Gelatinous yellow-green algae
| Gelatinous yellow-green algae | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Chlorosaccus | ||||||||||||
| Luther, 1899 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Chlorosaccus fluidus | ||||||||||||
| Luther 1899 |
The yellow-green algae ( Chlorosaccus fluidus ) is an alga that occurs in freshwater and belongs to the yellow-green algae (Xanthophyceae).
description
The species forms up to 15 millimeters in size, pale green colored colony-like thalli of various shapes, they can be spherical, leaf-like or irregularly shaped. These always grow superimposed on hard substrates (benthic), they can peel off with age and then float freely in the water. Colonies consist of a common gelatinous deposit , each with single, two or four coalesced cells , often in blunt, superficial cusps. These can be short and wart-like or long-pointed, sometimes even branched. The cells are 7 to 12 μm long with a diameter of 3 to 8 μm and are embedded near the surface, with the long axis perpendicular to the thallus. They are usually ellipsoidal in shape, but can take on a spherical or pear-shaped shape and have very thin cell walls. Each cell contains two or more (up to eight) wall-mounted chloroplasts without pyrenoids , and mostly oil droplets.
The species reproduces asexually by means of autospores and mobile zoospores . These have two flagella of different lengths, the longer one pointing forward (dragging flagella ). They develop individually or in pairs from vegetative cells. In addition, thick-walled akinetes are formed as survival stages.
Distribution and way of life
The species is specified from a variety of habitats, it occurs in running waters as well as in lakes and ponds , whereby it prefers nutrient-rich water. It is given mainly from cold waters and is found mainly in the winter months. It prefers to grow on other aquatic plants (epiphytic). Most of the find information comes from northern Europe, but there are finds south to Romania and Spain. There is also information from North America (North Carolina), Australia and New Zealand.
Taxonomy
The genus Chlorosaccus is monotypical . The species Chlorosaccus concarnensis Bourrelly and Chlorosaccus ulvaceus Messikommer & Vischer described in addition to the type species are now considered synonyms .
Literature and Sources
- Heinz Streble , Dieter Krauter : Life in a drop of water. Microflora and microfauna of freshwater. An identification book. 10th edition. Kosmos, Stuttgart 2006, ISBN 3-440-10807-4 .
- Chlorosacchus and Chlorosaccus fluidus on algaebase.org
- David M. John: The Freshwater Algal Flora of the British Isles: An Identification Guide to Freshwater and Terrestrial Algae. Cambridge University Press, 2002. ISBN 978-0-521-77051-4 . Chlorosaccus on page 252.
- John D. Wehr & Robert G. Sheath: Freshwater Algae of North America. Ecology and Classification. Elsevier (Academic Press), Amsterdam etc. 2003. ISBN 978-0-12-741550-5 . Chlorosaccus on page 453.