饥饿对云纹石斑鱼(Epinephelus moara)卵黄囊期仔鱼摄食和生长的影响

研究了在水温为(23±0.5)℃,盐度为29-30的培育条件下,饥饿胁迫对云纹石斑鱼(Epinephelus moara)仔鱼生长、摄食、存活等一系列的变化。结果显示,2.5日龄体长出现负增长现象,3日龄仔鱼开口摄食,4.5日龄卵黄囊和油球消耗殆尽;仔鱼摄食率随日龄的变化呈先升高后降低,最终为0,最大值出现在卵黄囊和油球消失之后的当天,即5.5日龄仔鱼达到最大初次摄食率,摄食率为66.67%;6日龄仔鱼的初次摄食率为最大初次摄食率的1/2,仔鱼达到不可逆点,其混合营养的时间为2-3 d,即仔鱼初次摄食率发生到达不可逆点的时间为2.5 d;云纹石斑鱼仔鱼孵化出膜后的3-6 d为其摄食的重要时期。     

齐口裂腹鱼仔鱼饥饿试验及不可逆生长点的确定

水温17.3～21.5℃,取刚孵出的同一批齐口裂腹鱼仔鱼,暂养于2.0 m×0.8 m×0.6 m玻纤缸中,养殖到5日龄、即开口前1 d时,将仔鱼随机分为A、B、C 3组,每组500尾。6日龄A组试验鱼开口投喂,B组和C组不投喂,研究饥饿胁迫对齐口裂腹鱼仔鱼生长、发育、存活、卵黄囊吸收、摄食率及摄食强度的影响,确定齐口裂腹鱼仔鱼的不可逆生长点,即仔鱼初次摄食率低于最高初次摄食率50%时的日龄。试验结果显示,饥饿对齐口裂腹鱼仔鱼全长、体长、体高、肛前长等生长指标具有极显著影响(P0.01),对眼径、鳔等组织器官发育具有明显影响;齐口裂腹鱼仔鱼混合营养期为7 d;齐口裂腹鱼仔鱼初次摄食率约为15%,第13～14日龄仔鱼的初次摄食率达到最高值100%,17日龄仔鱼到达不可逆生长点;齐口裂腹鱼饥饿组仔鱼50%累计死亡率出现日龄为19日龄,在饥饿不可逆生长点之后。试验结果表明,齐口裂腹鱼仔鱼具有较强的饥饿耐受能力,齐口裂腹鱼最佳投喂时间为9日龄,最晚开口时间不晚于14～15日龄。     

舟山褐牙鲆（Paralichthys olivaceus）仔鱼摄食和生长的研究

试验研究了褐牙鲆Paralichthys olivaceus仔鱼的摄食和生长。结果表明，仔鱼初次开口摄食时间在6日龄（16～18℃），初次摄食率为30％，8日龄饥饿仔鱼最大初次摄食率为65％，孵出后第9天达到不可逆点（PNR），混合营养期为3d左右。初次摄食强度和初次摄食率开始时较低，在卵黄囊耗尽时达最高，然后下降。随着饥饿时间的延长，仔鱼出现“负增长”，孵化第11天存活率仅为10％，12日龄全部死亡。     

叶尔羌高原鳅仔鱼饥饿试验及不可逆点的确定

为了更好地增殖和保护叶尔羌高原鳅（Triplophysa yarkandensisa）这一塔里木河水系优势土著鱼类，拟采用实验生态法，在水温（20±1）℃条件下，利用人工孵化获得叶尔羌高原鳅初孵仔鱼进行饥饿试验，确定仔鱼的不可逆点（PNR），并研究延迟投饵对仔鱼成活和生长的影响。结果显示，叶尔羌高原鳅仔鱼3日龄即开口摄食，进入混合营养期，仔鱼卵黄囊于6～7日龄消耗完毕，混合营养期维持仅为3～4 d。初次摄食点出现在3日龄时，摄食率仅为16.7%，初次摄食率最高达在7日龄，摄食率可达90%，PNR出现在仔鱼孵出后的8～9日龄。3日龄后饥饿对仔鱼卵黄吸收速度影响显著((P< 0.05)；摄食仔鱼生长呈线性增加，饥饿仔鱼生长呈现先升高后降低的趋势。叶尔羌高原鳅仔鱼的最佳投喂时间应在仔鱼开口后4d之内。研究表明：叶尔羌高原鳅仔鱼个体较小，对于初次摄食饵料的的选择范围较小，食谱范围窄，初孵仔鱼死亡率高，对于高原鳅属仔鱼开口饵料有待进一步开发。     

杂交鳜仔鱼饥饿试验及不可逆点的确定

在水温（24±1）℃条件下,对翘嘴鳜（♀）×斑鳜（♂）杂交所得的杂交鳜仔鱼进行饥饿试验,确定其初次摄食饥饿不可逆点（PNR）。研究结果表明：杂交鳜仔鱼4日龄开口,此刻仔鱼卵黄囊已吸收完毕,但油球仍在,仔鱼发育进入混合营养期。7日龄仔鱼油球吸收完毕,进入外源营养期,仔鱼混合营养期仅为3d。杂交鳜仔鱼初次摄食率开始时为15%,高峰期出现在油球即将耗尽时的6日龄仔鱼,可达70%。仔鱼不可逆点出现在7～8日龄,杂交鳜仔鱼具有初次摄食能力的时间为4～5d。     

延迟投饵对泥鳅仔鱼摄食、生长和存活的影响

试验分延迟0d、1d、2d、3d、4d、5d、6d、7d投饵和完全饥饿9个试验组,研究了延迟投饵对泥鳅仔鱼摄食、生长和存活的影响。结果显示：水温27℃±1℃时,泥鳅仔鱼3日龄开口,混合营养期2d,4日龄卵黄囊消失。开口当日初次摄食率为36%,最高初次摄食率出现在5日龄,达98%,饥饿不可逆点（PNR）在8～9日龄。延迟0d（正常投饵）和1d投饵组仔鱼体长一直呈增长趋势,至11日龄,两组仔鱼体长没有显著差异（P>0.05）;随延迟投饵天数的增加,仔鱼体长生长速度明显降低;完全饥饿组仔鱼3～5日龄呈正增长,随后转为负增长。延迟0d和1d投饵组,11日龄时仔鱼存活率分别为82.67%和89.33%,且两者无显著差异（P>0.05）;随延迟投饵天数的增加,11日龄时仔鱼存活率明显降低;完全饥饿组,11日龄时仔鱼全部死亡。     

饥饿对云纹石斑鱼(Epinephelus moara)卵黄囊期仔鱼摄食和生长的影响

研究了在水温为(23±0.5)℃,盐度为29?30的培育条件下,饥饿胁迫对云纹石斑鱼(Epinephelus moara)仔鱼生长、摄食、存活等一系列的变化。结果显示,2.5日龄体长出现负增长现象,3日龄仔鱼开口摄食,4.5日龄卵黄囊和油球消耗殆尽;仔鱼摄食率随日龄的变化呈先升高后降低,最终为0,最大值出现在卵黄囊和油球消失之后的当天,即5.5日龄仔鱼达到最大初次摄食率,摄食率为66.67%;6日龄仔鱼的初次摄食率为最大初次摄食率的1/2,仔鱼达到不可逆点,其混合营养的时间为2?3 d,即仔鱼初次摄食率发生到达不可逆点的时间为2.5 d;云纹石斑鱼仔鱼孵化出膜后的3?6 d为其摄食的重要时期。     

匙吻鲟仔鱼期饵料的研究

鱼类早期生长的细微差别对其存活以及整个生活史阶段的生长，有着不可估量的影响，而摄食是影响仔鱼期生长的最重要的外界影响因子之一。在水温19．5～20．5℃下，对匙吻鲟（Polyodon spathula）仔鱼的开口时间、适宜开口饵料和投饵率进行了研究。结果表明，匙吻鲟仔鱼在6日龄初次摄食，摄食率在7—8日龄迅速升高，9—10日龄达到100％，11-13日龄略有降低，14-15日龄迅速降低，不可逆点（PNR期）出现在15日龄；以轮虫作为开口饵料，仔鱼的存活率和生长优于丰年虫和颗粒饲料组；养殖水体中轮虫密度在120—150个／mL可满足仔鱼的生长需求。     

黑棘鲷仔鱼饥饿实验及不可逆点的确定

在水温18℃~19℃条件下，采用实验生态学方法研究了饥饿对黑棘鲷(Acanthopagrus schlegelii)仔鱼存活、生长发育及行为学特征的影响。通过测定仔鱼的初次摄食率和饥饿不可逆点(PNR)，确定了初次投喂的最佳时间。结果显示，黑棘鲷仔鱼3日龄开口摄食，4日龄卵黄囊消失，6日龄油球消失，混合营养期仅3 d，属容易遭受饥饿胁迫的鱼类。仔鱼开口时初次摄食率仅为30%，之后迅速提高，至5日龄达到最高的90%，之后逐渐下降，7日龄降至45%，到达PNR。饥饿组仔鱼在6日龄后开始出现生理性萎缩，全长与对照组相比差异显著(P<0.05)，进入PNR后，仔鱼活动能力显著下降，身体出现扭曲、畸形，死亡率急剧升高，至10日龄全部死亡。黑棘鲷仔鱼耐受饥饿能力较弱，建议开始投饵的最适时机为仔鱼开口后的4 d内。     

延迟投饵对杂交鲟仔鱼生长、摄食和存活的影响

为进一步了解杂交鲟(史氏鲟Acipenser schrenckii♂×达氏鳇Huso dauricus♀)仔鱼开口阶段的摄食习性,并为大批量培育人工苗种提供理论依据,在水温19~23 ℃条件下,研究了延迟投饵对人工繁殖的杂交鲟仔鱼生长、摄食和存活的影响。设置了投饵时间不同的6个试验组,每组30尾仔鱼,分别于孵化后9、10、12、14、16和20 d开始投喂剁碎的水蚯蚓;另设1个饥饿组作对照,试验过程中始终不投饵。每个试验组设2个平行,试验周期为30 d。结果显示:(1)杂交鲟仔鱼在孵化后9 d初次摄食,9~11日龄为混合营养期,20日龄不能建立外源营养的仔鱼进入不可逆点(PNR)期;(2)不同阶段杂交鲟仔鱼初次摄食率的变化规律为:开始较低,此后持续上升,11~19日龄仔鱼的初次摄食率维持在75 %~100 %,20日龄仔鱼的初次摄食率急剧下降至40 %;(3)延迟投饵3 d对杂交鲟仔鱼的存活率无显著影响;延迟投饵5 d以上,仔鱼的存活率急剧下降,饥饿组仔鱼在25日龄全部死亡;延迟投饵0、1和3 d的试验组,仔鱼体长和体质量增长无显著性差异(P>0.05),但与其他组仔鱼相比差异显著(P<0.05)。试验结果表明:杂交鲟仔鱼的最佳投饵时间为10~12日龄。     

Estimation of variation of virulence of Renibacterium salmoninarum by survival analysis of experimental infection of salmonid fish

The variation of virulence of Renibacterium salmoninarum , the causative agent of bacterial kidney disease (BKD) in salmonid fish, was studied by infecting rainbow trout, Oncorhynchus mykiss (Walbaum), with two isolates (strains 325 and 932) from diseased Atlantic salmon, Salmo salar L., and one isolate (strain 4366) from an apparently healthy Atlantic salmon. Coho salmon, Oncorhynchus kisutch (Walbaum), were injected with the strain 932 to estimate difference in fish species resistance. Fish were removed by random sampling for other study purposes, a study design possible with analysis of lifetime distributions incorporating both sampling-, death- and survival-times. At the end of the experiment, the rainbow trout infected with strains 325, 932 and 4366 had a survival probability of 33%, 51% and 72%, respectively. The coho salmon infected with strain 932 had a 26% survival probability. The strain differences were significant according to the log-rank test, and the risk ratio between the strains ranged from 1·8 to 5·4. The strain from the apparently healthy fish was least virulent. The survival of the fish species was different over time. Rainbow trout were more likely to die early in the time course, but high numbers of coho died later, resulting in an overall risk of mortality of 1·4 in favour of rainbow trout. Differences in virulence may reflect changed selective pressure on R. salmoninarum when introduced from feral stocks into the environment of fish farms.     

母猪胎衣不下的病因与防治要点

猪的胎盘属于弥散型胎盘,这种胎盘的结构特点和饲养管理的不当,常常导致母猪胎衣不下发生,给生猪的生产繁殖带来极大损失。本文针对母猪胎衣不下发生病因、综合防治进行详细阐述,旨在对预防和治疗胎衣不下能有所帮助。     

水硬度对七彩神仙鱼幼鱼发育的影响

采用不同硬度的水对七彩神仙鱼幼鱼进行饲养。6周龄幼鱼在硬度为7.94°dH±0.30°dH时饲养84d后,比在硬度为14.71°dH±0.23°dH水中的幼鱼个体大,生长速度快。表明较高硬度的水有利于七彩神仙鱼幼鱼的生长发育。     

虎斑乌贼受精卵卵黄营养成分分析

本实验对虎斑乌贼受精卵卵黄的营养成分进行分析,旨在探讨其幼体的营养需求量,为其幼体配合饲料研制提供参考数据。随机选取大约800个虎斑乌贼受精卵的卵黄,采用国家标准方法测定其水分、灰分、粗蛋白质、粗脂肪、氨基酸、脂肪酸和矿物元素含量。结果表明:1)虎斑乌贼受精卵卵黄中粗蛋白质含量为76.33%(干重基础);总氨基酸(TAA)和必需氨基酸(EAA)含量分别为71.22%和32.38%(干重基础),EAA/TAA为45.46%,氨基酸中以谷氨酸(Glu)含量最高(9.97%),必需氨基酸中亮氨酸(Leu)含量最高(7.58%)。2)其粗脂肪含量12.71%(干重基础);共检出17种脂肪酸,包括8种饱和脂肪酸(SFA)、5种单不饱和脂肪酸(MUFA)和4种多不饱和脂肪酸(PUFA),SFA、MUFA和PUFA分别占脂肪酸总量的43.47%、7.54%和49.25%,其中以DHA含量最高,达32.80%,EPA含量为7.70%,DHA/EPA为4.26。3)检测出Na、K、Ca、Mg、Sr、Mn、Fe、Cu、Zn、Al和As 矿物元素,微量元素中富含Zn、Al和Fe,含量分别为 0.77、0.71和0.43 mg/kg(鲜重基础)。由此可见,卵黄具有高蛋白、低脂肪,富含n-3PUFA的特点;虎斑乌贼幼体饲料中蛋白质需求量参考值为76.33%;氨基酸需求量参考值,如赖氨酸(Lys)为5.49%,蛋氨酸(Met)为2.63%;脂肪的需求量参考值为12.71%,DHA为4.17%,EPA为0.98%;微量元素需求量参考值,如Zn为2.77 mg/kg,Cu为0.19 mg/kg(干重基础)。     

斑节对虾虾苗活力检测方法

该研究通过肉眼观察、镜检，进行干露、饥饿、盐度突降、福尔马林等抗性试验，并采用病毒检测等方法，以期建立评估斑节对虾（Penaeus monodon）虾苗活力和质量标准。结果表明，斑节对虾健康虾苗具有趋光性、集群性，体表光洁，肌肉透亮，肠胃食物充盈等特性。测试虾苗干露时间以15min为宜，健康虾苗干露后能立即恢复活力，而病弱虾苗多出现死亡、昏迷现象；虾苗的成活率随饥饿时间的延长而降低，随福尔马林浓度升高和时间延长而降低，随盐度突降幅度增加而降低。健康虾苗能忍受100～200μL·L^-1福尔马林溶液30min，成活率近100％；在盐度20～30下虾苗的成活情况较好，而其在淡水中仅能存活1h。对虾苗进行病毒检测，可以避免养殖中因虾苗携带病毒而可能导致的病毒性疾病的暴发。     

金鳟、虹鳟苗种长途运输实例

鳟鱼发眼卵和旨种运输是养鳟生产的重要环节。发眼卵多在冬季和早春运输，苗种多在晚春和夏季运输。苗种运输大多以鱼篓充氧进行短距离汽车运输，长途运输冷水性鱼苗种的实例很少。本文总结了金鳟和虹鳟苗种长途运输方法，以期与养鳟业界共同交流提高。一、包装材料和方法内包装材料是苗种运输专用塑料袋，规格54×104cm，外包装是泡沫塑料箱，规格63.5×45.5×30．5cm，纸箱规格64×46×32．5cm。塑料袋采取双层式，内装苗种和水共12.5kg，其中苗种0.5-1．3kg，100－2000尾。起运前苗种停食1－2天。运鱼用水水温调至6℃，鱼、水入袋后袋内…     

Characterization of protease inhibitors of seminal plasma of cyprinids

Anti-proteinase activity was demonstrated in the seminal plasma of cyprinid fish species (bream, chub, ide, dace, asp, goldfish, roach, common carp) using electrophoretic techniques combined with a detection method based on inhibition of bovine trypsin. We found species-specific protease inhibitors in the seminal plasma of cyprinids. At least three bands of protease inhibitors with different migration rates could be identified by native PAGE. Higher variability was characterized for bands with slower migration rates. Visualization of inhibitors after SDS-PAGE under non-reducing conditions allowed estimation of their molecular weights. Apparent molecular weights were within the range of 51–59 and 47–54 kDa for the bands with slower and moderate migration rates, respectively. The molecular weight of fast migration bands for roach and common carp were estimated to 23 and 30 kDa, respectively. Inhibitors of common carp seminal plasma differed in their affinity toward serine proteases. Three inhibitors in common carp seminal plasma could be visualized using cod and bovine trypsin, but only two inhibitors (of high molecular weight) were recognized with chymotrypsin. There were differences in anti-proteinase activity and seminal plasma protein concentration in relation to the origin of common carp seminal plasma (breeding lines) and time of milt collection (spawning vs. post-spawning season).     

牙鲆刺激隐核虫病的防治

2005年七、八月份,乐亭、滦南一带多家工厂化牙鲆养殖场发生刺激隐核虫病,此种病虫害发病急、传染快、死亡率高。发生过该病的养殖场牙鲆死亡率一般都在50％～80％之间,这种病害给牙鲆养殖业带来很大损失。     

鱼类热忍耐温度研究进展

The paper is a review of the studies on the temperature of the thermal tolerance in fishes. It was described from four aspect: (1) The key parameters of temperature of thermal tolerance in fishes; (2) The influence factors of temperature of thermal tolerance in fishes; (3) The research methods of thermal effect of fishes; (4) The evaluation of effects of thermal pollution on fishes, especially, with the coastal power station will be‘built in China recent years, the effects of thermal discharge water on the marine fisheries resource wered iscussed.     

Histopathology of respiratory organs of certain air-breathing fishes of India

Air-breathing fishes have evolved bimodal respiratory mechanisms for exploitation of water (through gills and highly vascularized skin) as well as atmospheric air (through aerial respiratory organs, ABO). Mucous cells in these respiratory organs of variously stressed fishes exhibit periodic fluctuations in their density and staining properties. The main types of damage in the gills include congestion of blood capillaries (BLCs), periodic lifting and sloughing of respiratory epithelia of the secondary lamellae causing haemorrhage, extensive fusion of secondary lamellae and hyperplasia of the respiratory epithelia due to uncontrolled regeneration leading to asphyxiation, altered excretion, and death of the fish. Haemolysis has also been observed following lead exposure. The damage in the ABO of Heteropneustes fossilis includes sloughing of the epithelial cells, leading to haemorrhage causing decreased red blood corpuscles density and degeneration of the secondary gill lamellae with reduced respiratory area. Subsequent hyperplasia of the respiratory epithelia and fusion of gill lamellae increase the respiratory barrier distance. The BLCs often bulge out and protrude into the lumen, bringing blood nearer to air. The ladder-like pillar cell (PLC)-BLC components of the gill lamellae frequently collapse. Damage to the ABO of Channa striata is less severe. Often haemorrhaging due to bursting of extensively stretched BLCs causes aerial respiratory failure. Chloride cells of the ABOs also show hyperplasia. While the highly mucogenic epidermis of C. striata shows less damage, the epidermis of Clarias batrachus and H. fossilis shows severe wear and tear, sloughing, and haemorrhage. Side-by-side regeneration continues, causing altered histomorphology of the epidermis. The different gland cells also show periodic fluctuations in their density and staining. The dermis also shows severe damage with loosening of their connective tissue fibres. These fibres give stronger reactions for sulfated mucin that not only retain additional water molecules for continuance of skin breathing, but also bind the toxic ambient pollutants.