Serological survey for evidence of Leptospira interrogans in free-living platypuses (Ornithorhynchus anatinus)

Objective   To survey free-living platypuses for evidence of Leptospira interrogans .
Methods   A serological study of Leptospira antibodies was carried out on 21 platypuses captured between May and October 2001 in the Wollondilly River 200 km south of Sydney, New South Wales.
Results   Positive reactions, all to the L Hardjo serovar, were seen in 14 (66%) of the captured animals, with adult males showing a higher prevalence of antibodies than adult females. Several individual platypuses showed a high titre of L Hardjo antibodies, and some animals demonstrated cross-reactions to the serovars L Medanensis and L Kremastos.
Conclusion   The serological findings demonstrate that these animals are constantly exposed to infection with Leptospira in their environment, but it is not known if platypuses suffer from clinical leptospirosis or if they mount an immune response, but are unaffected by the bacteria. The prevalence of Leptospira infection among the platypus population could not be precisely estimated because of the unknown number of individuals inhabiting the Wollondilly River inside the survey property. Domestic livestock, mostly cattle, may be the major source of Leptospira infection. The effects of this disease on population dynamics and on reproduction in wild platypuses are not well understood. The role of other wildlife in the transmission and maintenance of Leptospira in the environment is unknown.     

河南境内四水系宽鳍鱲野生群体的遗传多样性

为准确掌握河南野生宽鳍鱲(Zacco platypus)群体遗传结构,本研究利用线粒体CO I基因检测了海河、黄河、淮河和长江水系宽鳍鱲群体的遗传多样性和种群分化情况。110个样品共检测出40个单倍型,平均单倍型多样性为0.92077,平均核苷酸多样性为0.02439。AMOVA分析显示,大多数遗传变异存在于宽鳍鱲群体间(60.59%),群体内的遗传变异为37.67%。系统发育树结果表明,长江水系宽鳍鱲群体遗传分化较大,一部分群体单独聚为一支,另外一部分群体与海河、黄河、淮河水系宽鳍鱲聚在一起,没有显示出明显的南北分化格局。种群历史动态结果推测宽鳍鱲群体经历过瓶颈效应,且该过程可能与第四纪中更新世气候波动有关。建议对河南境内的宽鳍鱲种群,特别是遗传多样性低的种群(海河水系)进行保护。     

Seasonal dynamics and yearly change in the abundance of metacercariae of <Emphasis Type="Italic">Parabucephalopsis parasiluri</Emphasis> (Trematoda: Bucephalidae) in the second intermediate host in the Uji–Yodo River,central Japan

An introduced pathogenic fish trematode, Parabucephalopsis parasiluri Wang, 1985 (Digenea: Bucephalidae), was studied to determine the seasonal fluctuation in its metacercariae abundance. The timing of the recruitment period of the metacercariae and the relationship between yearly fluctuation in metacercarial abundance and some environmental factors were also examined to develop an effective plan for disease control. Monthly changes in metacercarial abundance in the caudal fin of pale chub (Zacco platypus) and of the prevalence of the first intermediate host (golden mussel Limnoperna fortunei) suggest that P. parasiluri generally has an annual life cycle. The metacercarial abundance in chub increased when the water temperature fell below 7°C in winter, but the rapidity of the increase varied between 2007 and 2008. The fluctuations in the abundance of metacercariae in winter from 2001 to 2008 showed that mean flow rate and mean water level in January were negatively related to the infection level each year, and positively related to the mean water temperature. Based on these results, we propose a control plan for parabucephalopsiosis involving discharge control; that is, more than 50 m³/s (corresponding to 150 m³/s in the Yodo River) of water should be flushed from upstream dams for a period of at least one week starting on the day when the water temperature falls below 7°C.     

野生粗柄侧耳的生物学特性及其人工栽培

2004年9月首次实现了云南野生真菌粗柄侧耳的人工栽培.研究结果表明,野生粗柄侧耳菌丝生长最适温度为19～24℃,最适pH为5～6,而子实体发生最适温度为12～18℃,空气相对湿度80%～90%.适宜于该种人工栽培的常规培养料由锯末、棉子壳和碳酸钙组成.     

甬江溪口段宽鳍鱲的种群结构及繁殖力初步研究

利用鱼类种群调研法,于2015年8月至2016年4月在甬江溪口段收集宽鳍鱲(Zacco platypus)个体样本,研究该区域宽鳍鱲种群的年龄组成、性比、个体大小以及繁殖力等种群结构生物学特征。结果表明:(1)调查期间甬江溪口段宽鳍鱲种群由3个年龄组组成,其中2龄为优势年龄组;雄性个体中2龄组占雄体总数的55.5%,雌性个体中的2龄组占雌体总数的63%;(2)宽鳍鱲全长(L)的分布区间为7.0～14.0 cm,8.0～12.0 cm的个体占总数的87.83%;(3)体重(W)分布范围为4.0～36.0 g,其中体重5.0～13.0 g的个体占总个体数的72.75%;(4)根据不同性别(性别难辨、雌、雄、群体)拟合体重与体长的幂函数关系式:W_(ui)=1×10~(-4)L~(2.4917)、W_♀=2×10~(-5)L~(2.9337)、W_♂=3×10~(-5)L~(2.8471)和W=4×10~(-5)L~(2.8035);(5)雌雄个体比例127∶238与理论值1∶1存在极显著差异(P0.01);(6)重量法计数得出种群个体的绝对繁殖力平均值为(2 850.39±2 107.49)粒,分布区间为532.00～13 717.89粒,其中1 000～3 000粒占绝对优势(65.12%);个体体长相对繁殖力为(354.39±234.47)粒/cm,分布区间74.93～1 541.34粒/cm;体重相对繁殖力平均值为(363.73±178.55)粒/g,分布区间为91.25～1 027.56粒/g;比较了国内外不同地区间宽鳍鱲种群结构和繁殖力的异同。     

白洋淀流域宽鳍鱲遗传多样性及种群历史动态

基于线粒体Cytb和COI基因联合,对白洋淀流域沙河和拒马河宽鳍鱲种群遗传多样性及种群历史动态分析。结果表明：141个样本中检测出45个单倍型,种群间共享单倍型有2个。拒马河种群的单倍型多样性与核苷酸多样性(h=0.7120,π=0.01182)均高于沙河种群(h=0.4514,π=0.00313)。AMOVA分子方差分析、种群间遗传分化指数(FST)及系统发育树均表明2个种群间未出现明显分化,种群内变异(96.43%)大于种群间变异,种群之间存在较大的基因流(6.745)。中性检验、错配分析显示沙河种群和拒马河种群未经历过种群扩张,贝叶斯天际线点图显示沙河种群保持稳定,拒马河种群在0.004Ma前经历了种群扩张。白洋淀流域宽鳍鱲有效种群在0.175~0.125Ma前经历种群扩张,后维持稳定。结合单倍型网格图及系统发育树分析,沙河种群经历过奠基者效应。参考鲤科鱼类Cytb基因0.84%~1%/Ma的进化速率,2个地理种群的分歧时间为0.089~0.067Ma前。     

Preliminary investigation into the prevalence of mucormycosis in the platypus (Ornithorhynchus anatinus) in three catchments in north-west Tasmania

Objective To investigate the distribution and prevalence of mucormycosis in platypus (Ornithorhynchus anatinus) from the Inglis, Emu and Black-Detention catchment areas in north-west Tasmania. Procedure A field study was performed and resulted in the examination of 44 wild platypuses; in addition, one dead platypus and two live platypuses were examined after they were independently submitted to a local veterinary clinic. Results No cases of mucormycosis were conclusively diagnosed. One platypus with signs consistent with those previously described in cases of mucormycosis was captured in the Emu River catchment. However, laboratory tests did not provide a definitive diagnosis for the lesion. Two platypuses from the Inglis catchment area had signs very similar to those previously described in cases of mucormycosis, but laboratory tests found Corynebacterium ulcerans to be the likely cause of the cutaneous ulcers on one of these platypuses and an unidentified fungal agent to be the cause of a cutaneous nodule in the other. Conclusions These findings do not prove that mucormycosis is absent from the populations studied. However, they may indicate that the prevalence of disease is low. The possibility that Mucor amphibiorum is present in a subclinical form in platypuses, or infecting another reservoir, is not excluded. The findings also suggest that caution should be exercised when diagnosing mucormycosis based on clinical findings alone and raise the possibility that some cases may have been incorrectly diagnosed.