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1.
The diagnosis of the genus Khetella Beisel, 1977 is emended, and a new genus, Cretadmete, is described. Two new species belonging to these genera, K. trautscholdi and C. neglecta, are established from the Upper Hauterivian of Ulyanovsk (Volga Region).  相似文献   

2.
The genus Wolffia of the duckweed family (Lemnaceae) contains the smallest flowering plants. Presently, 11 species are recognized and categorized mainly on the basis of morphology. Because of extreme reduction of structure of all species, molecular methods are especially required for barcoding and identification of species and clones of this genus. We applied AFLP combined with Bayesian analysis of population structure to 66 clones covering all 11 species. Nine clusters were identified: (1) W. angusta and W. microscopica (only one clone), (2) W. arrhiza, (3) W. cylindracea (except one clone that might be a transition form), (4) W. australiana, (5) W. globosa, (6) W. globosa, W. neglecta, and W. borealis, (7) W. brasiliensis, and W. columbiana, (8) W. columbiana, (9) W. elongata. Furthermore, we investigated the sequences of plastidic regions rps16 (54 clones) and rpl16 (55 clones), and identified the following species: W. angusta, W. australiana, W. brasiliensis, W. cylindracea, W. elongata, W. microscopica, and W. neglecta. Wolffia globosa has been separated into two groups by both methods. One group which consists only of clones from North America and East Asia was labelled here “typical W. globosa”. The other group of W. globosa, termed operationally “W. neglecta”, contains also clones of W. neglecta and shows high similarity to W. borealis. None of the methods recognized W. borealis as a distinct species. Although each clone could be characterized individually by AFLP and plastidic sequences, and most species could be bar-coded, the presently available data are not sufficient to identify all taxa of Wolffia.  相似文献   

3.
The chromosomes of two species of Antarctic fishes,Notothenia (Gobionotothen) gibberifrons andNotothenia (Notothenia) coriiceps neglecta, were prepared by the air-drying method at the Polish Antarctic Station “Henryk Arctowski” during the austral summer 1984–1985. ForN. (G.) gibberifrons the diploid number is2n = 46 consisting of 2 metacentric (m) pairs, 1 submetacentric (sm) pair and 20 telocentric (t) or subtelocentric (st) pairs. ForN. (N.) coriiceps neglecta the diploid number is 2n = 22 consisting of 9 m pairs, 1 sm pair and 1st pair. Some aspects of karyological evolution of these fishes are discussed.  相似文献   

4.
A new species of Leptomyxida, named Rhizamoeba neglecta was found during studies of the amoeba fauna of the inner Lake Leshevoe located at Valamo archipelago (The Lake Ladoga, North-Western Russia). Light-microscopical and ultrastructural studies indicated that it represents a new species of Leptomyxida. The partial 18S rDNA sequence of this amoeba is very similar to that of Leptomyxa reticulata.. These organisms, however, are very different in LM morphology and biology. Organisms assigned to the genus Rhizamoeba do not form a single clade in the 18S rDNA tree. This may indicate that the genus is an artificial grouping or that a number of studied strains were misidentified. The phylogeny and the systematics of leptomyxids require further investigation.  相似文献   

5.
This experimental study quantified and compared particle-mixing and solute transport by the polychaetes Marenzelleria neglecta (2 g ww, 3200 ind. m− 2) and Hediste diversicolor (2 g ww, 800 ind. m− 2) in Baltic Sea sediments. Particle tracers (luminophores) were added to the sediment surface and their vertical distribution in the sediment was measured after 10 d. The rate of particle mixing was quantified using a gallery-diffusion model calculating the biodiffusion coefficient Db and the non-local transport parameter r. Bioirrigation was measured by adding an inert solute tracer (bromide) to the overlying water 1, 1.5 and 2 d before the end of the experiment, and quantified by calculating the net bromide flux and fitting the bromide profiles to a 1D diffusion model providing an apparent biodiffusion coefficient Da. The two polychaete worms displayed similar particle-mixing and solute transport efficiencies (based on total biomass) despite different modes of bioturbation. However, H. diversicolor was a more efficient particle-reworker and M. neglecta a more efficient bioirrigator, on an individual level. H. diversicolor buried a higher percentage (13%) of luminophores below the top 0.5 cm surface layer than M. neglecta (6%). Db did not differ between the two species (2.4 × 10− 3 cm2 d− 1) indicating a similar rate of diffusive mixing of the top sediment, however, the non-local transport parameter r was 2.5 y− 1 for H. diversicolor and zero for M. neglecta, suggesting no significant particle-transport below the biodiffusive layer by M. neglecta. The average individual net bromide fluxes obtained were ca. 0.01 mL min− 1 for H. diversicolor and 0.003 mL min− 1 for M. neglecta, corresponding to an area-specific rate of ca. 12 L m− 2 d− 1 at the used densities. Da did not differ between the two polychaetes, suggesting a higher individual solute exchange efficiency of M. neglecta considering the much higher ventilation rates reported for H. diversicolor than for Marenzelleria sp. The ongoing colonization of Baltic Sea sediments by M. neglecta at high densities may thus lead to an enhanced soluble release of both nutrients and contaminants. These results add information to the understanding of the potential effects of the invasion of M. neglecta on sediment biogeochemistry when competing with and/or replacing native species.  相似文献   

6.
Studies of Marenzelleria species were often hampered by identification uncertainties when using morphological characters only. A newly developed PCR/RFLP protocol allows a more efficient discrimination of the three species Marenzelleria viridis, Marenzelleria neglecta and Marenzelleria arctia currently known for the Baltic Sea. The protocol is based on PCR amplification of two mitochondrial DNA gene segments (16S, COI) followed by digestion with restriction enzymes. As it is faster and cheaper than PCR/sequencing protocols used so far, the protocol is recommended for large-scale analyses. The markers allow an undoubted determination of species irrespective of life stage or condition of the worms in the samples. The protocol was validated on about 950 specimens sampled at more than 30 sites of the Baltic and the North Sea, and on specimens from populations of the North American east coast. Besides this test we used mitochondrial DNA sequences (16S, COI, Cytb) and starch gel electrophoresis to further investigate the distribution of the three Marenzelleria species in the Baltic Sea. The results show that M. viridis (formerly genetic type I or M. cf. wireni) occurred in the Öresund area, in the south western as well as in the eastern Baltic Sea, where it is found sympatric with M. neglecta. Allozyme electrophoresis indicated an introduction by range expansion from the North Sea. The second species, M. arctia, was only found in the northern Baltic Sea, where it sometimes occurred sympatric with M. neglecta or M. viridis. For Baltic M. arctia, the most probable way of introduction is by ship ballast water from the European Arctic. There is an urgent need for a new genetic analysis of all Marenzelleria populations of the Baltic Sea to unravel the current distribution of the three species.  相似文献   

7.
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9.
W. John Hayden 《Brittonia》1990,42(4):260-270
Lectotypes are designated forAmanoa caribaea Krug & Urban andA. guianensis Aublet; presumed syntypes of the latter taxon are shown to be heterogeneous by inclusion of a previously unrecognized species. Four new species ofAmanoa are described:A. congesta from French Guiana and northeastern Brazil;A. gracillima from Manaus, Brazil;A. nanayensis from Amazonian Peru and adjacent Colombia and Brazil; andA neglecta from French Guiana and Surinam.Amanoa sinuosa is proposed as a new name for the later homonymA. robusta Leal. A key to the 13 neotropical species is presented.  相似文献   

10.
Although the area of Lake Yeniça?a is a potential candidate for RAMSAR convention, several anthropogenic factors compromise its biological diversity. This is mostly due to nutrient-rich water released from both point and nonpoint sources. Thirteen ostracod taxa (Candona neglecta, C. candida, Ilyocypris bradyi, Darwinula stevensoni, Cypridopsis vidua, Physocypria kraepelini, Cypria ophtalmica, Prionocypris zenkeri, Eucypris virens, Herpetocypris reptans, Pseudocandona compressa, Fabaeformiscandona fabaeformis Potamocypris cf. fulva) were found during this study. Potamocypris cf. fulva is a new record for the Turkish freshwater ostracod fauna. The first nine of these species have broad geographic ranges, implying high tolerance levels to different environmental variables. Based on the estimated species optima and tolerance levels, two species exhibited higher effective number of occurrences (C. neglecta, and D. stevensoni, respectively) than the other species. Three species (C. neglecta, D. stevensoni, I. bradyi) did not show significant correlation with any environmental variable we used. Both Canonical correspondence (CCA) and Pearson correlation analyses showed that temperature was the most effective predictor of species occurrence, followed by electrical conductivity and redox potential. In contrast, pH and dissolved oxygen of water were the least effective predictors. Approximately 71% of the correlation between community composition and environmental variables was explained by the first axis of the CCA diagram, which had a relatively low (7.7%) cumulative variance of species. The lower (560 μg/l) and the upper (2030 μg/l) levels of ammonia (NH3) exceeded the limits during winter season. The concentrations of total coliform and Escherichia coli bacteria were measured up to 10 × 107 cfu/ml and 10 × 103 cfu/ml, respectively. Results of physicochemical measurements, microbiological counts, and species data indicate that water quality of Lake Yeniça?a has been rapidly deteriorated by anthropogenic factors that are the main threat for not only the lake’s aquatic diversity but also human health around the lake.  相似文献   

11.
Kyu-Tek Park 《Journal of Asia》2018,21(3):1085-1093
Based on the material collected from Cameroon in 1913–1918 and Congo in 1993 which are preserved in the Carnegie Museum of Natural History, Pittsburgh, USA, a new genus Thubdora Park, gen. nov. and seven new species of the subfamily Torodorinae (Lecithoceridae) are described. They are Torodora efulenensis sp. nov., Dragmatucha hispidula sp. nov.; and five species of Thubdora: T. acutalis sp. nov., T. bilobella sp. nov., T. aciphalla sp. nov., T. ambliodes sp. nov., and T. cameroona sp. nov. In addition, six species of Lecithocera Herrich-Shäffer described by Viette, 1955, Viette, 1986 and Meyrick, 1931, Meyrick, 1933 are newly transferred to Torodora and its related genera, due to the male genital characters: Idiopteryx adella (Viette, 1955), comb. nov.; Thubdora decavella (Viette, 1955), comb. nov.; Thubdora mocquerysella (Viette, 1955), comb. nov.; Torodora kambanella (Viette, 1986), comb. nov.; Torodora masoalella (Viette, 1955), comb. nov.; Torodora monobyrsa (Meyrick, 1931), comb. nov.; and T. ochrometra (Meyrick, 1933), comb. nov. For the new species, images of adults with their labels and genitalia are provided.  相似文献   

12.
The density of Littorina neglecta Bean from an eelgrass meadow in Nova Scotia was highest in mid-summer (July 1979; 45059 per m2) but fell rapidly during late summer and early autumn due to high mortality of new recruits and two year old individuals. Density remained constant until the following spring when it increased, due to movement of some adults into the study area and the release of young by females (up to ≈ 34000 per m2). During most of the year individuals were found on vegetation (live and dead eelgrass and drift algae) but nearly all moved down to the mud surface during winter to avoid ice (up to 25 cm thick) which was present from December to early March. Movement of ice was not a source of mortality for L. neglecta. Size-frequency histograms showed distinct cohorts and it was possible to follow the growth of year classes. Maximum age was 3 yr and maximum shell height was 4.56 mm. Males and females matured when 1 yr old at 1.7 and 1.8 mm shell height respectively. Size-specific fecundity was very high for such a small littorinid. These life history attributes appeared to be related to the low probability of survival to the maximum age. L. neglecta consumed epiphytes and detrital particles from the surface of eelgrass leaves, and the proportion of eelgrass plants with epiphytes was always low. Grazer exclusion experiments showed that L. neglecta controlled the amount of epiphytes and detritus on eelgrass leaves, and the population thus had a limited food supply. There were significant positive relations between surface area of plants and the numbers of adult and 0 + aged L. neglecta during summer and at that time 0 + individuals were restricted to the base of plants where epiphyte biomass was lowest. Post-recruitment mortality was probably related to intraspecific competition for food. Predation by a naticid gastropod probably accounted for much of the mortality of 2 + aged individuals. L. neglecta has a major positive influence on the growth of eelgrass and probably contributes significantly to nutrient recycling in the eelgrass community.  相似文献   

13.
On the basis of collections from SW Wales and W Ireland it isshown that small (<5 mm) black and/or white Littorina occurringin the barnacle zone on exposed shores, of the L. neglecta shelltype, comprise three species. From their reproductive anatomythese correspond to L. saxatilis, L. arcana and L. nigrolineata,and are interpreted as analogous barnacle-dwelling ecotypesof these species. This adds to the evidence that L. neglectais not a distinct species, but an ecotype of L. saxatilis. (Received 1 June 1992; accepted 23 June 1992)  相似文献   

14.
Uptake of glycine and release of primary amines by the polychaete Nereis virens (Sars) and the mud snail Hydrobia neglecta Muus was investigated. In a flow system, Nereis virens had a net influx of glycine of 32 to 39 nmol·g?1 fresh wt·h from a 5-μM solution of glycine. Simultaneously, an efflux of primary amines of 14 nmol·g?1·h?1 was measured. The experiments indicated that glycine uptake and release of primary amines are two independent processes. Glycine was absorved by Hydrobia neglecta from 50-μM solutions at an influx of 175 nmol·g?1 organic wt·h?1, and simultaneously, there was an independent efflux of 25 nmol primary amine·g?1·h?1. In the experiments, released primary amines from both species increased the ambient concentration of primary amines, but after various periods of time these concentrations apparently stabilized. Finally, the significance of micro-organisms in amino-acid uptake experiments is considered.  相似文献   

15.
The subfamily Candoninae is the most diversified group in the Upper Miocene freshwater deposits of the Turiec Basin (Slovakia). The presence of Candoninae morphologically related to recent as well as Central Paratethys species reveals a problem between taxonomy based on soft body (zoological classification) and taxonomy based on hard part (paleontological classification). The current zoological classification is applied which reflects the real taxonomical relationships between species. The accent was put on the carapace morphological details to distinguish the species. Three described groups (Candona candida, C. neglecta and Candona of group indet) contain 7 new species – Candona densa, C. mocki, C. imaginaria, C. margueritae, C. singularis, C. sirveni et C. vahica.  相似文献   

16.
The monogonont Rotifera fauna of Lobo (Broa) reservoir (SP., Brazil), present in 12 samples collected on a single date during the cool season (26 August 1994), is listed and commented upon. In total, 102 species could be identified, three of which, Ascomorpha tundisii n.sp., Lecane broaensis n.sp. and Lepadella neglecta n.sp. are new to science. Lecane mitis Harring & Myers and Lepadella elongata Koste are redescribed. A note on the taxonomy of the Ascomorpha saltans-group is added.  相似文献   

17.
Recently we proposed that Rhodococcus equi (Magnusson 1923) Goodfellow and Alderson 1977 be transferred to a novel genus, Prescottia, as Prescottia equi comb. nov. However, in accordance with Principle 2 and Rule 51b(4) of the Bacteriological Code (1990 Revision), the bacterial genus name Prescottia Jones et al. 2013 is deemed illegitimate as this name has been used previously for a plant genus within the family Orchidaceae. Consequently, a new genus name, Prescottella gen. nov. is proposed for the bacterial taxon and a new combination Prescottella equi comb. nov. is proposed for the type species.  相似文献   

18.
In 1876 I.A. Portschinsky described two species of Diptera: Urellia muscipora Portschinsky (Tephritidae) and Phlebotomus grimmi Portschinsky (Psychodidae–Phlebotominae). The former name is a senior synonym of Goniurellia tridens (Hendel, 1910), but it was not used as a valid name since 1876 and should be rejected according to Articles 23.9.1.1 and 23.9.1.2 of the ICZN. The name Phlebotomus grimmi was in use in 1926–1984 as a valid name and as a senior synonym of Ph. sergenti Parrot, 1917 or Ph. caucasicus Marzinovsky, 1917. It is necessary to appeal to the International Commission on Zoological Nomenclature to establish the status of Phlebotomus grimmi Portschinsky, 1876.  相似文献   

19.
Summer blooms of the toxin-producing cyanobacteria Nodularia spumigena are frequent in the Baltic Sea and recent findings suggest that they may be an important food source for the benthos below the euphotic zone. To investigate the effects of settling spring and summer phytoplankton blooms on meiofaunal growth, we assayed concentrations of nucleic acids in three ostracod species (Candona neglecta; Heterocyprideis sorbyana and Paracyprideis fennica) and one genus of nematodes (Paracanthonchus spp.) after incubation in sediments with the one of the following food additions: (1) diatoms, (2) the cyanobacterium Nodularia spumigena, (3) Tetraphyll® as a known high-quality food source, (4) lignin as a refractory artificial food, and (5) control (no added organic matter). The ribosomal ribonucleic acid (RNA) content and RNA:DNA ratios of the tested organisms were lower in the cyanobacteria treatment than in the diatom treatment, with the difference in RNA:DNA ratios being statistically significant for all species except C. neglecta. Moreover, individuals incubated with N. spumigena showed RNA:DNA levels similar to those found in the lignin and control treatments. Furthermore, N. spumigena had lower concentrations of both enzymatically hydrolysable amino acids (EHAA) and eicosapentaenoic acid (EPA) than diatoms suggesting lower nutritional quality for consumers. These results indicate that recently settled summer blooms of N. spumigena are nutritionally poor and do not improve conditions for meiofaunal growth in Baltic sediments. In contrast, input of diatoms to the sediments during spring is crucial for meiofaunal growth.  相似文献   

20.
Digenetic trematodes are widespread among mud snails (Hydrobiidae) living in coastal lagoons and estuaries, but knowledge is generally lacking on their impact on these host organisms. We examined the survival rates of infected and non-infected experimental populations of two mud snail species,Hydrobia ventrosa (Montagu) andHydrobia neglecta Muus, exposed to desiccation, freezing and anoxia in the laboratory. Our experiments indicated that non-infected groups of both species had similar survival rates after being subjected to desiccation and anoxia, whereasH. ventrosa survived freezing better thanH. neglecta. However, infected groups ofH. neglecta specimens subjected to desiccation showed significantly lower survival rates than non-infected groups. Infected and non-infected snails of both species exposed to freezing and anoxia exhibited similar survival rates. The possible mechanisms by which parasites influence their hosts are discussed. It is unlikely that the parasites in the present case mediate the coexistence of the twoHydrobia-species, because the snail with the highest reproductive effort-H. neglecta-showed lower infection rates in situ than its congenerH. ventrosa.  相似文献   

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