Biogeographic barriers for freshwater biota can be effective at various spatial scales. At the largest spatial scale, freshwater organisms can become genetically isolated by their high mountain ranges, vast deserts, and inability to cross oceans. Isolation by distance of aquatic plants is expected to be stronger across than alongside mountain ridges whereas the heterogeneity of habitats among p...

Stem segments prepared from pondweed (Potamo geton distinctus A. Benn.) turions (overwintering buds) elongate in anaerobic conditions, whereas there is almost no elongation in air. The anaerobic elongation was accompanied by a decrease in dry weights of stem segments, mainly due to consumption of storage starch in the amyloplasts of stem cells. On the other hand, total contents of amino acids i...

As part of a bioprospecting program aimed at the discovery of potential anticancer drugs, two new guanidine-type alkaloids, nitensidines D and E (1, 2), and the known pterogynine (3), pterogynidine (4), and galegine (5), were isolated from the leaves of Pterogyne nitens. The structures of 1 and 2 were established on the basis of spectroscopic data interpretation. These compounds were tested aga...

A systematic investigation was conducted in Lake Taihu in autumn of 2013 and 2014, in order to understand the environmental fate of microcystins (MCs) and evaluate the health risk from MCs. Samples of water, algal cells, macrophytes, shrimps and fish were taken to detect MCs by HPLC-MS/MS after solid phase extraction. Widespread MC contamination in water, algal cells, macrophytes, shrimps and f...

Larvae of the freshwater moth Acentria ephemerella (Pyralidae, Lepidoptera) can fully develop on Myriophyllum spicatum, a submerged macrophyte containing 7-10% of its dry mass as tannins. We investigated the physicochemical gut parameters of larvae fed with M. spicatum or Potamogeton perfoliatus, a food plant lacking tannins, and the chemical fate of ingested polyphenols. Microelectrode studies...

Peat and lacustrine sediments are a valuable source of knowledge about past biodiversity. Plant macrofossil remains were identified in mires northeastern Poland’s Knyszyn Forest. Among them, the species currently absent this area, such as Potamogeton pusillus, P. friesii, filiformis, Myriophyllum alterniflorum, Cladium mariscus, have been found. In addition, history Betula humilis its possible ...

Grazing by the crayfish Procambarus clarkii (Girard) on the abundance of submersed sago pondweed, Potamogeton pectinutus (L.), was quantified during 1984 through 19K6 at Coyote Hills Marsh (Alameda County, California. USA). Annual marsh surveys indicated that P. pectinatus abundance dechned (from 70% to 0% of the marsh surface), whereas P. clarkii abundance increased (from 1.6 to almost 3.0 cra...

BACKGROUND AND AIMS Molecular evidence for natural primary hybrids composed of three different plant species is very rarely reported. An investigation was therefore carried out into the origin and a possible scenario for the rise of a sterile plant clone showing a combination of diagnostic morphological features of three separate, well-defined Potamogeton species. METHODS The combination of s...

The red-knobbed coot Fulica cristata experienced a dramatic population decline in Spain, where the common coot F. atra does not face conservation problems. This is puzzling because both species have similar ecologies. It has been suggested that habitat alterations affected the quality of food plants, and this impacted differentially both coots. To verify this, we conducted experiments to determ...

1 We used a combination of laboratory and field experiments to test the hypothesis that the burial depth of Potamogeton pectinatus tubers will vary with local sediment type and swan predation pressure. 2 In the field, mortality due to predation by swans decreased linearly with burial depth (from 100% at the surface to 55% at 225 mm depth) and with sediment clay content. Average tuber size showe...