Calothrix

Calothrix
	Calothrix confervicola , illustration
Systematics
Domain :	Bacteria (bacteria)
Trunk :	Cyanobacteria (Cyanobacteria)
Class :	Cyanobacteria (Cyanobacteria)
Order :	Nostocales
Family :	Rivulariaceae
Genre :	Calothrix
Scientific name
	Calothrix
	C. Agardh ex Bornet & Flahault

Calothrix is a genus from the tribe of cyanobacteria (blue-green algae).

description

Calothrix forms unbranched, blue-green, olive-green or brownish single-row threads (diameter from 4 to 80 µm) with short, cylindrical cells . Like all bacterial cells, these contain neither nuclei nor plastids . The threads are tight and have a strikingly polar structure. At the basal end of the thread there is a colorless, thick-walled cell, the heterocyst , which is used for biological nitrogen fixation . In some species there are some heterocysts in the middle of the thread. The other end ends in a hairline tip. Each thread lies with the basal heterocyst in a thin gelatinous sheath. The threads lie individually or in small groups, never in large aggregates. The growth occurs through cell division within the thread.

Reproduction

The asexual reproduction is done by hormogonia. These are small-cell thread fragments capable of sliding movements. Akinetes (thick-walled permanent cells) are rarely formed.

Sexual reproduction is absent in all cyanobacteria.

distribution

Calothrix lives as growth on the ground mainly on nutrient-poor waters and on aquatic plants, often in acid moor waters, in humid terrestrial locations, but also in hot springs. Calothrix parietina is a key organism for oligosaprobe waters.

Types (selection)

swell

literature

Karl-Heinz Linne von Berg, Michael Melkonian u. a .: The Kosmos algae guide. The most important freshwater algae under the microscope. Kosmos, Stuttgart 2004, ISBN 3-440-09719-6 .

Individual evidence

↑ Heinz Streble , Dieter Krauter : Life in the water drop. Microflora and microfauna of freshwater. An identification book. 10th edition. Kosmos, Stuttgart 2006, ISBN 3-440-10807-4 .

Web links

Commons : Calothrix - collection of images, videos and audio files

Calothrix on algaebase.org
Images of Calothrix

[1] Heinz Streble , Dieter Krauter : Life in the water drop. Microflora and microfauna of freshwater. An identification book. 10th edition. Kosmos, Stuttgart 2006, ISBN 3-440-10807-4 .