Rhodophyta, Red Algae
Bangia atropurpurea (Roth) C. Agardh = Bangia fuscopurpurea (Dillwyn) Lyngbye
Rhodophyta, Order: Bangiales; Family: Bangiaceae. The Bangia fuscopurpurea is the only species in this genus.
Fuscopurpurea fuscous means ‘brown’ and purpura means ‘purplish’ - describing the algal colour.
Individuals belonging to the species are soft, filamentous and unbranched. They contain a row or several rows of cells.
The thallus is less than 1 mm in width and is several centimeters in length.
The Bangia fuscopurpurea appears in shades of black.
The Bangia fuscopurpurea is darkly shaded, smooth and inhabits polluted beaches. It resembles bluegreen division algae, and may be mistaken for them.
The Bangia fuscopurpurea prefers polluted habitats. It grows in either fresh or salty water, and it transplants swiftly from one to the other. The cells are destroyed, but if done gradually, the alga can adapt to its new habitat. As expected, the spores are more resilient than the thallus to such changes. At one point, it was believed that the genus incorporated two species, but lately it has been proved that
Photo by Shlomit Katz. Bangia fuscopurpurea right: cellular arrangement of the thallus left: general view. individuals growing in fresh water and those growing in salt water belong to the same biological species.
Biology and reproduction
The Bangia fuscopurpurea’s life cycle resembles that of the porphyra. The life cycle of this species has also been described, including its microscopic stage (conchocelis), which develops upon the shell of a snail. The life cycle, especially the germination stage, is affected by the duration of daylight, and it quickly responds to environmental change. Sexual reproduction is very rare.
Individuals are quite different at various stages of their life cycle. Haploid and diploid individuals (with either one or two chromosome structures) have been found, and sometimes, the same thallus is haploid in its lower region and diploid further up. Colonies with different chromosome numbers have been found in various parts of the world.
Seasonality and distribution
The Bangia fuscopurpurea is found on Eastern Mediterranean shores in winter and spring. It is internationally distributed and found in nearly every sea in the world, including some fresh water reservoirs.
The number of species in this genus often changes. At present, nine species are numbered, although in the past it was believed that only one or two species existed, and these grew in different habitats (saline and fresh waters). In this region:
Bangia atropurpurea (Roth) C. Agardh = Bangia fuscopurpurea (Dillwyn) Lyngbye has been reported.
Photo by Shlomit Katz.