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%。     

Investigation to determine digestibility coefficients of various raw materials in diets for gilthead sea bream, Sparus auratus L.

A number of raw materials were tested to obtain the in vivo apparent digestibility coefficients of protein, lipid and gross energy for gilthead bream. Sparus auratus L., under controlled conditions. In the case of protein digestibility assessment, a standard in vitro method was also included for comparison. Protein digestibility coefficients were generally high, with values between 60% and 96% being observed for most of the materials studied. However, some exceptions were apparent in materials of both animal and plant origin. Lipid digestibilities also ranged between 50% and 90%. Values for energy digestibilities indicated a much greater variation, from 6% to 80%. These observations are discussed in relation to the nature and source of ingredients and to the type of processing technology employed.     

Effects of protein level of the diet on digestibility and growth of gilthead sea bream, Sparus auratus L.

A feeding trial with a duration of 12 weeks was conducted to determine the effects of various protein levels, in relation to diet digestibility and growth of the gilthead sea bream, Sparus aurata L. Four experimental fish meal/wheat meal based diets (A,B,C,D) containing 400, 450, 500 and 550 g kg^?1 protein, respectively, were tested. The increase of the fishmeal content of the diet led to an increment of dry matter digestibility. Apparent digestibility coefficients of protein and lipids were always very high (being near or even over 90%). Energy digestibility coefficients increased from diet A to diet D, which corresponds to a decrease in the wheat meal content of the diet. Voluntary feed intake increased with the decrease of protein content of the diet (from diet D to diet A). In the other sense, feed/gain ratio decreased regularly as protein percentage increased (from diet A to diet D). The most favourable feed/gain ratio, 1.07, was noted for the group receiving 55% protein (diet D). Fish on the lowest protein diet (Diet A) showed the highest protein efficiency ratio (PER) and the highest percentage retention of the digestible protein intake. Other than slight positive differences between fish fed diets with 500 and 550 g kg^?1 protein, no significant differences were observed for growth when dietary protein exceeded 450 g kg^?1. Beyond this level, no significant difference in final average individual weight was observed. Although it is generally considered that the dietary protein requirement for gilthead sea bream is 400 g kg^?1, our experiment demonstrates that to obtain high growth rates (>2.3% per day), a minimum of 450 g kg^?1 protein in the diet is necessary. However, the most favourable values for growth rates and feed/gain ratio are obtained with 550 g kg^?1 protein in diet, considering that no significant differences were observed for PER among diets B, C and D.     

单尾金鱼脑垂体切除的方法

在研究脑垂体或脑垂体激素的生理功能时,如果不把实验动物本身的脑垂体预先除去,就很难避免内源激素的影响,往往不能作出令人信服的结论。因此,切除脑垂体是研究脑垂体内分泌生理最常用的一种重要技术。 根据Pickford氏(1957)的记载从1911年以来已有19种硬骨鱼作脑垂体切除,这些手术大致都是从口腔顶或鳃腔剥除部分副蝶骨或在副蝶骨钻孔而切除的。这样的方法正如Chavin指出的往往不可避免的会损伤周围的血管特别是内颈动脉。根据我们的经验,大血管受损伤的鱼由于流血不止,死亡率很高,     

活饵料中n-3高度不饱和脂肪酸对黑鲷仔稚鱼生长和存活的影响

采用乳化油直接添加法,用n－3高度不饱和脂肪酸（n－3HUFA）含量不等的4种乳化油分别强化轮虫、卤虫活饵料,培育4组黑鲷仔鱼和稚鱼,各自历时15d,结果表明,n－3HUFA对黑鲷仔鱼和稚鱼的生长和存活均有重要影响。在该条件下,轮虫体内n－3HUFA含量为0．233％（湿重计）,卤虫体内n－3HUFA含量为4．273％（湿重计）时,仔鱼和稚鱼达到最佳生长和成活率。     

延迟投饵对真鲷,牙鲆仔鱼早期阶段摄食,存活及生长的影响

试验结果表明：（１）２日龄真鲷,牙鲆仔鱼初次摄食,在６￣７日龄和５￣６日龄,不能建立外源性营养的仔鱼分别进入ＰＮＲ期,而卵黄囊均在此前１￣２天已耗尽。混合营养期分别为３￣４天和１￣２天。（２）真鲷和牙鲆仔鱼在不同饥饰饿阶段初次摄食率的变化式型是：开始较低,此后逐步上升,高峰期出现在卵黄囊接近耗尽时,此后开始下降。记录到的最高初次摄食率分别为８６．７％和３５％。（３）牙鲆仔鱼体长的增长率随延迟投饵天     

Growth, food conversion, maintenance and long-term survival of gilthead sea bream, Sparus auratus L., juveniles after abrupt transfer to low salinity

Juveniles of gilthead sea bream, Sparus auratus L., with individual weight 1.92 g, were reared under salinities of 8, 18, 28 and 38%o. The transfer to lower salinities (8-28%o) was abrupt. The results showed that better daily growth rates and food conversion efficiencies (FCE) when growing at 28%o gave the best performance. Statistically, salinity values above 28%o do not significantly affect daily growth rates and daily voluntary food intake. Maintenance requirement decreases linearly with increasing salinity. In particular, a l%o decrease of salinity is associated with a 0.014 (% body weight day^-1) increase of daily maintenance requirement. Mortality rates are high at salinities of 8 and 38%o (65% and 20% respectively) and minimal (1-3%) for fish reared under intermediate salinities (18-28%o). Finally, scope for growth, expressed as the minimum difference between food amount eaten and food attributed to growth, is better when the fish are kept at a salinity of 28%o. This means that most of the food amount eaten is attributed to growth and food wastage is minimal. These results confirm that gilthead sea bream fry show best performance when reared at a salinity of 28%o.     

Pharmacokinetics of oxolinic acid in gilthead sea bream, Sparus aurata L.

This is the first study on the pharmacokinetic parameters of oxolinic acid (OA) in gilthead sea bream, Sparus aurata L. The kinetic profile of OA was studied after a single intravascular injection (20 mg kg⁻¹) in 100 g fish at 20 °C. The distribution half-life ( t _1/2α) and the elimination half-life ( t _1/2β) of the drug were found to be short (0.51 and 12.60 h, respectively). The drug penetration from the plasma to the tissues was adequate as the apparent volume of distribution of the drug at steady-state ( V _d(ss)) was found to be 2.11 L kg⁻¹. The mean residence time ( MRT ) of OA was short (14.25 h) and the total clearance rate ( Cl _T) of the drug was low (0.15 L kg⁻¹ h⁻¹). The bioavailability ( F %) of OA following oral administration (30 mg kg⁻¹) was also low (14%). Maximum values were observed for muscle at 0.5 h after injection, with levels declining as with subsequent sampling. At the first two time points (0.5 and 1 h) plasma levels of OA were higher than muscle, however, the reverse was evident for subsequent samples. Following oral administration, highest muscle levels were found at 16 h and, with the exception of the 24-h sampling, muscle OA concentrations were higher than plasma at all time points. The fast elimination of OA suggests short withdrawal times with reference to human consumption of treated fish.     

Evaluation of visible implant elastomer tags for tagging juvenile gilthead seabream (Sparus auratus L.); effects on growth, mortality, handling time and tag loss

The use of the fluorescent visible implant elastomer (VIE) tagging system in juvenile gilthead seabream, Sparus auratus L., between 7 and 18 g was examined. Four different colours (red, green, orange and yellow), three body positions (dorsal, lateral and caudal) and two orientations (horizontal and vertical) were tested. The mean tag application time for each fish was 15.7±0.32 s. There was no mortality associated with the method of tagging. The most visible tag colour was red. Injection orientation had a significant effect on length, width, fragmentation and fluorescent intensity of the tag. Horizontal tagging is recommended because of high fluorescent intensity, low fragmentation and for double tagging. There were no differences in growth between untagged controls and the VIE‐tagged fish.     

几种物质对金鱼的诱食活性

本文采用迷宫装置、通过液体实验的方法,研究了二甲亚砜和5种市售香精对金鱼的诱食活性。结果表明:二甲亚砜、葡萄香精和菠萝香精对金鱼有显著的诱食活性,而杨梅香精、荔枝香精和桔子香精则无诱食活性。     

拖网囊网网目及其对东海带鱼选择性的研究

本文介绍了东、黄海拖网囊网网目的套网系列试验结果，指出当带鱼的刺鱼体周相当于网目内周时，其体长一般大于这种网目对带鱼的50％选择体长。文中比较了按照刺鱼体周求算网目内径同用50％选择体长决定网目内径的不同之处。根据网目内径与刺鱼体长的相关式，提出保护东海带鱼资源的拖网囊网最小网目内径为56毫米，并依据网目的选择性及带鱼的生物学资料，讨论了采用这一网目尺寸的可行性。     

团头鲂血居吸虫病的病原及其防治的研究——包括一种新的描述

团头鲂血居吸虫病是1965年和1973年先后在湖北省浠水县鱼池发现。1.0—1.5寸大的鱼种往往因患此病而死亡。其病原体是文献中未报导过的两种血居吸虫,并一种命名为鲂血居吸虫新种Sanguinicola megalogramae sp.nov.另一种暂列为血居吸虫未定种Sanguincolasp。 较详细地观察和记述了鲂血居吸虫成虫的形态、生态,以及卵、毛蚴、尾蚴等的形态和发育情况。查清了鲂血居吸虫的中间宿主是一种扁卷螺——白旋螺 Gyraulus albus Muller,还进行了尾蚴对鱼苗的感染试验。 解剖材料表明:鲂血居吸虫在排卵季节(当年7—9月;翌年4-5月),成虫绝大多数寄生在心脏的动脉球内,其卵可随血液流至身体各部,但主要是到达鳃和肾。 通过组织病理观察,了解到由于大量虫卵充塞鳃小片造成机械损伤,阻碍鱼的气体交换,致使鱼苗或夏花鱼种窒息致死。每当鱼池中有大量尾蚴,在同一时间内有6—8个尾蚴侵入,鱼苗就出现畸形或死亡。 经过防治试验,提出消除中间宿主——白旋螺和杀灭鱼池中的尾蚴等方法和措施。     

东海舵鲣的早期发育和生殖习性

根据主要外部形态,如尾柄上色素的分布和身体各部位的比例值,我们鉴定在东海区的舵鲣属(Auxis Cuvier 1829)鱼类的仔稚鱼有扁舵鲣(Auxis thazard)圆舵鲣(Auxis tapeinoso-ma)和一种目前还未定到种,暂定为舵鲣(Auxis sp.)三种。根据其性腺成熟度及仔稚鱼出现的时间来推断,在东海的产卵期为3—9月,盛期为7、8月。较南海区的产卵期迟一些。产卵范围在北纬 25°30′-32°00′,东经125°以西海区。舵鲣鱼类仔稚鱼在东海的分布面很广,但多靠近陆岸和岛屿附近,一般分布在东经125°以西海区,水深一般为60—100米。栖息海区水温一般为27—29℃盐度为38,00—34,00‰。仔鱼分布与台湾暖流和长江冲淡水有夫,一般在长江冲淡水水舌边缘或台湾暖流和冲淡水的交汇区。台湾暖流向北移动,仔鱼的分布区也相应北移。7月以前分布在北纬28°以南,月份分布在北纬28°以北。     

真鲷人工繁殖与苗种培育的初步研究

广东遮浪海区真鲷于10月至次年3月繁殖,其盛期为11月中旬至1月中旬。对成熟亲鱼用 LRH—A和 HCG 注射均可达到自然产卵的效果。对仔鱼以轮虫作开口饵料,以后逐步改喂卤虫无节幼体和鱼虾肉浆碎片。其成活率前期高,由仔鱼期向稚鱼期转化后其成活率降低。经205天的培育,真鲷体长平均可达135mm、体重平均可达199g。     

电磁场对几种淡水鱼鱼苗胚胎期的出苗率、抗温变能力和后期生长速度的影响

对蟾蜍、鱼类胚胎的质子核磁弛豫的研究发现,在胚胎发育期中的神经胚期出现质子纵向核磁弛豫时间T_1值为一极大值。几年来,我们用各种物理手段对蟾蜍和几种淡水鱼胚胎在不同发育期进行物理刺激,发现在鱼类胚胎早期和神经期接受较强电场或磁场刺激后,不仅其后期生长速度显著加快,而且胚胎发育期抗温变能力有明显提高,孵化出苗率也有较大幅度增加。1989年5月,我们在上海嘉定县望新鱼苗场对团头鲂早期胚胎进行了中等规模(10公斤受精卵)电场刺激试验,取得了令人满意的后期结果。     

Characterization of β-haemolytic Group B Streptococcus agalactiae in cultured seabream, Sparus auratus L., and wild mullet, Liza klunzingeri (Day), in Kuwait

Streptococcus agalactiae was isolated from cultured gilthead seabream, Sparus auratus L., and diseased wild Klunzinger's mullet, Liza klunzingeri (Day), in Kuwait Bay, Arabian Gulf. Isolates were catalase negative, β‐haemolytic, Gram‐positive cocci and serogroup B. Experimental infectivity trials with mullet and seabream brain isolates in Nile tilapia, Oreochromis niloticus L., caused 100 and 90% mortality, respectively, within 7 days post‐inoculation indicating virulent S. agalactiae as the bacterial pathogen responsible for the epizootic in Kuwait Bay.