Ulothrix

Ulothrix

Ulothrix is occurring in fresh water and sea water species of the green algae group of Ulvophyceae. It comprises about 10 species.

Features

The representatives form unbranched filaments of a cell number. The cells are cylindrical. The threads have a diameter of 5 to 70 microns. The cells have a central or parietal cell nucleus and a parietal chloroplast. This is large and open or closed ring-shaped, and has several pyrenoids. The growth is by cell division in the thread.

Asexual reproduction occurs by the formation of several viergeißeliger zoospores in any thread cells. The zoospores pass through pores into the open and then grow into new threads. Sexual reproduction takes place by isogamy: in any thread cells form small, biflagellate gametes fuse together. The resulting zygote forms a rhizoid and thus forms a continuous phase ( Codiolum stage). Germination occurs with a reduction division, there arise 4-16 viergeißelige zoospores, that grow in each case to a thread.

Occurrence

The representatives of the genus live firmly seated in rivers and in the moving shore area of lakes. In spring and autumn they occur to a greater, in the summer they are rare.

Documents

• K.-H. Linne von Berg, K. Hoef -Emden, B. Marin, M. Melkonian: The Cosmos algae leader. The main freshwater algae under the microscope. Kosmos, Stuttgart 2004, pp. 264, ISBN 3-440-09719-6