Heliozoa (Centrohelea,Haptista, Hacrobia) of saline and brackish water bodies and watercourses of Russia

The species composition of centrohelid heliozoa (Centrohelida) in saline and brackish inland water bodies and watercourses with salinity 2.0–42.2‰ was studied in the subarid zone of Russia. Nine species (Polyplacocystis ambigua, Pterocystis foliacea, Choanocystis ebelii, Acanthocystis astrakhanensis, A. dentata, A. myriospina, A. pectinata, A. taurica, A. turfacea) are new for saline and brackish inland waters. A. astrakhanensis and A. taurica are new for the fauna of Orenburg region. The first data on centrohelidian fauna in saline rivers of Elton region were obtained. The fauna comprises Polyplacocystis ambigua, Pterocystis foliacea, A. turfacea and Choanocystis ebelii. C. ebelii is new for the protist fauna of Russia. Five species (Polyplacocystis ambigua, Pterocystis foliacea, A. pectinata, A. dentata, A. taurica) were recorded for the first time in saline and brackish waters and described as eurihaline. Morphological diagnoses of Acanthocystis dentata and A. taurica were completed.     

The systematics of Zoochlorella revisited employing an integrative approach

Symbiosis of green algae with protozoa and invertebrates has been studied for more than 100 years. Endosymbiotic green algae are widely distributed in ciliates (e.g. Paramecium, Stentor, Climacostomum, Coleps, Euplotes), heliozoa (e.g. Acanthocystis) and invertebrates (e.g. Hydra, Spongilla), and have traditionally been identified as named or unnamed species of Chlorella Beij. or Zoochlorella K. Brandt or referred to as Chlorella‐like algae or zoochlorellae. We studied 17 strains of endosymbionts isolated from various hosts and geographical localities using an integrative approach (nuclear encoded small subunit and internal transcribed spacer regions of rRNA gene sequences including their secondary structures, morphology, physiology and virus sensitivity). Phylogenetic analyses have revealed them to be polyphyletic. The strains examined belong to five independent clades within the Trebouxiophyceae (Choricystis‐, Elliptochloris‐, Auxenochlorella‐ and Chlorella‐clades) and Chlorophyceae (Scenedesmus‐clade). The most studied host organism, Paramecium bursaria, harbours endosymbionts representing at least five different species. On the basis of our results, we propose a taxonomic revision of endosymbiotic ‘Chlorella’‐like green algae. Zoochlorella conductrix K. Brandt is transferred to Micractinium Fresen. and Zoochlorella parasitica K. Brandt to Choricystis (Skuja) Fott. It was shown that Choricystis minor (Skuja) Fott, the generitype, is a later heterotypic synonym of Choricystis parasitica (K. Brandt) comb. nov. A new species, Chlorella heliozoae, is proposed to accommodate the endosymbiont of Acanthocystis turfacea.     

Biochemical Taxonomy of Symbiotic Chlorella Strains from Paramecium and Acanthocystis*

Biochemical and physiological characters of 5 symbiotic Chlorella strains, 4 of them from Paramecium (Ciliata) and one from Acanthocystis (Rhizopoda, Heliozoa), were studied. Four strains (3 from Paramecium and one from Acanthocystis) belong to the same species. This is characterized by the presence of hydrogenase, no formation of secondary carotenoids, no growth on mannitol, requirements for thiamine and vitamin B₁₂, and a G + C content of the DNA of 66.4–68.4 mol%; the limits of growth are at pH 5.5, at up to 1% NaCl, and at 26–30°C. The strains are somewhat heterogeneous in their utilization of inorganic nitrogen sources: only two of them are able to use nitrate, whereas all can grow with nitrite and ammonium. Thus, in two strains the nitrate-reducing system — in contrast to nitrite reductase — seems to be defective. Another strain, which has been claimed to be from Paramecium, belongs to C. protothecoides.     

Maltose excretion by the symbiotic Chlorella of the heliozoan Acanthocystis turfacea

Chlorella sp. strain 3.83, a symbiotic Chlorella isolated from the heliozoan Acanthocystis turfacea, excreted between 8% and 16% of assimilated ¹⁴CO₂ as maltose in the light (15000 lx), with a pH optimum around 4.8. This percentage increased when the illuminance was lowered (36% at 1700 lx). Release of [¹⁴C]maltose continued in darkness and could be inhibited by the uncoupler carbonyl cyanide p-trifluoro-methoxyphenylhydrazone and by diethylstilbestrol. Net efflux of maltose was observed even at a concentration ratio of extracellular/intracellular maltose of 7.8. Exogenous [¹⁴C]maltose (5 mM) was taken up by the cells with a rate <2% of that of simultaneous maltose release, indicating a practically unidirectional transport. It is concluded that maltose excretion is an active-transport process.Abbreviations DES diethylstilbestrol - FCCP carbonyl cyanide p-trifluoromethoxyphenyl hydrazone - p.c. packed cells This work was supported by the Deutsche Forschungsgemeinschaft. Thanks are due to Doris Meindl for skillful experimental help.     

Redescription of Piguetiella denticulata (Annelida, Clitellata, Naididae) from Japan and the Russian Far East, with a description of the genital organs in the species

A naidid oligochaete, Piguetiella denticulata Liang and Xie (Invertebrates of Wuling Mountains area, Southwestern China, pp 383–394, 1997), is redescribed based on new material from Japan and the Russian Far East, and its generic position is verified by an examination of the reproductive organs. P. denticulata closely resembles P. michiganensis in lacking eyes and dorsal hair chaetae, but it is distinguished from the latter by having intermediate teeth on both its dorsal and ventral crotchets. In Japan, P. denticulata is widely distributed and often abundant in mountain streams with sandy and gravelly bottoms.     

<Emphasis Type="Italic">Dicrogaster perpusilla</Emphasis> Looss, 1902 <Emphasis Type="Italic">sensu</Emphasis> Sarabeev &; Balbuena (Digenea: Haploporidae): a note of caution

Sarabeev & Balbuena (2003) considered Dicrogaster perpusilla Looss, 1902 and D. contracta Looss, 1902 (Digenea: Haploporidae) synonymous. They designated a neotype for the type-species, D. perpusilla, from a sample of specimens ex Chelon labrosus off West Thurrock, UK. The morphology of the material (three specimen lots) studied by these authors was re-examined in detail and compared with their data. The material labelled ‘D. perpusilla’ from off West Thurrock, from which the neotype specimen was selected, consists of 14 specimens; of these one might belong to Haploporus Looss, 1902 and one to Haplosplanchnus Looss 1902. A well-developed genital atrium was observed in 11 of the 12 remaining specimens, and they all possess large saccular caeca and a vitellarium consisting of two groups of loosely coalesced follicles rather than two compact masses. These features suggest that the 12 specimens of this lot may belong to Saccocoelium Looss, 1902, but the state of the material does not permit its reliable identification. The specimen designated by Sarabeev & Balbuena (2003) as the neotype of D. perpusilla represents a neogravid dorso-laterally mounted specimen and is unrecognisable. Although five of the six voucher specimens of these authors may represent Dicrogaster spp., the poor state of this material does not allow its accurate identification. The metrical data obtained from this voucher material indicate that juvenile and laterally mounted specimens have been used in the comparisons upon which the synonymy of D. perpusilla and D. contracta was suggested. The overall conclusion of the study is that the synonymy of D. contracta and D. perpusilla proposed by Sarabeev & Balbuena (2003) is based on questionable material. Since the neotype of D. perpusilla is unrecognisable, and a number of qualifying conditions of the ICZN in its designation were not met, the usage of the original conception of the type-species of Dicrogaster given by Looss (1902) is recommended.     

A New Species of Centrohelid Heliozoan Acanthocystis amura n. sp. Isolated From Two Remote Locations in Russia

A new species of centrohelid heliozoan Acanthocystis amura from the Amur River, the Far East of Russia was studied with light‐ and electron microscopy. Acanthocystis amura has simple oval plate scales (1.2–2.6 × 1.0–1.8 μm) with an axial thickening and a thin border as well as two types of spine scales. The spine scales of type 1 were 1.3–4.8 μm long and had four small hooks on their tips. The spine scales of type 2 were shorter, 1.0–3.6 μm long and had four teeth at the distal end. The morphology of A. amura resembles that of Acanthocystis quadrifurca. They both have similar spine scales but their plate scales are completely different. Acanthocystis valdiviense differs from the new species in absence of hook‐bearing scales. Molecular phylogeny based on 18S rDNA consistently placed A. amura into Acanthocystis nichollsi/Acanthocystis costata clade, but relationships between those three species were not resolved. Morphology of another centrohelid strain from another location (the South Urals) has been compared with that of the original strain and few minor differences in size characteristics of the scales have been revealed.     

Siliceous scales of filose-amoebae (Pompholyxophryidae,Rotosphaerida) from deep Southern Ocean sediments,including first records for the Southern Hemisphere

The world of protists remains largely unexplored. A thorough electron-microscopic investigation of a few microlitres of deep-sea sediment from 2,964 m water depth near the South Sandwich Islands (Southern Ocean) revealed siliceous scales of filose-amoeba protist species, two of which have not been reported previously from Antarctica or from elsewhere in the Southern Hemisphere. However, all the species are known from other oceans and, in one case, from freshwater habitats. The Antarctic protistan scales belong to four species of filose amoebae: Pinaciophora fluviatilis Greef 1869, Pinaciophora denticulata Thomsen 1978, Pinaciophora multicosta Thomsen 1978 and Rabdiaster reticulata (Thomsen 1979) Mikrjukov 1999 nov. comb. Our study shows that (1) none of the species has been recorded from the Australasian biogeograpical region, (2) Pinaciophora multicosta and Rabdiaster reticulata are new records for the Southern Ocean and for the Southern Hemisphere as a whole, (3) prior to this investigation, Pinaciophora multicosta had been reported once only, from the Baltic Sea (Europe). These results highlight the problem of undersampling in the study of the global distribution of protists.     

Armeria saviana sp. nov. (Plumbaginaceae) from central Italy

The new species Armeria saviana, endemic to an isolated mountain chain of the Tyrrhenian Antiappennine system in south Tuscany, central Italy, is described and illustrated. The plant is diploid with 2n=18. It can be distinguished from the related species A. denticulata (Bertol.) DC and A. canescens (Host) Ebel, mainly by leaf characters, capitula, bracts and flowers. The systematic position of the controversial taxon A. majellensis Boiss. subsp. ausonia F. Bianchini, to which the new species has formerly been assigned by some authors, is discussed. A lectotype for A. denticulata is designated.     

Zelandoperla maungatuaensis sp. n. (Plecoptera: Gripopterygidae), a new flightless stonefly species from Otago,New Zealand

ABSTRACT

A new wing-reduced species of the stonefly genus Zelandoperla Tillyard is described from Otago, New Zealand. Zelandoperla maungatuaensis sp. n. differs from a related species, Z. denticulata, primarily by lacking full wing development. We used morphological, geographical, and genetic evidence to assess the proposed status of Z. maungatuaensis sp. n. and Z. denticulata as separate monomorphic species, as opposed to conspecific members of a polymorphic species. High genetic divergence was found between distinctly allopatric populations, supporting the status of Z. maungatuaensis sp. n. as a distinct monomorphic species.     

The spores of Pteris cretica complex (Pteridaceae-Pteridophyta) in America

Spore morphology in the Pteris cretica complex, including Pteris brasiliensis, P. ciliaris, P. cretica, P. denticulata var. denticulata, P. denticulata var. tristicula, P. ensiformis, P. multifida and P. mutilata was examined using light and scanning electron microscope. The spores are trilete, triangular to circular in shape, with an equatorial thickening (= cingulum). Equatorial diameter ranges from 29 to 69 μm, and polar diameter from 18 to 53 μm. Exospore is proximally verrucate and distally rugate, with the exception of Pteris ensiformis, which has cones on both polar faces. Perispore is generally less than 1 μm thick, apparently single-layered in section, and translucent under light microscope. Spheroids were frequently observed on the surfaces of both perispore and exospore. Hyaline spores lacking cingulum were found in all specimens. Pteris brasiliensis, P. cretica and P. denticulata exhibit pronounced polymorphism and, in addition to trilete spores these taxa also produce atypical spores such as tetralete, monolete and intermediate types.     

Are tortoises important seed dispersers in Amazonian forests?

According to most studies on seed dispersal in tropical forests, mammals and birds are considered the main dispersal agents and the role played by other animal groups remains poorly explored. We investigate qualitative and quantitative components of the role played by the tortoise Chelonoidis denticulata in seed dispersal in southeastern Amazon, and the influence of seasonal variation in tortoise movement patterns on resulting seed shadows. Seed shadows produced by this tortoise were estimated by combining information on seed passage times through their digestive tract, which varied from 3 to 17 days, with a robust dataset on movements obtained from 18 adult C. denticulata monitored with radio transmitters and spoon-and-line tracking devices. A total of 4,206 seeds were found in 94 collected feces, belonging to 50 seed morphotypes of, at least, 25 plant genera. Very low rates of damage to the external structure of the ingested seeds were observed. Additionally, results of germination trials suggested that passage of seeds through C. denticulata’s digestive tract does not seem to negatively affect seed germination. The estimated seed shadows are likely to contribute significantly to the dispersal of seeds away from parent plants. During the dry season seeds were dispersed, on average, 174.1 m away from the location of fruit ingestion; during the rainy season, this mean dispersal distance increased to 276.7 m. Our results suggest that C. denticulata plays an important role in seed dispersal in Amazonian forests and highlight the influence of seasonal changes in movements on the resulting seed shadows.     

Description of Bryceella perpusilla n. sp. (Monogononta: Proalidae), a New Rotifer Species from Terrestrial Mosses,with Notes on the Ground Plan of Bryceella Remane, 1929

We here describe the new proalid rotifer species Bryceella perpusilla n. sp. on the basis of light and electron microscopy. The species, certainly representing one of the smallest rotifer and even metazoan species at all, was obtained in January 2008 from terrestrial mosses of North‐west Germany. Bryceella perpusilla n. sp. is distinguished from other species of the genus by the very small size, the slender body outline, the short apical styli, the triangular rostrum, the outward curving, blunt and rod‐shaped toes, the four‐nucleated vitellogermarium, the slender manubria and the caudally directed alulae. With our observations, that can be used for future cladistic analyses of the Proalidae, we are able to define the generic diagnosis of Bryceella more precisely and to give an adapted species key. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Molecular phylogeny, scale evolution and taxonomy of centrohelid heliozoa

Heliozoa are ubiquitous, unicellular phagotrophs with slender radiating axopodia for trapping prey. We sequenced 18S rRNA genes from 35 cultured centrohelid heliozoa (18 studied by electron microscopy) and 28 environmental libraries (18 freshwater, 10 marine), yielding 97 new sequences, this exceeding described species. Phylogenetic analyses show two major groups and that ancestral centrohelids probably had inner plate-like tangential and distinct outer radial silica scales, the latter diverging early into contrasting scale types seen in extant Pterocystis/Choanocystis and Acanthocystis/Raphidiophryidae. Scales were lost at least thrice. Pterocystis is paraphyletic, as was the classical family Acanthocystidae; Heterophrys was polyphyletic. Using scale morphology and rRNA sequences, we establish new families Pterocystidae (Pterocystis, Raineriophrys, Chlamydaster), Marophryidae (type Marophrys (Heterophrys) marina gen. et comb. nov.) and Choanocystidae, new suborders Pterocystina (Pterocystidae, Choanocystidae, Heterophryidae) and Acanthocystina (Acanthocystidae, Raphidiophryidae, Marophryidae), and ten new Pterocystis, Acanthocystis and Choanocystis species. Most clades are exclusively freshwater or exclusively marine; evolutionary transitions between these habitats have been rare.     

Copulatory Mechanics in the Funnel-web Spiders Histopona torpidaand Textrix denticulata(Agelenidae,Araneae)

The functional morphology of the copulatory organs of Histopona torpida(C. L. Koch, 1834) and Textrix denticulata(Olivier, 1789), investigated by semi-thin serial sectioning after freeze-fixation of the animals in copula, is described. In H. torpida, the long embolus runs through a precisely defined course in the membraneous genital pouch of the female vulva. The patellar apophysis locks the pedipalp in the female epigastric furrow. In T. denticulatathis is accomplished by the retrolateral tibial apophysis that gets hold at the female scape. In both species the conductor has a locking as well as a guiding function for the embolus. A comparison with previously investigated agelenids shows a surprising diversity in the function of the retrolateral tibial apophysis.     

Seed and Embryo Germination in Syringa vulgaris and S. reflexa as Affected by Temperature during Seed Development

A nitrogen source was needed for the flowering of Lemna gibba L., a long-day plant, and L. perpusilla Torr., a shortday plant. The level of endogenous amino acids analyzed by an Amino Acid Analyzer, rose during the first few inductive cycles, but was reduced during later stages of the flowering process. Serine and threonine levels increased during the light period and decreased during the dark period in L. perpusilla. Exogenous serine and threonine added to the culture medium at 10^?6M increased the rate of flowering by more than 35% over the controls. Cysteine inhibited flowering, while other amino acids had little or no promotive effect on flowering. Serine and threonine increased flowering rate in L. perpusilla only when added during a dark period of the inductive cycle. The addition of amino acids during a light period not followed by a dark period had no effect on flowering.     

Red- and yellow-footed tortoises, <Emphasis Type="Italic">Chelonoidis carbonaria</Emphasis> and <Emphasis Type="Italic">C. denticulata</Emphasis> (Reptilia: Testudines: Testudinidae), in South American savannahs and forests: do their phylogeographies reflect distinct habitats?

Using sequence data of the mitochondrial cytochrome b gene, we investigated phylogeographic differentiation of the Amazonian tortoise species Chelonoidis carbonaria and C. denticulata. While C. carbonaria is generally restricted to savannah habitats and adjacent forests, C. denticulata is associated with wet tropical and subtropical forests. Our study suggests a correlation between distinct habitat preferences and phylogeography of the two species. In Maximum Parsimony, Maximum Likelihood and Bayesian analyses, haplotypes of C. carbonaria cluster in several distinct clades reflecting the species’ patchy distribution in savannah habitats. By contrast, haplotypes of C. denticulata are only weakly differentiated; a finding also confirmed by parsimony network analysis. This suggests that the contiguous Amazonian rainforest allows gene flow between populations of the forest-dwelling C. denticulata throughout the range, but significantly impedes gene flow in C. carbonaria. The phylogeographic structure and extant distribution pattern of C. carbonaria is supportive of former Amazonian rainforest fragmentation, enabling the dispersal of savannah species. Based on fossil calibration, we dated divergence times for the C. carbonaria clades using a relaxed molecular clock, resulting in average estimates ranging from 4.0–2.2 mya. This implies that the onset of rainforest fragmentation could predate the Pleistocene considerably. Furthermore, our findings call for further research on geographic and taxonomic variation in C. carbonaria and for a reassessment of the conservation status of the distinct genetic units.     

印度血桐与中平树基因组调查及SSR分子标记分析

印度血桐与中平树是大戟科血桐属植物,该属植物具有多种药用价值,被广泛应用于民间医学中许多疾病的治疗,这两种植物种子中含有的神经酸也引起了研究者的高度关注。为确定适合印度血桐与中平树的全基因组测序研究策略,该研究采用二代高通量测序技术,结合生物信息学的方法首次测定了印度血桐与中平树的基因组大小、杂合率、重复率等基因组信息并初步分析了两种材料的SSR序列特征。结果表明:(1)印度血桐与中平树的基因组大小分别为986.84和946.23 M。(2)印度血桐与中平树的杂合率分别为0.75%和0.65%,重复序列比例分别为73.02%和71.5%。(3)通过对2种材料基因组序列的SSR特征分析,在印度血桐中共鉴定了4 499 185个SSR,在中平树中共鉴定了4 969 098个SSR。该研究结果为印度血桐与中平树SSR分子标记的筛选、开发以及全基因组深度测序提供了理论指导。