香鱼养殖技术

香鱼属鲑亚目、香鱼科、香鱼属。香鱼体细长而侧扁,头小而吻尖。身体上侧绿色,背缘黑色,两侧及下侧为白色,香鱼地方名:海胎鱼、秋生子,日本人称为鲇鱼,因能散发出诱人的香味而得名。香鱼体长10～30厘米,重50～100克,最大的可达500克左右。1生物学特性洄游习性香鱼多为1年生。每年的2～5月,当河水水温逐渐上升到10～15℃。接近于海水的温度时,在海里越冬的幼鱼(体长2～3厘米)便进入河口上溯。幼鱼在河川中生长发育.随着性腺的发育,又向河川下游洄游,在9～11月产卵。随着仔鱼的生长发育和水温的继续下降,幼鱼入海越冬。生活习性香鱼又名鲇鱼。…     

养殖香鱼体型异常的研究

香鱼 (Ｐｌｅｃｏｇｌｏｓｓｕｓａｌｔｉｖｅｌｉｅｓ )属鲑形目香鱼科 ,肉质细腻 ,体色美 ,味清香。香鱼在日本的养殖、放流及游钓业十分发达 ,在我国其养殖前景亦十分乐观。在香鱼的育苗及养殖过程中 ,经常见到一些 (1% -2 % )鱼体出现异常的体型 ,如”Ｖ”型或倒”Ｖ”型 ,尾部上翘的现象。本文通过采集体型异常的养殖香鱼 ,描述其形态学特征 ,并探讨了致畸原因。1　材料和方法香鱼标本主要采自温州乐清的几个养殖基地 ,共 2 9尾 ,其中 2尾是正常鱼。 (见表 1)表 1　香鱼标本的基本特征来源养殖状况数量体长 (ｃｍ)体重 (ｇ)平均范围方…     

荆江航道整治工程中透水框架集鱼效果初步评估

为了解荆江航道整治工程中透水框架的集鱼效果,分别于2014年5-6月和2015年5-6月,采用科学探鱼仪SIMRAD EY60和双频识别声纳(DIDSON)ARIS EXPORER 1800两种水声学设备,分别对荆江瓦口子水道的金城洲和太平口水道的腊林洲透水框架水域的鱼类分布情况进行了水声学监测,并对工程江段的鱼类进行了刺网调查。结果显示:采用刺网捕获鱼类17种共204尾,其中数量和重量最多的都是鳊鱼,分别占64.71%和39.62%。渔获物体长范围是10~80 cm,平均体长是(26.90±8.82)cm;EY60监测到腊林洲工程区鱼的数目是金城洲工程区的1.92倍,DIDSON监测腊林洲工程区鱼的数目是金城洲工程区的2.36倍;EY60监测到金城洲鱼类体长集中在5~10 cm,占55.24%,腊林洲鱼类体长集中在30~50 cm,占45.38%。结果表明,透水框架群对于鱼类具有一定的诱集效果。     

洛河鲹鲦个体生殖力的研究

2008年4-5月对洛河野生鲹鲦进行随机取样调查,共收集样本145(雌44,雄101)尾.测定成熟雌鱼体长(L)、体重(W)、年龄(A)、空壳重(BW)、卵巢重(GW)、怀卵量等指标,计数个体绝对生殖力(F),并计算出鲹鲦的体长相对生殖力(FL)、体重相对生殖力(FW)、肥满度(CF)和成熟系数(GSI)等,用6种数学模式拟合了鲹鲦个体生殖力与生物学指标间的关系.结果表明:①成熟雌性鲹鲦由0+-3+龄鱼组成;②个体绝对生殖力(F)范围为1937-39563粒,平均8436粒;体长相对生殖力(FL)范围为190-2586粒/cm,平均735粒/cm;体重相对生殖力(Fw)范围为110-865粒/g,平均383粒/g;③其个体绝对生殖力与体长、体重和年龄都呈抛物线函数相关,体长相对生殖力与体长、体重和年龄分别呈抛物线、直线和抛物线函数相关,体重相对生殖力与它们相关不显著.     

提高长尾鳕声学目标强度与其体长关系的速算能力

<正>长尾鳕渔业是新西兰最大的一个渔业。产卵长尾鳕的声学调查为长尾鳕资源的信息管理提供资源丰度指数。使用声学方法估算鱼类资源量,需要掌握一条鱼的声学反射,通常称为声学目标强度(TS)与该鱼体长度之间的关系。我们在此提供了使用安装在拖网上的声光系统(AOS)实地采集到的单条活     

香鱼养殖技术

香鱼（Plecoglossusaltivelis）属鲑亚目、香鱼科、香鱼属。香鱼体细长而侧扁，头小而吻尖。身体上侧绿色，背缘黑色，两侧及下侧为白色。香鱼地方名：海脂鱼、秋生子，日本人称为财鱼，因能散发出诱人的香味而得名。香鱼体长10－30厘米，重50－100克，最大的可达500克左右。一、生物学特性1．洄游习性香鱼多为一年生。每年的2－5月，当河水水温逐渐上升到10℃－15℃，接近于海水的温度时，在海里越冬的幼鱼（体长2－3厘米）便进入河口上溯。幼鱼在河川中生长发育，随着性腺的发育，又向河川下游涸游，在9－11月产卵随着仔鱼的生长发育和水…     

4种常见淡水养殖鱼类目标强度测定与差异分析

鱼类目标强度(target strength)的测量是渔业声学技术研究和应用的核心内容之一。2015年6―10月,在小型水槽内使用Bio Sonics DT-X(199kHz)科学探鱼仪发射水平声波,测量了4种共29尾不同鳔室结构的淡水养殖鱼类体侧向及背腹向(180°范围)的目标强度,并拍摄X光影像以了解鱼体鳔室结构及特征。其中瓦氏黄颡鱼(Pelteobagrus vachelli)7尾、鳜鱼(Siniperca chuatsi)9尾、鲫鱼(Carassius auratus)6尾、草鱼(Ctenopharyngodon idellus)7尾。结果显示,单体鱼目标强度与声波入射角度具有cos三次方函数关系,体侧向与背腹向上最大目标强度均出现于鱼体主轴垂直于入射声波时,最小目标强度出现于头尾方向朝向声波时,与最大目标强度相差10dB。不同种鱼类体侧向平均目标强度略大于背腹向0.5~5dB。单室鳔鱼类目标强度比相近体长的两室鳔鱼类小。对4种鱼类的目标强度与鱼体相关生物学指标进行主成分分析,体侧向与背腹向目标强度主要受体长、鳔长和鳔长/鳔高值的影响较大。通过目标强度与实验鱼全长、体长、体重的线性回归,获得体侧和背腹入射方向目标强度与3个生物学参数的关系式。本研究通过分析不同鳔室形态鱼种的回波特征差异,辅助判别长江内常见鱼类(如瓦氏黄颡鱼、鱖鱼、鲫鱼等)的声学信号,结果对于淡水水域水平原位监测时分析评估资源量相关参数具有参考意义。     

香鱼的生物学特性及养殖技术

<正> 香鱼(Plccoglossus altivelis)属鲑亚目、香鱼科、香鱼属。香鱼体细长而侧扁,头小而吻尖。身体上侧绿色、背缘黑色,两侧及下侧为白色。香鱼地方名:海胎鱼、秋生子、日本人称为鲇鱼,因能散发出诱人的香味而得名。香鱼体长10～30cm,重50～100g,最大的可达500g左右。     

光唇鱼雌性个体生殖力的测定

随机采集光唇鱼雌性个体样本12尾,测量其体长(L)、体质量(W)、净体质量(Wn)和性腺质量(Wo)等生物学指标。用质量法计数个体绝对生殖力,并对体长相对生殖力(FL)、体质量相对生殖力(Fw)和成熟系数进行计算,结果表明:个体绝对生殖力(F)在458~14254粒,平均3736粒。体长相对生殖力(FL)在50~1013粒/cm,平均346粒/cm。体质量相对生殖力(Fw)在19~151粒/g,平均85粒/g。绝对生殖力主要集中于1000~5000粒,绝对生殖力在10000粒以上的样本较少。体长相对生殖力主要分布于100~500粒/cm,而体质量相对生殖力主要集中于25~100粒/g。     

香鱼肌肉和鱼籽挥发性风味物质研究

为初探香鱼(Plecoglossus altivelis)肌肉清新无腥的原因和确定香鱼产生香气的特征性风味物质,采用顶空固相微萃取(HS-SPME)和气相色谱—质谱联用仪(GC-MS)分析方法,检测和比较了香鱼肌肉和鱼籽的挥发性风味物质。结果显示,香鱼肌肉和鱼籽的挥发性物质中,醇类所占的比例最大,分别为39.58%和27.29%;其次为烃类,分别为10.16%和13.65%;醛类在香鱼鱼籽和肌肉中的含量相差很大,分别为2.03%和6.90%。在香鱼肌肉和鱼籽的挥发性物质中,醇类和醛类对香鱼的风味起了决定性作用,醇类使香鱼产生清新的风味,而醛类的不同则是影响香鱼香气的主要原因。研究表明,在比较肌肉和鱼籽的挥发性物质组成中,对香鱼香气贡献较大的主要是(E)-2-庚烯醛、(E,E)-2,4-庚二烯醛、(E)-4-庚烯醛、2,4-癸二烯醛等物质。     

沿黄背河洼地水产综合开发的层次分析法

用层次分析法对沿黄背河洼地废弃土地资源分析计算,得出了“宜稻则稻,宜藕则藕,宜鱼则鱼,稻鱼兼作,鱼藕混养”的水产综合开发方案,并用于科技扶贫,取得了很好的效果。     

中国海洋鱼类种类多样性的研究

中国海洋迄今已记录有３０４８种鱼类，分属２８８个科，约占全球海洋鱼类总数的２３％，是世界鱼类种类最丰富的国家之一。种类多样性程度由南向北逐渐递减，南海高达２０５０种，但单种资源量小，黄渤海只有３２７种，但一些单种资源量较多，中国海洋针种以暖水种居多样性的高达８７．８％，也有大量暖温种和少数冷温种，但无真正冰水各，中国海缺乏世界级的高产渔获种类。     

绥芬河鱼类区系组成研究

绥芬河是我国注入北太平洋日本海的第二条水系。由于该水系地处寒温带,气候、地理环境和生态条件特殊,因而蕴藏着丰富的冷水性鱼类、溯河性洄游鱼类种质资源,仅大麻哈鱼类就有3种,每年5～10月回归溯河洄游:鲤科溯河性洄游鱼类有三块鱼、珠星三块鱼等,呈现出北太平洋日本海水系鱼类区系的特色,成为我国名贵珍稀经济鱼类地理分布的重要水域。在鱼类区系组成上,它与相邻的水域有着很大的差异,在我国北方水域鱼类演替和区系划分上有着重要的意义。关于绥芬河鱼类区系,国内外学者都进行过研究。笔者在2005～2006年采集了大量的鱼类标本,整理和增补了10种鱼类,对绥芬河鱼类区系作了初步的概述,为我国北方水域鱼类演替、区系区划研究、开发利用及资源保护提供了科学的依据。     

北盘江光照水电站建设前后鱼类资源变化

2009年9月和2010年5月,对北盘江光照水电站影响河段鱼类资源进行现场调查,采集鱼类45种,其中18种为新记录种,各河段鱼类组成特点与生态类型相符。结合相关文献资料,确定调查河段鱼类共71种,其中珍稀濒危鱼类4种,珠江水系特有鱼类3种。光照电站的建设对库区河段的鱼类资源影响显著,喜静缓流生境鱼类占76.5%,喜急流...     

Taxonomic and geographic gaps in understanding the functional effects of imperilled fishes on freshwater ecosystems

The effects that fishes have on rates of one or more ecosystem processes (hereafter referred to as functional effects) are often invoked as an important reason for imperilled species conservation. However, the degree to which we understand these effects is rarely evaluated for most groups of fishes. We assessed how well the functional effects of freshwater and diadromous fishes, one of the most imperilled groups of animals, are quantified to date. We found that 88% of studies considering the functional effects of imperilled North American fishes were conducted on one family, Salmonidae. Studies of the functional effects of fishes were also concentrated in Pacific drainages of North America, with few studies in hotspots of imperilled fish diversity such as the Southeastern United States, the arid Southwest and central Mexico. Our results demonstrate the vast taxonomic and geographic gaps in our functional understanding of imperilled fishes and highlight the need to broaden this work to justify the argument that they are functionally important in the ecosystems they inhabit.     

Method for underwater measurement of the auditory brainstem response of fish

ABSTRACT:   The auditory brainstem response (ABR) of fishes is commonly measured by bringing the heads of the fishes out of the water in a small tank. However, this method is inapplicable to experiments for large fishes that are economically important in large spaces such as the sea or in a large tank. This paper describes a method of recording, the ABR for fishes in water, without exposing the fish heads to air, by using a waterproof, insulated electrode. To evaluate the effectiveness of this method, the goldfish Carassius auratus was investigated, and the ABR waveform and auditory thresholds measured in water were compared with those measured on the surface. Both ABR waveforms and auditory thresholds showed similar trends between the two methods. The underwater ABR method is useful to measure the auditory thresholds of larger fish in natural or on-site environments such as the sea, net enclosures and large aquaria in which precise positioning of the fish is not possible. However, more improvement is needed to apply this method to large fishes.     

Induction of triploidy in the zebrafish, Brachydanio rerio (Hamilton)

Abstract. Triploidy was induced in the zebrafish, Brachydanio rerio (Hamilton), by varying all possible combinations of the time after fertilization (AF) (1-3min after insemination), temperature (36-42°C) and shock duration (1-7min). A thermal shock of 41°C for 4min, 2.5min AF ensured 100% triploidy and maximum (51%) survival. Induction of triploidy was confirmed by measurement of erythrocyte nuclear volume and chromosome counting. There was no significant difference in the growth rate of triploid and diploid fishes. All surviving triploids developed into males, and produced a few spermatozoa unable to fertilize normal eggs. A study on thermal and other characteristics required to ensure 100% triploidy rate in fish indicates that these characteristics are species specific.     

Shrimp egg counting with fully convolutional regression network and generative adversarial network

Accurate egg counting is the basic demand in the hatcheries of the aquaculture. However, the time-consuming, fallible manual counting is now still adopted in most situations. Also, many traditional automatic egg counting methods cannot provide enough high efficiency and accuracy, especially in densely-distributed cases. In this paper, we propose a novel convolutional neural network (CNN) based method for shrimp egg counting. Compared to traditional methods mainly based on contour detection or image segmentation, the proposed method exploits the density map regression and is more efficient in densely-distributed case even with severe occlusion. Firstly, a new dataset of the redclaw crayfish Cherax quadricarinatus eggs is collected, which includes 450 images with about 272,000 eggs annotated accurately. Also, a synthetic dataset generation method based on generative adversarial network (GAN) is proposed to avoid the onerous manual labeling, and has potential applications in the supervised learning for the densely-distributed eggs or larvae counting. Then, considering the advantages of no manual preprocessing and fine-grained feature extraction in CNNs, a shrimp egg counting network (SECNet) based on fully convolutional regression network (FCRN) is proposed to realize the counting through regressing the input image into its density map. The test results show the average counting accuracy of the proposed SECNet can be up to 99.2 % when the SECNet is pre-trained on the synthetic dataset and finetuned on the collected dataset. Finally, a simple and cheap computer vision based counting setup is built by using three off-the-shelf devices and a convenient operation program integrated with the SECNet is developed for a person computer, which provides an accurate, real-time, and highly-efficient egg counting way.     

甘肃土著鱼类资源概况及开发保护策略

甘肃水域资源较为丰富,分属黄河、长江、内陆河三大流域,九个水系,蕴育着百余种鱼类,其中55种为中国特有种。受人类活动的影响,鱼类生存的环境正在或已经受到破坏,土著鱼类的生物多样性迅速降低,许多物种濒临灭绝。本文就甘肃土著鱼类资源概况及开发利用中存在问题做了叙述,并就如何合理开发保护甘肃土著鱼类资源提出了可持续发展策略。     

北盘江光照水电站建设前后鱼类资源变化

2009年9月和2010年5月,对北盘江光照水电站影响河段鱼类资源进行现场调查,采集鱼类45种,其中18种为新记录种,各河段鱼类组成特点与生态类型相符。结合相关文献资料,确定调查河段鱼类共71种,其中珍稀濒危鱼类4种,珠江水系特有鱼类3种。光照电站的建设对库区河段的鱼类资源影响显著,喜静缓流生境鱼类占76.5%,喜急流或流水生境鱼类占23.5%;流水生境河段受影响较小,约90%鱼类喜流水生境。调查水域没有典型产漂流性卵鱼类的产卵生境,原记录的产粘性卵鱼类产卵场受影响较小。