Abundance and spatial distribution of Artemia salina in Lake Abert,Oregon

In 1981–1982 Abert Lake had an area of 200 km², with a mean depth of 2.5 m and a total dissolved salt concentration of 82 gl^-1. The spatial distribution and abundance of the brine shrimp, Artemia salina, were monitored for 1981–1982. In 1981 during the midsummer months, with sampling primarily in the eastern side of Abert Lake, brine shrimp populations showed peak densities of 2–4 ind. 1^-1. In 1982, peak abundance occurred in early July and ranged between 5–8 ind. 1^-1. Lakewide estimates of brine shrimp derived from 14 collecting stations and assuming a uniform distribution over the lake resulted in estimates of lakewide abundance of 3 × 10¹¹ adults with a total biomass of 7 × 10⁶ kg. The major algal species in the lake was a benthic filamentous green alga (Ctenocladus circinnatus).     

有毒亚历山大藻对卤虫存活率和摄食率的影响

研究了有毒亚历山大藻对卤虫存活率和摄食率两方面的影响,得出以下结论：在卤虫存活率实验中,有毒亚历山大藻在2000cells／ml的密度下,对卤虫具有致死效应,卤虫在24-168h内全部死亡;在摄食实验中,有毒亚历山大藻对卤虫的摄食产生明显的抑制作用,卤虫对有毒藻的平均摄食率明显低于无毒藻组和混合实验组。在加入无毒藻东海原甲藻的混合培养状态下。卤虫存活率上升,30-60min摄食率增加,东海原甲藻在一定程度上可以减轻塔玛亚历山大藻对卤虫的毒害作用。有毒藻产生的PSP毒素并非导致卤虫死亡的主要原因,毒害作用可能与出现在卤虫体外的黏附物质有关。通过对3个不同生长期卤虫的研究发现,后无节幼体卤虫对有毒亚历山大藻的毒害作用最为敏感。     

Biotoxic activity in the Mucorales

The toxigenicity of representatives of 15 species of Mucorales (Absidia glauca, Actinomucor elegans, Cunninghamella elegans, Helicostylum piriforme, Mortierella isabellina, Mortierella (Mucor) rammaniana, Mucor hiemalis, Mucor mucedo, Mucor spinosus, Phycomyces blakesleeanus, Rhizopus oligosporus, Rhizopus stolonifer, Syncephalastrum racemosum, Thamnidium elegans, Zygorhynchus moelleri) towards the larvae of brine shrimp (Artemia salina) and the growth of pea seedlings (Pisum sativum) and tobacco plants (Nicotiana tabacum) was evaluated. The fungi were cultivated on malt extract agar and aqueous solutions of the cultures were tested.Thamnidium elegans showed a marked toxic action towards brine shrimp (mortality: 74.1%) andPhycomyces, Actinomucor andSyncephalastrum were only weakly toxic. Length and weight of stems of pea seedlings were moderately reduced by extracts ofAbsidia, Cunninghamella, Zygorhynchus andThamnidium and to a lesser degree byMucor spinosus. Cunninghamella andMucor spinosus also inhibited the development of pea hypocotyls. The length of tobacco stems was reduced byMortierella ramanniana, Rhizopus stolonifer andCunninghamella elegans. Wilting or other toxic phenomena were never observed with both test plants. Considering the present results and data from literature it is suggested that species of Mucorales have only a weak toxigenicity.     

Bioactive phloroglucinols from the brown alga Zonaria diesingiana

Three phloroglucinols with a C-20 acyl side chain were isolated from marine brown alga Zonaria diesingiana. The structures were determined on the basis of NMR spectral analyses and comparison with data in the literature. They all showed antibacterial activity against Bacillus subtilis and Staphylococcus aureus and cytotoxic activity by inhibiting cell division in fertilized sea urchin eggs (Echinometra mathaei). These activities suggest their possible for pharmacological purposes. These phloroglucinols also showed toxicity against brine shrimp (Artemia salina), guppy fish (Poecilia reticulata), rice-land shrimp (Macrobrachium lanchesteri) and the diatom Chaetoceros gracilis. They probably act as chemical defenses against herbivores and also reduce surface fouling by epiphytic algae and larvae, suggesting their important roles in the marine ecosystem.     

Diet-induced variations in fatty acid content and composition of two on-grown stages of Artemia Salina

Three species of microalgae, the freshwater Euglena gracilis and themarine Dunaliella salina and Tetraselmis suecica, were fed tothe brine shrimp Artemia salina in order to compare their suitabilityin terms of fatty acid enrichment, and their effect on the biometric parametersof the zooplankter. The fatty acid content and composition were analyzed for the post-larval and pre-adult stages of Artemia fed the algae and theresults compared to the initial content of unfed 24-hour post-hatch nauplii.Differences in the total fatty acid content occurred between the three stages,the fatty acid profile being determined by the composition of the diet. A decreasing trend for almost all the individual fatty acids occurred throughdevelopment from post-larva to pre-adult with each of the three algal diets.Biometrical differences between Artemia fed the marine algae and that fed Euglena were not consistent in the post-larval stage, but became considerable in the pre-adult stage. Artemia fed with Euglena achieved twice the weight of animals fed the marine algae and showed thehighest length. The implications for the use of on-grown Artemia as afeed in larviculture of marine and freshwater fish and crustaceans are considered.     

The distribution and abundance of algae in saline lakes of Saskatchewan,Canada

Collections of algae, mainly planktonic, were made from 41 saline lakes in southern Saskatchewan ranging in salinity from 3.2 to 428 g l^-1. Algae in 7 phyla, 8 classes, 42 families, 91 genera and 212 species and varieties were identified. Fourteen species were restricted to hypersaline (50 g l^-1) waters and eleven of these were diatoms. In general, species diversity was inversely related to lake salinity. Algae that were important community constituents over a broad spectrum of salinities were the green algae Ctenocladus circinnatus, Dunaliella salina and Rhizoclonium hieroglyphicum, the blue-green Lyngbya Birgei, Microcystis aeruginosa, Oscillatoria tenuis, O. Utermoehli and Nodularia spumigena and the diatoms Melosira granulata, Stephanodiscus niagarae and Chaetoceros Elmorei. In general green algae were dominant when lake salinity exceeded 100 g l^-1 although diatoms played important roles in most of these highly saline lakes except for Patience Lake.     

Field measurements of ingestion and assimilation for the Australian brine shrimp Parartemia zietziana Sayce (Crustacea: Anostraca)

Ingestion and assimilation of the brine shrimp Parartemia zietziana were measured in the field. Populations in Pink Lake and Lake Cundare were used; both lakes are shallow (< 1 m), saline (> 60°/00), and located in western Victoria; they have tow primary production. P. zietziana relies largely on organic matter in lake sediment for food. Ingestion rate was measured in situ in Pink by following the uptake of ¹⁴C from labelled sediment. The rate of faecal pellet production was measured (in both lakes) by allowing animals to defaecate for 24 h in a net suspended in the lake. Ingestion rate varied from 0.35 to 13 01 × 10^–1 mg dry wt h^-1 individual^-1 for a range in dry weight of shrimp from 0.2 to 2.3 mg individual^-1; for a similar range in weight, defaecation varied from 0.08 to 2.03 × 10^-1mg dry wt h^-1 individual^-1. These rates were converted to joules and assimilation efficiencies of 30–60% calculated. Regressions showed that change in dry weight of shrimp accounted for > 90% of the variance in both rates.     

Structural elucidation and biological significance of 2-hydroxy-1-naphthaldehyde derived sulfonamides and their first row d-transition metal chelates

2-Hydroxy-1-naphthaldehyde derived sulfonamides and their first row d-transition metal chelates [cobalt (II), copper (II), nickel (II) and zinc (II)] have been synthesized and characterized. The nature of bonding and structure of all the compounds have been deduced from elemental analyses, infrared, ¹H NMR, ¹³C NMR, mass spectrometry, electronic spectra, magnetic susceptibility and conductivity measurements. An octahedral geometry has been suggested for all the complexes. The metal complexes were screened for their antibacterial and antifungal activities on different species of pathogenic bacteria and fungi and their biopotency has been discussed. The results of these studies revealed that all compounds showed moderate to significant antibacterial activity against all bacterial strains and good antifungal activity against various fungal strains. In-vitro cytotoxic properties of all the compounds against Artemia salina was also studies by brine shrimp bioassay.     

The molecular weight of Artemia ribosomes, as determined from their refractive-index increment and light-scattering intensity

Cytoplasmic ribosomes were isolated from the cryptobiotic embryos of the brine shrimp Artemia salina. Measurements of their refractive-index increments and light-scattering intensities give a value for their molecular weight of (3.4±0.2)×10⁶.     

Syntheses and Biological Activities of Danicalipin A Derivatives

Synthesis of three derivatives of danicalipin A, tetrachloride, trisulfate and a fluorescent probe was achieved through Wittig reaction strategy. Toxicity of the derivatives against brine shrimp (Artemia salina) as also investigated to provide useful information for the biological activity; i) less chloride derivative showed similar toxicity to danicalipin A, ii) the amphiphilic property, a characteristic feature of danicalipin A, was crucial because trisulfate considerably decreased the toxicity and iii) fluorescent derivative kept brine shrimp toxicity of danicalipin A.     

The American brine shrimp as an exotic invasive species in the western Mediterranean

The hypersaline environments and salterns present in the western Mediterranean region (including Italy, southern France, the Iberian Peninsula and Morocco) contain autochthonous forms of the brine shrimp Artemia, with parthenogenetic diploid and tetraploid strains coexisting with the bisexual species A. salina. Introduced populations of the American brine shrimp A. franciscana have also been recorded in these Mediterranean environments since the 1980s. Based on brine shrimp cyst samples collected in these countries from 1980 until 2002, we were able to establish the present distribution of autochthonous brine shrimps and of A. franciscana, which is shown to be an expanding invasive species. The results obtained show that A. franciscana is now the dominant Artemia species in Portuguese salterns, along the French Mediterranean coast and in Cadiz bay (Spain). Co-occurrence of autochthonous (parthenogenetic) and American brine shrimp populations was observed in Morocco (Mar Chica) and France (Aigues Mortes), whereas A. franciscana was not found in Italian cyst samples. The results suggest these exotic A. franciscana populations originate as intentional or non-intentional inoculations through aquacultural (hatchery effluents) or pet market activities, and suggest that the native species can be rapidly replaced by the exotic species. This revised version was published online in July 2006 with corrections to the Cover Date.     

Oxygen‐rich gas domes of microbial origin in the salt crust of the Great Salt Lake,Utah

Abstract

During the summer of 1977, a severe drought throughout the western part of the United States caused the north arm of the Great Salt Lake, Utah, to evaporate to its lowest level in a number of years, resulting in the precipitation of about 99.6% pure sodium chloride. At the extreme north end of the north arm, in the vicinity of Monument Point, low humidity combined with a shallow‐bottom gradient to form a salt crust along the lake margin in which gas‐emitting domes were common. The domes varied in size; each contained a large amount of gas that analysis showed to be 82 to 86% oxygen and 14 to 18% nitrogen, with <0.2% or no methane, and no detectable carbon dioxide. The bottom of the crust of the domes (3 to 4 cm thick) was a bright red color. Microscopic examination of this red zone revealed 3.5 × 10⁴ cells of Dunaliella salina, 2 × 10³ cells of D. viridis and 10⁸ to 10⁹ clumps of red halophilic bacteria per g of salt. Measurements in situ showed sufficient light (34 klx) and temperature (34°C) under the salt to favor the growth of the algae and associated bacteria within the water phase of the crust or in water immediately underneath the crust. Oxygen produced as a result of algal photosynthesis was trapped under the crust until the crust was either eroded by waves or broken under pressure, releasing the gas. The domes were not observed during the summers of 1978 and 1979.     

Secondary seed dispersal in Montrichardia arborescens (L.) schott dominated wetlands in Laguna Grande, Venezuela

Laguna Grande, Monagas State, Venezuela, is a shallow, V-shaped lake created by the confluence of two rivers. Montrichardia arborescens (L.) Schott. dominated wetlands cover most of the north and south arms and the littoral zone of the main body of the lake. The vegetation and seed banks of Montrichardia wetland sites were sampled in the north arm, south arm and main body five times from the end of the dry season in 1991 to beginning of the rainy season in 1992. The composition of the vegetation was similar and changed very little at all three sites during the course of the study. These wetlands had 53 species. Besides M. arborescens, other common species were Hamelia patens Jacq., Mikania cordifolia (L.) Wild., Sarcostemma clausum (Jacq.) Roem. & Schult., and Vitis caribaea L. In both the vegetation and seed banks, species richness was highest during the dry season. Altogether, the seed banks contained the seeds of 61 species of which 35 were also found in the vegetation. Seeds of three tree species were found in the seed banks that did not grow anywhere in the lake. In the seed bank, seeds of Cyperus odoratus L., Eleocharis interstincta (Vahl.) R&S, Ludwigia hyssopifolia (G. Don.) Excell, L. lithospermifolia (Mich.) Hara, Polygonum acuminatum H.B.K., and Sacciolepis striata (L.) Nash were the most abundant. Mean total seed density over the entire study was 6,500, 3,800, and 6,000 seeds/m² in the north arm, south arm, and main basin, respectively. Seed production and dispersal occur primarily during the dry season, and the highest seed densities at all sites were found in the dry season when there was no or little standing water. The lowest seed densities at all sites were found during the rainy season during which seed densities declined over 80% at the north and south arm sites. In the main body of the lake, however, seed densities during the rainy season, although lower than during the dry season, actually increased significantly from 3,600 seeds/m² in August 1991 to 6,000 seeds/m² in October 1991. A significant decrease in seed density in either the north or south arms or both and a significant increase in the main body site during the rainy season occurred for 5 of the 8 species whose seeds were the most abundant, for all life-form guilds, except hydrophytes and for the entire seed bank. Secondary dispersal by water currents during the rainy season appears to be transporting seeds from the north and south arms into the seed bank of the main body of the lake.     

Mycotoxins producing fungi and mycoflora of air-dust from Taif,Saudi Arabia

Using the dilution plate method, 70 species and 31 genera were collected from 20 dust samples on glucose (28 genera and 64 species) and cellulose Czapek's agar (22 genera and 46 species) at 28° C. The most common fungi were Aspergillus niger, A. flavus, A. flavus var. columnaris, Phoma glomerata, Fusarium oxysporum, Penicillium chrysogenum and Mucor racemosus; and A. nidulans, Phoma humicola, Drechslera spicifera and Stachybotrys chartarum on the two media, respectively.Toxicity test showed that about 85% of the isolates tested were toxic to brine shrimp (Artemia salina). Thin layer chromatographic analysis revealed that 13 out of 23 toxic isolates produced known mycotoxins. Toxins identified were: aflatoxins B₁ and B₂, Kojic acid and trichodermine.     

Occurrence and toxicity of Amphidinium carterae Hulburt in the North Arabian Sea

The occurrence and toxicity of Amphidinium carterae Hulburt is hereby reported for the first time from the North Arabian Sea on the coast of Pakistan. The concentrations of 1.2 × 10⁴ cells ml⁻¹ were found in intertidal pools that were also inhabited by the brown macroalga Sargassum wightii. Both wild and cultured A. carterae cells were tested for ciguatera toxicity through exposure to brine shrimp nauplii (Artemia salina) and albino mice. Although the brine shrimp did not appear to be affected mortalities in mice ranged between 13 and 16% at doses of 7.2 × 10⁴ and 2.5 × 10⁵ cells ml⁻¹, respectively. When mice were affected pharmacological effects such as muscle contraction in lower back area, increased respiration, immobility and paralysis in hind limbs were observed for 2 h. These effects appeared to be reversible and gradually disappeared within 24 h.     

The Seasonal Dynamics and Trophic Relations of the Plankton Components in Lake Peipsi (Peipus)

The seasonal dynamics of the biomass and production of phyto-, zoo- and bacterioplankton was investigated during the vegetation periods (from May to November) in 1985 and 1986 in the pelagial of the large eutrophic lake Peipsi (Estonia). The average values of productions per vegetation period for the investigation years were as follows: phytoplanktion − 203.5 gC · m⁻²; bacterioplankton − 37.9 gC · m⁻²; filter-feeding zooplankton − 20.6 gC · m⁻² and predatory zooplankton − 1.5 gC · m⁻². The herbivorous zooplankton production constituted 10.1% of primary production. This ratio indicates a direct relationship between zoo- and phytoplankton in the food chain — filtrators are feeding mostly on living algae and the detrital food chain seems of little importance. The dominance of large forms (Melosira sp., Aphanothece saxicola), in the phytoplankton during the major part of the vegetation period is assumed to be a result of high grazing pressure on small algae. Zooplankton grazing was investigated in situ in a specially constructed twin bathometer. Experimental measurements revealed, that zooplanktion presence in the experimental vessel actually stimulated the phytoplankton growth in many cases — the negative grazing values have been registered. That could be caused by the stimulation effect of nutrients (N, P), excreted by the concentrated zooplankton in the grazing chamber, which led to an increase of the nongrazed phytoplankton production. Bacteria have satisfied the zooplankton food requirements on average by 11%. Grazing on bacteria increased, when grazing on phytoplankton was somehow disturbed.     

Phytochemical Compounds of Euphorbia bivonae Extract and Their Cytotoxicity Effects on the Lethality of Brine Shrimp Artemia salina and Embryonic Kidney (HEK293) Cells

In this research article, we investigated the effect of Euphorbia bivonae extract compounds on the lethality of brine shrimp Artemia salina and on embryonic cell lines (HEK293) proliferation. Our GC/MS analysis revealed that the E. bivonae ethanolic extract contained essentially sitosterol, euphol, and lupeol. The 24-h LC50 was determined using the probit analysis method (LC50=357.11 mg l⁻¹). Depending on this cytotoxicity test result, E. bivona extract induced a significant increase in Superoxide Dismutase (SOD), Catalase (CAT), Glutathione-Peroxidase (GPx) activities, and lipid peroxidation (LPO) in A. salina larvae. In addition, the cytotoxicity effect of this extract had proved against the HEK293 cell lines in vitro. We suggest that the three compounds of E. bivonae extract (sitosterol, euphol, and lupeol) are the most responsible for this cytotoxicity. The possible application of this extract as an alternative natural antiproliferative is considered.     

2株海洋来源产浅蓝霉素A的异壁放线菌的分离和鉴定

利用抗菌及卤虫致死活性模型,从中国南海海底沉积物来源的微生物中筛选到2株放线菌SCSIO WJ01和SCSIO ZJ63,其发酵产物具有较强活性,经16S rRNA基因序列分析这2株放线菌均为异壁放线菌Actinoalloteichus sp.。HPLC-DAD分析显示2株放线菌能产生同一个主要的次级代谢产物,通过正相硅胶柱色谱、反相中压柱色谱、半制备高效液相色谱等手段,从SCSIO WJ01的发酵产物中分离获得了该化合物,运用ESI-MS、1H及13C NMR波谱分析鉴定为浅蓝霉素A(Caerulomycin A)。此外,还从SCSIO WJ01的发酵产物中分离鉴定了浅蓝霉素D。     

Great Salt Lake microbiology: a historical perspective

Over geologic time, the water in the Bonneville basin has risen and  fallen, most dramatically as freshwater Lake Bonneville lost enormous volume 15,000–13,000 years ago and became the modern day Great Salt Lake. It is likely that paleo-humans lived along the shores of this body of water as it shrunk to the present margins, and native peoples inhabited the surrounding desert and wetlands in recent times. Nineteenth century Euro-American explorers and pioneers described the geology, geography, and flora and fauna of Great Salt Lake, but their work attracted white settlers to Utah, who changed the lake immeasurably. Human intervention in the 1950s created two large sub-ecosystems, bisected by a railroad causeway. The north arm approaches ten times the salinity of sea water, while the south arm salinity is a meager four times that of the oceans. Great Salt Lake was historically referred to as sterile, leading to the nickname “America’s Dead Sea.” However, the salty brine is teaming with life, even in the hypersaline north arm. In fact, scientists have known that this lake contains a diversity of microscopic lifeforms for more than 100 years. This essay will explore the stories of the people who observed and researched the salty microbiology of Great Salt Lake, whose discoveries demonstrated the presence of bacteria, archaea, algae, and protozoa that thrive in this lake. These scientists documented the lake’s microbiology as the lake changed, with input from human waste and the creation of impounded areas. Modern work on the microbiology of Great Salt Lake has added molecular approaches and illuminated the community structures in various regions, and fungi and viruses have now been described. The exploration of Great Salt Lake by scientists describing these tiny inhabitants of the brine illuminate the larger terminal lake with its many facets, anthropomorphic challenges, and ever-changing shorelines.     

Nearshore and pelagic abundances of Artemia monica in Mono Lake,California

The spatial distribution and abundance of the brine shrimp, Artemia monica, in Mono Lake, California were determined during 1982 and 1983. Peak abundances of shrimp occur in midsummer and reach densities of 15–17 individuals l^-1 in the nearshore regions and 6–8 individuals 1^-1 in the pelagic region. The brine shrimp were non-uniformly distributed both vertically and horizontally. The coefficient of variation in shrimp abundance among stations within the nearshore region was similar to that found in the pelagic region. On two of the nine dates, nearshore densities were 3 to 4 times greater than those in the pelagic zone, and on average the brine shrimp appear to be slightly over-dispersed to the nearshore region. However, including nearshore abundances in lakewide estimates will usually result in a change of less than a 10%.