河蟹幼体对盐度变化忍受力的初步研究

本试验对河蟹氵蚤Ⅱ～Ⅴ幼体及１～２日龄大眼幼体在盐度变化情况下的忍受力进行了观察，试验结果显示：氵蚤Ⅱ～Ⅲ幼体发育期盐度日降幅不宜大于１‰；氵蚤Ⅳ～Ⅴ幼体发育期盐度日降幅不宜大于２‰～３‰；至１～２日龄大眼幼体阶段盐度日降幅于５‰以下对存活率已无多大影响。     

羊病的一般观察法

<正>羊合群性较强,对疾病的忍受力也强,所以患病初期症状不明显,不易被发现。因此,饲养管理人员要学会识别羊病的技能,对保证羊群健康十分重要。饲养管理人员要经常细心地观察羊群,及时发现病羊,及时治疗,避免造成较大的损失。1.放牧观察健康羊在放牧时总是争先恐后地吃草,而且吃得快,对放牧人员发出的口令反应迅速。     

怎样提高养猪综合效益

1．选择养猪模式 （1）家庭散养适合饲养本地猪我国各地的土种猪一般都具有耐粗饲、耐饥饿、对恶劣环境忍受力强、适合本地气候、抗寒耐热性能好、不易患病等特点。米糠、废弃的饭菜以及野菜野草等都可用来饲喂生猪。如果利用这些物质，再适量投入一些玉米、麸皮等，这样算起来养猪成本还是比较低的。如果只是零散养猪，最好不要饲养瘦肉型猪。     

Strategic studies on the biodiversity sustainability in Yunnan Province, Southwest China

With an area of 394,000 km2 (4.1% of China's total area) and specific diversified geographical environments, Yunnan houses over 18,000 species of higher plants (51.6% of China's total), 1,836 vertebrate species (54.8% of China's total) and multitu-dinous species of rare, endemic and epibiotic wildlife, ranking first in species richness value and endemicity rate of China's biodiver-sity, thus becoming a rare gene bank of wildlife species with the most concentrated distribution of important wildlife taxa and a key terrestrial biodiversity region of global significance. Despite its evident abundance and endemism, however, the biodiversity is faced with threats of ecological fragility and human disturbances in socioeconomic development resulting in attenuation of biodiversity, degradation of ecosystems and serious loss of species, thus, it needs to be carefully studied for its sustainability. Based on the analy-ses of the geographical diversity, the macro material bases of Yunnan's biodiversity were reviewed and six characteristics of the pro-vincial biodiversity were described in the ecosystems, forest types, species compositions, endemic species, genetic resources, etc. By appraising the present status of the provincial biodiversity conservation, the facts that the biodiversity coexisted with fragility were revealed so that eight key disadvantageous factors in the provincial ecological fragility causing serious biodiversity loss were sum-marized and described in this paper. In order to satisfy the two-fold needs of biodiversity sustainability and socioeconomic develop-ment, eight strategies for the sustainable development were intensively elaborated by borrowing certain theories in modern conserva-tion biology, recycling economics and some successful innovations, and by giving comprehensive consideration to the ecological fragility mechanism, nature reserve construction, environmental protection and the exploitability of resources for biodiversity sus-tainability and socioeconomic development. Accordingly, relevant targets, principles, tactics and measures for effective biodiversity conservation and sustainability were suggested to lay a solid theoretical foundation and reliable scientific basis for the biodiversity and socioeconomic sustainable development.     

斑鳜鱼苗对6种常见药物的忍受力实验

用敌百虫、硝酸亚汞、孔雀石绿、硫酸铜和硫酸亚铁合剂、漂白粉、食盐6种药物对斑鳜鱼苗进行毒性实验。测得6种药物在水温21~22℃时对平均全长为(1.0±0.1)cm的斑鳜鱼苗的安全浓度依次分别为0.058、0.046、0.073、0.32和1.747 mg/L。斑鳜鱼苗对敌百虫等6种药物的敏感性与一般养殖鱼类不尽相同,根据已求安全浓度与常见遍洒剂量相比较,得出斑鳜鱼苗对6种药物的敏感性大小依次为:硝酸亚汞>敌百虫>孔雀石绿>硫酸铜合剂>漂白粉>食盐。