Exceptionally well-preserved giant spermatozoa in male and female specimens of an ostracod Cypria ophtalmica (Crustacea: Ostracoda) from Late Glacial lacustrine sediments of Southern Carpathians, Romania

Exceptionally well-preserved giant spermatozoa observed between abundant decalcified carapace valves of ostracods (Crustacea: Ostracoda) were found in Late Glacial to Holocene (14,400 to 10,000?cal?years bp) lacustrine sediments in the southern Romanian Carpathians. Analysis by scanning electron microscopy and laser scanning confocal microscopy revealed good preservation of the appendages enabling specific identification as Cypria ophtalmica (Candonidae) and indication of the presence of both female and male specimens based on the sexual dimorphism of the second antenna. This record represents the oldest and richest direct evidence of virtually morphologically unaltered animal spermatozoa preserved in females after mating.     

Introgressive Hybridisation als Evolutionsfaktor bei den Gattungen Bosmina und Daphnia (Crustacea,Cladocera)

The Science of Nature -     

蛀木生物钻刺团水虱是否改变红茄冬红树林的分布形状?

为了评价东非不同空间尺度(1m尺度～l00km尺度)红树林分布区等足类甲壳动物蛀木虫钻刺团水虱(团水虱属)在美国红树红茄冬气生根中出现的情况,进行了野外调查研究.     

蛀木生物钻刺团水虱是否改变红茄冬红树林的分布形状?

为了评价东非不同空间尺度(1m尺度～l00km尺度)红树林分布区等足类甲壳动物蛀木虫钻刺团水虱(团水虱属)在美国红树红茄冬气生根中出现的情况,进行了野外调查研究.     

Evolution through cold and deep waters: the molecular phylogeny of the Lithodidae (Crustacea: Decapoda)

The objectives of this work are to use gene sequence data to assess the hypothesis that the Lithodinae arose from ancestors with uncalcified abdomens in shallow waters of the North-East Pacific, investigate the monophyly and interrelationships of genera within the Lithodinae and to estimate the scale and minimum number of biogeographic transitions from the shallow environment to the deep sea and vice versa. To do this, phylogenetic analysis from three mitochondrial and three nuclear markers was conducted using minimum evolution, maximum likelihood and Bayesian methods. The Lithodinae as defined to include North Pacific genus Cryptolithodes may be paraphyletic, with the Hapalogastrinae and Cryptolithodes as sister taxa. This implies that the soft-bodied abdomen of the Hapalogastrinae might not be plesiomorphic for the Lithodidae. Paralomis, Lopholithodes, Phyllolithodes, Lithodes and Neolithodes share a common ancestor, from which the North Pacific Hapalogastrinae did not descend. Lithodid ancestors are likely to have had a north Pacific, shallow water distribution and to have had planktotrophic larvae. North Pacific genus Paralithodes is paraphyletic; P. brevipes is the most basal member of the genus (as sampled) while P. camtschaticus and P. platypus are more closely related to the genera Lithodes and Neolithodes. Genera Lithodes, Neolithodes and Paralomis (as sampled) are monophyletic if Glyptolithodes is included within Paralomis. Lopholithodes is closely related to, but not included within, the Paralomis genus. Paralomis is divided into at least two major lineages: one containing South Atlantic, West African, and Indian Ocean species, and the other containing Pacific and South American species. Several species of Paralomis do not resolve consistently with any other groups sampled, implying a complex and possibly rapid global evolution early in the history of the genus. Relationships within the Lithodes genus vary between analytical methods, suggesting that conclusions may not be stable. Consistently, however, Indian Ocean and Pacific forms—L. murrayi, L. longispina and L. nintokuae form a group separated from Atlantic species such as L. santolla, L. confundens, L. maja and L. ferox.     

黑龙江省莲花山第四纪火山

本文论述了黑龙江省莲花山火山的火山景观、喷发时代、岩石学和岩石化学、构造和经济地质。根据莲花山火山石龙岩同位素测年和第四纪地层层序资料,其喷发时代属早更新世。新取得的岩石的稀土元素、微量元素、幔源包体和巨晶资料表明其岩性和五大连池相似,又略有差别。作者认为莲花山和尖山为五大连池火山往-西南的延伸。广义的五大连池火山群包括五大连池、莲花山和尖山,共21座火山锥。     

中国第四纪黄土古环境研究若干进展

随着技术进步和多方位研究进展,第四纪古环境研究向着多元古环境替代指标、高分辨率古气候研究、气候变化的多种驱动因素等方面发展。文章总结了中国黄土古环境研究中的主要替代性指标,包括黄土磁化率、黄土粒度、植物硅酸体、孢粉组合、蜗牛化石、碳氧同位素和^10Be、黄土与古土壤。概述了当前对黄土—古土壤的时间标尺、末次冰期的短尺度气候事件以及东亚古季风变化机制的认识。     

辽宁省第四系地下水库勘察规划

通过分析辽宁省水资源的供需现状、基础地质气候条件以及重点对第四系河谷的野外实地调查,同时根据地方经济的发展趋势、地下水库的功能,论证了辽宁省地下水库开发的必要性和可行性,指出该省的下辽河平原、辽西部分山问河谷、辽西辽南的滨海河谷适宜修建地下水库,并制定了第四系地下水库勘察规划,即把辽宁省规划为5个地下水库勘察区(地下水库已勘察区或建成区、近期地下水库勘察区、中期地下水库勘察区、远期地下水库勘察区、未规划地下水库勘察区).     

Ultrastructure of spermatozoa of <Emphasis Type="Italic">Onthophagus taurus</Emphasis> (Coleoptera,Scarabaeidae) exhibits heritable variation

Sperm competition is thought to be an important selective pressure shaping sperm form and function. However, few studies have moved beyond gross examinations of sperm morphology. Sperm length is subject to sexual selection via sperm competition in the scarab beetle Onthophagus taurus. Here, the structure and ultrastructure of spermatozoa in this species were investigated using light and electron microscopy. Spermatozoa were found to be filiform, measuring about 1,200 mm in length. The sperm head consists of a three-layered acrosome and a nuclear region bearing the anterior extension of the centriole adjunct. Acrosome and nuclear regions are bilaterally symmetric, with their axes of symmetry being orthogonal to each other. Head and flagellar structures are connected by a well-developed centriole adjunct. The sperm heads are asymmetrically surrounded by accessory material and embedded into the cytoplasm of the spermatocyst cell. The accessory material is produced inside the spermatids and then transferred to the outside due to a new membrane formed around the sperm’s organelles. The old spermatid membrane separates the accessory material from the cyst cell. The flagellum contains a 9+9+2 axoneme, two accessory bodies, and two mitochondrial derivatives of unequal size. The major mitochondrial derivative is significantly larger than the minor one. The axoneme is arranged in a sinusoidal manner parallel along the major mitochondrial derivative. The spermatozoa show no progressive motility when released in buffer solution which is likely to be the result of the flagellar arrangement and the structure of the major mitochondrial derivative. The cross-sectional area of the minor and the major mitochondrial derivatives show different patterns of genetic variation. The data provide the first estimates of genetic variation in sperm ultrastructure for any species, and give evidence for the persistence of genetic variation in ultrastructure required for the rapid and divergent evolution that characterizes spermatozoa generally.     

安丘-莒县断裂莒县盆地段晚第四纪以来的活动特征

野外调查研究结果表明，安丘-莒县断裂莒县盆地段是一条晚第四纪以来强烈活动的断层。根据断层走向、活动时代及活动性质的变化，可分为两段。董家坡-武家曲坊段和武家曲坊-太湖段，总长度约30km。从滑动速率的分布来看，董家坡-武家曲坊段全新世早期右旋水平滑动速率为1．83mm／a，垂直滑动速率大约为0．37mm／a；全新世晚期右旋水平滑动速率为0．86mm／a，垂直滑动速率大约为0．17mm／a。武家曲坊-太湖段晚更新世早期断裂右旋水平滑动速率为2．78mm／a，垂直滑动速率为0．65mm／a。全新世晚期右旋水平滑动速率为1．37mm／a。垂直滑动速率为0．18mm／a。上述资料表明，安丘-莒县断裂带盆地段的断裂活动无论是时间上还是空间上都有差异，晚更新世以来断裂的活动性有减弱的趋势，全新世时期断裂的活动北段比南段强。     

安丘-莒县断裂莒县盆地段晚第四纪以来的活动特征

野外调查研究结果表明,安丘-莒县断裂莒县盆地段是一条晚第四纪以来强烈活动的断层.根据断层走向、活动时代及活动性质的变化,可分为两段.董家坡-武家曲坊段和武家曲坊-太湖段,总长度约30km.从滑动速率的分布来看,董家坡-武家曲坊段全新世早期右旋水平滑动速率为1.83mm/a,垂直滑动速率大约为0.37mm/a;全新世晚期右旋水平滑动速率为0.86mm/a,垂直滑动速率大约为0.17mm/a.武家曲坊-太湖段晚更新世早期断裂右旋水平滑动速率为2.78mm/a,垂直滑动速率为0.65mm/a.全新世晚期右旋水平滑动速率为1.37mm/a.垂直滑动速率为0.18mm/a.上述资料表明,安丘～莒县断裂带盆地段的断裂活动无论是时间上还是空间上都有差异,晚更新世以来断裂的活动性有减弱的趋势,全新世时期断裂的活动北段比南段强.     

浙江宁波地区Z03孔第四纪磁性地层研究

浙江宁波地区第四纪以来沉积了较大厚度的海陆交替沉积物,对其进行划分和对比,对研究该区第四纪地层至关重要。宁波南部滨海平原Z03孔揭示该区伴随多次海侵—海退,形成数个沉积旋回,其岩性多变,沉积相复杂。文章通过对Z03孔进行磁性地层研究,结合钻孔岩性特征、光释光测年和~(14)C测年数据,建立可靠的磁性地层框架。结果显示,Z03孔所有样品均位于布容正向时内,且包含了3个全球性极性漂移事件和1个地方性亚时,自下而上分别为布莱克事件、拉尚事件、哥德堡事件以及宁波亚时;80.0~87.0 m样品记录了中更新世和晚更新世之交的布莱克事件,上更新统底界定于79.2m处;42.2~44.0m样品记录了拉尚事件;21.0~23.0m样品记录了全新世和更新世之交的哥德堡事件,全新统底界定于23.6m处。     

淮河流域平原区第四系含水层划分及特征分析

以中国地质调查局资助的《淮河流域环境地质调查》项目为依托,对收集到的区域基础地质和水文地质资料进行了二次开发。并根据近三年来淮河流域环境地质调查项目新取得的水文地质钻孔资料、水化学及同位素样品分析结果,科学地对淮河流域平原区第四系含水层进行了划分和印证,结合项目阶段研究成果,对淮河流域平原区第四系含水层特征进行了初步分析和总结。     

An acanthocephalan parasite increases the salinity tolerance of the freshwater amphipod <Emphasis Type="Italic">Gammarus roeseli</Emphasis> (Crustacea: Gammaridae)

Studies of the influence of parasites on host fitness generally conclude that parasites have a strong negative effect on their hosts. In this study, we have investigated experimentally the role of Polymorphus minutus, an acanthocephalan parasite, on the salinity tolerance of the freshwater amphipod Gammarus roeseli, one of its intermediate hosts. Unexpectedly, P. minutus-infected gammarids were more tolerant to salinity stress than uninfected ones. The mean lethal salt concentrations for 50% mortality of hosts tested were 17.3 (infected) and 9.7 g/L (uninfected). The parasitic load (one or two parasites per host) did not affect the result. The size of hosts had no significant influence on the salinity tolerance of either infected or uninfected gammarids. The mobility of all types of gammarid decreased when the salinity exceeded 9.0 g/L, but there was no significant difference between infected and uninfected gammarids. We discuss the higher salinity tolerance of infected amphipods in relation to O₂ consumption and osmoregulation. Finally, we demonstrate that the salinity tolerance is enhanced in the parasitized amphipod but without a significant change in behavior or an osmoregulatory adjustment.