SOME REMARKS ON CHENJIAWO FAUNA──On the First Appearance of Peking Man Fauna

I.CORRELATIONBETWEENL0ESSSECTI0NAND0XYGENIS0TOPESTAGESIntheYuanloessarea,manyscientiststhinkthatthesedimentsarecontinuousandtheclimaticrecordsareperfect.Thisdoesnotappeartobeaccurate.Sedimentationwasdiscontinuousinmanysections.Forexample,manyscientistsarguethatS2corresp0ndstooxygenisot0peStage7(Liu,l985,KuklaandAn,l989;Dingetal.,l990).lnfact,S2includesthreelayersfS2SSl,S2LLlandS2SS2.Dingetal.(l990)reportedthatthereisathickunitofloessbetweenS2SSlandS2SS2intheBaicao…     

秸秆还田对耕作黑土中小型土壤动物群落的影响

为了考察秸秆还田对耕作黑土中土壤动物群落结构的影响,2009年到2011年在黑龙江省海伦市进行了定点实验,调查了样地A(17kg秸秆+含高浓度催腐剂还田)、样地B(8.5kg秸秆+含低浓度催腐剂还田)、样地C(对照样地),样地D(8.5kg秸秆还田),样地E(17kg秸秆还田)的中小型土壤动物群落结构。共获取中小型土壤动物21779只,分别隶属于58个类群。其中,甲螨亚目、姬跳虫科、棘跳虫科与驼跳科4个类群土壤动物在本地区是最适应环境变化的土壤动物类群。土壤动物群落结构分析表明,对照样地C中土壤动物密度最高(46591.67只/m~2),土壤动物类群最多(17.17),土壤动物优势度指数最大(0.37),样地D中土壤动物丰富度指数最多(2.63),样地A中土壤动物多样性指数最高(1.72),样地B中土壤动物均匀性最高(0.64)。同时,各样地土壤动物基本都具有表聚性,样地A中土壤动物更趋于生存于上层土壤。综合比较分析表明,样地A秸秆还田方式相对来说最利于土壤动物生存。主成分分析表明,不同秸秆还田方式对土壤动物密度、甲螨亚目动物类群、节跳虫科类群、前气门亚目类群影响较大,是耕作黑土中对秸秆还田方式反应敏感的土壤动物指标,今后可以作为考察耕作黑土秸秆还田肥力效应的评价指标。另外,CAA分析表明:受土壤环境因子影响较大的土壤动物类群多为研究区域内优势类群与常见类群,土壤动物的密度与土壤中有机质、有机碳、碳氮比与全磷的含量关系最为密切。     

玉米-大豆间作和施氮对红壤地中小型土壤动物群落特征的影响

通过2年田间定位试验(2013—2014),利用干漏斗法收集土壤中小型动物,探讨不同种植模式(玉米单作、玉米大豆间作、大豆单作)和施氮(0、150 kg·hm^-2)对红壤土壤动物数量和群落结构的影响.结果表明: 两年取样共捕获土壤中小型动物8349只,分属3门10纲29目,优势类群为蜱螨目和弹尾目.2013年间作和施氮均提高了玉米拔节期土壤动物的平均密度.2014年土壤动物类群数较2013年有明显的增加,施氮条件下的土壤动物平均密度较不施氮有所增加.两年多因素方差分析结果表明,种植模式和生育期对土壤动物平均密度、类群数和多样性指数都无显著影响.但在2014年,施氮显著影响了土壤动物类群数、Simpson指数和密度-类群指数;种植模式与玉米生育期的交互作用显著影响了土壤动物平均密度和类群数,同时对密度-类群和丰富度指数也有显著影响;施氮和生育期的交互作用显著影响了Simpson指数、密度-类群指数和Shannon指数.从两年的土壤动物群落去趋势分析结果来看,红壤地土壤动物群落在种植模式和施氮水平之间均没有明显的差异,群落组成的变化与玉米生育期相关.合理施氮条件下的玉米-大豆间作模式有利于提高红壤地土壤中小型动物平均密度和类群数,保持较好的多样性.     

Documentation of the presence of Gmelinoides fasciatus (Stebbing, 1899) and the native benthic fauna in the Volga River at Tver (Tver Region,Russia)

In the Volga Basin, the small Baikalian amphipod Gmelinoides fasciatus was introduced in 1965 into the Gorky reservoir in order to enhance fish production; it appeared in 1986 in the Rybinsk reservoir and we recorded it during monitoring activities in 2006 at Tver. In total, at the monitoring site Tver/Migalovo 69 benthic invertebrate taxa were identified. We compared data from three summer seasons. During summer low flow period Gmelinoides fasciatus did not exceed a share of 12.6% considering individual (ind) densities (mean abundance 165 ± 104 ind m^?2) and 14.2% considering biomass (mean biomass 0.39 ± 0.44 g m^?2). Abundances and biomass of G. fasciatus were shown to be stable over three years and no increase was observed. The monthly dataset (March–November 2008) revealed dynamics in relation to the native benthic communities and it was shown that the maximal densities of Gmelinoides did not exceed 587 ind m^–2. Understanding the effects on benthic communities caused by the invasive amphipod Gmelinoides fasciatus is crucial in order to predict further developments in European inland waters and to establish management strategies.     

Invasion of an indigenous Perna perna mussel bed on the south coast of South Africa by an alien mussel Mytilus galloprovincialis and its effect on the associated fauna

The introduced mussel Mytilus galloprovincialis is progressively increasing in abundance along the south coast of South Africa. Quantitative 0.1 m² samples were collected in the mid-zone of an indigenous Perna perna mussel bed in the 1980s prior to the arrival M. galloprovincialis (12) and in the 2000s during the M. galloprovincialis invasion (16). In addition, in situ counts of M. galloprovincialis were done on eight occasions between 1993 and 2005, and in the low- and high-zones on four occasions. In the mid-zone M. galloprovincialis was absent until 1987, its mean densities were low (< 15 individuals/0.1 m²) between 1993 and 1996, but thereafter increased steadily, peaking in 2004 (at 721 individuals/0.1 m²), before declining in 2005 (331 individuals/0.1 m²). The greatest densities of M. galloprovincialis were recorded at the high-zone (1121 individuals/0.1 m²) and the smallest in the low-zone. As M. galloprovincialis numbers increased, there was an associated, but smaller decline in P. perna numbers and the overall density of mussels increased significantly (P < 0.05). No major change was recorded in the size composition of P. perna. The density of associated fauna differed significantly (P < 0.01) between sampling dates with the lowest and highest values being recorded near the ‘beginning’ (2001) and ‘end’ (2005) of the invasion period respectively. These differences were largely due to variations in the density of barnacles, and the toothed barnacle Chthamalus dentatus appeared to be the only associated faunal species that was directly affected by the M. galloprovincialis invasion, experiencing a significantly (P ≤ 0.05), but temporary decline in density and biomass values.     

Studies of oogenesis in the rotifer,Asplanchna

Summary Oocyte development in Asplanchna brightwelli was studied by observation through the transparent body wall of living females and by electron microscopy. During oogenesis, which requires four to six hours, the oocyte increases in volume approximately 1000-fold. Most of its cytoplasm appears to be derived from the vitellarium by direct flow through the cytoplasmic bridge. This flow is rapid enough to be easily observed in the living female at low magnifications. Ribosomes, mitochondria, cortical granules, and lipid droplets were observed in the bridge area in electron micrographs.RNA synthesis during oogenesis was studied by means of autoradiography. Very little synthesis could be demonstrated in oocyte nuclei at any period of oogenesis, whereas the vitellarium nuclei show active incorporation of ³H-uridine throughout the reproductive life of the adult female. Most of this RNA is subsequently transferred to developing oocytes.This research was supported by USPHS Grant GM 121183 to Dr. C. W. Birky, Jr.     

The phlebotomine sandflies of Venezuelan Amazonia

Phlebotomine sandflies were surveyed in two ecologically contrasted areas, the northern moist and southern wet tropical forests, of the Territorio Federal Amazonas, Venezuela. Three new taxa and twenty-one new records were added to the previously known species list for Venezuelan sandflies, which now totals eighty species. Both sexes of Lutzomyia (Psychodopygus) killicki sp.n., L. (Trichophoryomyia) bettinii sp.n., L. (Nyssomyia) olmeca reducta subsp.n. and and the females of L. bernalei Osorno et al., Brumptomyia pintoi Costa Lima and L. begonae (Ortiz & Torres) are described and illustrated.     

A set of microsatellite primers for the striped possum,Dactylopsila trivirgata (Petauridae: Marsupialia)

The New Guinean endemic dactylopsilines are members of the Petauridae possum family, represented in Australia only by the striped possum Dactylopsila trivirgata. The shy nature and low density of this species have hampered studies of its ecology to date, so we developed nine highly variable polymorphic microsatellite markers to enable molecular genetic analysis of population structure and mating system parameters. This will add substantially to our understanding of the behavioural ecology of this species. The low degree of cross‐amplification of the primers in other petaurid species lends weight to other evidence suggesting that this family underwent a relatively early radiation.