Notes on three algae of small bodies of water

The algae here described are Quadricoccus laevis Fott, Dichotomococcus curvatus Korshikov and Gloeodendron ramosa Korshikov. They were found in Cheshire, England.     

Phytoplankton of small bodies of water

Recent records of Basichlamys sacculifera (Scherff.) Skuja, Pascheriella tetras Korshik., Chrysolykos planktonicus Mack and a species of Quadricoccus Fott are given for Cheshire.     

On two fresh water red algae from Dehradun

Summary The present communication deals with morphological features of a new fresh water species of the genus AcrochaetiumNaëg. (A. sarmaii sp. nov.). The occurrence of Compsopogon iyengarii is also recorded for the first time from a locality in North India.     

Differentiated macrophyte types as a habitat for rotifers in small mid-forest water bodies

The rotifer community structure may be shaped by a variety of environmental factors, including biological parameters, such as predation or competition, as well as by physical-chemical factors, among which the kind of macrophyte substratum and parameters relating to the trophic state and to the catchment area conditions are of great importance. Another impact on rotifer composition, abundance and frequency may be expected when considering differentiated macrophyte types (including helophytes, nymphaeids and elodeids) within a group of eight ponds located within a mid-forest catchment area, which was the main aim of the present study. Detailed analysis on the participation of indicator eutrophic rotifer species provided an additional goal of this investigation in order to qualify the trophic state of this kind of water body located within the Wielkopolska region, in the central western part of Poland. The presence of 117 taxa, including 7 species that are rare or infrequently distributed in the Polish fauna was recorded. The number of taxa and rotifer abundance differed greatly in respect to the specific water body and to the type of substratum. The vegetated zones dominated by elodeids were characterised by the most various and most abundant rotifer communities as well as by the highest values of the Shannon-Weaver index. This reflects a positive relationship between the heterogeneity of habitat and the structure of rotifer communities. It was also found that helophytes and the open water zone possessed the highest, while elodeids the lowest percentage of eutrophic species.     

Notes on freshwater red algae from West Malaysia

This paper deals with a collection of freshwater red algae from Peninsular Malaysia. Five species and one variety of them,Ballia pinnulata, Batrachospermum beraense, B. cylindrocellulare, B. tortuosum, Caloglossa ogasawaraensis var.latifolia andTuomeya gibberosa are described here as new taxa and the other three species,Batrachospermum vagum, Hildenbrandia rivularis andSirodotia delicatula are recorded here for the first time from Malaysia. This is a part of the studies of Lake Bera in the IBP Joint Programme between Malaysia and Japan, supported by the Japan Society for the Promotion of Science.     

Diatom algae from some water bodies of northeastern West Siberia: Communication 2. Pennatophyceae

In the studied water bodies of the northeast of the Western Siberia, Bacillariophyta dominates the flora of planktonic organisms by species abundance. Among them, class Pennatophyceae is distinguished by the highest species richness. The first electron microscopic studies of pennate diatom algae allowed obtaining complete data on the species composition of Pennatophyceae at the modern level. Discovered were 213 taxa from 53 genera, including 98 new to the region, 56 new and rare to the flora of Russia, and forms identified only to the genus. The taxonomy of the genera Nitzchia, Stauroneis, Pinnularia, and Navicula s.s. is the richest.     

Specifics and challenges of assessing exposure and effects of pesticides in small water bodies

Small water bodies (SWB) are freshwater ecosystems of high ecological relevance. However, they receive considerably higher inputs of pesticides compared to larger water bodies owing to their close connection to adjacent agricultural fields in combination with their low water volume or discharge. Monitoring of the pesticide contamination of lentic and lotic SWB is a challenging task as various spatial and temporal factors affect pesticide’s maximum peak concentrations in the water bodies. We present an overview of the major challenges that can complicate the detection of exceedances of regulatory acceptable concentrations. Pesticide data from streams encompassed by the Danish pesticide monitoring program show that the highest pesticide concentrations are found in SWB. A ditch monitoring in a German orchard reveals that event-driven sampling following spray application outperforms the widely used automatic water sampling at fixed intervals, and we therefore suggest that the latter should replace the former in SWB. Furthermore, we suggest that gathering of quantitative data on pesticide pollution of lentic SWB should be given priority in future research.     

Notes on the ecology of some species of fresh-water algae

Summary Data are given on the ecology of some 50 species of fresh-water algae. The response of species to temperature, light intensity and a current of water is recorded in a table and notes on the habitat factors important for most species are given. Data are from both field and laboratory observations. An attempt is made to group species according to their response to important habitat factors.

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Zusammenfassung Angaben über die Ökologie von 50 Arten von Süßwasseralgen werden gegeben. Die Reaktion der Arten auf Temperatur, Lichtstärke und Wasserströmung wird angegeben, zusammen mit Bemerkungen über die Habitatsumstände, die für meiste Arten wichtig sind. Die Angaben stammen von Laboratorien and Feldbeobachtungen.Ein Versuch werde gemacht, die Arten nach ihren Reaktionen auf wichtige Habitatsfaktoren zu klassifizieren.State University of New York at Binghamton

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North Carolina State University at Raleigh     

Control of invasive American bullfrog Lithobates catesbeianus in small shallow water bodies

Setting up cost-efficient control programs for alien invasive species requires the development of adequate removal methods in combination with insights in population size and dynamics. American bullfrog Lithobates catesbeianus is an alien invasive species, which is suspected to cause substantial ecological damage around the globe. However, control of bullfrog populations is difficult, as no conclusive management measures have yet been determined. We investigated how double fyke nets could contribute to bullfrog management by assessing the tadpole population size in 10 permanent small shallow water bodies. Two population size estimate methods were applied, being the catch–depletion and mark–recapture method. Catchability of bullfrog tadpoles proved to be very consistent over ponds and methods, with one catch per unit of effort (one double fyke net for 24 h) retaining on average 6 % of the tadpole population. Population density varied considerably among ponds, ranging from 950 to 120,804 larger tadpole individuals/ha. Using these insights in developing a cost-efficient eradication program for the species, we projected the number of catch efforts needed to reduce tadpole numbers to a threshold that more than likely affects final bullfrog population size. Predictions indicated that for the specified thresholds the use of eight double fyke nets at a time is most cost-efficient in high abundance populations, while using five double fyke nets seems most suitable in low abundance populations. What the exact threshold number of remaining tadpole individuals should be is uncertain, but forecasts demonstrate that only half of the budget would be needed when aiming at a drop to fewer than 100 remaining tadpoles than when a decrease to fewer than 10 remaining tadpoles is pursued. Given the fairly limited cost of bullfrog management with double fyke nets, however, it may be worthwhile to fully reduce the tadpole population.     

The use of rotifer communities to provide a preliminary national classification of small water bodies in England

The rotifer species present in samples from 180 small water bodies, or ponds, in England were identified and listed for each pond. These communities were used to provide a system of classification of ponds applicable on a national basis, using the program TWINSPAN. Sites were also ordinated using DECORANA to identify major trends within the data set. The environmental factors most highly correlated with rotifer community were: (a) conductivity (P<0.001), (b) pH (P<0.001) and (c) permanence of water body (P<0.001). Out of 167 species, 32 were acting as indicators. It is suggested that a pond classification could be based on these species alone.     

The relationship between planktonic algae and bacteria in a small lake

The seasonal changes and vertical distribution of the aerobic and anaerobic bacteria in a small edaphically eutrophic lake which exhibited thermal and chemical stratification are described. There was some correspondence between the phytoplankton and particularly the aerobic bacteria but this was not consistent. Increases in the numbers of anaerobic bacteria coincided with the low dissolved oxygen concentrations in the hypolimnion when algal populations were first senescent and then increasing actively in size.     

Spring bloom development of microbenthic algae and associated invertebrates in two reaches of a small lowland stream with contrasting sediment stability

SUMMARY. 1. Population growth rates and relative competitive abilities of the rotifer Keratella cochlearis f. tecta and the small-bodied cladoceran Daphnia ambigua were studied under different schedules of food addition but equal total food quantity (per 4-day interval). The initial population growth rate of Keratella was significantly affected by the feeding schedule and by the presence of competitors, while that of Daphnia was affected by neither factor. Population densities of both species tended to increase as the frequency of food addition increased.
2. Daphnia suppressed and excluded Keratella from mixed-species cultures when food was provided intermittently at a high concentration, but it failed to exclude the rotifer when food was provided in a near-continuous supply at low concentration. Keratella had only a minor suppressive effect on Daphnia in all mixed-species treatments.
3. Starvation experiments indicate that Daphnia is able to withstand food shortages for significantly longer periods of time than Keratella . These and other results indicate that the outcome of interspecific competition between these species may be influenced by me frequency and concentration at which food is supplied. Daphnia ambigua is competitively superior to K. cochlearis when food is concentrated or 'pulsed', but much less so when ambient food levels are chronically low. Patterns of food availability may have important effects in determining the relative abundance of rotifers and small cladocerans in natural zooplankton communities.     

Developmental expression of a neurofilament-M and two vimentin-like genes in Xenopus laevis

A hamster vimentin cDNA probe has been used to isolate and characterize three Xenopus laevis intermediate filament genes, named XIF1, XIF3 and XIF6. Of these, XIF6 shows 89% homology at the amino acid level to a portion of porcine neurofilament-M. XIF6 is transcribed solely in nervous tissue of embryos, commencing at the late neural tube stage. Expression is totally dependent on an interaction between mesoderm and ectoderm during gastrulation and can be used as a marker of neural induction. XIF1 shows 94% homology and XIF3 83% homology to hamster vimentin at the amino acid level over a region of the protein. Although XIF1 and XIF3 show more homology to vimentin than to any other intermediate filament gene, they have distinct temporal and spatial patterns of expression. XIF1 expression most resembles that of vimentin in higher vertebrates, being expressed in embryonic myotome and nerve cord, whilst XIF3 is unusual in that its expression is restricted predominantly to the head in tailbud embryos.     

Studies on R-phycoerythrins from two Antarctic marine red algae and a mesophilic red alga

R-phycoerythrin was purified from two benthic red algae, Iridaea cordata and Phyllophora antarctica, obtained growing at ?2°C under thick sea ice off the coast of Antarctica. For the I. cordata protein, the molecular mass was 245,000 Da, and its secondary structure was 60% α helix, 17% β sheet, 16% turn, and 7% other. The light-harvesting faculties of the I. cordata protein resembled those of R-phycoerythrins from mesophilic red algae and were distinctive from the novel R-phycoerythrin from P. antarctica. Deconvolution of the visible absorption spectrum of R-phycoerythrin from I. cordata indicated a minimum of five component bands having maxima at 568, 558, 534, 496, and 481?nm. R-phycoerythrins from the mesophilic Porphyra tenera and psychrophilic Phyllophora antarctica had the same five bands. The protein from Phyllophora antarctica obtained its unique spectrum from a more intense component at 482?nm, and a less intense band at 533?nm. This change was probably produced by a replacement of phycoerythrobilin by phycourobilin. A temperature study of the circular dichroism CD was obtained for R-phycoerythrin from I. cordata from 4 to 80°C. Laser time-resolved fluorescence studies on R-phycoerythrin showed bilin to bilin energy transfer with a 60.2-ps lifetime, which should occur by the Förster resonance. The similarities in spectra between the proteins from I. cordata and Porphyra tenera and the different spectrum for the protein from Phyllophora antarctica show that only particular antarctic habitats require unique R-phycoerythrins.     

Centric diatom algae (Centrophyceae) of ultraoligotrophic Lake Elgygytgyn and water bodies of its basin (Chukotka,Russia)

The electron microscopy study of algae from Lake Elgygytgyn and the water bodies of its basin has revealed 21 taxa of centric diatoms of specific and intraspecific ranks. Nine new species and varieties have been found, including Aulacoseira distans var. nivaloides, A. distans var. septentrionalis, Discostella guslyakovyi, which are rare for the flora of Russia; an endemic species (?) Pliocaenicus seckinae; and six interesting forms from the genus Aulacoseira identified only to the genus. The list of Centrophyceae of Beringia has been broadened.