Studies on the helminth parasites of freshwater fishes of the Sudan

2419 freshwater fishes from the Sudan were examined for helminth parasites and found to harbour one monogenean species, 15 species of adult digenetic trematodes, three species of larval trematodes, 16 species of adult cestodes, 13 species of adult nematodes, two species of larval nematodes and three species of acanthocephalans. Four species of adults and four species of larval worms are recorded for the first time in the Sudan and 30 new hosts are listed. The intensity of infestation of each species, the host-specificity and the variations in the infestation of fishes are discussed. The helminth fauna of the Sudan is compared with that of other African countries.     

三峡库区资源植物的现状与保护

据调查统计,三峡库区有资源植物2070种,其中药用植物1006种、纤维植物104种、油脂植物76种、观赏植物74种、野果植物54种、芳香植物54种、树脂树胶植物68种、淀粉及糖类植物52种,鞣科植物32种、珍稀植物49种、其它类型植物465种。论述了三峡库区资源植物的分类及保护现状。     

Biogeographical indices of the freshwater fish spatial distribution in the upper reaches of the Yangtze River

The spatial distribution of freshwater fish species (Total species and Unique species) in the upper reaches of the Yangtze River was studied, focusing on the spatial distribution of geographic ranges. Two biogeographical indices: environmental resistance (R₅₀), anisotropy (A₅₀) and a fractal dimension method were used to identify the relationship between them and spatial distribution of freshwater fish. R₅₀ quantifies the loss of biotic resemblance occurring from any point in the map to the rest of the study area. A₅₀ quantifies the extent to which the perimeter: area ratio of the geographical ranges of all species whose distributions overlap at any particular location depart from the perimeter of area ratio of a circle. We concluded that the western of the study area is populated by a large number of total and unique species, the eastern part with the total species richness, the middle regions populated by small number of unique species, the mid-west region populated by small number of total species, and the mid-eastern region populated by a large number of total species. We also analyzed how topology affects the spatial arrangement of species, species density has strong curvilinear correlation (species density increases with increased of fractal dimension), the species density in the tributaries is lower than that in mainstream. The results and methods used give us detailed information about the spatial distribution of species, so as to illuminate the species distribution and change by the human activities.     

Comprehensive and Comparative Analysis of the Helminth Fauna of the Dominant Colonial Seabird Species on the Murman Coast

This work reports the results of the long-term study of the helminth fauna of the dominant colonial seabird species (common guillemots, Brünnich’s guillemots, kittiwakes, great black-backed gulls, and herring gulls) in the western, central, and eastern parts of the Murman coast. The presence of 52 parasitic worm species (18 trematode species, 21 cestode species, 11 nematode species, and 2 acanthocephalan species) was demonstrated. In the western, central, and eastern regions, the respective numbers of 32, 43, and 34 helminth species were registered. Twenty species of seabird parasites were found to be ubiquitous along the Murman coastal zone. Local foci of the trematode Maritrema arenaria and cestode Laricanthus lateralis infestation along the western part of the Murmansk coast were revealed. The highest helminth species diversity (38 species) was demonstrated for the herring gull; the lowest (7 species), for the common guillemot. Four parasite species were common for the helminth fauna of all bird species. A significant number of helminth infections were mixed ones (complexes of two or three bird species with the common helminth species in different combinations). The highest similarity of the helminth fauna was revealed in the pairs of the common guillemot and the Brünnich’s guillemot and of the great black-backed gull and the herring gull. A few parasitic worm species detected only in a single bird species were registered. The particularities and the possible causes of the geographical distribution and specificity of helminthes were analyzed, and a comprehensive assessment of the parasitological situation in the Murman coastal zone was performed.     

An updated list of the ticks of Ghana and an assessment of the distribution of the ticks of Ghanaian wild mammals in different vegetation zones

Twenty one species of ticks belonging to five genera of the family Ixodidae (Order Acari, sub-order Ixodida) - Amblyomma, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus (including the sub-genus Rhipicephalus (Boophilus)) - were collected from 1260 mammals, representing 29 species, 14 families and 6 orders, in four vegetation zones in Ghana during the period 1971-1978. Four other species were collected from humans in 1977. In all, eight species appeared to be new records for Ghana: Amblyomma tholloni Neumann; Dermacentor circumguttatus Neumann; Haemaphysalis houyi Nuttall & Warburton; Ixodes loveridgei Arthur; Ixodes oldi Nuttall; Ixodes vanidicus Schultze; Rhipicephalus complanatus Neumann; Rhipicephalus cuspidatus Neumann. The updated list of tick species in Ghana given here includes 41 species of ixodid ticks and four species of argasid ticks. Most species have been found in neighbouring regions of West Africa but 56 of the 121 different combinations of ixodid tick species and host species found in the collection described here have not apparently been reported before. The new combinations recorded here bring the total number of different combinations of ixodid tick species and mammalian host species now reported in Ghana to 151. The tick species found on wild mammals in Ghana mostly differed from those reported from domestic stock by other authors. The data showed that different tick species occurred in different vegetation zones and that most species displayed a pronounced preference for certain groups of related host species. Some tick species were found in the savanna feeding mainly on large bovids and/or suids; others were found in forests feeding mainly on small bovids, large rodents or small carnivores.     

Branches in the lines of descent: Charles Darwin and the evolution of the species concept

Charles Darwin introduced a novel idea into the concept of species, namely that species are branches in the lines of descent (segments of population lineages). In addition to this novel evolutionary component, Darwin's species concept also retained an older taxonomic component, namely the view that the species category is a taxonomic rank; moreover, he adopted amount of difference as a criterion for ranking lineages as species. Subsequent biologists retained both components of Darwin's species concept, although they replaced Darwin's ranking criterion with ranking criteria that either are more objectively defined or relate more directly to the biological bases of lineage separation and divergence. Numerous alternative ranking criteria were proposed, resulting in a proliferation of species definitions and a controversy concerning the concept of species. That controversy can be resolved by distinguishing more explicitly between the theoretical concept of species and the operational criteria that are used to apply the concept in practice. By viewing the various alternative ranking criteria as operational indicators of lineage separation rather than necessary properties of species, the conflicts among competing species concepts are eliminated, resulting in a unified concept of species. A brief examination of the history of biology reveals that an important shift related to the unified species concept has been emerging ever since Darwin reformulated the concept of species with an evolutionary basis. The species category is effectively being decoupled from the hierarchy of taxonomic ranks and transferred to the hierarchy of biological organization. Published 2011. This article is a US Government work and is in the public domain in the USA. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 19–35.     

On the nature of the species problem and the four meanings of 'species'

Present-day thought on the notion of species is troubled by a mistaken understanding of the nature of the issue: while the species problem is commonly understood as concerning the epistemology and ontology of one single scientific concept, I argue that in fact there are multiple distinct concepts at stake. An approach to the species problem is presented that interprets the term 'species' as the placeholder for four distinct scientific concepts, each having its own role in biological theory, and an explanation is given of the concepts involved. To illustrate how these concepts are commonly conflated, two widely accepted ideas on species are criticized: species individualism and species pluralism. I argue that by failing to distinguish between the four concepts and their particular roles in contemporary biological theory, these ideas stand in the way of a final resolution of the species problem.     

Contribution to the Microlepidoptera Fauna of the South of Krasnoyarsk Territory and the Republic of Khakassia

This paper provides a list of 125 species from 22 families of Microlepidoptera collected in the south of Krasnoyarsk Territory and in the Republic ofKhakassia, with 63 species (50%) and 2 families (Bucculatricidae and Elachistidae) recorded in the region for the first time, and 11 species from 6 families being new to Siberia: Cauchas fibulella, Nemophora fasciella, N. minimella (Adelidae), Phyllonorycter sorbicola, Phyllocnistis extrematrix (Gracillariidae), Cosmiotes freyerella, Elachista subocellea (Elachistidae), Caryocolum alsinella, Scrobipalpula diffluella (Gelechiidae), Agonopterix intersecta (Depressariidae), and Ypsolopha horridella (Ypsolophidae). Three species are new to science: Phyllonorycter sp. and Phyllocnistis verae (Gracillariidae) from the suburbs of Krasnoyarsk and Chrysoesthia sp. (Gelechiidae) from the Republic of Khakassia. Almost half of the faunistic findings belong to two families, Gelechiidae (34 species) and Gracillariidae (24 species). In the former family, the number of species distributed in Krasnoyarsk Territory and/or Khakassia was increased by 1.5 times based on our collection. Trophic specialization remains unknown only for 7 of the 125 species. Most (90%) of the remaining 118 species are phytophagous, the others are saprophagous; 53 species are known as leaf miners. Phytophagous species feed on plants of 36 families and 21 orders. The largest number of microlepidopteran species inhabit plants of the orders Rosales and Fagales (25 and 24 species, respectively). Twelve species are known as pests: Tineidae (4 species), Gracillariidae, Gelechiidae (2 species in each), Argyresthiidae, Choreutidae, Lyonetiidae, and Plutellidae (one species in each). Four pest species have expanded beyond the Palaearctic in the last century: Choreutis pariana (Choreutidae), Scrobipalpa atriplicella (Gelechiidae), Plutella xylostella (Plutellidae), and Niditinea fuscella (Tineidae).     

黄土高原蕨类植物区系特点的初步研究

对黄土高原的蕨类植物区系组成、分类及其特点进行了研究。结果表明,黄土高原有蕨类植物26科、53属、184种及3变种,种类较多的科有蹄盖蕨科（30种）、鳞毛蕨科（26种）、水龙骨科（20种）、铁角蕨科（12种）、卷柏科（12种）、中国蕨科（11种）及裸子蕨科（10种）等。这７科的种类共计１２１种,占本地区总种数的64.71%。种类较多的属有鳞毛蕨属（13种）、郑柏属（12种）、耳蕨属（11种）、铁角蕨属（11种）、蹄盖蕨属（10种）、瓦韦属（10种）、铁线蕨属（9种）及岩蕨属（9种）等。这8属的种类共计85种,占本地区总种数45.46%,黄土高原蕨类植物区系属的地理成分可划分为15个分布区类型。热带、亚热带分布类型的有18属,占总属数的41.86%,北温带及寒带分布类型的有22属,占总属数（世界分布属除外）的51.16%,其中,亚洲分布类型的最多,计有16属,占总属数的37.20%,表明黄封同原蕨类植物区系是温带类型,区系地理成分以华北区蕨类植物为主,同时也集中了华中、华东、东北、西北以及西南的蕨类植物。而中国特有的分布属只有1属。     

Partitioning of vegetative trophic resources in the rodent community in the Terek-Kuma Lowland in the Republic of Daghestan

We have studied the quantitative and qualitative diet features of the rodent species in arid conditions of the Terek-Kuma Lowland in the Republic of Daghestan. We have determined the species composition, proportion, and diversity of food resources in the diets of the studied rodent species. The diet of rodents consists of various plants species. For example, the diet of Meriones tamariscinus consists of 29 plant species; M. meridianus, 40 species; Cricetulus migratorius, 26 species; Sylvaemus fulvipectus, 34 species; and Mus musculus, 30 species. The share of exclusively consumed plant species did not exceed 10% of the total amount of food. All pairs of rodent species have low or medium rate of diet overlapping.     

Hydromedusae of the Mediterranean Sea

Mediterranean hydromedusae can be classified in several categories: common species, widely distributed throughout the Mediterranean and rare species reported from the Pacific, Indian or Atlantic Oceans; seasonal species comprising cold-season species with a boreal affinity and warm-season species with a hot to temperate affinity; neritic and mid-ocean species; surface species and meso-, infra-, and bathypelagic species. Holoplanktonic species are known to be associated with stable hydrological conditions (offshore waters, deep waters, summer and winter homothermy), whereas meroplanktonic species are more likely to be found in more disturbed hydrological conditions (coastal waters, surface waters, spring and autumn periods of temperature fluctuation). A general pattern of medusa distribution is established based upon comparative study throughout the Mediterranean.     

Geographical patterns in species richness of the benthic polychaetes in the continental shelf of the Gulf of California, Mexican Pacific

The present study is the first attempt to describe meso-scale patterns in the species richness of polychaetes along the Gulf of California, which stretches from about 23°N to 31°N. We examine herein the spatial changes in species distribution and explore the overlapping of species’ ranges towards the centre of the Gulf, to test whether the mid-domain effect (MDE) could explain an expected mid-domain peak in species richness. The faunal composition and the latitudinal range of 244 species of polychaetes recorded along the continental shelf of the Gulf of California were analysed in latitude bands of 1°. The species composition changes around the Gulf’s archipelago (~29°N), and the highest values of species richness are found at the 25° (197 species) and 26° (193 species) of latitude. Although the species richness pattern could be described by a parabolic shape, the regional trend was not strongly consistent with the peak of diversity at 27°N (176–191 species) predicted by the mid-domain effect: the random sorting of species’ ranges within spatial domain does not explain satisfactorily the geographical patterns of diversity. Nevertheless, a partial contribution of MDE to these natural patterns of diversity could be detected, and the increase in species richness towards middle latitudes was basically determined by species with distribution ranges larger than 6°. The low level of significance between the empirical species richness pattern and the mid-domain model prediction for polychaetes in the Gulf does not restrict their use as a model for exploring the randomness of the diversity patterns.     

On the distribution of broad-winged moths (Lepidoptera, Oecophoridae) of the Palaearctic fauna

The Palaearctic fauna of broad-winged moths (Oecophoridae with the subfamilies Oecophorinae, Pleurotinae, and Deuterogoniinae) comprises 47 genera and 329 species. The number of species rapidly increases from north to south, from 19 species in the Euro-Siberian taiga Region to 149 in the Mediterranean Region, but the Scythian steppe Region (30 species) and Sethian desert Region (49 species) have relatively poor faunas because the majority of oecophorid species are trophically associated with arboreal plants. The proper desert species are very rare among Oecophoridae moths, and the majority of species in the Sethian desert Region occur in the mountains. The number of endemic species is also greater in southern regions; it amounts for more than half of the total number of species in the Hesperian and Orthrian evergreen forest regions and in the Sethian desert Region. The faunas of European (62 species) and Far Eastern (67 species) deciduous forests comprise close numbers of species but are very different, having only 5 species in common. This fact indicates their long isolation. The Oecophoridae are represented in the Palaearctic mainly by the genera with a small number of species, except for 2 genera, Pleurota (100 species) and Promalactis (85 species). The distribution patterns of these genera are opposite: the species of Pleurota are numerous in the south of West Europe and in North Africa, their number quickly decreasing from west to east and only 2 species being present in China (Wang, 2006). The species of Promalactis are numerous in Southeast Asia, their number quickly decreasing from east to west: 3 species occur in Tibet and only 1, P. splendidella (Amsel, 1935), in Israel and Turkey.     

Harvest mites of the family Trombiculidae in the steppe zone of the southeastern Ukraine

Virgin and cultivated biotopes of the Sea of Azov area of Donetsk Province were investigated for parasite coenoses of small mammals. 469 animals and 210 nests were collected, Apodemus sylvaticus, Mus musculus, Microtus arvalis and Cricetulus migratorius being the most abundant species. In all 2940 larvae of trombiculids (18 species) were found on animals and in their nests (2846 specimens on animals and 94 specimens in nests). Two species, Hoffmannina theodori and Doloisia skljari, are new for science, the latter being the first find of the genus Doloisia member in the fauna of the USSR. The majority of parasites are collected from rodents inhabiting virgin biotopes (2328 specimens) while in cultivated biotopes 189 specimens were collected. More rich is the species composition of trombiculids in virgin biotopes (13 species) as compared to that in cultivated ones (5 species), Neotrombicula earis, N. japonica, N. autumnalis and N. vulgaris being mass species. 8 species of larvae are recorded from the nests of rodents. Seasonal dynamics of the abundance of mass species, their occurrence, index of abundance and infection intensity are shown.     

Zoogeographical analysis of the hoverfly fauna (Diptera, Syrphidae) of the northwestern Caucasus

The hoverfly fauna of the northwestern Caucasus comprises 257 species of 72 genera. They possess 32 types of ranges that could be united into 11 groups of ranges. Widespread species from the basis of the hoverfly fauna in the region: species with narrower ranges, those distributed in more than one zoogeographical region, and those distributed in more than one dominion, constitute 12.9%, 63.1%, and 24% of the fauna, respectively. The hoverfly fauna of the northwestern Caucasus is composed of nemoral species common for Europe and Mediterranean basin, and also by species widespread in the Palaearctic (92.9%). Autochthomous species constitute 5.5%, and species of the eastern Palaearctic origin, 1.6%. Hoverfly species with zoophagous larvae are the most widespread. The fraction of such species is low among species with narrowly local ranges (12.5%) and high among species with ranges including more than one dominion. Phytophagous species are wider represented among hoverflies with narrowly local ranges (44.7%) than among flies with interdominion ranges (8%). Ranges of dendrobiontic saprophagous species are determined by the presence of arboreal vegetation and no widespread polytopic hoverflies are found in this group. The distribution of mycetophagous species, commensals, and terrestrial saprophagous species is determined by the presence of fungi, ranges of some hymenopterans, and the presence of decaying plant remnants.     

广东亚热带森林木本植物幼苗生长特性研究

研究了广东亚热带42种木本植物幼苗的生长及其与物种的生态特性、生活型、种子大小的相互关系.较强光下(H,66.8 μmol m-2s-1)乔木幼苗的茎高和茎生物量显著高于灌木幼苗的相应值,但在较低光下(L,33.7 μmol m-2s-1)两者无显著差异.而阳性植物、耐阴植物和中间型植物之间,茎高和茎生物量无显著差别.乔木幼苗的叶面积和叶生物量比灌木幼苗大,但灌木幼苗的叶片数较乔木幼苗多.大种子种和小种子种幼苗之间,阳性植物、耐阴植物和中间型植物幼苗之间的叶片数和叶面积一般无显著差异.阳性植物幼苗比耐阴植物幼苗侧根数多.乔木幼苗的根生物量和根/茎比显著高于灌木幼苗在较高光下,阳性植物幼苗的根/茎比较耐阴植物幼苗高,但在较低光下无明显差异.45 d幼苗的根生物量与种子重量呈显著的正相关,而90 d幼苗无明显的相关.乔木幼苗个体生物量显著高于灌木幼苗.幼苗相对生长率和叶面积比的大小呈现如下顺序阳性植物＞中间型植物＞耐阴植物,但只有阳性植物和耐阴植物之间有显著差异.阳性植物、中间型植物和耐阴植物幼苗之间的单位叶率无显著差异.     

Species composition of the parasitic cenoses of gerbils

Complex studies of parasitic cenoses of four species of gerbils were carried out in Turkmenia. Over 60 forms of parasites were found out as follows: three species of blood parasites, 12 species of Coccidia, 8 species of cestodes, 12 species of nematodes, one species of Acanthocephalus, three species of chigger mites, 15 species of gamasid mites, 6 species of ixodid ticks, fleas and lice. The list of species of parasites with regard to their hosts is provided.     

Molecular analysis of the phylogenetic relationships among the diploid aegilops species of the section Sitopsis

RAPD analysis was used to study the intraspecific variation and phylogenetic relationships of S-genome diploid Aegilops species regarded as potential donors of the B genome of cultivated wheat. In total, 21 DNA specimens from six S-genome diploid species were examined. On a dendrogram, Ae. speltoides and Ae. aucheri formed the most isolated cluster. Among the other species, Ae. searsii was the most distant while Ae. longissima and Ae. sharonensis were the closest species. The maximum difference between individual accessions within one species was approximately the same (0.18-0.22) in Ae. bicornis, Ae. longissima. Ae. sharonensis, and Ae. searsii. The difference between the clusters of questionable species Ae. speltoides and Ae. aucheri corresponded to the intraspecific level; the difference between closely related Ae. longissima and Ae. sharonensis corresponded to the interspecific level. The section Sitopsis of the genus Aegilops includes six diploid species containing the S genome, which is regarded as an ancestor of the B genome of cultivated wheat. The species of the section are thought to be closest to the genus Triticum. Note that the taxonomic status of some forms of the section Sitopsis is questionable. For instance, Ae. speltoides and Ae. aucheri are variously considered as individual species or as a single species, Ae. speltoides. The situation with Ae. longissima and Ae. sharonensis is similar. Thus, although the group includes only diploid species and is well studied morphologically, its phylogeny and taxonomy are still questionable.     

The functional trait space of tree species is influenced by the species richness of the canopy and the type of forest

Analysing how species modify their trait expression along a diversity gradient brings insight about the role that intraspecific variability plays over species interactions, e.g. competition versus complementarity. Here, we evaluated the functional trait space of nine tree species dominant in three types of European forests (a continental‐Mediterranean, a mountainous mixed temperate and a boreal) growing in communities with different species richness in the canopy, including pure stands. We compiled whole‐plant and leaf traits in 1719 individuals, and used them to quantify species trait hypervolumes in communities with different tree species richness. We investigated changes along the species richness gradient to disentangle species responses to the neighbouring environment, in terms of hypervolume size (trait variance), shape (trait relative importance) and centroid translation (shifts of mean trait values) using null models. Our main results showed differences in trait variance and shifts of mean values along the tree diversity gradient, with shorter trees but with larger crowns in mixed stands. We found constrained functional spaces (trait convergence) in pure stands, suggesting an important intraspecific competition, and expanded functional spaces (trait divergence) in two‐species admixtures, suggesting competition release due to interspecific complementarity. Nevertheless, further responses to increasing species richness were different for each forest type, waning species complementarity in sites with limiting conditions for growth. Our results demonstrate that tree species phenotypes respond to the species richness in the canopy in European forests, boosting species complementarity at low level of canopy diversity and with a site‐specific pattern at greater level of species richness. These outcomes evidence the limitation of functional diversity measures based only on traits from pure stands or general trait database values.     

福建省崇武潮间带贝类的分布

在福建省祟武潮间带共采得标本178种,根据其中48种贝类的水平分布与垂直分布特点,它们对温度的适应性质可分为4个类群：暖湿带种占3．3％;亚热带种占57．6％;广温广布种占35．8％;热带种占3．3％。