Habitat,density, and spatial distribution of <Emphasis Type=Italic>Rivulus giarettai</Emphasis> (<Emphasis Type=Italic>Actinopterygii</Emphasis>, <Emphasis Type=Italic>Cyprinodontiformes</Emphasis>) in southeastern Brazil

We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR) in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlandia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot) of R. giarettai was about 13 times higher in FFW than in DR. In FFW, the density of R. giarettai was highest at intermediate amounts of substrate (plant mass) and it was positively rank-correlated with the depth, and the number of arthropods. Individuals occurred in an aggregated distribution. The aggregated pattern could be related to a concentration of individuals in microhabitats neither too much exposed nor completely saturated by plants. R. giarettai was relatively abundant and tolerant to slight man-made habitat modifications. Damming appeared to be especially problematic by negatively affecting its density.     

<Emphasis Type=Italic>Boletus kermesinus</Emphasis>, a new species of <Emphasis Type=Italic>Boletus</Emphasis> section <Emphasis Type=Italic>Luridi</Emphasis> from central Honshu,Japan

Boletus kermesinus, a new species of Boletus section Luridi, is fully described and illustrated based on the materials collected in subalpine coniferous forests of central Honshu, Japan. It has distinctive features of dark-red basidiomata having distinct viscidity in the pileus surface, usually unchanging flesh, discolorous red pores, and an entirely reticulate stipe becoming coarsely lacerate-rimose with age.     

Manifestation of salt tolerance of <Emphasis Type=Italic>Spirulina platensis</Emphasis> and <Emphasis Type=Italic>Spirulina maxima</Emphasis> cyanobacteria of the genus <Emphasis Type=Italic>Arthrospira (Spirulina)</Emphasis>

The salt tolerance of two representatives of genus Spirulina (Arthrospira) Spirulina platensis and Spirulina maxima has been investigated. They both are the wide-spread objects of photobiotechnology and it has been shown that the content of 5–15 % sea-water in medium has not caused the decreasing of biomass yield more than 15–20% as compared with control. The further decreasing of biomass was proportionate to sea-water content in medium. The investigation of reactivity of native (intravital) exometabolites secreted into cultural medium has showed that the sea-water content influence the oxidative activity (OA) of exometabolites and hour’s rhythmics.     

Recovery of photosynthetic capacity in <Emphasis Type=Italic>Vaccinium vitis</Emphasis>-<Emphasis Type=Italic>idaea</Emphasis> during mild spells in winter

Recent studies suggest that evergreen plants may maintain their photosynthetic capacity through the winter. Since mild winters are predicted to be more frequent in the future, the metabolic activity of plants is also likely to increase. The aim of the present study was to assess how various environmental factors, such as temperature, photoperiod and preceding frost, affect the recovery of photosynthesis during a mild spell in winter. The recovery of photosynthesis was studied in a series of growth chamber experiments where the overwintering of lingonberry (Vaccinium vitis-idaea) was interrupted by an intermittent warm spell of 1 week during different phases of winter. Rapid activation was observed in all the experiments during the first 3–4 days. No obvious effects of the phase of winter or photoperiod on the recovery of photosynthesis were observed, but a severe freezing treatment prior to the warm spell retarded the recovery significantly. Once recovered, however, lingonberry was able to maintain high rates of photosynthesis even at near-freezing temperatures, which prevail in their natural sub-nivean environment. The apparent quantum yield of photosynthesis remained high through the winter for lingonberry. This may prove advantageous for evergreen dwarf shrubs which overwinter in dim environments under snow.     

<Emphasis Type=Italic>Hyptis maya</Emphasis>, a new species of <Emphasis Type=Italic>Lamiaceae</Emphasis> from Belize,Central America,and the closely related <Emphasis Type=Italic>H. lanceolata</Emphasis>

A new species of Lamiaceae from Belize: Hyptis maya is described and illustrated. It is closely related to the more widespread H. lanceolata Poir., with which it is compared.     

Antidiatom and antibacterial activity of epiphytic bacteria isolated from <Emphasis Type=Italic>Ulva</Emphasis><Emphasis Type=Italic>lactuca</Emphasis> in tropical waters

Bacteria and diatoms are primary colonizers of marine surfaces and hence play a crucial role in the attachment and subsequent growth of macroorganisms. It has been suggested that the temperate green alga Ulva lactuca relies on the defence provided by the epiphytic bacterial community to regulate surface fouling of colonising organisms. In this study, ten resident bacterial isolates from tropical U. lactuca were tested for their antibacterial and antidiatom properties that may regulate surface colonization on the algae. Sixty percent of the epiphytic isolates expressed antibacterial properties against other resident bacteria and 80% had antidiatom activity against the pennate diatom, Cylindrotheca fusiformis. Isolates of the Pseudoalteromonas genus showed both- antibacterial and antidiatom activities, while members of the genus Bacillus, Vibrio and Shewanella mostly possessed antidiatom activity. Our results show that a high proportion of bacterial isolates from tropical U. lactuca, like that of their temperate counterparts contain antibiotic properties that might impact on the bacterial community composition and prevent fouling by diatoms.     

Discovery of <Emphasis Type=Italic>Ophiostoma tsotsi</Emphasis> on <Emphasis Type=Italic>Eucalyptus</Emphasis> wood chips in China

Ophiostoma species such as O. quercus are the most frequent causal agents of sapstain of freshly felled hardwood timber and pulpwood. Many species are regarded as economically important agents of wood degradation. The aim of this study was to identify a collection of Ophiostoma isolates, resembling O. quercus, found on stained Eucalyptus pulpwood chips in China. DNA sequences of the internal transcribed spacer regions, including the 5.8S region, of the ribosomal DNA, and parts of the β-tubulin and elongation factor-1α genes, revealed that the isolates were not O. quercus. Surprisingly, they represented O. tsotsi, a wound-infesting fungus recently described from hardwoods in Africa. In addition, sequence data from an isolate from agarwood in Vietnam, identified in a previous study as belonging to an unknown Pesotum species, were also shown to represent O. tsotsi. A high level of genetic variability was observed among isolates of both O. quercus and O. tsotsi. This was unexpected and suggests that both species have been present in Asia for a significant amount of time.