海豚妈妈痛失爱子

佳偶天成 2004年11月26日,“海洋世界”水族馆的全体员工早早地上班了,今天是一只叫“奇奇”的雌海豚临产的日子。这是一个非同寻常的日子,因为即将出生的小海豚可能成为我国大陆在人工环境下首次成功繁育的海豚。     

养殖鱼类链球菌病病原的分离鉴定及其16S rDNA分析

从患病的海水网箱养殖鱼中分离到5株链球菌,分别命名为HD-1、HD-2、HD-3、HD-4和HD-50。常规生化结果表明,其中4株即HD-1、HD-2、HD-3和HD-4为海豚链球菌(Streptococcus iniae);另外1株即HD-50为停乳链球菌(Streptococcus dysgalactiae)。分别对上述分离菌株的16S rDNA进行PCR扩增和测序,并与NC-BI中收录的其它链球菌的16S rDNA序列一起进行聚类分析并构建了系统发生树,确定其分类地位。分子分析结果与生化鉴定结果一致。攻毒实验表明以上4株S.iniae均能引起罗非鱼发病,呈现典型的链球菌病症状,并能从发病的罗非鱼脑、心、肝肾和血液中成功回收S.iniae。以上生化和分子生物学鉴定以及罗非鱼攻毒实验结果表明养殖鱼类链球菌病的主要病原为S.iniae,这与国外有关鱼类链球菌病病原的研究报道一致。     

海豚相助 鲨口脱险

在墨西哥尤坦半岛以东约35km的太平洋洋面上，有一座风光旖旎、气候宜人的石灰岩小岛，这就是美洲著名的度假胜地科苏梅尔岛。 怦然心动的海底巡游 2006年3月26日，来自美国的路易斯·马丁和他26岁的妻子黛安娜在岛上旅游度假。自从4天前马丁夫妇来到科苏梅尔岛起，他们就一直陶醉在岛上迷人的自然景色之中，每天都兴致勃勃地四处漫游。     

海豚海狮也反恐

由于海洋面积大,防御力量相对薄弱,恐怖分子在海洋上的恐怖袭击越来越多。因此,近年来濒海国家也加强了海上反恐行动。最近,美国海军在一则公报中说,位于西雅图附近皮吉特湾的基策普-班戈海军基地有潜艇、军舰和试验室,     

基于信息熵的改进海豚群算法及其桁架优化

针对基本海豚群算法易陷入局部最优的缺陷,提出了基于信息熵的改进海豚群算法,引入信息熵来度量海豚群搜索阶段的不确定性,控制搜索阶段的选择概率,降低盲目搜索,克服了基本海豚群算法搜索阶段易陷入局部最优和早熟收敛的缺陷。将改进后的算法应用到桁架结构的优化中,并与其他算法优化结果进行了比较,证明了改进的算法在收敛速度和寻优精度方面有更好的表现,将其应用到桁架结构优化设计中,为结构优化设计提供了一种有效的方法。     

海洋中的动物兵

在未来战争中,最能“大出风头”的动物,是海中的海豚、海豹、海狮和鲸等海洋动物。海洋巡逻兵目前,有的国家训练一些鲸、海狮、海豹等海洋动物从事海上导航、巡逻及侦察活动。近年来,美、俄、日等国海军还专门训练鲸、海豹、海狮、海豚等海洋动物去执行深海中的侦察和警戒工作,     

海豚“烹制”墨鱼大餐

最近澳大利亚科学家发现,海豚竟然会“烹制”墨鱼大餐。当时科学家正在海底研究墨鱼的繁殖情况,突然一只海豚猛冲过来,它把海藻丛中的墨鱼赶到海底的宽阔地带,然后用嘴巴叼住墨鱼猛烈地撞击海底;接着它叼着墨鱼尸体在海底不断清洗,直到海水冲刷干净墨鱼体内的墨汁：最后海豚又把可怜的墨鱼在海底沙子中使劲碾磨,直到坚硬的墨鱼骨被剔了出来。这时海豚才开始放心享用“烹制”好的墨鱼大餐。     

Population status, threats and conservation of the Yangtze finless porpoise

The Yangtze finless porpoise （Neophocaena phocaenoides asiaeorientalis） is currently limited to the middle and lower reaches of the Yangtze River from Yichang to Shanghai, China, and the adjoining Poyang and Dongting Lakes. Its population size has decreased remarkably during the last several decades due to the heavy impact of human activities, including overfishing of prey species, water development projects that cause attendant habitat loss and degradation, water pollution, and accidental deaths caused by harmful fishing gear and collisions with motorized vessels. It was estimated that the number of remaining individuals was down to approximately 1800 in 2006, a number that is decreasing at a rate as high as 5% per year. Three conservation measures - in situ and ex situ conservation and captive breeding have been applied to the protection of this unique porpoise since the early 1990s. Seven natural and two ＂semi-natural＂ reserves have so far been established. Since 1996, a small group of finless porpoises has been successfully reared in a facility at the Institute of Hydrobiology of the Chinese Academy of Sciences; three babies were born in captivity on July 5, 2005, June 2, 2007 and July 5, 2008. These are the first freshwater cetaceans ever born in captivity in the world. Several groups of these porpoises caught in the main stream of the Yangtze River, or rescued, have been introduced into the Tian＇e-Zhou Semi-natural Reserve since 1990. These efforts have proven that, not only can these animals survive in the area, they are also to reproduce naturally and successfully. More than 30 calves had been born in the reserve since then, with one to three born each year. Taking deaths and transfers into account, there were approximately 30 individuals living in the reserve as of the end of 2007. Among eight mature females captured in April 2008, five were confirmed pregnant. This effort represents the first successful attempt at off-site protection of a cetacean species in the world, and establishes a solid base for conservation of the Yangtze finless porpoise. A lesson must be drawn from the tragedy of Chinese River Dolphin （Lipotes vexillifer）, which has already been declared likely extinct. Strong, effective and appropriate protective measures must be carried out quickly to prevent the Yangtze finless porpoise from becoming a second Chinese River Dolphin, and save the biodiversity of the Yangtze River as a whole.     

卵形鲳鲹主要致病链球菌多重PCR诊断技术的建立

【目的】快速、准确地检测卵形鲳鲹(Trachinoms ovatus)感染无乳链球菌(Streptococcus agalactiae)、停乳链球菌(Streptococcus dysgalactiae)、海豚链球菌(Streptococcus iniae)和格式乳球菌(Lactococcus garvieae)4种主要的致病菌,为卵形鲳鲹的健康养殖提供依据。【方法】针对4种致病菌的特异基因设计特异性引物cfb-F/cfb-R,tuf-F/tuf-R,Si-F/Si-R,PLG-F/PLG-R,建立多重PCR反应体系,通过调试各引物对之间的最佳比例以及最适退火温度,对反应体系进行优化及灵敏度测试。2014年6~8月,应用该体系对北海及湛江各养殖场的发病卵形鲳鲹进行检测,然后用通用引物扩增16SrRNA基因,经测序、比对检测体系的准确性。【结果】反应体系中cfb-F/cfb-R,tuf-F/tuf-R,Si-F/Si-R,PLG-F/PLG-R的最适浓度分别为0.2μmol/L,0.08μmol/L,1.6μmol/L和0.4μmol/L;最优退火温度为54.3℃;4种目标菌的检测灵敏度为5×10~(-2) ng/μL;11份病原样品检测中,2份出现海豚链球菌的目的条带,4份出现无乳链球菌的目的条带,5份未见目的条带,和测序分析结果一致。【结论】多重PCR方法能代替传统的微生物检测方法特异、快速、灵敏地检测4种致病菌。     

非资源消费型野生动物旅游风险感知研究：澳大利亚班布里海豚探索中心实证

通过对前往澳大利亚班布里海豚探索中心的访客进行调研,运用因子分析、K-means聚类分析、方差分析等定量方法,分析游客对在野外生境中接触海豚的风险感知程度及差异性。通过探索性因子分析,共识别和提取野生动物旅游风险感知量表的3个维度:体验质量风险、舒适性风险和身体安全风险。受访者感知程度最强为体验质量因子,其次为舒适性,最后为身体安全。运用K-means聚类分析方法,依据量表均值得分,将受访者分为3类:弱风险感知、强风险感知和中等风险感知,而样本总体对接触海豚风险感知程度归属为弱风险感知,认为接触海豚是相对安全的活动。通过独立样本t检验和方差分析,对比不同游客特征对野生动物旅游风险感知的差异性。结果发现,人口社会学特征中,除性别外,不同年龄、收入和家庭状况在风险感知程度上均存在显著性差异;旅游行为中,旅游经历、旅行同伴、消费额和停留时间对风险感知具有显著性差异,信息来源途径无显著性差异;满意度和重游意愿对风险感知都具有显著性差异。