Prey Selection by the Water Bug Aphelocheirus aestivalis Fabr. (Heteroptera: Aphelocheiridae)

Feeding experiments were conducted in situ in flow through boxes to determine the vulnerability of different prey types (the mayfly larvae Baetis, Ephemerella and Ecdyonurus spp., the caddisfly larva Hydropsyche spp. and the crustacean Gammarus spp.) to the predaceous water bug Aphelocheirus aestivalis and to estimate the predation impact of Aphelocheirus on prey populations. Experiments with equal densities of mixed prey and experiments where each prey was tested individually revealed that Baetis and Ephemerella were most vulnerable to Aphelocheirus predation: Hydropsyche, Ecdyonurus and Gammarus were little/not preyed upon. The present results suggest that vulnerability of prey depends mainly upon prey mobility and microhabitat overlap between predator and prey and that feeding behaviour of Aphelocheirus resembles more that of megalopterans than of stoneflies. Experiments with different prey densities (120–720 prey m⁻²) showed that the predation rate of Aphelocheirus increased with increasing prey density. Experiments with different substrates documented that mortality rates of prey decreased with increasing substrate complexity. When substrate conditions were complex mortality rates in the control and in the experimental boxes were the same which suggest little importance of Aphelocheirus predation on mayflies in the study site.     

The food pump of Aphelocheirus aestivalis F. as compared with that of typical Naucoridae (Heteroptera)

The heteropteran cibarium forms a sucking pump which conveys fluid foods into the pharynx. The food pumps of Hydrocorisae have the additional function of grinding or filtering particulate matter; they contain ridges, hairs, and sclerotized processes which have probably evolved at least twice among the hydrocorisine families. Aphelocheirus, like the Naucoridae, possesses a modified anteclypeus and a tripartite type of food pump. The main sucking action occurs in the pump's anterior and posterior regions, while the middle region is specialized for grinding and filtering. The anteclypeus has broadened and fused with other parts of the cranium, and is thus braced against the pull of the powerful cibarial dilator muscles. In the Naucoridae the three regions of the pump have the same functions as those of Aphelocheirus. The pumps of the five naucorid genera here studied are structurally very similar to each other but differ considerably from that of Aphelocheirus. Cibarial morphology, as well as respiratory differences, thus supports the contention that Aphelocheirus is not a member of the Naucoridae but should be placed in a separate family.     

Notes on the distribution of phytoplankton in some Kenya waters

The distribution of the major plankton algae in a number of Kenya waters is described. The lakes and dams are shown to fall into ecological groups related to figures for the pH, conductivity and alkalinity of their waters and characterised by the dominance of certain types of alga. The composition of the phytoplankton collected at approximately monthly intervals from Sasumua and Ruiru reservoirs is described. Plankton periodicity is demonstrated for both waters and is shown to be related to rainfall. The periodicity of plankton in Lake Naivasha is noted.     

First report on Wolbachia endosymbiosis in freshwater Aphelocheirus aestivalis (Heteroptera: Aphelocheiridae) and its potential impact on genetic diversity of host

Alphaproteobacteria Wolbachia have been described as endosymbionts of approximately half of all aquatic insect species. These bacteria might affect not only reproduction but also the genetic diversity of its hosts. In the present study we identified Wolbachia endosymbiosis in freshwater true bug Aphelocheirus aestivalis F., 1794 (Heteroptera: Aphelocheiridae). Despite the fact that A. aestivalis is widely distributed in Europe, it occurs rather locally, often in isolated populations. Taking into account that Wolbachia, close relationships and past demographic phenomena could affect the genetic diversity of its host, we analyzed mitochondrial (COI and 16S) and nuclear (internal transcribed spacer 2) markers determined for A. aestivalis individuals collected from five populations. Moreover, we compared obtained COI sequences with those deposited in GenBank. Analyses revealed low genetic differentiation among samples tested, as well as low variation among determined COI sequences and those downloaded from the database. Although Wolbachia infection could correlate with decreasing mitochondrial diversity of its host, we suggest that low genetic variation observed in tested A. aestivalis samples (at both mitochondrial and nuclear levels) is a result of populations’ close relationships, past demographic phenomena or is characteristic for this species. Detailed analysis of the wsp gene fragment revealed two distinct strains of Wolbachia infecting A. aestivalis. Both of them belong to supergroup A, also found in other arthropods.     

中国锦鸡儿属植物资源研究—分布及分种描述

记录了锦鸡儿属（Cargana Fabr.)植物的资源分布,并对该属66种植物（小叶锦鸡儿,柠条锦鸡儿,中间锦鸡儿,树锦鸡儿,黄刺条,锦鸡儿,红花锦鸡儿,密叶锦鸡儿,鬼箭锦鸡儿,毛掌叶锦鸡儿,白毛锦鸡儿,甘蒙锦鸡儿,矮锦鸡儿,繁花锦鸡儿,矮脚锦鸡儿,狭叶锦鸡儿,毛刺锦鸡儿,柄荚锦鸡儿,秦晋锦鸡儿,北京锦鸡儿,南口锦鸡儿,五台锦鸡儿,昆仑锦鸡儿,库车锦鸡儿,短叶锦鸡儿,变色锦鸡儿,二色锦鸡儿,白皮锦鸡儿,青甘锦鸡儿,川西锦鸡儿,云南锦鸡儿,猫耳锦鸡儿,陕西锦鸡儿,长爪锦鸡儿,甘肃锦鸡儿,扁刺锦鸡儿,青海锦鸡儿,二连锦鸡儿,弯枝锦鸡儿,昌都锦鸡儿,楔翼锦鸡儿,高山锦鸡儿,藏北锦鸡儿,尼泊尔锦鸡儿,沦江锦鸡儿,吉降职一锦鸡儿,文县锦鸡儿,粗刺锦鸡儿,西藏锦鸡儿,刺锦鸡儿,粉刺锦鸡儿,草原锦鸡儿,阿拉套锦鸡儿,伊犁锦鸡儿,阿尔泰锦鸡儿,镰叶锦鸡儿,中亚锦鸡儿,邦卡锦鸡儿,绢毛锦鸡儿,白刺锦鸡儿,多叶锦鸡儿,新疆锦鸡儿,刺叶锦鸡儿,粗毛锦鸡儿,准噶尔锦鸡儿,吉尔吉斯锦鸡儿）的特征,习性及分布进行了详细描述。     

树锦鸡儿的分布式样及其生态适应

树锦鸡儿为典型的中生植物,既是锦鸡儿属的模式种,又是该属植物的原始种。本文认为树锦鸡儿的分布式样为西西伯利亚东南部（阿尔泰—萨彦）—东亚北部（华北—东北—远东）间断分布种。在西西伯利亚东南部地区,本种为寒温型常绿针叶林西伯利亚落叶松和西伯利亚冷杉林下及林缘的伴生种,在东亚北部地区本种为中温型和暖温型夏绿阔叶林蒙古栎和辽东栎林下及林缘灌丛的伴生种。     

The recapture of British salmon in Irish waters

In the years 1972 to 1974, inclusive, a total of 50 salmon originally tagged as smolts in British rivers were recaptured in Irish waters. Although it is not possible to give precise reasons for these changes, some factors can be largely eliminated. The results do, however, indicate that salmon and grilse derived from British rivers occur in Irish inshore waters to a greater extent than was generally accepted.     

豆科锦鸡儿属(Caragana Fabr.)植物地理分布与分化研究

豆科锦鸡儿属约80种,可以明确地分为6组14系。编绘了79个种的分布图,在此基础上,描述了每个种的分布范围和生存生境,以系和组为单位探讨了锦鸡儿属植物各类群的分布规律,并进一步研究了种类形成和演化过程。Sect. Caragana为东亚--蒙古高原分布型,其Ser. Caraganae的种类在东亚地区随纬度的变化呈现出明显的地理替代分布规律, Ser. Microphyllae在蒙古高原地区随经度的干旱梯度变化呈现出清晰的种类替代关系,本组各系间也有明显的地理替代分布现象。Sect. Prunosa为东亚--中亚间断分布型。Sect. Longispina为喜马拉雅分布型。Sect. Tragacan thoides为环青藏高原--北极高山分布型。Sect. Frutescentes广泛分布于亚洲干旱地区。Sect. Chamlagu为东亚分布型。本属种类可分为6个分布型,分布型之间的关系揭示了亚洲干旱区植物区系形成的渊源和联系。Sect. Caragana为本属的原始类群,起源于东亚,曾广泛分布于亚洲大陆,随青藏高原的隆起,原始类群就地分化形成不同的类群,在此基础上迁移分化适应,形成了现代多样的分布格局,中亚为本属的分化中心。     

Abundance and distribution of Legionellaceae in Puerto Rican waters.

Waters in marine and freshwater areas of Puerto Rico were analyzed for the presence of Legionella spp. by direct fluorescent antibody assay with guinea pig confirmation. Several species, including L. bozemanii, L. dumoffii, L. gormanii, L. longbeachae, L. micdadei, and L. pneumophila, were widely distributed among all sites. Legionellaceae, including L. pneumophila, were found in high densities in water collected in the rain forest from epiphytes in trees 30 ft. (about 9.25 m) above the ground. Both interspecific and intersite variations were significant. L. pneumophila was the most abundant species at all sites, with average densities of 10(4) cells ml-1, very close to the range which is potentially pathogenic for humans. Densities of L. pneumophila were highest in sewage-contaminated coastal waters. These are the highest densities of Legionella spp. ever reported for marine habitats. Densities of L. pneumophila were positively correlated with concentrations of sulfates, phosphates, and pH. A survey of 88 fatal atypical pneumonia cases at a Puerto Rico hospital showed that 15% of the patients had L. pneumophila infections. This study establishes L. pneumophila as a relatively common cause of atypical pneumonia in Puerto Rico and suggests natural aquatic habitats as possible sources or reservoirs of pathogenic Legionella spp. in the tropics.     

Notes on the ecology and distribution ofBidens pilosa L. in Cuba

The authors give the known distribution ofBidens pilosa L. in Cuba, discuss some features of its ecology, its diaspore production, and enumerate its parasites known in Cuba.     

Molecular markers reflect differentiation of Fusarium oxysporum forma speciales on tomato and forma on eggplant

Selective pressure induces pathogens to change their method of infection and, sometimes, causes species to become infectious. Pathogenic fungi must differentiate different morphological and physiological properties during the process of host specialization in their life cycle. In the present study, we conducted a genetic investigation and compared similarities within a generation of Fusarium oxysporum forma speciales (f. sp.) infecting tomato and forma (f.) infecting eggplants using selected ISSR and RAPD markers, two horticultural commodities belonging to the same taxon of the Solanaceae. Interestingly, genetic data showed that fungi belonging to F. oxysporum f. sp. infecting tomato have a close genetic relationship with the fungi f. infecting eggplant. Furthermore, F. oxysporum f. sp. infecting tomato showed less genetic variation than F. oxysporum f. melongenae, suggesting that it could be developed more recently during host adaptation. On the other hand, the gene sequence of inter-simple sequence repeat (ISSR) markers resulting in high polymorphism showed matches with gene sequences encoding specific proteins related to pathogenicity of F. oxysporum species. These findings support the notion that selected ISSR markers can be used to follow host-associated divergence of F. oxysporum species infecting tomato and eggplant and that differentiation of their specific genes can also be related to pathogenicity and development as predictive studies before initiating detailed sequencing analysis.     

Observations on Furcellaria fastigiata (L.) Lam. forma aegagropila Reinke in Danish waters together with a note on other unattached algal forms

Summary The unattached populations of Furcellaria fastigiata forma aegagropila in Danish waters exhibit characteristics which are paralleled to a remarkable degree by those possessed by communities of unattached algae in other parts of the world. These characteristics include sterility, multiplication by vegetative means, and the adoption of a form, devoid of holdfast organs, which commonly has a globular or subglobular habit suited to rolling about on the sea bottom. Branching is often profuse and patent and may be accompanied by a thallus diameter far smaller than that of the attached form. Vegetative multiplication may be effected by fragmentation, and, as in F. fastigiata forma aegagropila, by a small accessory lateral branches which function as propagulae. The latter originate in a manner somewhat different from that of the axial regenerated branches produced on decapitated thalli and on thalli which have been more than superficially wounded. Evidence suggests that much of the unattached population of this latter species in the central Kattegat is made up of diploid thalli.All loose lying forms ultimately originate from attached species, which possess or can adopt certain characteristics which enable them to survive in the unattached state.

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Résumé Les colonies sans attaches de Furcellaria fastigiata forma aegagropila dans les eaux danoises montrent des carat`eres qui sont parallèles à un degré remarquable à ceux possédés par d'autres communautés d'algues flottantes dans les autres parties du monde. Ces caractères comprennent la stérilité, la multiplication par des moyens végétatifs, et l'adoption d'une forme, dépourvue d'organes de préhension, généralement sphérique ou quasi sphérique, adapté à se mouvoir sur le fond de la mer. La formation de branches est souvent abondante et évidente et peut être accompagnée d'un diamètre thallique bien plus petit que celui de la forme fixe. La multiplication végétative peut être effectuée par fragmentation, et comme chez F. fastigiata forma aegagropila, par moyen de petites branches latérales accesoires qui fonctionnent comme des propagulae. Ces dernières prennent leur naissance d'une manière quelque peu différente de celle des branches axiales régénérées produites sur thalles décapités et sur thalles qui ont été plus que superficiellement blessés. Léxpérience suggère que beaucoup de colonies flottantes de cette dernière espèce dans le Kattegat central sont formées de thalles de forme diploide.Toutes les formes libres et flottantes prennent leur origine en dernier ressort des espèces fixes, qui poss`edent ou peuvent adopter certains caractères qui leur permettent de survivre dans l'état de liberté.

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Most of the observational work in this paper was carried out in the Department of Botany, Aberystwith.

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Personal communications with Herr Fuglede of Skiber.     

Impact of acidification and eutrophication on macrophyte communities in soft waters in The Netherlands I. Field observations

During the last decades a strong decline has been noticed in the number of waters dominated by “Littorellion” species, mostly isoetids such as Lobelia dortmanna L., Isoetes lacustris L. and Littorella uniflora (L.) Aschers. Sixty-eight waters, which were known to be dominated by L. uniflora after 1950 were investigated. In 1980, L. uniflora appeared to be absent or to have strongly decreased in 53 (78%) of the waters. In 41 of them, Littorella had been replaced by submerged Juncus bulbosus L. and/or Sphagnum spp. These changes seem to have been caused by changed inorganic carbon budgets as a consequence of acidification.In the remaining 12 waters, eutrophication of the water and/or sediment seems to be responsible for the changes in the plant communities. Enrichment with phosphate of the mineral sediment alone, leads to luxurious growth of submerged, rooted macrophyte species such as Myriophyllum alterniflorum DC and Ranunculus peltatus Schrank, whereas phosphate-enrichment of both sediment and water leads to luxurious growth of pleustophytes such as Riccia fluitans L. and Lemna minor L. in small, shallow waters, and to plankton bloom and luxurious growth of epiphytes in larger, deeper waters.In these cases light limitation seems to be responsible for the disappearance or decline of the “Littorellion” species.     

Observations on Furcellaria fastigiata (L.) Lam. forma aegagropila Reinke in Danish waters together with a note on other unattached algal forms

The unattached populations of Furcellaria fastigiata forma aegagropila in Danish waters exhibit characteristics which are paralleled to a remarkable degree by those possessed by communities of unattached algae in other parts of the world. These characteristics include sterility, multiplication by vegetative means, and the adoption of a form, devoid of holdfast organs, which commonly has a globular or subglobular habit suited to rolling about on the sea bottom. Branching is often profuse and patent and may be accompanied by a thallus diameter far smaller than that of the attached form. Vegetative multiplication may be effected by fragmentation, and, as in F. fastigiata forma aegagropila, by a small accessory lateral branches which function as ‘propagulae.’ The latter originate in a manner somewhat different from that of the axial regenerated branches produced on decapitated thalli and on thalli which have been more than superficially wounded. Evidence suggests that much of the unattached population of this latter species in the central Kattegat is made up of diploid thalli. All loose lying forms ultimately originate from attached species, which possess or can adopt certain characteristics which enable them to survive in the unattached state.     

Notes on the distribution ofLepilemur septentrionalis andL. mustelinus in Northern Madagascar

The superfamily Lemuridae, which includes some of the most primitive extant primates, is confined to the island of Madagascar. The speciesL. septentrionalis lives in the north of Madagascar. The geographical distribution of each of the four recognized subspecies is fairly well defined except for the southern limits of the southernmost subspecies, namelyL. s. andrafiamenensis. Similarly the southern and northern limits of distribution ofL. mustelinus are uncertain. Two expeditions were carried out, one in the south of the Andrafiamena mountain chain, the other in the north of the eastern forest, south of Vohemar to gain new information concerning the present southern limits ofL. septentrionalis and northern limit ofL. mustelinus. L. s. andrafiamenensis was found to the left of the Ambilobe-Vohemar road from Betsiaka to Maromokotra and on the left bank of the river Loky, to the coast.L. mustelinus was found only on the right bank of the river Lokoho to the coast. Both survey indicate smaller ranges than those indicated in recent publications, probably a result of continued human encroachment.     

Identification, distribution, and toxigenicity of obligate anaerobes in polluted waters.

A seasonal occurrence of obligately anaerobic bacteria, predominantly of the genera Bacteroides and Clostridium, in a polluted water site has been observed. The number of anaerobes varied from 1.8 X 10(3) cells/ml in the warmer months to 10 cells/ml in winter. Several isolates were toxigenic, indicating a potential human health hazard.