Ecological structure of psammic rotifers in the ecotonal zone of Lake Piaseczno (eastern Poland)

The structure of the psammic rotifer community in three ecotonal zones (arenal, interface, eulittoral) of a mesotrophic lake (Lake Piaseczno; Leczna – Wlodawa Lakeland, eastern Poland) was studied in June and September of 1996 and 1997. A total number of 48 taxa, belonging to three different groups of psammon (eupsammon, hygropsammon and hydropsammon), were identified: 6 psammobionts, 16 psammophiles and 26 psammoxens. In each ecotonal zone, rotifers were clearly differentiated both qualitatively and quantitatively, depending upon the season and chemical factors. For instance, species diversity indicates a positive correlation with three chemical parameters: pH, chemical oxidation demand and PO₄ ^3- concentration.     

Decontamination of coal mine effluent generated at the Rajrappa coal mine using phytoremediation technology

Toxicity of the effluent generated at the Rajrappa coal mine complex under the Central Coalfields Limited (CCL, a subsidiary of Coal India Limited) in Jharkhand, India was investigated. The concentrations (mg L^?1) of all the toxic metals (Fe, Mn, Ni, Zn, Cu, Pb, Cr, and Cd) in the coal mine effluent were above the safe limit suggested by the Environmental Protection Agency (EPA 2003). Among these, Fe showed the highest concentration (18.21 ± 3.865), while Cr had the lowest effluent concentration (0.15 ± 0.014). Efforts were also made to detoxify the effluent using two species of aquatic macrophytes namely “‘Salvinia molesta and Pistia stratiotes.” After 10 days of phytoremediation, S. molesta removed Pb (96.96%) > Ni (97.01%) > Cu (96.77%) > Zn (96.38%) > Mn (96.22%) > Fe (94.12%) > Cr (92.85%) > Cd (80.99%), and P. stratiotes removed Pb (96.21%) > Fe (94.34%) > Ni (92.53%) > Mn (85.24%) > Zn (79.51%) > Cr (78.57%) > Cu (74.19%) > Cd (72.72%). The impact of coal mine exposure on chlorophyll content showed a significant decrease of 42.49% and 24.54% from control values in S. molesta and P. stratiotes, respectively, perhaps due to the damage inflicted by the toxic metals, leading to the decay of plant tissues.     

煤矿复垦区土壤水动力学特性对下渗过程的影响

煤矿复垦区土壤水对植物生长、溶质运移以及土壤环境的变化起着至关重要的作用。定量揭示煤矿复垦区土壤水下渗过程是亟待诠释的关键科学问题。本研究通过测定典型矿区不同深度土壤非饱和导水率、容重、总孔隙度和粒径等水动力学参数,结合染色示踪试验,刻画矿区非饱和带土壤水运移过程。染色示踪结果显示30、60 L和90 L这3种实验下渗水量条件下,水流沿X方向侧向扩散的最大距离分别为10、30 cm和35 cm,沿Y方向侧向扩散的最大距离分别为10、25 cm和30 cm。互相关函数显示随着下渗水量增大,水流扩散作用也在加强,但过多水量并没有明显增加下渗深度和扩散距离。吸力大于300 hpa时,0.01—0.05 mm土壤粒径含量和非饱和导水率呈负相关关系;吸力和非饱和导水率采用指数函数拟合效果较好(r~20.9),对拟合参数a、b和土壤容重(x)进行回归分析:a=0.0015x~2-0.00499x+0.0004,b=0.0583x~2+0.1234x-0.072。同一吸力下土壤容重大的土样非饱和导水率较小;吸力值为300 hpa是非饱和导水率的转折点;非饱和导水率和土壤容重呈现负相关关系,和总孔隙度呈现正相关关系,且二者的相关性随吸力的增加而降低。     

Experimental studies into the feeding biology of rotifers in brackish water

Mass developments of rotifers of the genus Brachionus, and especiallyof B.quadridentatus, occur regularly in the largely hypertrophicchain of shallow waters (‘boddens’) south of theDarss-Zingst peninsula (Southern Baltic). Interest in the autecologyof the species is, therefore, considerable. Various food sourceswere used in laboratory experiments to ascertain the food requirementsof B.quadridentatus, determine its filtration and ingestionrates, and assess its food particle size-selection ability.Growth experiments showed that the chlorophyceans Nannochlorissp. and Chlorella vulgaris possess considerable nutritionalvalue for the species, whereas abundances declined when Microcystisfirma, detritus from Enteromorpha sp. and only bacteria (Pseudomonas),respectively, were provided as food sources. Filtration ratesvaried between 0.02 and 1.73 µl ind.^–1 h^–1,and ingestion rates between 121 and 5560 cells ind.^–1h^–1, depending on the filtration rate and algal concentration.Investigations into food particle size selection using fluorescentlatex particles revealed that particle size influences foodparticle intake. When particles of different sizes were mixed,the animals showed a preference for the larger particles andingested the smaller ones with a diameter of 1–2 µmless efficiently. The brackish water species Brachionus plicatiliswas studied besides B.quadridentatus in all experiments. Theformer species proved to be superior both in its range of utilizableparticle sizes and its growth rate. The experiments with laboratorycultures were backed up by studies performed with various rotiferspecies taken from natural populations.     

香溪河库湾轮虫现状及水质评价初探

香溪河是长江三峡水库湖北省最大的支流。通过对香溪河库湾(下游河段)一周年的调查,发现轮虫80种,其中占优势的有13种。轮虫密度在不同样点差异显著,样点Ⅸ最低(仅为68.96 ind./L),样点Ⅵ最高(为1505.83ind./L);对9个样点进行聚类分析,可分为4组,第1组为样点Ⅰ至Ⅴ,第2组为样点Ⅵ,第3组为样点Ⅶ、Ⅷ,第4组为样点Ⅸ;除样点Ⅸ外,沿着水流方向,轮虫密度逐渐降低;在时间上差异也显著(P<0.01),9月份最高(2664.17ind./L),12月份最低(85.00ind./L)。水质评价表明香溪河库湾属于中污染。     

The species composition of rotifers in the water reservoirs of Central Vietnam

The rotifer fauna has been studied in four water reservoirs in the Khanh Hoa Province, Central Vietnam. A total of 65 species and subspecies and 22 genera representing 15 families have been found; 25 species and subspecies are identified as new to Vietnam. Morphometric characteristics are given for Filinia camascela Myers, Brachionus donneri Brehm, and B. dichotomus reductus Koste et Shiel. The rotifer fauna of Central Vietnam and those of other countries of Southeast Asia are compared. Some of the tropical and subtropical species recorded have been repeatedly reported from Russia.     

露天煤矿煤粉沉降对矿区周边主要植物的生理影响

随着新疆准东煤田开采的日益加剧,露天开采及运输造成的煤粉尘不仅影响区域大气环境,同时在一定程度上影响周边植物的生理生长。为探讨煤粉尘对周边植物的生理影响,以准东露天煤矿周边人工绿化树种白榆、乡土植物梭梭和柽柳为研究对象,通过野外控制实验,探究覆尘、无尘条件下3种植物的光合生理特性的变化。结果表明:煤粉沉降对3种植物的光合生理均产生了明显影响,覆尘叶片在不同光照强度下净光合速率、气孔导度、蒸腾速率均降低,净光合速率柽柳(18.6%)梭梭(28.3%)白榆(30.7%),气孔导度梭梭(24.1%)柽柳(30.9%)白榆(33.2%),蒸腾速率梭梭(16.7%)白榆(18%)柽柳(39.1%);煤尘对白榆、梭梭的影响主要为非气孔因素,对柽柳的影响有待继续研究。因此露天煤矿开采造成的粉尘会在一定程度上影响周边植物的光合生理过程,抑制其生长,长期排放可能会导致植被覆盖度降低。     

Exploring the land use changes in Eastern Poland: statistics-based modeling

Abstract

The study analyzed changes in surface areas of individual land use types in five administrative regions of Poland in the eastern-most part of the country. Annual time series for the following variables were used: agricultural land, forest land, built-up and urbanized land, and wasteland. The primary objective of the paper was to assess land use changes (LUC) in Eastern Poland in 2002–2016. The paper employed a Mann-Kendall (MK) test and Cox-Stuart (CS) test for monotonic trend and the autoregressive-moving-average (ARMA) model. The deterministic part was selected with the Akaike criterion. The power of the tests was estimated using the Monte Carlo simulation in order to assess their reliability. The results indicate a trend in each of the four series in all the five voivodeships. For forest and built-up land, the trend was upward in each voivodeship. A downward trend was found for the agricultural land and wasteland in all the voivodeships except the Podkarpackie Voivodeship. The results can help regional and local authorities to properly monitor LUC.     

Aquatic invertebrates in final void water bodies at an open-cut coal mine in central Queensland

Abstract  We describe the diversity of aquatic invertebrates colonising water-filled final voids produced by an open-cut coal mine near Moura, central Queensland. Ten disused pits that had been filled with water from <1 year to 22 years prior to the survey and three nearby 'natural' water bodies were sampled in December 1998 and again in March 1999. All invertebrates collected were identified to family with the exception of oligochaetes, cladocerans, ostracods and copepods, which were identified to these coarser taxonomic levels. Sixty-two taxa were recorded from >20 000 individuals. The greatest familial richness was displayed by the Insecta (33 families) followed by the mites (Acari) with 12 families. While natural water bodies held the greatest diversity, several mine pits were almost as rich in families. Classification analyses showed that natural sites tended to cluster together, but the groupings did not clearly exclude pit sites. Mining pits that supported higher diversity tended to be older and had lower salinity (<2000 µS/cm); however, salinity in all water bodies varied with rainfall conditions. We conclude that ponds formed in final voids at this mine have the potential to provide habitat for many invertebrate taxa typical of lentic inland water bodies in central Queensland.     

Workshop on rotifers in ecotoxicology

The aim of the workshop on rotifers in ecotoxicology was to stimulate discussions on new developments in the field. Discussions about the use of biomolecular tools indicate that gene expression analysis with rotifers should be available in the next few years. Such analyses will be a great asset as they enable ecotoxicologists to study molecular mechanisms of toxicity. Rotifers also appear as useful tools in the risk assessment of pharmaceuticals and their metabolites that find their way into aquatic ecosystems because their sensitivity to some of these substances is higher than that of cladocerans and algae. The nature and extent of the impact of potential endocrine disruptors on aquatic invertebrates is another poorly resolved issue for which rotifers are a promising tool. Indeed, rotifers seem to be particularly sensitive to androgenic and anti-antiandrogenic substances, whereas copepods and cladocerans are typically more affected by estrogens and juvenile hormone-like compounds. Besides their usefulness in these emerging fields of aquatic ecotoxicology, it was emphasized that research with rotifers on basic issues like, e.g., toxicant interference with predation, competition, or interspecific and interclonal variation in ecotoxicological tests is still needed. Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont & R. Rico-Martínez Advances in Rotifer Research     

Parallelism in the evolution of rotifers

The carbon uptake by the roots of three common submersed macrophytes, Myriophyllum spicatum, Heteranthera dubia and Vallisneria americana, was measured in situ under a range of pH and dissolved inorganic carbon (DIC) concentrations. After 4–8 weeks of growth in ¹⁴C labelled sediments, less than 1.5% of the total C found in the shoots originated from root uptake. Between species, significant differences in C uptake by the root were found and root development alone could explain most of the observed variance (84%). C uptake by the roots of aquatic macrophytes thus appears to be restricted to small, rosette-shaped plants growing in poorly mineralized waters.     

Contribution to the study of african rotifers: rotifers from Mali

In samples collected from different parts of the Republic of Mali (W-Africa), ninety-two taxa of rotifers were identified. Some were present in different forms; 56% were cosmopolitan, 19% thermophilous with a wide distribution, 20% tropicopolitan and 5% cold-stenothermous. These latter species seem to be relicts of palaeoclimatic conditions in Africa.     

Dominant diatoms in the interglacial lake sediments of the Middle Pleistocene in Central and Eastern Poland

Diatom studies carried out in Central and Eastern Poland have shown a diversified composition and considerable changes of relative frequency of dominant diatoms in profiles of lake sediments of the Mazovian and Ferdynandovian interglacials. Cyclotella spp. are dominant in a large part of the sediment profiles at Adamówka, awki-7 and Wola Grzymalina-59 and, at Krpiec and Podlodów, Stephanodiscus is also common while at Biaa Podlaska and Falcice, Aulacoseira is most abundant. Cyclotella comta var. lichvinensis and C. vorticosa are the typical diatoms in the Mazovian Interglacial. In the sediments representing the Ferdynandovian Interglacial, the characteristic diatoms are Cyclotella cf. reczickiae and the Stephanodiscus rotula/niagarae complex.     

A perspective on aging in rotifers

Most research on aging in rotifers has been performed with populations, not with individuals. As a consequence, the dependent variable in these studies is usually either mean lifespan or rate of survivorship. After a brief consideration of the literature published since the last major review (King, 1969), the results of a series of experiments are presented. Males and females of three genetically distinct clones of Brachionus plicatilis were used for a factorial life table analysis at three different temperatures. The results of these experiments indicate several potential problems in using populations to study the aging process of individuals. These problems derive from the fact that lifespan is only one component of fitness, and its relative duration may not reflect the evolutionary success of the clone. That is, lifespan is free to vary in response to both stochastic and deterministic events without significantly reducing fitness. Under these conditions, neither mean lifespan nor pattern of survivorship will provide meaningful data on the determinants of individual senescence.We gratefully acknowledge the aid and advice of William R. Rice in conduct of the regression analysis. This work was supported by grants from the National Science Foundation and National Institutes of Health to CEK.     

Some considerations on the geographical distribution of rotifers

In the course of investigations on the systematics and zoogeography of rotifers, the author found that 48% of all taxa treated showed a limited distribution (most were periphytic or benthic periphytic species from shallow waters). The following species were limited to the Palaearctic Region: Marine: Synchaeta triophtalma Lauterborn, S. vorax Rousselet, and S. curvata Lie-Pettersen. Brackish water: Colurella dicentra (Gosse), C. halophila Wulfert, and C. unicauda Eriksen. Among Holarctic species, Notholca psammarina Buchholz & Rühmann and the two semi-species N.(striata) bipalium (O. F. Müller) and N(striata) striata (O. F. Müller) are discussed. A series of warm-stenothermic species were found to be pantropical: Lecane leontina Turner, L. monostyla (Daday), L. harringi (Ahlstrom), Lepadella latusinus (Hilgendorf), Trichocerca chattoni (de Beauchamp), and Platyias leloupi Gillard, while Lecane plesia Myers and L. punctata (Murray) seemed to be confined to the Neotropical Region. The data collected also suggest that:

1. i) Keratella wirketissi Kutikova, K. kamtchatica Kutikova, K. cruciformis (Thompson), and K. eichwaldi (Levander) might be good species.
2. ii) Brachionus forficula Wierzejski, an Old World species, is a geographical vicariant of both B. havanaensis Rousselet and B. trahea Murray from the New World.
3. iii) Cases of ecological vicariance are found in Testidinella elliptica (Ehrb.) and T. clypeata (O. F. Müller) from fresh and brackish water respectively; Keratella cruciformis (Thompson) and K. eichwaldi (Levander) from the sea and brackish water respectively; Keratella quadrata (O. F. Müller), K. valga (Ehrb.), and K. tropica (Apstein), dominant in arctic to cold-moderate, in warm-temperate, and in subtropical-tropical climates respectively.

Some rotifer species are presently in expansion: the cases of K. tropica and of Brachionus falcatus Zacharias in Europe are analysed. A related case is that of man-made faunas: the presence of Brachionus havanaensis in Sangchrist Lake, Ill., USA, and the Rotifer fauna of the River Loire (France) are discussed.