Difference between Trentepholia and Red cells
Flaws about the official report
The Electron microscopy studies are not done to see whether Flagella are present or not. (if the SEM and TEM showing biflagellate or quadri-flagellate then it can be conclude that the spores are trentepohlia spores and the reason for the red rain was due to local origin)
The report unable to give the exact species name of the genus- Trentepohlia.
The report unable to answer the questions regarding the origin of huge quantity of red spore can reach the rain clouds and the mechanism by which a large number of spores go up into the air simultaneously.
the culture medium used was suitable for growth of algae and fungi and any algae or fungi in the rain water as a contaminant can grow easily. Trentepohlia may very well be included with the red cells as contaminants. Just because these Trentepohlia that contaminated the original red rain water grew into a type of algae doesn't mean the red rain cells are of that type of algae.
Difference between red rain cells and Trentepohlia
There are marked differences between red rain cells and Trentepohlia spores
So far about 40 species of Trentepohliales were discovered in the world. Among this which type of species caused the red rain of Kerala were unknown, or no species level identification was done in the "official report". The main characteristics that distinguish the order Trentepohliales from other Chlorophycean green algae are the presence of ß-carotene, haematochrome and its unique flagellar apparatus.
Unfortunately the SEM image of Red rain cells does not showing any Flagella. So it is NOT TRENTEPOHILA
The haematochrome inside the Trentepohlia is spherical in shape (microscopically, see below) but the red rain cells have drastic shape variation.
On dry heating the colour of the Trentepohlia starts changes after 80 deg c and further the haematochrome get decayed after 100 deg C. But the red rain cells are very stable at 150 deg c and the colour change will occur only at 300 deg c.
None of the Trentephliales will survive in the submerged condition for long duration but the red rain cells are stable in rain water even after 8 years without any preservative.
T umbrina on brick (above) & at 40x (below) T aurea on trees (above) & at 100 x (below) & T Umbrina in the right side below
motile cells (haematochrome) of trentepohlia umbrina , aurea & red rain cells . The Gamatangia of all Trentepohliaes cannot distinguished microscopically and looks exactly circular. But the red cells have drastic shape variation
Gamatangia of T Aurea @ 100 x
Gamatangia of T umbrina @ 100 X
Red cells @ 100 X
Difference between the trentepohlia and red cells can be clearly visualized in the SEM images
SEM image of the red cell
SEM image of the spore of the Trentepohlia Image Courtesy : Morphological Examination and Phylogenetic Analyses of Phycopeltis spp. (Trentepohliales, Ulvophyceae) from Tropical China
Huan Zhu, Zhijuan Zhao, Shuang Xia, Zhengyu Hu, Guoxiang Liu Published: February 2, 2015
https://doi.org/10.1371/journal.pone.0114936
SEM image of the Gamatangium (spore of the trentepohlia ) can be seen here
Almost all Gamtangia of Trentepohlias are same
There are other reasons also to say the red rain cells are different from trentepohila spores...
Comparative Studies on red-rain cells and Trentepohlia spores
A. Santhosh Kumar & Godfrey Louis
manuscript submitted and rejected (without reviewing due to prejuduice ?) by FEMs microbiology, basic Microbiology, Current Microbiology
later accepted by
International Journal of Recent Scientific Research Vol. 4, Issue, 8, pp.1205- 1209, August, 2013