WebSep 23, 2015 · Species from the genus Oricymba are studied from freshwater ecosystems of Vietnam and Laos. Three species were found in Vietnam, namely O. japonica, O. subovalis and O. perjaponica comb. nov. The two last species are new taxa for the diatom flora of Vietnam. A new species is described from Laos, O. voronkinae sp. nov., and its … Several systems for classifying the individual diatom species exist. Fossil evidence suggests that diatoms originated during or before the early Jurassic period, which was about 150 to 200 million years ago. The oldest fossil evidence for diatoms is a specimen of extant genus Hemiaulus in Late Jurassic aged amber … See more A diatom (Neo-Latin diatoma) is any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a … See more Diatoms are generally 2 to 200 micrometers in size, with a few larger species. Their yellowish-brown chloroplasts, the site of … See more Most centric and araphid pennate diatoms are nonmotile, and their relatively dense cell walls cause them to readily sink. Planktonic forms in open water usually rely on turbulent mixing of the upper layers of the oceanic waters by the wind to keep them suspended in … See more Distribution Diatoms are a widespread group and can be found in the oceans, in fresh water, in soils, and on damp surfaces. They are one of the dominant … See more Diatoms are protists that form massive annual spring and fall blooms in aquatic environments and are estimated to be responsible for about half of photosynthesis in … See more Diatom cells are contained within a unique silica cell wall known as a frustule made up of two valves called thecae, that typically overlap one … See more Reproduction and cell size Reproduction among these organisms is asexual by binary fission, during which the diatom divides into … See more

Diatom - an overview ScienceDirect Topics

WebSpecies See text Cymbella is a diatom genus in the family Cymbellaceae including over 800 species. Species. Cymbella abbottii Cymbella aculeata Cymbella acuta Cymbella acuta Cymbella acutea Cymbella adnata … WebDec 13, 2024 · The NRSA suggests that reducing nutrient pollution and improving habitat will improve the biological health of rivers and streams. By using diatoms, EPA is one step closer to solving this issue. Genus-level, trait-based multimetric diatom indices for assessing the ecological condition of rivers and streams across the conterminous United … debate topics for office

Diversity in the Globally Distributed Diatom Genus - PLOS

WebHere, we analyse the biogeography of six species of the diatom genus Bacteriastrum with apparently contrasting distribution patterns. Occurrence data obtained from metabarcode reads in samples from Ocean Sampling Day (OSD) sites and from Tara Oceans stations as well as from their observational records included in biodiversity data repositories ... WebMar 9, 2024 · Two new species of Meridion (Bacillariophyta, Tabellariaceae) are described from Unalaska Island (Aleutian Islands, USA) based on light and scanning electron microscope investigations. ... Two new species of the diatom genus Meridion ... J.L. (1975) Fossil freshwater diatomaceous earth from Kenai Peninsula, Alaska. Microscopy, The … WebApr 10, 2024 · Within any given taxocenosis of benthic diatoms (BDT), the distribution of the taxa relative abundances renders them as very abundant,... Find, read and cite all the research you need on ... debate topics for school students