又出现一个高位;持续黑暗组中,24 h内的摄食强度均较低;对照组中,仔鱼摄食强度在9:00~17:00比较高,其后开始降低,23:00~3:00降低为0。持续光照组中,仔鱼的摄食强度在9:00达到最高,平均每尾23.6个丰年虫;对照组和持续黑暗组仔鱼的摄食强度均在15:00达到最大值,分别为20.4、11.2个丰年虫。仔鱼的摄食强度依次为:持续光照组﹥对照组﹥持续黑暗组,且对照组、持续光照组及黑暗组仔鱼白天的摄食强度比例分别为89.9 %、64.6 %、80.3 %。结果表明,菊黄东方鲀仔鱼属于典型的白天摄食类型。在菊黄东方鲀人工育苗过程中,应选择在白天投喂饵料,采用晚上适当开灯的方法增加光照强度,可以提高仔鱼的摄食活力,增强摄食强度,促进生长,缩短室内繁育时间。     

牙鲆仔鱼轮虫日摄食量及摄食节律的研究

为了解牙鲆仔鱼对轮虫的摄食量和昼夜摄食规律，我们对孵化5-7天的仔鱼进行连续的摄食观察。结果表明，5．6、7日龄的仔鱼．平均全长分别为3．62、3．68、4．07mm；轮虫日摄食量分别为19个／尾、27个／尾、32个／尾；仔鱼摄食主要在白天进行．昼夜摄食比例平均为83．5％和16．5％，在10：00到12：00及16：00到18：00出现摄食高峰。     

大黄鱼仔鱼摄食节律与生长的初步研究

本文研究了大黄鱼仔鱼的昼夜摄食习性及生长。实验结果表明:全长5.0—5.5mm的大黄鱼仔鱼具有明显的昼夜摄食节律,白天摄食,夜间不摄食。白天有三个摄食高峰,以下午13:00最高,早上9:00和下午17:00次之。仔鱼在12日龄前生长较慢,12日龄后生长明显加快。全长与日龄之间的关系可用方程TL=3.7545e~(0.047D)表示。     

不同光照周期下鲇幼鱼的日摄食节律

水温(23±1)℃,研究了鲇幼鱼自然光照、持续光照(自然光或日光灯作光源)和持续黑暗条件下的日摄食节律.试验结果表明,3种光照周期下,鲇幼鱼昼夜均有连续摄食特性,期间具有明显的摄食高峰(夜间)和低谷(白天),鲇幼鱼有明显的日摄食节律;持续黑暗与自然光照周期下的鲇幼鱼日摄食节律基本一致,持续光照与自然光照周期下的鲇幼鱼日摄食节律有所差异.研究证明,鲇幼鱼在3种光照周期下均属于典型的夜晚摄食类型;光照周期的改变对鲇幼鱼的日摄食率无显著影响(P>0.05).     

红鳍东方鲀仔鱼轮虫日摄食量的研究

为了解红鳍东方鲀仔鱼对轮虫的摄食量和昼夜摄食规律，我们对孵化16天的仔鱼进行轮虫日摄食量的试验。结果表明，16日龄的仔鱼，平均全长7．015mm，轮虫日摄食量为360个／尾，昼夜比例为79．0%和21．0%，在9：00到11：00及17：00到19：00出现摄食高峰。     

不同光周期下红螯螯虾幼虾摄食节律的研究

在不同光周期下对红螯螯虾(Cherax quadricarinatus)幼虾的摄食节律进行了研究。结果显示:红螯螯虾具有明显的日摄食节律,24 L(持续光照)、12 L∶12 D(12 h光照:12 h黑暗)和24 D(持续黑暗)光周期下,其摄食率、摄食量和摄食发生率均在19∶00-21∶00和5∶00-7∶00出现峰值,分别为:13.01%和15.58%、20.82%和14.75%、12.77%和16.89%,属晨昏型摄食。光周期和不同时段对红鳌幼虾摄食无显著的交互作用(P>0.05)。     

黑鲪早期发育与摄食的初步观察

对黑鲪Sebastes schlegelii早期发育及摄食进行了研究。结果表明,在水温15.4～16.0℃、盐度30～32、pH8.4的培养条件下,黑鲪初产仔鱼全长为6.07±0.25mm,腹部有残存的卵黄囊;1日龄仔鱼全长为6.21±0.31mm,大部分仔鱼进入摄食期,开口饵料为经小球藻强化过的褶皱臂尾轮虫;20日龄仔鱼全长为8.81±0.40mm,开始增投经营养强化的卤虫无节幼体,仔鱼进入快速生长期。依照TL=aD3+bD2+cD+d方程式,对仔鱼个体的全长与日龄进行回归,得到其生长模型为:TL(mm)=0.0096D2-0.0415D+6.7503(R2=0.9877)。仔鱼耐受饥饿的时间临界点(PNR)发生在产出后第4天(3日龄),不可逆转饥饿期的时间为2d。黑鲪仔稚鱼在24h内均有不同程度的摄食。1日龄仔鱼的摄食高峰出现在8:00,5日龄仔鱼摄食高峰则出现在16:00,12日龄仔鱼的摄食强度在12:00达到最大,相应的摄食率高峰出现在16:00,19日龄仔鱼在12:00～0:00出现摄食率高峰,24日龄稚鱼的摄食强度在12:00达到最大,30日龄稚鱼的摄食高峰出现在12:00～16:00,且16:00的峰值明显高于12:00,24h内摄食率达到100%。结果表明,黑鲪仔稚鱼无明显的摄食节律,属于全天摄食型,摄食高峰出现在白天。     

美洲西鲱仔鱼不可逆点及仔、稚鱼摄食特性研究

在水温(20.5±1.0)℃的条件下,采用实验生态学的方法,对美洲西鲱(Alosa sapidissima)仔鱼在饥饿状态下的生长、形态、不可逆点(PNR)及仔、稚鱼期的摄食节律进行了研究,旨在阐明美洲西鲱早期发育过程中的摄食规律和特点。实验结果表明,美洲西鲱初孵仔鱼全长(7.45±0.15)mm,体质量为(2.15±0.03)mg,卵黄囊体积为(5.99±0.13)mm3,第5日龄,仔鱼卵黄囊被完全吸收。对照组仔鱼全长及体质量随着卵黄囊的消耗、外源性营养的建立逐渐增加;饥饿组仔鱼自6日龄开始,全长及体质量开始呈现负增长,至10日龄全部死亡。美洲西鲱初孵仔鱼初次摄食时间在3日龄,摄食率为46.67%,5日龄摄食率达到最大为89.29%,PNR发生在7~8日龄,综上所述,美洲西鲱仔鱼最佳投喂时间应在2~3日龄。美洲西鲱仔、稚鱼摄食节律研究表明,美洲西鲱早期仔鱼(4日龄)昼夜摄食高峰出现在14:00,平均摄食量达到0.14 mg;晚期仔鱼(17日龄)在10:00和14:00出现较高的摄食量,分别为0.92和1.36 mg;28日龄稚鱼在10:00、14:00和18:00 3个时间段维持着较高的摄食量,摄食量分别为1.77、2.45和1.55 mg,属于典型的白天摄食类型,且随着仔稚鱼的生长发育,摄食高峰期逐渐延长。美洲西鲱仔、稚鱼各阶段的日摄食率分别为20.08%(4日龄)、29.48%(17日龄)和12.41%(28日龄),可将其作为美洲西鲱日投喂量的参考标准。     

大泷六线鱼仔鱼摄食及生长的研究↑（*）

本文以大泷六线鱼(Hexagrammosotakii)人工孵化所得的卵黄囊期仔鱼为材料,对仔鱼早期阶段的摄食及生长情况作了实验研究。结果表明:在13.5～14℃条件下,大泷六线鱼仔鱼6日龄开始摄食,约8日龄卵黄囊耗尽,10日龄饥饿仔鱼进入PNR期,混合营养期为2d;饥饿仔鱼的开口率(初次摄食率)开始较低,此后上升,到卵黄囊耗尽时达高峰(63%),以后又下降。仔鱼前期的生长率平均为0.254mm/d,饥饿仔鱼生长几乎停止,同期喂食仔鱼的生长率亦下降为0.102mm/d;摄食仔鱼在孵化后20d内的全长(L)和日龄(d)的相关式为L=0.085d 7.04。仔鱼存在昼夜摄食节律,在1昼夜中有2个摄食高峰,分别出现在14:00和20:00。     

宝石鲈摄食节律和日摄食率的初步研究

为了解宝石鲈昼夜摄食规律和日摄食量,采用饱满度指数法在7-9月对124尾宝石鲈在不同昼夜节律下的摄食节律和日摄食率进行了研究。试验结果表明,9:00-17:00为摄食高峰期,凌晨1:00摄食活动最弱,翌日5:00摄食强度明显升高。7-9月,该鱼的日摄食率(用占体质量的百分比表示)分别为6.07%、3.34%、2.37%。宝石鲈有明显的摄食节律,属于白天摄食类型。     

黄颡鱼早期发育阶段的摄食节律及日摄食率

研究了黄颡鱼早期发育阶段摄食的昼夜节律性及日摄食率。结果如下：黄颡鱼仔稚鱼摄食具有明显的昼夜节律性。胃平均饱满指数在仔鱼前期、仔鱼后期和稚鱼期分别于21：00、3：00、6：00达最高峰，均于15：00达最低值。不同发育阶段的日摄食率分别为：仔鱼前期69.96%，仔鱼后期28.84%，稚鱼期10.00%。     

漠斑牙鲆仔鱼摄食节律的研究

在实验室条件下研究了漠斑牙鲆仔鱼摄食节律。试验结果表明：漠斑牙鲆仔鱼摄食具有昼夜节律性，其摄食活动主要在白天进行，在10：00光照度为400lx时摄食最为活跃，抵达摄食高峰，仔鱼夜间不摄食，全天表现明显的摄食节律。     

Feeding rhythm and growth of the tongue sole, Cynoglossus semilaevis Günther, during its early life stages

The feeding rhythm and growth characteristics of the early life stages of the tongue sole, Cynoglossus semilaevis Günther, were studied. Larvae began to prey on rotifers about 2–3 days after hatching at 23°C. About 12 days after hatching, larvae had grown to 8–9 mm in total length and were able to prey on Artemia larvae. As the larvae grew, they showed an increasing feeding capacity and a distinct feeding rhythm. Feeding intensity for day‐6 larvae was highest at 12:00 and 18:00 hours, about 2–3 h after the maximum feeding incidence. The highest levels of feeding intensity for day‐16 larvae occurred between 09:00 and 18:00 hours. By day 26, when the larvae had metamorphosed, feeding capacity had again increased considerably and, in contrast to the earlier stages, feeding intensity peaked at 18:00 and 24:00 hours concurrently with feeding incidence. Thus, tongue sole were found to have different feeding rhythms in the pre‐ and post‐metamorphosis stages, with the highest feeding activity in the daytime during the larval planktonic stage, and at night during the juvenile benthic stage. The estimated maximum daily feeding rates were 65%, 40% and 11% of body weight on days 6, 16 (larvae) and 26 (juveniles) respectively. Size variation increased markedly with development.     

Effects of Feeding Time on Growth,Survival, and Food Conversion Ratio of Huso huso Fingerlings

This study was carried out to determine the effect of feeding time on growth parameters, food conversion ratio, and survival rate of Huso huso fingerlings (2.11 ± 0.03 g) over a period of five weeks. Fish in triplicate tanks were fed a commercial pelleted diet four times every 24 h on one of four schedules: at 08:00, 11:00, 14:00, and 17:00 h (day feeding); at 08:00, 12:00, 18:00, and 22:00 h (day/night feeding); at 18:00, 21:00, 24:00, and 06:00 h (night feeding); or at 08:00, 12:00, 18:00, and 22:00 h (full dark feeding). At the end of the experimental period, fish in the day-fed group had significantly (P < 0.05) better final weight, daily growth rate, specific growth rate, survival, condition factor, and food conversion ratio than day/night and night-fed groups. Performance of fish fed under full dark conditions was intermediate between day-fed and the other groups. In terms of rearing costs, daytime feeding of Huso huso is the most efficient.     

池养条件下瓦氏黄颡鱼仔稚鱼摄食节律和日摄食率研究

对池养条件下瓦氏黄颡鱼(Pelteobagrus vachelli)早期发育阶段的摄食节律进行了研究。结果表明:每日5:00~9:00及17:00~21:00瓦氏黄颡鱼的饱满指数相对较高,15:00~17:00最低,表明瓦氏黄颡鱼属于晨昏摄食型;在仔鱼出膜后的第5、10、15、20、25和30天瓦氏黄颡鱼的日摄食率分别为44.79%、33.72%、23.21%、19.92%、16.58%和10.27%,呈逐渐下降趋势。     

Transpositional feeding rhythm of loach <Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis> from larvae to juveniles and its ontogenesis under artificial rearing conditions

The diel feeding rhythm and ontogenesis during early life stage of loach Misgurnus anguillicaudatus were investigated under experimental conditions (light: L 06:00–18:00, D 18:00–06:00 h). Morphological and behavioral developments of loach from newly hatched to 40 days after hatching were observed. Larvae were able to prey on daphnia 3–4 days after hatching at 23 ± 0.5°C. As the larvae grew, they showed an increasing feeding capacity and a distinct feeding rhythm. Feeding intensity and incidence for day-4 larvae were highest at 10:00 and 16:00 h. The highest levels of feeding intensity for day-12 larvae occurred at 08:00, 12:00, and 18:00 h as did feeding incidence. By day 20, when the larvae metamorphosed, the highest levels of feeding intensity occurred at 06:00, 18:00, and 24:00 h and were concurrent with the highest feeding incidence. After metamorphosis, feeding capacity had again increased considerably and, in contrast to the earlier stages before day 20, feeding intensity for day-30 juveniles peaked at 05:00 and 20:00 h, about 1–2 h after the maximum feeding incidence. The feeding rhythm of loach juveniles at day 40 was almost the same as the day-30 juveniles. The estimated maximum daily feeding rates were 43.1%, 33.4%, 19.0%, 12.8%, and 5.8% of body weight on days 4, 12, 20, 30, and 40, respectively. Thus, loach was found to have different feeding rhythms in the pre- and post-metamorphosis stages, with the highest feeding activity in daytime during the larval planktonic stage before metamorphosis, and intensely nocturnal feeding behavior during the juvenile benthic stage after metamorphosis.     

黄颡鱼早期发育阶段摄食的研究

本实验采用实验生态学的方法，分别对池养9、13、17、23日龄黄颡鱼的食物组成，选食行为和昼夜摄食节律进行了研究。结果表明，黄颡鱼早期发育阶段主要摄食浮游动物，其食物组成随仔稚鱼的生长而变化。摄食初期（黄颡鱼9日龄时）主要食物为枝角类和轮虫，其中枝角类数量和重量百分比分别为86.71%和89.65%，占绝对优势。之后，黄颡鱼的摄食范围进一步扩大，从23日龄开始，由主要选食枝角类转为主要选食桡足类，桡足类所占数量百分比也从初期的3.29%上升到23日龄时的26.68%；而且，从13日龄开始，摇蚊幼虫等底栖动物所占比重呈上升趋势，从初期的54.84%到23日龄的69.52%，始终在食物组成中占主要优势。黄颡鱼摄食具有明显的昼夜节律性，9日龄时摄食高峰值出现在20:00（897.7），低峰值出现在19:00（161.8）；13、17、23日龄仔稚鱼胃平均饱满指数均于4:00达最高峰（914.1、1113.1和199.7），于19:00、19:00和16:00达最低值，分别为50.9、60.9和76.6，夜间时段摄食水平显著高于白天时段，黄颡鱼仔稚鱼明显表现为晚上摄食类型。