Home / Chlorophyceae / Unicells / Flagellated / Pterosperma
Click on images for larger format
Name derivation:
Classification:
Pterosperma Pochet 1893; 19 of 21 species descriptions are currently accepted taxonomically (Guiry and Guiry 2103). Order Pyramimonadales; Family Pterospermataceae
Morphology:
Unicellular green algae that occurs in two phases. In the coccid stage cells are surrounded by a double wall. The inner wall is weaker while the outer wall is more durable. The alae divide into two halves. The mature cells contain a single nucleus at first, and numerous chloroplasts. Cell divisions take place in the mature, resulting in the formation of a large number of quadriflagellate swarmers. These are released through a slit in the outer wall,after bursting through the inner cell. Swarmers have 4 very long flagella (3-10 times cell diameter). Each cell contains a single chloroplast and lacks an eyespot (Guiry and Guiry 2013). The cells then switch to a motile phase thought to occur due to lunar phases.
Similar genera:
Habitat:
Occur in all seas and usually rise to the surface due to large amounts of lipids found in the cells. They are usually not found in large numbers.
References:
Guiry, M.D. and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 10 September 2013.