Past and present state of the ichthyofauna of Lake Lugano

The evolution of the ichthyofauna of Lake Lugano (Lago di Lugano) during the past 120 years is characterized by the introduction of eight new fish species and by the possibly natural addition of the blenny (Blennius fluviatilis) in recent years. Introduced Salmonids such as charr (Salvelinus alpinus) and whitefish (Coregonus sp.) have established strong populations during the first half of this century, but have declined drastically thereafter. Likewise, the population of the native shad (Alosa fallax lacustris) has diminished significantly. A hydroacoustic survey of the pelagic fish stock of Lake Lugano in 1989 revealed the presence of a dense bleak (Alburnus albidus) population at 0 to 14 m depth. No other fish were found to be present in the pelagic zone. Oxygen and temperature distributions seem to confine the bleak to the uppermost layer in summer. In winter, very few fish were located by echosounding. Growth of bleak and roach (Rutilus rubilio) was difficult to interpret since data for comparison are lacking. Growth of perch (Perca fluviatilis) in the littoral zone was found to be slower than in other eutrophic lakes, for no obvious reason. Possible ways of restructuring the pelagic fish community are discussed.     

吉林省大布苏国家重点化石产地的猛犸象-披毛犀动物群

猛犸象-披毛犀动物群是晚更新世时期北半球最具代表性的典型哺乳动物群,该动物群的化石在中国东北地区广泛分布,其演化、发展乃至灭绝与古人类文明的发展有密切的关系。综述猛犸象-披毛犀动物群的概况,从动物组合、古地理分布、古生态环境等方面介绍了该生物群之全貌。以吉林省大布苏国家重点化石产地为例,对该产地出土的猛犸象-披毛犀动物群化石标本进行了最新的统计(分属6目13科21属23种),对其化石组合特征进行了分析,并对在东北地区深入开展该动物群研究的意义进行了探讨。     

长白山玄武岩台地土壤动物多样性及其生态地理分布

于2014年春、夏和秋季对长白山玄武岩台地原始针阔混交林、次生针阔混交林、次生落叶阔叶林及耕地土壤动物进行研究。结果表明：大型土壤动物的多样性,春季次生针阔混交林为最高,夏季和秋季原始针阔混交林为最高,耕地在3个季节均为最低;中小型土壤动物的多样性,春、秋两季原始针阔混交林为最高,夏季次生针阔混交林为最高,耕地在3个季节仍为最低。根据一维方差分析可知春、夏、秋3个季节原始针阔混交林、次生针阔混交林和次生落叶阔叶林土壤动物类群和平均密度均显著高于耕地（p<0.05）;而各生境土壤动物的类群和平均密度季节变化差异不显著（p>0.05）。各生境土壤动物的多样性呈现出随土层深度的增加而降低的趋势。土壤温度、速效P、有机质和土壤湿度的变化是影响长白山玄武岩台地土壤动物多样性地理分布的主要因子。     

西藏羌北地区石炭纪■类动物群及其分带

西藏羌北地区石炭纪■类动物群是笔者等于2004年首次发现的,并将动物群所在层位建立了瓦垄山组,该套地层中产大量的■类化石,种属多,分布连续。经研究,自下而上建立6个■类化石带:(1)Eosta ffella mosquensis带,(2)Millerella-Eostaf fella带,(3)Pseudostaf fella-Eostaf fella带,(4)Pro-fusuliena带,(5)Fusulina-Fusulinella带,(6)Protriticites-Triticites带。该套含竹蜓类化石地层的发现,为研究羌北地区晚古生代构造活动提供了信息,也为研究该区石炭纪地层、古生物、生物古地理、区域性地层划分和对比提供了依据。     

Does groundwater influence the sediment fauna beneath a small, sandy stream?

Gradients in the sediment fauna comprising groundwater (GW) and hyporheic taxa were investigated in the sand/silt-bottomed Marbling Brook in Western Australia. The structure of sediment invertebrate assemblages from Marbling Brook sediments and the adjacent GW were studied at five sites over 1 year and hydrological interactions were characterized using a suite of abiotic factors. Although all five stream sites were upwelling, the sites differed in the degree of hydrological interactions between GW and surface water. Sediment fauna taxa abundances were not correlated with any of the abiotic factors investigated and did not change gradually with depth. Faunal assemblages in the stream sediments were distinct from faunal assemblages in alluvial GW. While water exchanged between alluvial GW and sediment water, as shown by abiotic factors, the distinct differences in faunal assemblages indicated an unpredicted complexity in the catchment with fundamentally different hydrogeological situations on the decimetre scale. Sampling in sandy sediments needs to take this small-scale variability into account.     

Physiochemical conditions of Folsomia candida occurrence in a shallow coastal Lake Michigan aquifer

An insect, Folsomia candida, was found in a shallow aquifer along the southwestern coast of Michigan. F. candida is a standard organism for soil toxicity testing but its occurrence in groundwater is uncommon to rare, or has been under-reported in the literature. Attempts to correlate the presence of F. candida to water and soil parameters yielded: (1) F. candida is present in the upper 15–25 cm of topsoil, but absent in the underlying vadose zone except directly above the water table, regardless of the presence in groundwater; (2) F. candida is most abundant in groundwater 4.3–5.0 m below land surface; (3) Most F. candida occur in wells with dissolved oxygen ranging from 4 to 5 ppm; (4) F. candida is most abundant in water between about 14 and 18°C; (5) F. candida is abundant in groundwater with high concentrations of Cl⁻, Na⁺, and K⁺; and, (6) Small differences in pore space volume determine the feasibility of F. candida occupancy, but not the presence of F. candida in the study area.     

贵州晚二叠世—早三叠世介形虫动物群的演变

贵州有许多二叠系至三叠系的连续剖面，沉积类型多样，生物化石丰富，其中介形虫化石不但类型多，数量也很丰富，保存完好，发展阶段明显。即长兴阶介形虫类型多，数量也多，壳饰复杂，以具瘤刺的为多，早三叠世早期介形虫贫乏，数量及类型都不多，壳饰以光滑或具微细纹饰的为主。根据这些介形虫类型和数量的变化，以及壳饰特征的研究，表明二叠系与三叠系界线附近的介形虫动物群也同其它生物一样发生了重要变化。为二叠－三叠系界线     

西藏羌北地区石炭纪(竹蜓)类动物群及其分带

西藏羌北地区石炭纪(竹蜓)类动物群是笔者等于2004年首次发现的,并将动物群所在层位建立了瓦垄山组,该套地层中产大量的(竹蜓)类化石,种属多,分布连续.经研究,自下而上建立6个(竹蜓)类化石带:(1)Eostaffella mosquensis带,(2)Millerella-Eostaffella带,(3)Pseudostaffella-Eostaffella带,(4)Profusuliena带,(5)Fusulina-Fusulinella带,(6)Protriticites-Triticites带.该套含(竹蜓)类化石地层的发现,为研究羌北地区晚古生代构造活动提供了信息,也为研究该区石炭纪地层、古生物、生物古地理、区域性地层划分和对比提供了依据.     

青岛岩礁附植小型底栖动物ATP含量的研究

2004年10～12月对青岛太平角潮间带2种海藻（鼠尾藻和羊栖菜）上附生的小型底栖动物进行了连续3个月的采样调查,并进行了附植小型底栖动物优势类群和线虫优势种类ATP含量的测定.2种海藻上共采得12个小型底栖动物类群,平均丰度为518.9nds./g dwt algae,海洋线虫和桡足类为优势类群,两者的相对丰度之和大于84%.鼠尾藻上的线虫ATP含量平均为5.57ng/ind.（以下单位相同）,桡足类为4.69;羊栖菜上的线虫ATP含量平均为2.46,桡足类为15.06.共鉴定出海洋线虫28种或分类实体.2种海藻上的线虫优势种类均是刮食食性的三齿棘线虫（Acanthonchus tridentatus）.不同粒级海洋线虫的个体干重为0.14～32.65μg/ind.,ATP含量为1.18～297.64ng/ind.,C/ATP比值为43∶1～99∶1.     

江西修水地区早志留世早期笔石动物群研究

江西修水地区下志留统新开岭组中上部笔石化石自下而上可分为３个带：①Ｐｒｉｓｔｉｏｇｒａｐｔｕｓ ｃｙｐｈｕｓ－－Ｍｏｎｏｃｌｉｍａｃｉｓ带;②Ｐｒｉｓｔｉｏｇｒａｐｔｕｓ ｇｒｅｇａｒｉｏｕｓ带;③Ｍｏｎｏｇｒａｐｔｕｓ带。通过与其它地区同期笔石带对比,发现本区笔石动物群属扬子区和江南区的过渡类型,并且早志留世早期可能存在一定规模的间断。