SURVEY OF SWIMMING POOL ALGAE OF THE PHOENIX, ARIZONA, METROPOLITAN AREA1

Thirteen genera of algae were collected and identified from 110 swimming pools in the metropolitan area of Phoenix, Arizona. They included seven cyanophytes (Calothrix, Lyngbya, Oscillatoria, Nostoc, Phormidium, Plectonema, Pleurocapsa), four chlorophytes (Chlamydomonas, Diogenes, Oocystis, Roya), and two chrysophytes (Pleurochloris, Nitzschia). Pleurochloris pyrenoidosa Pascher was the most common swimming pool alga, occurring in 67% of the pools sampled. Species of Phormidium and Plectonema were the next most abundant, with species of Chlorophyta least common, occurring in less than 5% of the swimming pools surveyed. Algae occurred in swimming pools under a wide range of physicochemical conditions. A correlation between physicochemical parameters monitored and the appearance of a particular algal species was not evident.     

Effects of laundry wastewater on benthic algae in ditches in the Netherlands

Summary A modified, artificial substrate method was used to study the effects of laundry wastewater on benthic algae in a polder in the western part of the Netherlands. In a polluted ditch a clear chemical gradient was found with regard to the parameters conductivity, B.O.D., C.O.D., NH₄, ortho-P, total-P and Cl, showing decreasing values with increasing distance from the polluting source. pH and oxygen values showed the opposite. Algae, such asEuglena viridis, Nitzschia palea andOscillatoria spp. were positively correlated with the amount of pollution, while others, such asChrysochaete brittannica, Chrysophaera gallica, Cocconeis placentula andSynedra ulna showed a negative correlation with the amount of pollution. The results of algal counts are evaluated by means of diffenent methods,e.g. similarity coefficients, species abundance curves, diversity and saprobity indices. In different seasons benthic algal biomass proved to be a good indicator of pollution, except very close to the polluting source. The role of algal periodicity, influencing species composition, diversity and saprobity values, and biomass growth, has been discussed. The need of revising the saprobity system for stagnant ditches in the Netherlands, using artificial substrates, has been stressed.     

Diatoms as water quality indicators in the upper reaches of the Great Fish River,Eastern Cape,South Africa

This study focused on the spring-fed upper reaches of the economically important Great Fish River with the aim of determining if diatoms could be used for biomonitoring in semi-arid conditions in southern Africa. Five sites were monitored monthly from 2010 to 2012. Of the 269 diatom taxa belonging to 51 genera identified, the dominant taxa were mostly those considered to be pollution-tolerant: Amphora pediculus, Craticula buderi, Fragilaria biceps, Nitzschia frustulum, Nitzschia paleacea, Planothidium lanceolatum and Rhopalodia gibba. A number of diatom-based numerical indices were used to infer water quality, including the generic diatom index, the specific pollution sensitivity index, the biological diatom index, and percentage pollution-tolerant valves, which forms part of the UK trophic diatom index. All index scores showed the Great Fish River to be impacted, and showed significant correlations of diatom species abundance with pH, NO₃-N, electrical conductivity, NH4-N and CaCO_3. Analysis revealed EC and NO3-N as the main environmental drivers affecting diatom community composition, followed by pH and PO4-P. The percentage of diatom deformities at all sites was high, at 3.5%. Diatom indices showed the river to be impacted by decades of agricultural activity, which was confirmed by chemical water analysis. Thus diatom indices can be used for biomonitoring in semi-arid areas.     

The evolution of glutathione metabolism in phototrophic microorganisms

Summary Of the many roles ascribed to glutathione (GSH) the one most clearly established is its role in the protection of higher eucaryotes against oxygen toxicity through destruction of thiol-reactive oxygen byproducts. If this is the primary function of GSH then GSH metabolism should have evolved during or after the evolution of oxygenic photosynthesis. That many bacteria do not produce GSH is consistent with this view. In the present study we have examined the low-molecular-weight thiol composition of a variety of phototrophic microorganisms to ascertain how evolution of GSH production is related to evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols to fluorescent derivatives, which were analyzed by highpressure liquid chromatography. Significant levels of GSH were not found in the green bacteria (Chlorobium thiosulfatophilum andChloroflexus aurantiacus). Substantial levels of GSH were present in the purple bacteria (Chromatium vinosum, Rhodospirillum rubrum, Rhodobacter sphaeroides, andRhodocyclus gelatinosa), the cyanobacteria [Anacystis nidulans, Microcoleus chthonoplastes S.G., Nostoc muscorum, Oscillatoria amphigranulata, Oscillatoria limnetica, Oscillatoria sp. (Stinky Spring, Utah),Oscillatoria terebriformis, Plectonema boryanum, andSynechococcus lividus], and eucaryotic algae (Chlorella pyrenoidsa, Chlorella vulgaris, Euglena gracilis, Scenedesmus obliquus, andChlamydomonas reinhardtii). Other thiols measured included cysteine, -glutamylcysteine, thiosulfate, coenzyme A, and sulfide; several unidentified thiols were also detected. Many of the organisms examined also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability that was quenched by treatment with 2-pyridyl disulfide or 5,5-bisdithio-(2-nitrobenzoic acid) prior to reaction with mBBR. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of reactive disulfides. The distribution of GSH in phototrophic eubacteria indicates that GSH synthesis evolved at or around the time that oxygenic photosynthesis evolved.     

Daphnids respond to algae-associated odours

Using a Y-tube olfactometer, it was found that Daphnia galeatax hyalina moves to the arm with odour from either of two ediblealgal species (Scenedesmus acuminatus and Oscillatoria limnetica)rather than to the alternative arm with clean water. However,no differential response was observed when odours of the toxiccyanobacterium (Oscillatoria agardhu) were tested. We suggestthat odours associated with edible algae attract Daphnia whereasnon-edible algae do not elicit attraction of Daphnia.     

The ingestion and assimilation of algae by Nais elinguis (Oligochaeta: Naididae)

Summary Nais elinguis was offered equal densities of three algal species under controlled conditions. Colonies of Scenedesmus quadricauda were ingested at significantly lower rates than cell of Nitzschia kutzingiana and Chlorella vulgaris. Labelled cells of N. kutzingiana were more rapidly and more efficiently assimilated than those of the other algae. Cells of S. quadricauda were viable in the faeces.This work confirmed conclusions from other studies with respect to the role of algae in the nutrition of Nais elinguis and other freshwater benthic herbivores.     

Population dynamics and ecology of subdominant phytoplankton species in a shallow hypertrophic lake (Albufera of Valencia,Spain)

Long-term population dynamics and ecology of the abundant but non-dominant phytoplankton species of the shallow hypertrophic lake the Albufera of Valencia (Spain) are described for the period 1980–1988. The lake is used as a reservoir for the surrounding ricefield cultivation. It is continuously dominated by three filamentous blue-green algae, Planktothrix agardhii, Pseudanabaena galeata and Geitlerinema sp. Horizontal differences of the phytoplankton were less important than annual and seasonal variations. An annual increasing trend was observed for Planktolyngbya subtilis, Planktolyngbya contorta, Cylindrospermopsis raciborskii, Microcystis incerta, Nitzschia palea var. tenuirostris and Rhodomonas lacustris var. nannoplanctica, whereas Anabaenopsis elenkinii, Scenedesmus acuminatus, Scenedesmus quadricauda and Cyclotella meneghiniana showed an opposite trend. This pattern seems related to the increase of nitrogen and phosphorus loading in the lake and certain hydrological changes occurred in the latter years of the study. Seasonal pattern of the subdominant species showed the presence of Cyclotella meneghiniana, Scenedesmus species and Chlamydomonas spp. in spring, during moderate water renovation rates and phosphate availability. Periodicity shifted to blue-green algae and Nitzschia species in summer and early autumn, during reduced phosphate levels and initial low but later high water renewal. Autumn and winter species, such as Monoraphidium contortum, Nitzschia gracilis, Rhodomonas lacustris var. nannoplanctica and Cryptomonas erosa, were mainly related to light intensity and temperature. Although the lake has a typical hypertrophic phytoplankton assemblage, the general seasonal variation of the species is similar to that often described in temperate lakes. Diatom species composition differs to that cited in other shallow hypertrophic lakes of Europe.     

Microalgae for use in tropical aquaculture I: Gross chemical and fatty acid composition of twelve species of microalgae from the Northern Territory,Australia

Twelve species of microalgae, isolated from north Australian marine, freshwater and hypersaline environments, were grown under controlled conditions of temperature, pH, photon flux density and salinity, and analysed for ash, total protein, water soluble carbohydrates, chlorophylla, total lipids, total fatty acids and fatty acid composition. Highest levels of the polyunsaturated fatty acid eicosapentaenoic acid [20:5(n-3)] were found in the marine diatoms.Nitzschia (frustulum) andN. closterium (23.1% and 15.2% of total fatty acids, respectively). None of the species studied had levels of docosahexaenoic acid [22:6(n-3)] greater than 1.1 % of total fatty acids. None of the chlorophyte species contained significant levels of either 20:5(n-3) or 22:6(n-3). The highest total fatty acid concentration of all species in the study was found in the freshwater chlorophyte speciesScenedesmus dimorphus (105 mg g^–1 dry wt). The hypersaline speciesDunaliella salina had the highest total lipid content (28.1% dry wt), followed byN. closterium, N. (frustulum) andNavicula sp. (24.2–27.8% dry wt).Chlamydomonas sp. had the highest protein content (66.9% dry wt).N. (frustulum) was highlighted as a possible useful source of lipids and polyunsaturated fatty acids in mixed microalgal diets for mariculture organisms used in tropical aquaculture.Author for correspondence     

Sucrose metabolism in green algae I. The presence of sucrose synthetase and sucrose phosphate synthetase

Summary The presence of sucrose synthetase and sucrose phosphate synthetase has been demonstrated in two species of green algae:Chlorella vulgaris andScenedesmus obliquus. Partial purification from crude extracts allowed the determination of the kinetic constants of algae enzymes. They are very similar to the ones reported for enzymes from higher plants.Dedicated toLuis F. Leloir on his seventieth birthday.     

Descriptions of new Neotropical Lycoperdininae (Coleoptera: Endomychidae) and their phylogenetic placement

Two new genera and three new species of Lycoperdininae (Coleoptera: Endomychidae) from South America, are described and illustrated based on adults: Hylaperdina n. g., along with H. brevicornis n. sp. from Ecuador and H. costariciensis n. sp. from Costa Rica, and Chileanus n. g., along with C. talca n. sp. from Chile. Their most likely placement within the Lycoperdininae is discussed. A key to genera of the neotropical Lycoperdininae is provided.     

Food selection by Labeo Rohita (Ham.) and its feeding relationship with other major carps

Selectivity of food byLabeo rohita (Ham.) was studied in a stocking pond (Moat), by calculating an Electivity index (E) for each food organism as described byIvlev (1961). It was found thatL. rohita was definitely selective in its feeding. In case of fingerlings, there was a strong selection for zooplanktonic organisms (Arcella andDifflugia among protozoans,Keratella andBrachionus among rotifer andDaphnia andCyclops among crustaceans) and smaller algae (Cosmarium andClosterium among desmisd,Euglena andVolvox among phytoflagellates and algal spores and zygotes) while most of the phytoplanktonic organisms, belonging to green algae, diatoms and blue green algae, were avoided. In case of adults, a strong negative selection was observed for all zooplanktonic organisms and a strong positive selection for most of the green algae and diatoms (Ankistrodesmus, Zygnema, Spirogyra, Selenastrum, Pediastrum, Scenedesmus, Tetraspora, Stephanodiscus, Naviculla, Diatoma, Synedra andNitzchia). However, all blue green algae were avoided.The feeding relationship ofL. rohita with other major carps,Cirrhina mrigala (Ham.) andCatla catla (Ham.) was studied in two different habitats, pond and river. It was observed that in both habitats all three species were found to feed on almost similar types of food organisms, but the quantity of any food item eaten by adults differed markedly from one species to another and the food items which were dominant in one species, were of secondary importancce for the other two species. The adults ofL. rohita were found to feed mainly on phytoplankton and macrovegetation, the main food of adultC. mrigala was decayed organic matter, sand and mud supplimented by plankton, while the food of adultC. catla was chiefly composed of zooplankton, and some phytoplankton. Hence there was no true identity of feeding habits between the adults of any two species. However, there was an indication of competition for food between the fingerlings of all three species, because all of them feed mainly on zooplankton (Crustaceans, rotifers and protozoans). However, such feeding habits lasted a very short time only and as the fishes grew, their feeding habits diverged.     

TOXICITY OF THE PESTICIDE ZECTRAN ON PHOTOSYNTHESIS,RESPIRATION, AND GROWTH IN FOUR ALGAE1,2

The insecticide Zectran decreased both respiration and photosynthesis in Oscillatoria terebriformis and Synechococcus lividus at concentrations between 0.5 and 12.5 ppm, whereas Navicula pelliculosa and Scenedesmus quadricauda were, relatively unaffected by these, same concentrations in the short-term, manometric experiments. In long-term growth experiments all 4 species exhibited a toxicity threshold between 1 and 10 ppm Zectran.     

Influence of four herbicides on the algal flora of a prairie soil

Summary Four herbicides (2,4-D, trifluralin, MCPA and TCA) were applied at two concentration levels to isolated cores of a grassland loam soil. After herbicide contact times of 1, 5, and 20 days, samples were taken and the algal population estimated both quantitatively and qualitatively using two selective mineral salts media. Thirty one genera of algae were identified as occurring in the soil. Of these, Chlamydomonas, Chlorococcum, Hormidium, Palmella, and Ulothrix proved to be so sensitive to the four herbicides that they were rarely isolated from the cores after treatment. Other algal genera were found to be less sensitive, and the theoretical percentile sensitivity of fifteen genera was calculated. Chlorella, Lyngbya, Nostoc, and Hantzschia were found to be the most resistant algae, having percentile sensitivity to all four herbicides of less than 50%. Some algal genera varied in their sensitivity to each of the herbicides. Scytonema was sensitive to all of the herbicides except 2,4-D, while Tolypothrix showed a greater tolerance to MCPA. In the top cm of the soil, the reduction in cell numbers experienced by many algal genera after herbicide treatment was offset by an increase in the population of Chlorella. Stichococcus, Oscillatoria, and Spongiochloris all exhibited the ability to recover rapidly after a reduction in cell numbers resulting from the application of one of the herbicides. An overall reduction in cell numbers was noted for the algae growing preferentially on a nitrogen-free medium (i.e. potential nitrogen-fixers). re]19760511     

The influence of daylength,light intensity and temperature on the growth rates of planktonic blue-green algae

The in vitro growth rates under continuous light of the four dominant blue-green algae in Lough Neagh, Anabaena flos-aquae Bréb., Aphanizomenon flos-aquae Ralfs fa. gracile Lemm., Oscillatoria agardhii Gom. and Oscillatoria redekei van Goor were slower than in situ rates from Lough Neagh that had been corrected for hours of light received by the algae. However, by culturing on a 6: 18 light-dark cycle in vitro growth rates were obtained that were similar to the in situ rates. Under continuous light small species showed the fastest growth with Oscillatoria redekei the dominant species. However, this pattern was almost completely reversed under the light-dark cycle with Oscillatoria redekei only exhibiting the fastest growth rate under low light conditions. This observation showed agreement with Lough Neagh field data which showed that Oscillatoria redekei reached its maximum crop in April while the other three species were dominant during the summer months. Compared to the generally assumed high thermal tendency of blue-green algae the temperature maxima of the four species were low. No growth was observed at 35°C for any species while Anabaena flos-aquae was severely inhibited at 25°C.     

A note on the nutrition of Stylaria lacustris (Oligochaeta: Naididae)

Stylaria lacustris (L.) was offered ¹⁴C-labelled algae. The ingestion rate of diatoms was 0.79 g carbon/hour at 19°C. Diatoms (Nitzschia actinastroides) were well assimilated, green algae (Scenedesmus acuminatus) were practically not assimilated. The less assimilable algae are ingested at higher rates, indicating a regulation mechanism. Biomass doubling time was estimated to be about 3.6 days at 19°C.     

Species composition of phytobenthos in the littoral of Lake Xolotlán (Managua)

The species composition of the phytobenthos in the littoral of Lake Xolotlán (Managua) was determined. Sampling was carried out in November 1987 (end of the rainy season) and in July–August 1988 (rainy season). Sixty-eight taxa were identified;viz. 47 Bacillariophyceae, 13 Cyanophyta and 8 Chlorophyta. The presence of diatom species likeNavicula veneta, Nitzschia amphibia andNitzschia palea indicate eutrophic conditions, high ionic concentration, alkaline conditions and intense organic pollution.     

Assessment of Water Pollution using Diatom Community Structure and Species Distribution — A Case Study in a Tropical River Basin

A study on biological assessment of water pollution using diatom community structure and species distribution was carried out in the Linggi River Basin, Malaysia which was polluted by various urban, industrial and agricultural wastes. A total of 86 diatom taxa belonging to 21 genera were recorded from all eight sampling stations located in the basin, of which 70 species were found on artificial substrates; the remaining 16 species were recorded exclusively on natural substrates. The number of diatom species observed between the stations varied from 22-47 species. The dominant diatom species in decreasing order of abundance were Eunotia vanheurckii, Nitzschia palea, Achnanthes saxonica, Gomphonema parvulum and Achnanthes minutissima. The most common clean water species were Achnanthes minutissima, A. linearis and Synedra rumpens. The most tolerant species were Nitzschia palea followed by Gomphonema parvulum and Pinnularia braunii. Eunotia vanheurckii and Navicula cryptocephala occurred in high densities at both unpolluted and polluted stations and can be considered as the common facultative or indifferent species. Although a large number of species were recorded at the unpolluted stations, equivalent number of species were also found at the moderately polluted stations. However, the number of species was reduced at grossly polluted stations. Nevertheless, a marked variation in species association exists between the unpolluted and polluted stations, but not among the polluted stations to distinguish the type and degree of pollution.     

Comparative electrophoretic study on ribosomal proteins from algae

The proteins from cytoplasmic ribosomal subunits of eight species of algae were analyzed by two-dimensional gel electrophoresis. The molecular weights of the proteins were in the range of 10,000 to 55,000. We have compared the protein patterns from the ribosomal subunits of the different species to those of Chlamydomonas reinhardii. It was quite clear that there are many similarities in the protein patterns of all the investigated species. We found for Chlamydomonas eugametos 48, Chlamydomonas noctigama 42, Chlorogonium elongatum 47, Scenedesmus obliquus 40, Chlorella fusca 35, and Euglena gracilis 35 proteins which were homologous to those of Chlamydomonas reinhardii. For the colorless flagellate Polytoma papillatum, we detected 45 proteins homologous to Chlamydomonas reinhardii, so that the generally assumed close relationship between Chlamydomonas and Polytoma is confirmed.     

The ecology of algae in the Moruya river,Australia

The standing crop of benthic and planktonic algae in the Moruya River, Australia, was, in general, low compared with values given for northern hemisphere rivers. Diatoms always accounted for more than 90% of the algae on the sediments with the most common species being typical of holarctic flora. The relative abundance of each of six predominant taxa was similar at the three sampling localities and did not show marked seasonal variation. However, Gomphonema spp. contributed a relatively greater number in the downstream area whereas Cocconeis placentula Ehr. was comparatively more abundant upstream. The highest standing crop (1.47 × 10⁶ cells/cm²) was found downstream and in the calmest part of the river between January and March, coincident with maximum water temperatures. A true phytoplankton succession comprising filamentous chlorophytes, Scenedesmus, Melosira varians Ag., Dactylococcopsis, Eudorina and Merismopedia was observed at the most downstream site during the spring and summer, with a maximum standing crop of 126.7 × 10³ cells/litre being attained in December. The gut of larval lampreys > 100 mm contained large numbers (44,000–525,000 cells) of algae. Scenedesmus and Dactylococcopsis occurred much more frequently in the gut than in either the sediment or water, but the reverse was true for filamentous algae.     

人工滩涂湖泊滴水湖浮游藻类群落特征

于2009年3月—2010年2月逐月对中国最大人工滩涂湖泊——滴水湖的浮游藻类群落特征进行研究。利用CANOCO4.5软件对浮游藻类数据和环境因子数据进行典范对应分析(CCA),以揭示浮游藻类对生态环境的响应。结果表明:全年共检测到浮游藻类186种及变种,隶属于8门92属,其中绿藻门种类最多,其次是蓝藻门和硅藻门;主要优势种为小席藻、微小平裂藻、银灰平裂藻、不定微囊藻、弱细颤藻、啮蚀隐藻、四尾栅藻、扁圆卵形藻;藻类的年均丰度和年均生物量分别为(4552.29±4591.33)×104cells·L-1和8.15±6.63mg·L-1,藻类现存量各月份间差异极显著(P<0.01),但站点间差异不显著;多样性分析显示,藻类物种多样性较好;典范对应分析表明,水温、总氮等是影响滴水湖藻类群落结构的主要因素。