The histology of dermal glands of mating Breviceps with comments on their possible functional value in microhylids (Amphibia: Anura)

During mating male and female Breviceps become ‘glued’ together. The distribution of multicellular dermal glands varies between the sexes. The mate has a large number of holocrine glands on the ventrum, while the female has similar glands on the dorsum of the back. II thus appears that both sexes contribute to the ‘glueing’ mechanism. New hypotheses to explain the adhesion between the sexes are proposed, viz., that the shift to terrestrial habils and subterranean laying in Breviceps have secondarily resulted in male si2e diminution. In other microhylids which adhere during aquatic oviposition, yet demonstrate a terrestrial morphology and habits, bouyancy is suggested to be of primary functional value.     

枝角类生态毒理学研究进展

对枝角类生态毒理学研究作了概述,主要包括枝角类生态毒理学研究常用种类、生态毒理学研究的领域、毒性试验常用方法,分析了目前枝角类生态毒理研究存在优点和不足,指出其生态毒理学研究需要加强的方面.     

中国枝角类一新记录种（甲壳纲：双甲目）

本文描述了采自江西省的一种枝角类——网纹盘肠蚤,为我国的新记录种。     

克氏原螯虾几种动植物饵料的培育

针对克氏原螯虾天然性饵料的合理利用问题,阐述了几种适于克氏原螯虾养殖的常用动植物饵料及其培育技术,具体包括小浮萍移植、采收、日常管理和防病除害,伊乐藻的栽培与栽后管理,红虫的施肥培育与捞取等,为克氏原螯虾养殖生产提供借鉴。     

Does synergized pyrethrin applied over wetlands for mosquito control affect Daphnia magna zooplankton or Callibaetis californicus mayflies?

BACKGROUND: Public health agencies may apply aerosolized synergized pyrethrin over wetlands repeatedly to control mosquitoes. This concerns wildlife managers because studies have shown the accumulation of pyrethroids, which are chemically similar to pyrethrin, in sediments in amounts that can be toxic to invertebrates. The authors tested whether repeated applications of synergized pyrethrin over wetlands caused mortality of two aquatic invertebrates: the zooplankton Daphnia magna Straus and a mayfly, Callibaetis californicus Banks. Fifteen wetland mesocosms were either exposed to repeated pyrethrin sprays or were protected by lids. Invertebrates in screened cages were placed in mesocosms before the fifth and eleventh spray, and directly into wetlands before spray 11. Six mesocosms were exposed to spray deposition. Caged adult mosquitoes were used to verify that sprays drifted over mesocosms. Sediments were analyzed for insecticide residues.RESULTS: There were no detectable effects of synergized pyrethrin on 36 h survival of Daphnia or mayflies, but most exposed adult mosquitoes died. Some exposed sediments yielded pyrethrin (< or =34.5 ng g(-1)); most showed piperonyl butoxide (PBO) (< or =14.9 ng g(-1)).CONCLUSIONS: Deposition of aerosolized 25% pyrethrin + 5% PBO may contaminate wetlands, but its application at rates used for mosquito control did not produce detectable effects on indicator species.     

三峡水库澎溪河库湾枝角类的种类组成与时空分布

为了解澎溪河枝角类的种类组成、时空分布特点以及三峡水库蓄水对库湾回水末端区域枝角类的影响,为防治三峡水库富营养化和水华发生提供基础资料,于2013年3月(春季)、6月(夏季)、9月(秋季)、12月(冬季)对澎溪河库湾6个断面(河口、双江、黄石、高阳、养鹿和渠口)的枝角类进行了调查。结果显示,4次采样共采集到枝角类7属、7种,透明溞(Daphnia hyalina)、简弧象鼻溞(Bosmina coregoni)、短尾秀体溞(Diaphanosoma brachyurum)为全年优势种,优势度值分别为0.330、0.128、0.034;受上游2个断面(养鹿和渠口)3月份枝角类的影响,澎溪河库湾春、夏、秋、冬枝角类密度(65.9、17.4、4.0、0.6个/L)呈递减趋势,生物量(20.6436、0.6772、0.1072、0.1469 mg/L)基本呈递减趋势;从下游至上游,澎溪河库湾河口、双江、黄石、高阳、养鹿、渠口采样断面枝角类密度(0.5、1.4、11.4、18.8、50.3、49.6个/L)和生物量(0.0348、0.0528、0.6230、1.1538、15.1529、15.3450 mg/L)呈递增趋势。     

Gammarus aequicauda and Moina salina in the Crimean saline waters: New experimental and field data on their trophic relation

Gammarus aequicauda (Amphipoda) and Moina salina (Cladocera) are dominant species and promising objects for aquaculture in hypersaline lakes. In the Crimean hypersaline lake Moynaki, population dynamics of their abundance was studied and experiments on feeding were also done. In 2018 and 2019, the average concentrations of G. aequicauda and M. salina differed between the thickets of sea grass Ruppia and the areas without Ruppia. The concentration of G. aequicauda in the thickets was on average from 52 to 126 times higher than in the Ruppia‐free areas. Moina demonstrated the opposite trend. There was a significant negative correlation between the abundances of these species in the Ruppia thickets (R = ?0.746, p = .005). The experimental results on trophic relation showed that the amount of Moina eaten by one G. aequicauda varied from 0.04 to 9.80 ind./hr and depended on the average Moina concentration. Calculation showed that the gammarid population consumed about 1.0%–1.5% of available preys per day. Gammarids were able to graze up to 60%–65% of the Moina population in 10 days. To develop integrated multi‐trophic aquaculture in saline/hypersaline waters, character of ‘gammarus–moina’ trophic relation and the biological peculiarities of these species must be taken into account.     

基于枝角类和桡足类多样性的白洋淀水环境监测与评价

雄安新区的建立促使白洋淀水环境及生物资源监测与保护尤为重要。为研究白洋淀枝角类和桡足类群落结构时空变化特征及与水环境因子的相互关系,运用典型相关分析（canonical correlation analysis ,CCA）对2019年春季、夏季、秋季所测定的白洋淀枝角类和桡足类丰度、多样性指数及水环境因子进行多元统计分析。基于DNA条形码技术鉴定出白洋淀枝角类和桡足类共8 科17属26种,全年分布的优势种有简弧象鼻溞（Bosmina coregoni）、透明温剑水蚤（Thermocyclops hvalinus）和胸饰外剑水蚤（Ectocyclops phaleratus）。丰度和生物多样性指数特征存在时空差异,主要表现为区域性分布变化大于季节性变化,且在空间上均表现为南部区域大于北部区域。枝角类和桡足类与水环境相关性结果表明,温度（T）、透明度（TMD）、营养盐等通过影响枝角类和桡足类生长发育、摄食、繁殖等活动来调节其丰度及群落组成结构特征,而S、Pb、Zn为关键影响因子,对枝角类和桡足类丰度呈显著负相关。对白洋淀进行长期的物种研究和生态环境监测及保护,可以为水利工程实施和雄安新区建设提供参考,实现资源可持续利用和发展。     

水库中枝角类种群数量变化与环境因子的关系

对山东枣庄郭村水库中枝角类的种群数量变化进行定性和定量研究,探讨了不同环境因子对枝角类的影响。结果表明：枝角类的数量与水温、PH值和溶氧呈显著正相关关系。