Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3
result(s) for
"Freshwater algae North America Classification."
Sort by:
Atlas of diatoms (Bacillariophyta) from diverse habitats in remote regions of western Canada
High-resolution LM images of diatoms from remote regions of western Canada are presented as a contribution to our knowledge of diatom floristics, ecology and biogeography in North America. Approximately 600 taxa are imaged in 132 plates. Genera with the most taxa are Cymbella (19 taxa), Cymbopleura (29), Encyonema (23), Encyonopsis (15), Eunotia (77), Gomphonema (42), Navicula (47), Neidium (20), Nitzschia (35), Pinnularia (50) and Stauroneis (34). Diatoms were collected from diverse habitats in four of North America’s major biomes: Arctic tundra, taiga, Rocky Mountains and Pacific rainforest. Many of the photographed taxa could not be identified to species and are likely new to science. Other taxa may represent new records for North America or Canada. Images of voucher specimens are keyed to individual collection sites. Detailed descriptions of the collection sites include GPS coordinates, colour photographs, vegetation, algal substrates, elevations, pH, temperature and conductivity. Samples were collected from natural substrates in fresh to brackish, flowing and standing waters. Voucher slides are deposited in the Montana Diatom Collection (Helena) and the University of Montana Herbarium (Missoula). Cleaned diatom frustules have been deposited in the Diatom Herbarium of the Academy of Natural Sciences of Philadelphia.
Journal Article
Molecular studies of Dinophysis (Dinophyceae) species from Sweden and North America
Diarrhoeic shellfish poisoning has increasingly become a problem throughout the world. Because the causative organisms
Dinophysis
spp. cannot be cultured in the laboratory, new approaches are needed to obtain ecological and physiological information. In this study,
D. acuminata
.
D. norvegica
and
D. acuta
were collected directly from field samples and used in polymerase chain reactions. The D1-D2 region of the large-subunit ribosomal RNA gene was amplified, cloned and sequenced. Sequence analyses showed that
D. acuminata
and
D. norvegica
were nearly identical (> 99%), and that
D. acuminata
showed an intraspecies variation of 0.8%. The
D. acuta
sequence was 98.7% similar to that of
D. acuminata
. The slight differences between
D. norvegica
and
D. acuminala
suggest that they may have evolved into separate species rather recently. Phylogenetic analyses show that species within the Dinophysiales order should be included in the 'GPP complex', a lineage associated with a diverse array of taxa within the orders Gymnodiniales, Prorocentrales and Peridiniales. The Prorocentrales and Dinophysiales would be sister groups within the GPP complex. Amplification of Swedish
D. acuminata
isolates always resulted in a single LSU rDNA fragment. In contrast, amplification of the North American
D. acuminata
always produced two distinct fragments. The longer (735 bp) fragment showed 99.3-1 00% homology among all sequenced clones of different
D. acuminata
field isolates. The shorter gene fragment had a 70 bp deletion, but it was otherwise highly homologous to the larger gene fragment. This fragment is possibly a pseudogene and might be an important genetic marker. A variable region that is suitable as a target for a probe to identify
Dinophysis
was also identified.
Dinophysis
specificity was confirmed for the probe, in that hybridization to cultured representatives of dinoflagellates and environmental samples containing mixed phytoplankton assemblages resulted in specific labelling of
D. acuminata
.
D. norvegica
and
D. acuta
, but not other dinoflagellates. No labelling of
D. rotundata
was observed.
Journal Article