鱼类脲酶比活力研究     

曹志华  罗静波 《湖北农学院学报》2001,21(1):39-42

通过对鲤、团头鲂、鲫、草鱼、乌鳢、革胡子鲶、黄鳝、鲢和鳙9种食性不同的鱼的脲酶比活力进行比较，结果显示：食性与脲酶比活力存在一定的相关性。草食性与滤食性的草鱼和鲢、鳙脲酶比活力明显高于其他几种鱼，肉食性与杂食性鱼脲酶比活力明显要低。9种鱼脲酶主要分布在前肠和中肠，后肠脲酶比活力很低，与前、中肠相比存在显著差异。  相似文献   

湖南省鱼类寄生虫及其病原区系调查研究     

金燮理  戴振炎  刘晓燕  曾谷初  张壁奎  贺顺莲  向建国 《湖南农业大学学报(自然科学版)》1993,(4)

1989～1992年,对湖南省的鱼类寄生虫及其病原区系进行了调查研究.在84种鱼类中(分属7目15科),发现鞭毛虫3科4属6种;孢子虫1科1属5种;粘孢子虫6科8属56种;纤毛虫7科8属24种;单殖吸虫5科13属86种;复殖吸虫14科20属32种;绦虫5科7属9种;线虫10科15属18种;棘头虫5科8属9种;蛭类1科1属1种;瓣鳃类1科1属1种;甲壳类3科8属21种.在268种寄生虫中,有18种待进一步鉴定的新种,并发现10个虫种的新寄主;有184种为湖南省的新纪录.全部寄生虫都绘有插图和种的简要记述.对鱼类危害比较严重,能引起鱼病的寄生虫,在相应部分作了有关的说明.  相似文献   

中国胆毒鱼类的研究     

伍汉霖  陈永豪等 《上海水产大学学报》2001,10(2):102-108

在我国民间想念吞服鱼胆可治目疾，然而因吞服鱼胆面 引起的中毒，危害身体健康事件时有发生，自1964-1999年的35年中，据不完全统计吞服有毒鱼胆而中毒的人类达451人，其中死亡达83人，死亡率为18.04%，本文主要叙述鱼胆中毒的概况，胆汁有毒成分（鲤醇），动物实验，中毒症状及治疗，经动物实验及多年的调研共发现12种淡水鱼类的胆汁有毒，它们均是鲤科鱼类，从理论上阐明吞服任何鲤科鱼类的鱼胆均是危险的。  相似文献   

Design and evaluation of a translocation strategy for the fringed darter (Etheostoma crossopterum) in Illinois     

William J. Poly 《Biological conservation》2003,113(1):13-22

The fringed darter (Etheostoma crossopterum) was introduced into two streams where neither the fringed darter nor any other species of the same subgenus occur but that otherwise have suitable habitat. Darters were collected from two streams in the Cache River basin, and a combination of darters from each source stream were moved to the receiving streams, which also were in the headwaters of the Cache River basin (20 males and 40 females to each). Darters were moved in late March 2001 at the beginning of their reproductive season, which continues for approximately 2 months. Fringed darter nests were present within 3 days at both introduction sites and nests were found thereafter until late May at which time searching for nests was terminated. Twenty-five nests were found in 2001 compared with 168 nests in 2002. A total of 8714 eggs were counted in 22 nests during 2001 with a mean of 413 eggs per nest (n=19 nests). In September 2001 and 2002, surveys for juveniles and adults indicated successful recruitment in both streams. Mean size of juvenile darters differed significantly between the two introduction sites in 2001. The design of this study allowed for a rapid, initial assessment of the translocations, aspects of which appeared successful. Moving fishes at the beginning of their reproductive season could increase the chance of successful reproduction and eventual establishment. The protocol for translocation of fringed darters might be applicable to other similar and endangered darters such as Barrens (Etheostoma forbesi), relict (E. chienense), and duskytail darters (E. percnurum). Sampling was conducted in other areas of the Cache River basin in search of additional populations of fringed darters. An updated account is given of the distribution of the fringed darter in Illinois.  相似文献   

550鱼营养补充料对水生环境及其微量元素含量的影响     

朱钟海  袁慧  汪振根  易厚生  陈铁桥 《湖南农业大学学报(自然科学版)》1992,(Z3)

试验于1990年在岳阳市南湖渔场进行.观察结果表明,添加4g550鱼营养补充料(浓度为16ppm)的试验组,其浮游生物数量最多,且生长繁殖快,浮游植物主要为绿藻门和硅藻门,浮游动物的优势种为秀体蚤;水体和浮游生物中微量元素含量也比其它浓度组高.水体中的微量元素含量随550鱼营养补充料的添加而递增.  相似文献   

六片式拖网在几内亚渔场的适用性     

蒋传参 《上海水产大学学报》1995,4(3):210-218

拖网渔具必须适应渔场和捕捞对象的特征，这对提高渔获效果是十分重要的。本文对几内亚渔场所使用的48．78×56．64m六片式拖网的规格和主要性能参数作了具体分析，并对网衣配置、装配工艺和几个部位的工艺性处理作了详细的说明。通过生产实践和与其它几种网型的比较，证明了该种类型的拖网的优越性，以期对今后的渔业生产有所帮助。  相似文献   

Improving the detection of rare native fish species in environmental DNA metabarcoding surveys     

Jack Rojahn  Dianne M. Gleeson  Elise Furlan  Tim Haeusler  Jonas Bylemans 《水产资源保护:海洋与淡水生态系统》2021,31(4):990-997

1. The presence of threatened or endangered species often strongly influences management and conservation decisions. Within the Murray–Darling Basin (MDB), Australia, the presence of threatened native fish affects the management and allocation of water resources. In New South Wales, these decisions are currently based on traditional fisheries data and a predictive MaxEnt model. However, it is important to verify the model's predictive power given the implication it may have, but this requires methods with a high detection sensitivity for rare species.
2. Although the use of environmental DNA (eDNA) monitoring, in particular eDNA metabarcoding, achieves a higher detection sensitivity compared with traditional methods, earlier surveys in the MDB have shown that the highly abundant and invasive common carp (Cyprinus carpio) can reduce detection probabilities for rare species. Consequently, a polymerase chain reaction (PCR) blocking primer designed to block the amplification of carp eDNA could increase the detection probabilities for rare native species while simultaneously reducing the required sampling effort and survey costs. Although PCR blocking primers are often used in ancient DNA and dietary studies, no aquatic eDNA metabarcoding study to date has evaluated the potential benefits of using PCR blocking primers.
3. A laboratory and field-based pilot study was used to address this knowledge gap and assess the impact of a blocking primer, targeting cyprinid fishes (including carp), on the detection probabilities of native species and the minimum sampling effort required.
4. Results showed that the inclusion of the blocking primer increased the detection probabilities for native species by 10–20% and reduced the minimum required sampling effort by 25–50%. These findings provide important insights into possible methods for optimizing eDNA metabarcoding surveys for the detection of rare aquatic species.

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A new optimal foraging model predicts habitat use by drift-feeding stream minnows   总被引：3，自引：0，他引：3  

G. D. Grossman  P. A. Rincon  M. D. Farr  R. E. Ratajczak Jr 《Ecology of Freshwater Fish》2002,11(1):2-10

Abstract – There is substantial need for models that accurately predict habitat selection by fishes for purposes ranging from the elaboration of ecological theory to the preservation of biodiversity. We have developed a new and highly tractable optimal foraging model for drift‐feeding fishes that is based on the profitability of occupying varying focal‐point velocities in a stream. The basic model can be written as: I_x = (E_x * P_x) = {(D * A * V) * [1/(1 + e^{(b + cV)})]} ? S_x, where: (1) I_x is the net energy intake at velocity x; (2) E is prey encounter rate; (3) P is prey capture success rate which can be modelled as 1/(1 + e^{(b + cV)}) where b and c are fitting constants from the prey capture success curve; (4) D is the energy content of prey (J/m³) in the drift; (5) A is the visual reactive area of the fish; (6) V is velocity (cm/s); and (7) S is the cost of maintaining position (J/s). Given that D, A and S can be considered constant over the range of velocities occupied by these fishes, the model reduces to e^{(b + cV)} = 1/(cV ? 1) which we solved iteratively to yield an optimal focal‐point velocity for species in each sample. We tested the model by comparing its predictions to the mean focal‐point velocities (i.e. microhabitats) occupied by four species of drift‐feeding minnows in two sites in a stream in North Carolina, USA. The model successfully predicted focal‐point velocities occupied by these species (11 out of 14 cases) in three seasonal samples collected over 2 years at two sites. The unsuccessful predictions still were within 2 cm/s of the 95% confidence intervals of mean velocities occupied by fishes, whereas the overall mean deviation between optimal velocities and mean fish velocities was small (range = 0.9 and 3.3 cm/s for the warpaint shiner and the Tennessee shiner, respectively). Available focal‐point velocities ranged from 0–76 to 0–128 cm/s depending on site and season. Our findings represent one of the more rigorous field tests of an optimal foraging/habitat selection model for aquatic organisms because they encompass multiple species and years, and for one species, multiple sites. Because of the ease of parameterization of our model, it should be readily testable in a range of lotic habitats. If validated in other systems, the model should provide critical habitat information that will aid in the management of riverine systems and improve the performance of a variety of currently used management models (e.g. instream flow incremental methodology (IFIM) and total maximum daily load calculations (TMDL)).  相似文献   

应用葡萄球菌A蛋白协同凝集试验快速检测3株鱼类致病菌   总被引：5，自引：0，他引：5  

李学勤  王振英 《水产科学》1997,16(6):12-15

本试验用富含葡萄球菌Ａ蛋白的国际标准菌株ｃｏｗａｎＩ分别标记３株引起民鱼类致病的荧光假单胞菌、鳗弧菌和鲁克氏耶尔森菌的特异高兔血清制成ＳＰＡ诊断液，建立了检测估摸力的协仙凝集试验。将待检病料增减１６－１８ｈ用该法检测３ｍｉｎ可判定结果，比常规玻片敏感２５－５０倍；经交叉试验和重复性试验，表明特异性强，敏感性高可重复性好，一具有简便快速经济等特点。适用于基层鱼场，可用于淡水鱼类病原菌的快速鉴定，疫情  相似文献   

建立冷水性鱼类天然种质资源库可行性研究报告     

张觉民  王昭明  张辑五 《水产学杂志》1993,(1)

我国地处北纬35°以北和海拔千米以上国土,约占全国总面积的75％,在这广大的高纬度或高海拔地带的山区,林区河流、湖泊,多属水温常年偏低的冷水水域。其中栖息的冷水性或喜冷性鱼类初步统计有56种,隶属于11科30属。其主要经济种类有七鳃鳗科、鲟科、鲑科、茴鱼科、胡瓜鱼科、狗鱼科、鲤科及鳕科等8科中的20种。冷水性鱼类的特点为:对生态环境有其特定要求,常年生活在水温不超过20°、水质澄清、底质砂砾、砾石,溶氧含量较高的山林区流水水域;繁殖水温多在16℃以下;种群数量小,地区分布不平衡,肉食性种类多,生长速度快,肉质好,多属名特优鱼品。受种种原因的影响,现存冷水性鱼类种群数量减少趋势明显,有的种类已成珍稀或濒危状态。为了保护和增殖我国贵重的冷水性鱼类种质资源,并进而对若干经济种类逐步开发利用,经过调查,提出了在黑龙江省宁安县钻心湖建立冷水性鱼类天然种质资源库的可行性考察报告,阐述了多种主要冷水性鱼类的特性;钻心湖的水域环境基本情况,现有的基础条件,建库的规划设想及其经营方式与效益予测。供有关郎门参考。  相似文献