江鳕人工繁殖试验

江鳕(Lota lota)属鳕形目,鳕科,江鳕属。肉食性。环境条件好、食物充足时,当年鱼可长到300克、两年鱼可长到800克以上,笔者所见最大个体达8千克。在0～26℃的水域中生存,体被暗纹,有细小圆鳞,体表有金钱豹类似的花纹,所以在新疆当地俗称"金钱豹",在黑龙江有地方名:山鲶鱼、山怀子。江鳕的肉质细腻鲜美,无肌间刺,特点是其肝脏大而味美,是鳕科鱼类中制造鱼肝油的唯一淡水品种。在我国仅分布于新疆的额尔齐斯河及东北的黑龙江水系及鸭绿江上游。     

江鳕孵化条件的研究

江鳕(Lota lota),地方名山鲶鱼、山怀子.属鳕形目(Gadiformes)鳕鱼科(Gadidae).是鳕科鱼类中唯一的淡水种,广泛分布于45°N以北内陆水域和海湾处,是高纬度水域珍贵的经济鱼类,在我国仅新疆的额尔齐斯河、东北的黑龙江水系及鸭绿江上游有分布.江鳕是典型的冷水性鱼类,其在酷寒期于冰下行生殖洄游并于水温近0 ℃(0.1～0.2 ℃)时产卵的特殊习性,使其成为防冻、抗寒及低温状态下生命活动等方面研究的特种材料.     

江鳕苗种的试养驯化

<正>江鳕属鳕形目,鳕科,江鳕属。我国只产江鳕一种,又称山鲇鱼。2013年5月,北京市从新疆引进了江鳕苗种,在国家级北京鱼类良种场暨北京水产科学研究所十渡基地开展试验,现将试养结果总结如下:一、材料与方法1.试验地点北京水产科学研究所十渡基地位于房山区十渡镇,交通便利;东傍拒马河,地下水资源丰富,水质清新,符合渔业用水标准。2.试验条件试验在基地育种车间内进行。试验池为圆形玻璃钢材料,直径2米、高50厘米,中间排污;进水采取喷淋式,缸内安装微孔曝气装置,水中     

江鳕-龄鱼种培育技术研究

<正>1培育设施江鳕1龄鱼种培育池采用室外水泥池,大小6m×6m×0.8m。水深控制在0.6m左右,池底用石棉瓦搭建遮阳棚,高度约15cm左右,石棉瓦下放置数堆鹅卵石,池中间再摆放数个不透明粗管,给江鳕提供避光栖息的场所。夏天天气炎热时,培育池上方搭遮阳网,避免阳光直射到培育池内。2水源和水流控制江鳕1龄鱼种培育用水采用水库底层水,经过充分沉淀、曝气后使用,依水位差自流入培育池,水流大小控制在1m3/h,夏季水流加大至1.5     

江鳕小瓜虫病的治疗

江鳕（Lota lota）属鳕形目,鳕科（Gadidae）,江鳕属。俗称山鲶鱼,鲶鱼。为鳕科鱼仅有的淡水种类、生活于欧、亚及北美的冷水江河及湖泊中,为典型的冷水性鱼类。江鳕肉质细腻,肌间刺较少,肝脏大,占其体重的6％～9%,味极鲜美,食用极佳,也是制造鱼肝油的鳕科中唯一淡水鱼,在当地售价较高,可以说是当地的重要经济鱼类。     

岩原鲤苗种培育技术

岩原鲤Procypris rabaudi（Tchang）隶属鲤形目、鲤科、鲤亚科、原鲤属,通过近几年研究,岩原鲤规模化繁育技术进一步成熟,苗种产量有较大幅度提高。     

鲶鱼的人工繁殖及苗种培育技术

鲶鱼（Silurusasot。）属鲶形目、给科、鲶属。鲶鱼不仅生长快,个体大,而且耐低温,耐低氧。同时肉质细嫩,营养丰富,味道鲜美,属高蛋白低脂肪的食品,深受消费者欢迎。目前国内正在开发利用鲶鱼资源,满足市场需求,为了解决鲶鱼苗种的问题,本文将鲶鱼的人工繁殖及苗种培育技术措施总结如下：1．鲶鱼的人工繁殖（1）亲鱼的选择从池塘或湖泊捕捞群体中选择体重在0．5－2kg之间,无病无伤,体质健壮的给鱼作为繁殖亲本。雌鱼腹部膨大,松软有弹性,轻压腹部能挤出卵粒,雄鱼腹部狭小,轻压腹部能挤出白色精液,雌雄比例为2：1。（2）雌…     

鲶鱼苗种培育技术

一、苗种培育 鲶鱼苗种培育全过程大致可分为四个阶段进行: 1.免投喂期:鱼苗刚出膜,全长约0.7～0.8厘米。此时,鱼苗的卵黄囊还未消失,鱼苗集群于池底角落,微微颤动,鱼群显青黄色,只有少数鱼苗离开池底无目的游动,     

杂交金鳟苗种培育技术

金鳟隶属鲑形目、鲑亚科、鲑属,是虹鳟体色发生突变的一个变种,后经选育而成的体色呈金黄色的突变品系。纯系金鳟体质较弱,抗病力低,而与虹鳟的杂交一代体质明显优于纯系亲本金鳟,从稚鱼至成鱼较其亲本表现出摄食力强、耐高密度饲育的优势。它体色富贵华丽,姿态优雅端庄,肉味鲜美可口,除食用外还适于观赏,是目前中国养鳟业的新秀。加强苗种培育,是金     

黑龙江流域江鳕的胚胎发育

采用固定后剥离卵膜后拍照的方法,在平均水温1.61℃下系统观察了黑龙江流域江鳕（Lota Iota Linnaeus）的胚胎发育。根据发育特征,将江鳕整个胚胎发育过程分六个大的发育阶段。黑龙江流域江鳕受精卵为淡黄色,近似圆球形,具有微粘性,比重略大于水,内部紧靠卵膜分布大量的脂肪滴,吸水膨胀后卵径为1.01±0.11mm,在平均水温为1.61℃水温条件下受精卵至破膜共历时1746h,需4106.98℃.h,进一步细分为21个发育时期。将黑龙江流域江鳕和新疆额尔齐斯河流域江鳕的胚胎发育过程进行了对比分析,为黑龙江流域江鳕的人工养殖和自然资源的复壮提供了基础资料。     

江鳕苗种培育技术

江鳕(Lotalota,burbot)又名山鲶鱼、山怀子、山鳕,是鳕形目(Gadiformes)、鳕科(Gadidae)中唯一的淡水鱼类,属于典型高寒水系的冷水性鱼类,分布于欧洲里海、黑海的河道、港湾,我国新疆额尔齐斯河、黑龙江水系及鸭绿江上游,北美洲部分河流。江鳕营养丰富,药用价值也较高,目前其自然种群数量急剧下降,且     

Factors affecting the population viability of the burbot,Lota lota

Abstract Population viability analysis (PVA) is a frequently used conservation tool for the assessment of long‐term survival of populations. Based on demographic information from published literature, a PVA model using VORTEX was constructed for the burbot Lota lota (L.), a freshwater fish species believed extinct in the United Kingdom since the 1970s. The model was constructed to evaluate the persistence of a single burbot population over a 100‐year period as part of an assessment of the feasibility of reintroducing the species to rivers of its former distribution in England. Population persistence was highly variable and dependent on juvenile survival and spawning regularity. Under high juvenile survival scenarios, all populations persisted and were maintained at the carrying capacity. At low juvenile survival, population persistence was highly influenced by spawning regularity. Sensitivity analysis indicated that females must successfully spawn approximately every second year to guarantee 95% population survival. The analysis suggests that the long‐term viability of any potential reintroduced burbot population will be dependent on the environmental conditions related to spawning success.     

Early development and allometric growth patterns in burbot Lota lota L.

This study analyzed the morphological development and allometric growth patterns of Lota lota L. (burbot) larvae reared under controlled laboratory conditions. From hatching to day 50, twenty larvae were sampled each [between 1 and 14 days post-hatch (DPH)] or every second day (between 14 and 50 DPH) and measured under a stereoscopic microscope using analytic software. Based on the external morphology, the different stages during early development of burbot were identified: yolk sac larva 0–8 DPH [3.92–4.37 mm total length (TL)]; preflexion larva 9–26 DPH (4.57–12.06 mm TL); flexion larva (between notochord degradation and its replacement with rays) 28–34 DPH (14.00–16.34 mm TL) and postflexion larva/juvenile 36–50 DPH (18.20–29.27 mm TL). Allometric growth patterns of some parameters (e.g., total length, head length, body length, tail length, head depth, body depth, eye diameter) were modeled by a power function and described by the growth coefficient. Organogenesis and changes of body proportions in burbot larvae were more rapid and complex during the yolk sac and preflexion phase of development as larvae developed most of their sensorial, feeding, respiratory and swimming systems and after notochord flexion, when most morphological changes were related to the progressive transformation from pelagic larva to demersal larva/juvenile.     

Genetic diversity and population structure of burbot Lota lota in Germany: Implications for conservation and management

The genetic structure of the gadiform fish species, burbot Lota lota L., was investigated across Germany to derive management options for facilitating the preservation of genetic diversity. Sequence analysis of the mitochondrial control region (n = 244) and microsatellite analysis (n = 861) of specimens from 20 sites revealed genetic structuring between major river basins, and particularly between lake and river habitats. The admixture zone between the Eurasian and West European phylogenetic clades in Lake Constance was confirmed and expanded to include the drainage basins of the rivers Rhine and Schlei/Trave. Haplotype distribution and private haplotypes in single river basins indicated population differentiation and imply that German burbot constituted an important part of the entire species' diversity. The derived genetic structuring has implications for future stocking programmes and the preservation of the adaptive potential of burbot, a guiding species for oligotrophic lakes in Europe.     

Recruitment of burbot (Lota lota L.) in Lake Erie: an empirical modelling approach

Stapanian MA, Witzel LD, Cook A. Recruitment of burbot (Lota lota L.) in Lake Erie: an empirical modelling approach.
Ecology of Freshwater Fish 2010: 19: 326–337. Published 2010. This article is a US Government work and is in the public domain in the USA Abstract – World‐wide, many burbot Lota lota (L.) populations have been extirpated or are otherwise in need of conservation measures. By contrast, burbot made a dramatic recovery in Lake Erie during 1993–2001 but declined during 2002–2007, due in part to a sharp decrease in recruitment. We used Akaike’s Information Criterion to evaluate 129 linear regression models that included all combinations of one to seven ecological indices as predictors of burbot recruitment. Two models were substantially supported by the data: (i) the number of days in which water temperatures were within optimal ranges for burbot spawning and development combined with biomass of yearling and older (YAO) yellow perch Perca flavescens (Mitchill); and (ii) biomass of YAO yellow perch. Warmer winter water temperatures and increases in yellow perch biomass were associated with decreases in burbot recruitment. Continued warm winter water temperatures could result in declines in burbot recruitment, particularly in the southern part of the species’ range.     

Variations in the activity of digestive enzymes along the intestine of the burbot Lota lota expressed by different methods

The activities of major digestive hydrolases (proteases, amylase, lipase and esterases) along the intestine were studied in the burbot Lota lota (L.) using different methods of activity expression. The enzyme activities were determined both in the whole gut segments and in the isolated mucosa, and then expressed in terms of tissue mass and protein content in the samples. Further, the cumulative activities of these enzymes in the pyloric caeca were compared with those in the rest of the intestine to estimate the overall contribution of these regions to digestion. The data obtained suggest the essential role of the pyloric caeca in the digestion of the burbot. In addition, the variations in the pH values along the intestine and the changes in the enzyme activities with incubation temperature were examined. The study proved the method of enzyme activity expression to be a key factor influencing the outcome of the experiment.     

The effect of meal size on the rate of gastric evacuation of burbot, Lota lota (L.)

Abstract– The effect of meal size on the gastric evacuation rate of burbot Lota lota (L.), was determined at a constant temperature of 1.5°C. Burbot were fed vendace Coregonus albula (L.), in varying amounts from 1.0% to 12.6% of burbot weight. Although gastric evacuation rate decreased exponentially with increasing meal size, the absolute amount of food evacuated per day (g. day⁻¹ increased when meal size increased. The estimated maximum daily gastric evacuation rates were 0.8, 1.3 and 1.6 g/day with meal sizes 1%, 5% and 10% of burbot weight (200 g). No difference in gastric evacuation rate was observed between meals of the same size (8 g) but which consisted of either one or three vendace.