鲈鱼亲鱼海水网箱培育研究

鲈鱼(Late olabrax japonicus)亲鱼在厦门火烧屿海水网箱中培育性腺能成熟,主要措施是在适当的放养密度下加强日常管理,掌握好饲料的日常投喂及注意病害防治。本实验开始于1993年11月—1997年1月,各年度(1993—1994、1994—1995、1996—1997年)雌亲鱼成熟率分别为36％、97％、76.3％、91.4％,雄系鱼成熟率为70—100％;获产率100％。     

海水网箱养殖鲈鱼的主要病害及防治方法

<正> 随着海水鱼类网箱养殖规模的不断扩大、集约化程度的不断提高,以及受养殖环境污染、管理技术措施相对滞后等诸多因素的影响,海水网箱养殖鱼类的病害频繁发生且日趋严重。病害已给养殖生产造成了极大的经济损失,严重阻碍了海水网箱养殖业的稳定与发展。因此,探索海水网箱养殖鱼类病害的防治方法已成当务之急。我们已用了四     

纳米催化微电解海水的杀菌效果及斜带石斑仔鱼对其适应性的研究

水质的调控是决定养殖生产成败的一个关键因素,目前已有化学和物理等水处理方法被应用到水产种苗和养殖生产,对改善水产养殖的生长环境具有一定效果,但这些方法仍存在各种不同的弊端.本文通过纳米催化微电解技术对海水杀菌效果的研究,以期确定该仪器的最低完全杀菌的处理当量;利用不同的处理当量了解斜带石斑鱼(Epinephelus coioides)仔鱼对水体中游离氯的耐受范围,并在石斑鱼的苗种培育生产中进行了可行性的实验.研究结果表明:该技术对海水的消毒杀菌效果非常显著,处理当量在1.06 W·h/t以上时,杀菌效果可达到100％,该当量处理每吨海水的用电成本约为0.053分;斜带石斑仔鱼可耐受的最高处理当量为4.08 w·h/t,该当量已达到完全杀菌的效果,且持续抑菌效果良好,因此该处理当量可应用到石斑鱼苗种的实际生产中.利用纳米催化微电解海水产生游离氯的消毒作用,以灭活养殖环境水体中的病原生物,达到净化水体,抑制病原性疾病的目的,在水产动物种苗与养殖生产中具有一定的推广运用价值,且具较好的环保功效.     

温,盐度对鲈鱼早期仔鱼生长及存活率的影响

本文就温度,盐度以及不同降低盐度方法对鲈于仔鱼的生长及存活进行实验,经一星期的培养,结果表明,１;钙鱼仔鱼在盐度３０－３‰的海水中都能生长,以２０‰的存活率最高达９９％。２．每经６小时逐渐降低盐度５‰的仔鱼存活率高于大幅度骤降盐度。３．温度１４．７－１４．９℃和１８．３－１９．７℃,以盐度３０‰生长快,５‰生长缓慢。     

黄金鲈鱼初孵仔鱼投饵技术的研究

在水温20±0.5℃,日光照周期16h:8h条件下,黄金鲈鱼初孵仔鱼投喂卤虫无节幼体的合理密度为5只/mL。7日龄仔鱼的饱食指数为13%,排空时间2.0~2.5h,最佳投饵量为体重的60%。     

鲈鱼Lateolabrax japonicus (Cuvier) 幼鱼对饵料中蛋白质、脂肪、碳水化合物需求量的研究

本文研究了鲈鱼幼鱼对饵料中蛋白质、脂肪、碳水化合物的适宜需求量,结果表明：当饵料中蛋白质含量为44.1%,脂肪含量为8.9%,碳水化合物含量为12.1%时,鲈鱼幼鱼生长迅速,且成活率高。     

工厂化养殖废水与普通海水养殖鲈鱼的对比试验

我地区目前海水工厂化养殖面积达200万m2,养殖企业600余户,每天产生大量养殖废水。由于工厂化养殖为流水养殖,养殖废水中含有大量残饵,如果不有效利用,不仅浪费资源增加养殖成本,而且残饵富集过多还易使水体富营养化,造成水质恶化。为了充分利用这一资源,     

中草药对鲈鱼诱食活性的研究

以鲈鱼为实验对象,采用迷宫装置研究中草药单体及中草药复合剂对鲈鱼Lateolabrax japonicus(Cuvier et Valencinnes)的诱食活性.结果表明,中草药单体的诱食效果比中草药复合剂诱食效果好.不同的中草药单体对鲈鱼的诱食效果差异明显,阿魏对其有显著的诱食作用,陈皮的诱食作用次之.同时发现鲈鱼对肉桂、白芷、山楂和大茴香有一定的趋避反应.不同的中草药复合试剂对鲈鱼的诱食效果差异较大,其中,中草药组合栀子 陈皮 阿魏对鲈鱼有显著的诱食作用,而中草药组合陈皮 栀子对其有显著的抑制作用.     

斑节对虾苗对不同比重海水适应性的研究

在我国南方沿海的对虾养殖中，往往于放苗阶段遇到大雨而使养殖池水的比重发生急剧变化，从而影响虾苗放养后的存活率。因此，了解斑节对虾苗对海水比重突变的适应能力，在养殖生产上是十分必要的。为此，我们进行了不同大小斑节对虾苗对不同海水比重变化的适应性的研究，旨在为养殖生产提供参考依据。现将结果报告如下。     

应用间接荧光抗体技术快速检测花鲈病原菌——鳗弧菌

以花鲈（Lateolabrax japonicus)弧菌病的病原菌-鳗弧菌（Vibrio anguillarum)W-1为抗原,制备兔抗血清;利用异硫氰酸荧光素标记的羊抗兔免疫球蛋白（FITC-IgG）为荧光标记二抗,并以罗丹明标记的牛血清白蛋白为背景染色,建立检测鳗弧菌的间接荧光抗体快速检测技术。应用该技术对人工感染后的花鲈组织（肌肉、鳃、肠、肾）样品和养殖水体样品进行了鳗弧菌检测,结果显示间接荧光抗体技术不仅可以用于诊断发病的感染花鲈,也可用于检测带菌状态或未发病的感染花鲈。     

大批量注射花鲈疫苗方法的研究

研究了大批量注射疫苗中不同麻醉剂FA100的浓度、不同注射深度、不同注射部位和不同注射流程对体长(20.0±1.2)cm花鲈成活率的影响。试验结果表明,用麻醉剂与海水体积比为1∶2000的麻醉剂麻醉后,将鱼轻轻滑至容器壁腹腔注射,注射深度4 mm,成活率最高,可以避免鱼体表机械损伤,提高注射效率和成活率。利用此方法9 d共注射花鲈21万尾,成活率高达99.76%。     

Intra-cohort cannibalism among larval stages of perch (Perca fluviatilis)

Cohorts of perch larvae, hatched within 24 h, developed into a bimodal body size distribution as early as 6 days after commencement of external food uptake. At this development stage, intra-cohort cannibalism occurred among larval perch individuals of larval stage V (body size: 10.5±0.26 mm, 95% c. l.) on smaller siblings. In experimental trials the consumption rate (C: no. of prey/predator·hour) increased exponentially with size of predatory perch (L: mm) and at 21°C was expressed by the relationship log C=3.406·log L-3.848 (n=10, r²=0.98, P<0.001). For predatory perch in larval stage V, consumption rate was reduced when Daphnia pulex were added, while not in later stages. Perch larvae experimentally forced to live as true piscivores without additional food items developed from stage V to stage IX (15.8±1.34 mm) within the same time as those fed on Daphnia alone, but with increased mortality.     

Growth of 0+ perch (Perca fluviatilis) predating on 0+ bream (Abramis brama)

Abstract – Larvae and juveniles of perch Perca fluviatilis and bream Abramis brama of Lake Speldrop, a highly eutrophicated gravel-pit lake in the floodplain of the Lower Rhine, were used in laboratory experiments to study predation of perch on bream. In the first series of experiments (control), 0+ perch of 30 mm total length (TL) did not prey on 0+ roach of about 24 mm TL. The perch fed only on zooplankton, resulting in low growth rates of 0.17 mm  ·  day⁻¹. In the second series of experiments, perch (30 mm TL) were combined with 0+ bream with an average TL of 14 and 19 mm at different ratios. As in the first series, even a nine-fold higher amount of zooplankton food had no significant influence on the growth rate of perch, regardless of the perch:bream ratio. At a perch: bream ratio of 7:1 and 4:4 all bream were eaten by the perch and restocked twice daily. At the end of the experiment, the TL of perch at a perch:bream ratio of 7:1 was significantly lower compared to a perch:bream ratio of 4:4 (mean growth rates at 7:1 of 0.16 mm  ·  day⁻¹ and at 4:4 of 0.35 mm  ·  day⁻¹). At the perch:bream ratio of 1:7, perch fed on bream in varying amounts, averaging between 3 and 12 bream per day and per individual. After 20 days, the final length of these fish was always significantly higher than the TL of perch at other perch:bream ratios and increased in correlation to number of bream eaten per day (mean growth rate 1.13 mm  ·  day⁻¹). The results are discussed with respect to the piscivore-dominated fish community of the eutrophied Lake Speldrop. ^Note     

The effect of predation on stunted and nonstunted white perch

Gosch NJC, Pierce LL, Pope KL. The effect of predation on stunted and nonstunted white perch.
Ecology of Freshwater Fish 2010: 19: 401–407. © 2010 John Wiley & Sons A/S Abstract – Predation is widely regarded as a means to prevent or minimise the establishment of a stunted (high density of slow growing individuals) population. We investigated the effect of predation on two different white perch Morone americana populations (stunted and nonstunted) by examining the stomach contents of piscivorous fishes. White perch and gizzard shad dominated piscivore diets in Branched Oak Lake, whereas white perch dominated piscivore diets in Pawnee Lake. White perch consumed in the stunted population (Branched Oak Lake) were larger and older than white perch consumed in the nonstunted population (Pawnee Lake). Many of the consumed white perch in the stunted population were sexually mature and had the opportunity to spawn at least once. In contrast, all of the consumed white perch in the nonstunted population were sexually immature. Predation may have reinforced the stunting of white perch in Branched Oak Lake through removal of the largest, oldest individuals.     

Comparison of exploited and unexploited yellow perch Perca flavescens (Mitchill) populations in Nebraska Sandhill lakes

Exploitation can have a pronounced effect on fish populations. Yellow perch, Perca flavescens (Mitchill), populations in Nebraska Sandhill lakes were sampled in 1998 and 1999. Three of the 29 lakes containing yellow perch have been closed to fishing for at least 10 years. Unexploited yellow perch populations had fast growth rates, but age structure was similar to exploited populations. For unexploited lakes combined, mortality and condition were not different from exploited lakes. However, one unexploited lake, Marsh Lake, had the fastest growth, highest proportion of older fish and highest condition of all populations sampled. This lake had low interspecific competition and high invertebrate abundance, which likely resulted in fast growth and high condition. However, size structure and growth were also related to lake productivity. Although exploitation may affect yellow perch populations, other factors (food availability, predators and lake productivity) also play an important role in structuring these populations. Regardless, these results indicate the potential of yellow perch in Nebraska Sandhill lakes given no exploitation.     

The effects of dietary digestible protein and digestible energy content on protein retention efficiency of juvenile silver perch Bidyanus bidyanus (Mitchell)

Effects of varying dietary digestible protein (DP) and digestible energy (DE) on protein retention efficiency (PRE), weight gain, protein deposition and carcass composition for silver perch (Bidyanus bidyanus, Mitchell) were studied. Using digestibility data for silver perch, we formulated three series of diets with different DE contents (13, 15 or 17 MJ DE kg^?1). For each series, a ‘summit’ diet containing an excess of protein for silver perch (based on previous research) and a ‘diluent’ diet with only 10–13% DP were formulated. By blending the summit and diluent diets together in different ratios, five diets with different DP contents were produced for each DE series. A commercial diet was also included to give 16 experimental diets in total. Eight juvenile fish (mean initial weight 1.2 g) were stocked into each of 64 × 70‐L acrylic aquaria and then each of the 16 diets was randomly allocated to four replicate aquaria. Tanks were supplied with partially recirculated water (75%) at 25–27°C. Fish were fed restrictively, twice per day, based initially on 3.5% body weight day^?1 with 40% of the ration given at 08:30 hours and 60% given at 15:00 hours for 59 days. Quadratic functions were fitted to each energy series to describe the relationship between DP content of diets and PRE (the asymptote of these functions were used to predict maximum PRE). For low DE (13 MJ kg^?1), mid‐DE (15 MJ kg^?1) and high DE (17 MJ kg^?1), the dietary DP contents to give maximum PRE were 24.7%, 26.1% and 30.1% respectively. Carcass fat decreased with increasing DP and increasing DP:DE ratio. Varying the dietary protein and DE also influenced other indices of fish performance. ‘Optimum’ dietary protein therefore depends on several factors. For fish fed, restrictively, the protein content needed to maximize PRE is lower than the content needed to maximize weight gain or minimize carcass fat. For fish fed to satiation, the lowest protein content for maximum weight gain is lower than for fish fed restrictively.     

Effects of varying dietary protein to lipid ratios on growth performance and body composition of juvenile pike perch (Sander lucioperca)

The present study investigated the effect of varying dietary protein‐to‐lipid ratios (P/L) on growth performance and body composition of pike perch (Sander lucioperca) fingerlings with an initial body weight of 1.35–1.40 g. Triplicate groups were reared during 56 days in recirculation systems and fed six experimental diets containing three dietary levels of lipid (90, 130, 170 g kg^?1 of dry matter, d.m.) combined with two levels of dietary protein (470, 540 g kg^?1 d.m.). During the experimental period the fixed feeding rates decreased from 10% to 5% of the total fish biomass per day. In contrast to previous results obtained with this species, the present study clearly demonstrated the occurrence of protein sparing effect. The best results for feed conversation ratio and specific growth rates were obtained in the treatments containing highest lipid level: diet 3 (P/L 47/17) and diet 6 (P/L 53/17). The d.m. and crude lipid contents of pike perch whole body increased in direct proportion of the dietary lipid levels. No difference was observed on crude protein and ash content among the treatments. Increasing hepatosomatic index at highest dietary lipid level suggested a limited lipid utilization of percids.