三线闭壳龟控温养殖技术

为促进三线闭壳龟驯养繁殖业发展,从2007年开始,我们在常温人工养殖技术基础上进行三线闭壳龟的控温人工养殖试验,采用温室立体养殖池养殖方式,刚孵化出的稚龟经2年养殖成平均体重1k9的商品龟,     

八种主要经济龟类简介及其养殖前景（一）

本文主要介绍了黄喉拟水龟、三线闭壳龟、乌龟、黄缘盒龟、平胸龟、四眼斑龟、鳄龟、红耳龟的形态特征与生活习性、养殖技术及人工养殖前景。     

黄缘盒龟健康养殖技术

黄缘盒龟(Cistoclemmys flavomarginata)俗名金头龟、黄缘闭壳龟等。因其背甲上的缘盾腹面为黄色，故名黄缘盒龟。目前，野生黄缘盒龟数量较少，国内仅有小规模养殖，且繁殖率低，不能满足市场需求，因此，健康养殖黄缘盒龟对保护野生动物和提高经济效益都有双重作用。     

珍贵龟种简介

金头龟（Cuora flvomarginata）,学名黄缘盒龟或黄缘闭壳龟，别名夹板龟、断板龟、呷蛇龟、克蛇龟、驼背龟等，通称闭壳龟，又称北系金钱龟，与南方热带三线红边壳龟（南系金钱龟）并列。     

珍贵龟种欣赏

金头龟 金头龟,学名黄缘盒龟或黄缘闭壳龟,别名夹板龟、断板龟、呷蛇龟、克蛇龟、驼背龟等,通称闭壳龟,又称北系金钱龟,与南方热带三线红边闭壳龟(南系金钱龟)并列.但上述两个品系还有品种之分.如金头龟中有黄金头龟、乌金头龟、红金头龟等多种,人工饲养以黄金头龟、乌金头龟居多.     

黄缘闭壳龟保护现状和养殖技术研究

正黄缘闭壳龟又称黄缘盒龟,俗称断板龟、金头龟、夹板龟等,龟科、盒龟属,是一种古老的,被人们誉为"活化石"动物,目前已被列入世界濒危物种,河南省重点野生保护动物。近年来,由于生态环境的破坏和人为的泛捕滥杀,黄缘闭壳龟的野生资源日益减少,种群面临灭绝。为了保护这一珍稀的龟类,我们对其进行一些研究,保持其能继续生存繁衍。2002年,农业部批准建设信阳黄缘闭壳龟救护中心,2004年,河南省人民政府批准建立信阳黄缘闭     

黄缘闭壳龟稚龟的形态学特征统计分析

利用生物统计学的方法对黄缘闭壳龟稚龟的体高、腹甲长、体重、腹甲宽、背甲长、背甲宽、尾长7个形态学指标进行了分析,结果如下:稚龟的体重(Y)与体高(X)的一元回归方程为Y=8.577X-3.6359,相关系数37.6237,F0.05,F0.01检验极其显著。体重(Y)与腹甲长(X)的一元回归方程为Y=4.4567X-4.7986,相关系数16.9280,F0.05,F0.01检验极其显著。体重(Y)与腹甲宽(X)的一元回归方程为Y=5.0134X 7.4741,相关系数14.4394,F0.05,F0.01检验极其显著。体重(Y)与尾长(X)的一元回归方程为Y=11.2736 0.5968X,相关系数0.3135,F0.05,F0.01检验极不显著。体重与其它6个形态学指标的一元回归方程除尾长以外均极其显著,这为人工养殖黄缘闭壳龟时,在选择育种和预测其生长能力等方面提供了科学依据。     

金钱龟及其快速生态养殖技术

金钱龟学名三线闭壳龟,是最为珍贵的龟种之一,其经济价值名列龟中之首,成龟价格在每千克22000元以上,50～100g的稚龟每只2000元以上,为普通龟的数十倍到百倍。目前市场缺口较大,往往出现有价无货的现象,因此,人工养殖金钱龟前景十分看好。     

温度对黄缘闭壳龟孵化和稚龟表型特征的影响

为研究温度对黄缘闭壳龟受精卵孵化和稚龟表型特征的影响,采用恒温孵化法,设置3个孵育温度(26±0.5)、(28±0.5)、(30±0.5)℃,每个温度放置卵30个,检测孵化期、孵化率和孵化稚龟表型特征并进行统计分析。试验结果表明,28℃试验组的孵化成功率最高,达到93.3%,孵化期75 d,相对较短,所孵幼体的体质量和13个表型性状显著高于26℃试验组(P0.05),有利于幼体的生长;依据孵化率高低、稚龟体质量和表型特征大小,28℃是黄缘闭壳龟在北京及周边地区孵化的适宜温度条件。因此,孵化温度显著影响龟卵孵化效果和稚龟表型特征,该试验结果对黄缘闭壳龟在京津冀地区的繁育孵化具有重要的参考价值。     

黄缘盒龟人工养殖观察研究

通过建立模拟自然条件的养殖池,对黄缘盒龟的活动、产卵、受精及孵化等开展养殖观察研究。结果表明：黄缘盒龟表现为喜阴暗潮湿地,黄缘盒龟具有一次交配至少保持两年有效的受精特性;温度变化对其影响大,是其活动和孵化时间的主要影响因素;孵化中不同比例孵化介质对孵化时间没有明显的影响,孵化介质覆盖厚度对孵化率有影响;卵重的大小与孵化时间没有必然的联系。     

Plankton populations at the bifurcation of the North Pacific Current

As the eastward‐flowing North Pacific Current approaches the North American continent it bifurcates into the southward‐flowing California Current and the northward‐flowing Alaska Current. This bifurcation occurs in the south‐eastern Gulf of Alaska and can vary in position. Dynamic height data from Project Argo floats have recently enabled the creation of surface circulation maps which show the likely position of the bifurcation; during 2002 it was relatively far north at ∼53°N then, during early 2003, it moved southwards to a more normal position at ∼45°N. Two ship‐of‐opportunity transects collecting plankton samples with a Continuous Plankton Recorder across the Gulf of Alaska were sampled seasonally during 2002 and 2003. Their position was dependent on the commercial ship’s operations; however, most transects sampled across the bifurcation. We show that the oceanic plankton differed in community composition according to the current system they occurred in during spring and fall of 2002 and 2003, although winter populations were more mixed. Displacement of the plankton communities could have impacts on the plankton’s reproduction and development if they use cues such as day length, and also on foraging of higher trophic‐level organisms that use particular regions of the ocean if the nutritional value of the communities is different. Although we identify some indicator taxa for the Alaska and California currents, functional differences in the plankton communities on either side of the bifurcation need to be better established to determine the impacts of bifurcation movement on the ecosystems of the north‐east Pacific.     

Factors Affecting the Trout Fishery at Grafham Water

In this paper some of the controllable factors affecting angling catch at Grafham Water trout fishery are examined and an attempt made to relate them. There appears to be a close relationship between annual catch and annual stocking in the case of rainbow trout. The relation of the brown trout catch to other factors is rather different; the main reason is probably a higher frequency of survival into later seasons and slower growth. The effect of growth rates and other less quantifiable factors is discussed.     

A closer look at the bacteriology of nitrification

The mineralizing ability of nitrifying bacteria is well known among aquaculturists, but the underlying bacteriology is abstruse. The proceeding literature review details sources of nitrogenous fish waste and peculiarities of the Nitrobacteraceae family, including survival mechanisms, frailties, and intrinsic kinetics. Fundamental catabolic and anabolic reactions are elucidated, as is the implication of reducing power allotment for respiratory efficiency. Attention is paid to the paramount role of nitrifiers in biofiltration and recommendations are made for future recirculating aquaculture research.     

Safeguarding the welfare of farmed fish at harvest

Fish welfare at harvest is easily compromised by poor choice of handling and slaughter methods, lack of attention to detail and by unnecessary adherence to fish farming traditions. The harvest process comprises fasting the fish to empty the gut, crowding the fish, gathering and moving the fish using brails, fish pumps, and sometimes also road or boat transport and finally stunning and killing the fish. The harvesting processes commonly used for bass, bream, carp, catfish, cod, eel, halibut, pangasius, salmon, tilapia, trout, tuna and turbot are outlined. These harvesting processes are discussed; the consequences for fish welfare identified and practical tests which can be made at the harvest site highlighted. Welfare at harvest for the majority of farmed fish species can be improved by adopting and adapting existing procedures already known to be beneficial for fish welfare through their use in other fish farming systems or with other species. It is seldom necessary to develop completely new concepts or methods.     

Development of the Trout Fishery at Grafham Water

The paper describes the development of the trout fishery at Grafham Water, and considers the various factors having a bearing on the changing nature of the fishery as the lake becomes more mature.     

Predator and prey events at the entrance of a surface-oriented fish collector at North Fork Dam,Oregon

Quantifiable estimates of predator–prey interactions and relationships in aquatic habitats are difficult to obtain and rare, especially when individuals cannot be readily observed. To overcome this observational impediment, imaging sonar was used to assess the cooccurrence of predator-size fish and juvenile salmonids, Oncorhynchus spp., at the entrance to a floating surface collector (FSC) in the forebay of North Fork Dam on the Clackamas River, Oregon (USA). Imaging sonar can be used to transform active sound waves into visual data, making it possible to obtain continuous underwater observations on the presence and interspecific interactions between predator-size fish and prey (juvenile salmonids). Hourly counts of smolt-size fish tracks, diel phase, water clarity and river discharge were used as covariates within a zero-inflated Poisson model to determine how these factors may influence the number of predators in front of the FSC. Both the number of smolt-size fish tracks and diel phase had the strongest effects on the number of predator-size fish tracks, with more predator-size fish tracks observed during the daytime, and as the number of smolt-size fish tracks increased. Additionally, the presence of predator-size fish may affect the abundance and direction of travel of juvenile salmonids, as fewer smolt-size fish were observed when predators were present, and a greater proportion of smolt-size fish were observed travelling away from the FSC when predator-size fish were present. This study provides estimates of predator and prey fish abundance in the vicinity of surface collection systems at moderate-sized hydropower projects and could help resource managers better understand mechanisms that can influence the survival and passage behaviour of juvenile salmonids using surface collection structures at dams.     

Efficiency of fisheries is increasing at the ecosystem level

Managing fisheries presents trade‐offs between objectives, for example yields, profits, minimizing ecosystem impact, that have to be weighed against one another. These trade‐offs are compounded by interacting species and fisheries at the ecosystem level. Weighing objectives becomes increasingly challenging when managers have to consider opposing objectives from different stakeholders. An alternative to weighing incomparable and conflicting objectives is to focus on win–wins until Pareto efficiency is achieved: a state from which it is impossible to improve with respect to any objective without regressing at least one other. We investigate the ecosystem‐level efficiency of fisheries in five large marine ecosystems (LMEs) with respect to yield and an aggregate measure of ecosystem impact using a novel calibration of size‐based ecosystem models. We estimate that fishing patterns in three LMEs (North Sea, Barents Sea and Benguela Current) are nearly efficient with respect to long‐term yield and ecosystem impact and that efficiency has improved over the last 30 years. In two LMEs (Baltic Sea and North East US Continental Shelf), fishing is inefficient and win–wins remain available. We additionally examine the efficiency of North Sea and Baltic Sea fisheries with respect to economic rent and ecosystem impact, finding both to be inefficient but steadily improving. Our results suggest the following: (i) a broad and encouraging trend towards ecosystem‐level efficiency of fisheries; (ii) that ecosystem‐scale win–wins, especially with respect to conservation and profits, may still be common; and (iii) single‐species assessment approaches may overestimate the availability of win–wins by failing to account for trade‐offs across interacting species.     

The coldwater marine aquarium at the British Antarctic Survey

A low-temperature marineaquarium has been maintained at the British Antarctic Survey(BAS) headquarters in Cambridge for over 15 years. In 1988 acompletely new aquarium system was designed and construct ed toprovide a cold-water environment for holding a variety ofAntarctic fishes and invertebrates. The philosophy behind the newAntarctic aquarium is to provide a controlled environment in asystem that is simple to maintain. One of the most importantenvironmental conditions is the provision of a continuous low airtemperature and controlled sea water temperature, to facilitatethe transfer of specimens between holding and research facilitieswithout there being a significant difference between air andwater temperatures. In this way specimens are freed from thedangers of temperature stress. This paper describes how theseconditions have been established. It outlines the design,construction and operation of the BAS Marine Aquarium, one of theUK's most unusual marine researchfacilities.     

泼河水库底泥中细菌群落的调查

在2017年5月份和9月份以及2018年3月份在信阳市泼河水库底泥采样三次,探究不同时间段泼河水库底泥中细菌的群落结构。提取底泥样品中细菌微生物的DNA,并利用PCR扩增技术对DNA扩增某一个基因,构建16S rRNA基因文库,并利用高通量测序技术进行序列测定,分析不同时间段泼河水库底泥中细菌群落的组成和特点。研究发现,在不同的时间段内泼河水库底泥细菌群落结构发生了演替,且在三个时间段内在科的分类水平上共有192种细菌,所占比例为77.4%,说明泼河水库中77.4%的细菌群落结构组成是长期变化很小的,12个样品物种组成共覆盖45种,其中厌氧绳菌目Anaerolineaceae_uncultured、黄单胞菌目Xanthomonadales_uncultured为优势种群。     

What was hot at the fourth World Fisheries Congress?*

Given the current crisis in global fisheries, how well are we doing at managing fisheries? This short paper describes as summarises the results of a systematic assessment of the scientific papers presented at the Fourth World Fisheries Congress, the theme of which was ’Reconciling fisheries with conservation’. Over 200 papers were presented, 70% of which were based on natural sciences, focusing on issues such as biodiversity, species at risk, resiliency, ecosystem modelling, and ecosystem indicators. Encouragingly, over 60% of the papers scored medium to high for their potential contribution to reconciling fisheries with conservation. However, although the human dimensions of fisheries were recognized, few studies involved stakeholders beyond their roles of objects to study. Communication of scientific research findings, particularly to the general public, was notably absent and emphasised as one of the key challenges in achieving sustainability and in reconciling fisheries with conservation.