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问：如何建造乌龟产卵场？答：乌龟产卵场要求与甲鱼产卵场不一样，乌龟一般在泥土中产卵，在没有泥土时，乌龟产卵受影响。乌龟的产卵场分露天式产卵场和遮雨式产卵场。露天式产卵场就是在乌龟产卵季节，将乌龟池埂四周的杂草铲除并修成一定的坡度（围墙边高，池水边低）... 相似文献
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工厂化饲养乌龟的初步研究 总被引：1，自引：0，他引：1
乌龟在自然条件下生长缓慢，采用控温养殖可加速其生长在甲鱼养殖效益滑坡的情况下，可将乌龟作替代更新养殖品种、但乌龟的养殖技术远落后于甲鱼、大规模人工控温饲养乌龟技术还处于探索阶段。１９９７年１０月至１９９８年１０月在湖北广水特种水产养殖场工厂化养鳖温室内，上海水产大学与该场进行控温饲养乌龟的试验、试验总成活率为６５．３０％，主要是在刚下池１周内死亡较多．死亡乌龟四肢及头颈严重水肿，解剖内脏器官无异常现象。如果不蓄水，１周内无１只死亡，但蓄水后，即使水深只有３０ｃｍ，乌龟很快开始死亡，１周后死亡减少… 相似文献
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一般说来，乌龟的适应性和抗病力都比较强，不易患病。人工养殖时，只要注意随时搞好清洁卫生，常常更换饲养池的水，乌龟一般都不会生病。但有时也会发生如下疾病和敌害： 相似文献
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The technique and sites of blood sampling in the Herman's tortoise (Testudo hermanni hermanni) are explained. Advantages and disadvantages of each site (Vena coccygealis dorsali, Vena ulnaris) are discussed in comparison to cardiac puncture and clipping a nail. The diagnostic importance of blood examination is shown. Normal values of important blood parameters in clinically healthy animals (n = 17) are given, determined by a dry chemistry system (Kodak Ektachem). 相似文献
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We used a red-foot tortoise (Geochelone [Testudo] carbonaria, SPIX 1824) to describe in detail a successful method to induce the expulsion of the ova in tortoises. Apart from the dosage of oxytozine, the importance of the simulation of physiological environmental conditions for oviposition as well as the compensation of a potentially present Ca-deficit (50 mg/kg, Ca-Sandoz 10%, i.p.) is considered. The generally accepted dosage of up to 4 l. U./kg oxytozine, i.p., in tortoises proved to be too low in turtles. The drug dosages and other therapeutic measures against dystocia in different races and families of turtles are specified in tabular form. Finally the causes of dystocia and egg-retainment are discussed. 相似文献
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In a population of about 130 tortoises, consisting mainly of Hermann's tortoises (Testudo hermanni) and Four-toed tortoises (Agrionemys horsfieldii), 50% of the reptiles died within 3 months in autumn 1987. Post mortem analysis of 5 necropsied turtles revealed thick, caseous coatings in the upper digestive tract, hepatomegaly and enteritis. By microbiological examination a lot of ubiquitous bacteria could be isolated. By electron microscopy of concentrated and negatively stained gut specimens herpes virus particles were found in two Hermann's tortoises and one Four-toed tortoise. Isolation experiments in embryonic turtle tissue cultures showed no evidence of a cytopathogenic agent. The results are discussed in respect of their importance for the high mortality observed in the population of mediterranean land turtles. 相似文献
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叙述了青蛙、克氏原螯虾、乌龟、河蟹、黄鳝和泥鳅对钉螺和蚊幼的摄食对比实验，结果表明，它们每天摄食多少顺序为：对钉螺、克氏原螯虾＞乌龟＞河蟹＞青蛙；对蚊纹，乌龟＞克氏原螯虾＞泥鳅＞黄鳝或青蛙＞河蟹，在疫区对金钱蟹和克氏原螯虾进行摄食钉螺的定性观察发现：在放养了实验动物的生态小区内，钉螺种群数量明显减少，通过本实验和近8的年来的研究工作，形成了四种水生动植物净化疫水的生态经济模式；1）芋、蛙、鳝、鳅、蚓、菜；2）莲、菜、龟或鳖、鳝、鳅；3）莲藉、河蟹、泥鳅；4）芦伟或荻、克氏原螯虾或沼虾、泥鳅。 相似文献
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基于12SrRNA序列研究龟鳖类的系统进化特征 总被引：2，自引：0，他引：2
为研究龟鳖类的系统进化关系,以期为龟鳖类的保护和合理开发利用提供基础资料,测定了15种龟类线粒体12SrRNA基因片段的序列。比对后获得一致序列长为433 bp,有191个变异位点,总变异率为43.2%,其中简约信息位点108个。A、T、G、C的平均含量分别为21.46%、34.42%、25.85%和18.27%。A+T含量(55.9%)高于G+C含量(44.2%)。在433个核苷酸位点中,有插入/缺失35个,转换为34,颠换为21,转换/颠换比率为1.67。与NCBI上其它一些龟鳖的序列进行比对后,得到414 bp的一致序列,其中236个为变异位点,总变异率为57.00%;简约信息位点181个。A、T、G、C的平均含量分别为35.7%、22.2%、18.1%、24.0%。A+T含量(57.9%)高于G+C含量(42.1%)。在414个核苷酸位点中,转换为30,颠换为14,转换/颠换比率为2.12。基于Kimura双参数模型分析龟鳖类种间、属间、科间遗传距离,并用邻接法构建分子系统树。结果显示:7种闭壳龟种间差异在0~0.043,平均为0.022;淡水龟科属间遗传距离为0.007~0.140,平均为0.074;曲颈龟亚目9个科间(不包括平胸龟)遗传距离为0.055~0.197,平均为0.139。由此认为,淡水龟科与陆龟科亲缘关系比龟科更近;不支持将闭壳龟属拆分为闭壳龟属和盒龟属;支持将平胸龟属归为鳄龟科的一个属。 相似文献
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乌龟鲍曼不动杆菌的分离鉴定及药敏试验 总被引：2，自引：0，他引：2
自患病乌龟肝脏中分离出1株优势菌DL01221,对其进行形态学观察、生化试验、16SrRNA基因序列分析,同时采用Kriby-Bauer纸片扩散法进行药物敏感性试验。试验结果表明,该菌为革兰氏阴性球杆菌,将该菌株16SrRNA序列进行同源性和系统进化树分析,发现它与鲍曼不动杆菌处于同一群,同源性超过98%,结合菌株形态和生化指标,确定该菌株为鲍曼不动杆菌。致病性试验结果显示,其对乌龟具有较强的致病作用;耐药性结果显示其对头孢他啶、卡那霉素及氟罗沙星敏感,对其他多种抗生素耐药。 相似文献
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Trends in coho marine survival in relation to the regime concept 总被引：2，自引：0，他引：2
There was a synchronous and significant decrease in marine survival of coho salmon in the Strait of Georgia, Puget Sound, and off the coast from California to Washington after 1989. This large-scale, synchronous change indicates that trends in coho marine survivals were linked over the southern area of their distribution in the north-east Pacific, and that these linkages were associated with a common event. Indicators of large-scale climate change (the Aleutian Low Pressure Index) and of recent regional climate change (the April flows from the Fraser River) also changed abruptly about the same time. The synchrony of trends in marine survival of aggregates of coho stocks from three distinct marine areas and trends in climate indices implies that climate/ocean changes can have profound impacts on the population dynamics of coho salmon. The trend towards low marine survival may persist as long as the trends in the climate indicators do not change. 相似文献
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Abstract– Studies were performed with both a mechanical and a photosensory arrangement of the experimental tanks. Silver (migratory) eels were more active than yellow (stationary) eels. Comparison of pooled data on yellow eels tested under natural geomagnetic field conditions with those on eel tested under unnatural ones prcded no evidence of difference in activity. Silver and yellow eels showed stronger activity during the 6 days around new moon compared with the phase around full moon as well as a peak before new moon and a smaller peak before full moon. Under each kind of unnatural field condition, the activity relationships reversed or were cancelled. The directional choice of eels under natural conditions (controls) pointed to magnetic NW and mostly also in the opposite direction. When the magnetic north was changed by 90°, the tested yellow eels followed this change to about the same degree. The additional change of both the inclination (from 68° or 45° or 30°) and total intensity (by a reduction to 31% of the natural field) resulted in a change of the preferences of about 90° relative to magnetic north. Reversal of magnetic north by 180°, which is identical to a change of the inclination from 68° to 112°, also resulted in a change of the preferences by about 90°. Three experiments using compensation of both the horizontal and the vertical geomagnetic field led to circular directional preferences at random in two cases and in one case to about NW of the residual field magnetic north. The navigational abilities of the eel, on the basis of its magnetic sensitivity, are discussed. 相似文献
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Christopher M. Free Tracey Mangin John Wiedenmann Conner Smith Halley McVeigh Steven D. Gaines 《Fish and Fisheries》2023,24(2):248-262
Climate change is altering the productivity of marine fisheries and challenging the effectiveness of historical fisheries management. Harvest control rules, which describe the process for determining catch limits in fisheries, represent one pathway for promoting climate resilience. In the USA, flexibility in how regional management councils specify harvest control rules has spawned diverse approaches for reducing catch limits to precautionarily buffer against scientific and management uncertainty, some of which may be more or less resilient to climate change. Here, we synthesize the control rules used to manage all 507 US federally managed fish stocks and stock complexes. We classified these rules into seven typologies: (1) catch-based; (2) constant catch; (3) constant escapement; (4) constant F; (5) stepped F; (6) ramped F and (7) both stepped and ramped F. We also recorded whether the control rules included a biomass limit (‘cut-off’) value or were environmentally linked as well as the type and size of the buffers used to protect against scientific and/or management uncertainty. Finally, we review the advantages and disadvantages of each typology for managing fisheries under climate change and provide seven recommendations for updating harvest control rules to improve the resilience of US federally managed fisheries to climate change. 相似文献
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2000年7月至9月在山东半岛南部沿海鲐繁殖海域的鱼类养殖网箱中,应用胃含物法测定了渤海优势鱼种鲐的摄食、生态转换效率等生态能量学参数。结果表明,(1)在饵料不受限制时,鲐的摄食量和生长呈不规则波浪式变化,其波距比较恒定,但波高变化较大;(2)鲐的瞬时胃含物重量随时间变化可用指数模型St=9.0876e-0.1868t描述,瞬时排空率Rt=0.1868g·(100g)-1·h-1(按湿重计算);(3)按Eggers公式可求得鲐日摄食量Cd=(15.60±2.55)g·(100g·d)-1(按湿重计算)或(69.84±11.42)kJ·(100g)-1·d-1;(4)实验期间鲐体重随时间的变化可用线性方程Wt=2.23t+16.71描述,由该式可求得其相对平均日生长量Gd=3.72g·(100g)-1·d-1或30.00kJ·(100g)-1·d-1;(5)由于已知的平均日摄食量和平均日生长量,可求得鲐生态转换效率Eg=23.85%(按湿重计算)或42.96%kJ。 相似文献