The species was collected (in high density) from subsurface plankton tows (100 micron mesh size) in the Persian Gulf in autumn. Both colonial (max 3 specimens) and unicellular forms were present in the samples.
Hi, may be it is diatom genus Climacodium but I can't see apertures between cells.
Good evening,
Sorry but that does not seem to be a living organism.
Greetings!
It looks like the diatom Helicotheca tamesis (Shrubsole) Ricard, erlier called Streptotheca tamesis. Due to nomenclatural reasons, the genus name Streptotheca was replaced by Ricard by Helicotheca. The species of the genus Climacodinium are characterised by large apertures between the cells, as stated correctly by Tatiana Belevich. The similar Mediopyxis helysia Kühn et al. has two small apertures between neibouring cells of the colony. .
Dear Tatiana,Bharathi, Cihelio, and Malte,
Thank you very much for your useful comments. I also thought of Helicotheca but the point is that unicellular forms were also very common (much more than colonies) in the samples.
Thank you for the comment.
We also observed regularly single cells of H. tamesis, but they were always rare in comparision to colonies. May high temperature cause the occurence of single cells ?
Best wishes
Malte
were colonies straight or twisted? I have left the field of diatomology long ago, but my first reaction to the picture was Rhizosolenia.
Dear Domenico,
Thank you for your comment. The observed colonies were twisted.
Dear Suchismita and Abdulrahman,
Thank you for your help. I will use Helicotheca/Streptotheca thamensis as the species name.
This is Heliocotheca (= Streptotheca) tamensis (SHRUBSOLE) RICARD (centric diatoms).
Best regards
Lothar Täuscher
Dr. rer. nat. Lothar Täuscher
- Diplombiologe -
Petersburger Str. 44
D-10249 Berlin
Dear Amir,
Agreed with the identification as Helicotheca/Streptotheca thamensis.
A couple of papers are attached for your reference.
1.Phytoplankton succession during a red tide of Skeletonema costatum in Jiaozhou Bay of China,D Liu, J Sun, J Zou, J Zhang - Marine Pollution Bulletin, 2005 - Elsevier
2. Species Diversity of Marine Planktonic Diatoms around Chang Islands, Trat Province,K Teanpisut, S Patarajinda - Kasetsart Journal ,2007 - chm-thai.onep.go.th
Good luck!
Dear Jackson,
Thank you for approving the identification and also for providing references
Best regards
Helicotheca tamesis (Shrubsole) M.Ricard
( Ricard, M. (1987). Atlas du Phytoplankton Marin. Vol. 2. Diatomophycées. pp. 1-297. Paris: Éditions du Centre National de la Recherche Scientifique. )